Conference vmszoo::rc

    How oeas one manage to keep an RC glider aloft ro 8 hrs?
    
    its my understanding that the batteries won't last more than 90
    mins.
    
    md

    Marc,
    
    The obvious answer is the glider guys use larger capacity airborne
    packs [as space permits] but this is only part of the answer.  Glider
    types, when in lift, tend to use "much" less current since, most
    of the time, the pilot is layed back in his chaise-lounge just keeping
    track of the ship and making very few control inputs.  When he "does"
    make an input, generally it's just a "kiss" of rudder to keep the
    bird in the general vicinity.                       
    
    Therefore, the receiver is the only component drawing any power to
    speak of and it's just drawing idle current; hence "much" more flight time
    can be had from the battery in a sailplane than from the same battery in
    a power plane.  The same explanation applies to the transmitter
    though some serious glider guys strap on additional/larger packs
    to the backside of the Tx case.
    
    Adios,	Al

    Just a comment about battery life.  The transmitter battery draw
    is totally independent of whether you are moving the sticks around.
    The transmitter typically is good for 2 hours on a 500 mahr pack.
    The receiver battery drain is very much a function of the number
    of servos in the plane, and the amount of torque they are providing.
    If you have easy to move control surfaces and you don't move the
    sticks much and the servos have some deadband, then the battery
    drain will be low.
    
    Charlie
    

You know, I've heard that about the transmitter, but I swear I'm
only getting about 45 minutes worth out of my transmitter.  I
completely replaced all the batteries last summer, and that
helped, it was only about 15 minutes before! I frequently look at
the back case of the tx and debate about tearing into it to find
some leakage or other.  Any ideas?

Now, I'm talking about the time it will take to get to 8.8 V. Are
you running your batteries lower?   When I cycle it at 250 mA it
seems to run about 1 1/2 to 2 hrs to get there from a full
charge.   

Oh! the transmitter is a Futaba FP5-LK, about 1981 vintage.
Anker, you have one don't you -- what's your experience?

    GAve the AQUILLA a good look over during the weekend.. This is not
    slam-bang thank you quick build kit. THis an ideal one for the finicky
    builder. I was particularly impressed with the wing construction
    
    Now, there was this device shown on the plan called a thermal sniffer.
    It can be located in two place: in the cokpit or behind the wing.
    
    CAn anyone give move details one what this device can do for me?
    
    Re: long flight times: I reading the paperwork that comes with the
    kit that one flies gliders with a minimum of interference. SOmething
    like free flight with RC interference. Also, judicious use of the
    trims on the box will help the glider on its way (say set up it
    to circle in a thermal and then take a coffee break while nature
    does its thing.
    
    md
    
    

        Re:< Note 399.17 by CLOSUS::TAVARES "John--Stay low, keep moving" >

        John,
        
                My Futaba's  are  of  much  newer vintage.  They are both
        Conquests,  one  AM  the  other  PCM  (5NLP).  When  I  cycle  my
        batteries I leave the tranmitters on until the needle drops  into
        the  red  area.  It takes several hours on my transmitters.    45
        minutes sounds  much  too  short.  They must either have improved
        transmitter  performance dramatically,  or  you  have  a  serious
        current drain.
        
        Anker

    re saving juice on the transmitter: I wonder if it is reasonable
    to consider turing the transmitter off when the glider is an
    obvious flight path that is not going to require any inputs ?
    
    comments anyone ?
    
    md

    Marc,
    
    Don't do it!  The absence of a carrier/reference signal can confuse
    the receiver, causing the servo's to "hunt" for some place to call
    neutral, usually resulting in all the servo's running to one end
    and stopping there [with obvious results].  If this "weren't" the
    case, the receiver would, bare minimum, be more susceptible to stray,
    potentially interfering signals.
    
    Adios,	Al

Anker: Sorry about that; I was thinking of a note a while back
where we were talking about transmitter mods.  Oh well.

A thermal sniffer is a small transmitter that goes into your
airplane.  There is a vertical rate sensing device in the
transmitter that sends a tone.  When the plane rises, as during a
thermal, the pitch of the tone goes up; when it sinks the pitch
goes down.  It is very sensitive, and can detect lift too small
to see.  The pilot wears a small receiver with an earphone to
detect the tone.  Apparently it is a must for competition.  The
most common sniffer that I know of is made by ACE (but of
course). 

    
    RE: turning off the transmitter - true, the servos stay put on some
    systems, but that's only in the absence of signals near your frequency.
    If you try that at the club field with other transmitters on nearby
    channels the servos will go berserk.  And that's not the bad part!
    You might think that if it happened you could just turn on your
    transmitter and pull out of that spiral.  But what often happens
    is that the servos travel farther than their normal throw.  This can
    lead to binding or breaking of a control linkage and (obviously)
    catastrophic results.
    
    Bill

< Note 399.24 by LEDS::LEWIS >
>                  -< Xmitter should go on first and off last >-
...    
>    transmitter and pull out of that spiral.  But what often happens
>    is that the servos travel farther than their normal throw.  This can
>    lead to binding or breaking of a control linkage and (obviously)
>    catastrophic results.

Empirical evidence please (with types and brands of radios).
My Futaba FM radio stalls servos so I believe my current drain goes
up if I turn the Tx off first.  My Futaba AM radio does none of this
however.  JR - I'm not sure.  I've left my Tx off many times
and left the Rx on while at a busy field and never saw anything
but a few jitters.  I have jammed servos past their limits - I forget
what I did wrong to cause that - but it wasn't Tx off Rx getting hit
by stray signals.

Granted caution must be used - but this subject originally came up
when speculating how the glider pilots stay up 8 hours.
Does anybody know how they really do it?

Your point is well taken Bill and I wouldn't personally want to try
this without more data about my Rx.  I'm sure the new JR PCMs would
do what you want - but then PCMs draw more current than pre-PCMs.

              _!_      
Bye        ----O----   
Kay R. Fisher / \     

================================================================================

    re-.24...
    
    I respectfully but strongly disagree about turning on the transmitter
    first:  It's a great way to shoot someone down!
    
    The receiver should be turned on first; if the servos look like
    they're jittering or even being controlled by another radio, you
    had better find out where the signal's coming from BEFORE you turn
    on your transmitter.
    
    If someone is on your freq and forgot to pin the board (or if you
    forgot to look), it's better to take an off chance of a hurt servo
    (very unlikely, in my humble opinion) than to risk being the cause
    of shooting someone down by turning on your transmitter!
    
    Frank.

    Kay, 
    PCM transmitters draw more power, due to the type of transmission.
    However, the receiver should not draw any more power than either
    AM or FM.  If there is a difference, it would be insignificant since
    the power consumption of a receiver is generally caused by the servo
    load.
    
    Ken

    How glider pilots COULD keep it up all day on nice days:
    	
    	A standard 4" X 1/4 pie-slice solar cell puts out .4 volts at
    	250 mA.  So - you have more than adequate current, just need
    	6 volts.  You will need 15 pie-slices, or just to make it look pretty,
    	four 4" diameter cells, (each cell cut in quarters, and all
    	wired in series. 
    	
    	Cells don't weigh much- a 4" UNCUT (whole-circle) cell only
    	weighs about 10 grams (they're very thin).  You can get away
    	with a smaller-than-standard Rx battery (since it will get re-
    	charged continuously in flight!)
    
    	Put the cells IN the wings (on thin balsa), sheet over them
    	with clear monokote (don't stick the monokote directly to the
    	cells, leave a small air gap), and you ought to be able to
    	stay up as long as the sun is out and the transmitter has
    	juice (6-volt car battery :-) )   
    
    	Okay, who wants to try this?
                                    

I don't know what causes servos to run to one side and jam.  I
have experienced it with my out of calibration homemade
transmitter; for some reason when I turn it off one servo in
particular tended to jam.  I have mainly experienced it with cheap
servos, especially the ones made in Taiawan (sp?) and sold by
Polks.   Though it also happened with an ACE servo, and one made
by Royal.  I can tell you that it isn't nice to the gears when it
does this!  No problems with my Futaba, but I haven't fooled with
it -- yet. :-) 

All articles on long duration flying I've read use a very
carefully flown larger than usual battery pack in the plane, and
a car battery booster for the transmitter.  Its should be very
simple to hook a small regulator to the output of a 12V battery
and run the transmitter through the charging plug.  Maybe a small
wiring change in the Tx, but nothing complicated in the least. 

    
    Re .27 -
    
    I hear what you're saying Frank, but I still stand by my statement
    that the transmitter should be turned on first and off last.  I
    agree that proper safeguards should be taken against shooting
    someone down, but turning on the receiver and risking servo
    damage (regardless of how unlikely) wouldn't be high on my list.
    If I lost an afternoon of flying because of a stripped servo gear
    I'd kick myself all the way home.  BTW I've never shot anyone down,
    mainly because I follow the rules set out by the club and follow
    my own additional safeguards as I'm sure many people do.
    
    To Kay - I've seen the servo go past it's normal travel in an
    Airtronics CS7P-AM and Futaba FP-4NL when the transmitters were off.
    It appears to be MUCH more likely for this to happen when you
    turn two transmitters on at the same frequency, because the signals
    add or subtract to generate very long or very short pulses to the
    servos.  But when your transmitter is off, the AGC at the front
    end of the receiver will be cranked up to full gain, straining
    to find that signal.  Other channels intermodulating with each
    other can and will be recognized by your receiver.  The PCM
    systems should be more immune to this if they do more sanity-checking
    of the signal, but I don't know how much more immune.
    
	Bill
    

    RE -.552:     Hi Flipper! (See below)
    
    KAY-  EASY DOES IT!!  That's a sailplane you're flying, not a stick
    being dragged through the air by a propeller. (OK, I know I'm about
    to get flamed by every _power jockey_ out there! :>)
    
    But seriously, what's happening is called porpoising (sp?).  It
    comes from elevator over-control on a relatively slow ship.  Once
    started, it seems to go on forever.  The best way to counteract
    it, once it starts, is too feed in slight down elevator and increase
    it slightly at every rise.  This will dampen the effect within several
    cycles.  The best way to avoid it completely is to not press the
    climb into the stall area.  High up elevator then stall will net
    less height than will a gentle thermal climb with no backslide.
    
    Do you find the upstart gives a reasonable altitude?  It sure seems
    attractive, only needing about 300' vs the 800' needed to deploy
    a full highstart.  I'd like to hear more about this.
    
    Regards,
    Frank.
    

I did it.  I caught my first thermal.
More accurately - it caught me.

At lunch today Kevin Ladd, Dan Snow and I all went to the Action site.

Dan successfully flew the Pilgrim I and showed me his under construction
Pilgrim II.  Looks interesting - save your money guys you never know when
Dan will take the money and run.

Kevin flew a Jug (P47) he got at the 495th auction.
Flew nice after he spent most of the lunch hour fighting with
the engine.

About my 4th or 5th upstart the wind blew like crazy - that's when
Kevin took the Jug up.  When I let go the wind took the glider
back behind me and really stretched the upstart out.  I thought
for a while that the stake must have pulled out of the ground so 
I dove the glider off the upstart.  Then I just let it fly itself
and up and up and up.  

I even did a couple of loops.  I brought it down closer after I started
to get worried about it but it went back up 2 or 3 more times.  I was flying
at about the same height as Kevin with his Jug.  The wind was coming from
the parking lot of the Concord Auto Auction so that probably explains why
there was so much good thermal activity.

I read somewhere that its quite a thrill when you catch your 100th thermal
just like when you catch your first thermal.

Anyway - fun did happen at lunch time.
Now I have to create a special flight box that understands gliders.

              _!_      
Bye        ----O----   
Kay R. Fisher / \     

================================================================================

1.  Good gliders:

	I've often read that the T tail gliders are better because
        among other things they get less damage on landing.  I've never
	really understood that until the day before yesterday.  I was
	flying at Acton during lunch hour.  My second flight I did a
	perfect landing about 5 feet in front of myself.  As I
	greased it onto the grass - crack! - I broke the starboard horizontal
	stabilizer and elevator off.  Just some tuff grass.

	Guess I'm used to seeing power planes nose over that I always
	figured that a T tail was just asking for trouble.

	Also one day I noticed that landing in grass that the grass
	cut thru my rubber bands!

	So I'll never buy another glider unless it satisfies two
	criteria.  High (T or V) tail.  No rubber bands on the side
	(ala Power Trainer setup).  The gentle lady has a rubber band
	mounted wing but the dowels go for and aft in the center so
	tall grass can't cut thru them on landing.

2.  Windy days

	Yesterday I was flying in the WIND.  Strongest I've been
	up in so far.  It was kinda fun but the Drifter II is so slow
	that I couldn't go looking for thermals because I couldn't
	penetrate the wind.  On one landing it was actually going
	backwards relative to the ground.  The tow hook acted like
	a Navy tail hook for landing - neat!

3.  Hanger rash

	Today I brought the glider in.  After driving an hour to work
	with two cars (my wife following) cause I needed mine with
	the glider in it at lunch time - I turned into the DEC parking
	lot and my flight box slid across the back of the station 
	wagon and CRACK!  It broke off my port horizontal stabilizer
	and elevator.  Rats! I'm still trying to find some Zap at work
	and have hopes for a lunch launch.

4.  High starts

	Got the Airtronics heavy duty high start - what an improvement
	over my wimpy up-start.

This is not a rambling topic - but some of you must have some glider
wisdom to share.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    Kay,
    
    	If your really into gliders then I suggest that you transfer
    to Colorado Spring Co. Some of the best RC times I've had were when
    I was in CXO for two months back in 85. I joined the PPSS and had
    a great time. 
    	The best 2 meter glider I have seen was a sagitta 600 with straight
    wing panels and ailerons. This ship was set up with ailerons,elevator
    rudder and spoilers. The guy even had ballisting tubes in each wing
    panel.
    	The best open class glider I've ever seen was the Windsong.
    Unbeleavable!
    	Wait until you launch off of a winch.
    	In CXO we used to fly off of a turf farm that was 1/2 mile across.
    The PPSS and a Denvor club had a mutual arangement where by they
    rotated club sponsored event. This allowed each club to hold one
    soaring event per month. They were planned two weeks apart from
    each other. In this way every other week you had an event to go
    to on a sunday.
    	When I let Mike Hickman was working on his LSF V. He needed
    only his 8 hr. slope soaring event. Randy Renolds was an LSF IV.
    Both of these individuals help me a lot and I'm very greatful for
    the great memories.
    
    						Tom

    Kay,
    
    Like you, I discovered that gliders with low horizontal stabilizers
    are especially prone to damage. I have a Sig Riser, which is very
    similar to your Drifter II. While flying at the Acton field, I had
    the very same experience: greased it in for a beautiful landing,
    walked over to it and found the stab half pulled off. Matter of
    fact, the whole tail section is so fragile that I've probably repaired
    it a dozen times in a year. All it takes is one evil lump of grass.
    
    Both of these planes are built with the philosophy of light weight
    and low wing loading, so they float great (I saw yours at the fun
    fly, and it glides very nicely). But I think the price paid is
    questionable structural integrity.
    
    My second glider, which I've almost finished building, follows a
    different philosophy. The fuse contains more plywood and hardwood.
    The wings are constructed with a full D-tube from root to wing tip,
    and attach to the side of the fuse using two steel rods. And the
    stab is located halfway up the fin, about 3 inches above the base
    of the fuse. I haven't flown it yet, but I expect it to be far more
    forgiving of hard landings than the Riser. The price paid here is
    the higher wing loading, so I suspect it will fly faster than the
    lighter plane. But if I did a good job building it, I think it will
    be just as efficient a flyer. I can't wait to find out.
    
    Dave Walter
    

My first RC plane was a House of Balsa 2T, a two meter, T-tail
glider.  I really do mean my first RC plane, because when I first
threw it, I had never flown RC before.  This was with my home
brew transmitter and receiver (I built everything but the actual
tx and rc modules).

That plane drove me nuts, and it also had a very short lifetime.
The T-tail, which was built according to the plans, had a piece
of Nyrod snaking up through the fin to operate the elevator.  The
blasted thing would twist the fin when it actuated, despite there
being little discernable friction in the joints.  I think it was
for two reasons, first imperfect alignment in the nyrod going up
through the tail, and because the tail portion of the fuse was
too small in cross-section, and because the stab had just the
area at the top of the fin, about 1/8 inch wide, to hold on to. 

I would take it to the field throw it once, or twice if I was
lucky, and take it home with the stab broken off.  The last
repair of the fuse had the fin and stab glassed together. 

OK so I picked the wrong plane for my experiments.  I wound up
designing one around the ACE foam wings that worked pretty well. 

Anyway, I've been gunshy about the T tail since then, I think its
next to impossible to design one that stays  together for very
long.  This configuration is great for someone that is good
enough to make consistent gentle landings, but very poor for
someone who gives it the knocks.

    My suggestions......
    
    	1, Slow down when entering the parking lot.....you must be one
    of the maniac drivers who drives like their on the Boston freeway.
    Oh I forgot, you are one of those boston freeway drivers....:-)
    
    	2, Go to your locat hardware store and buy one of those bungy
    cords. Tie down the flight box. By the way what are you doing with
    a flight box when all that is needed is the plane,radio and a rubber
    band to launch it? :-)
    
    	3, Rebuild the horizontal stab but this time laminate on the
    top and the bottom some carbon fiber strips from tip to tip. This
    can most time be done along the trailing edge of the stab. Also
    you couls use some strips on the leading edge. Maybe sandwich it
    between two pieces of balsa.
    
    I think you shall find that with the better/competition designs
    the horizontal stab is designed in two pieces and is removable.
    
    					Tom

>    I think you shall find that with the better/competition designs
>    the horizontal stab is designed in two pieces and is removable.

Glad you brought that up.  This could probably be a new subject but
since they seem most common in gliders I would like to here what
you other noters think about mounting wings and stabs on tubing
and not fastening them in with anything.  I couldn't believe my 
eyes when I saw someone put the horizontal stabs and there was 
no retainer of any kind to keep them in.  The guy at the fun fly
with the Airtronics Sagitta 600 had wings like that.  Just slide
them on and don't worry about it.  Sure would feel better with
a rubber band going thru the fuselage to a hook on each wing.

Anybody ever see one of these flying surfaces fall off?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    The glider I referred to is a Top Flite Metrick. The wings are held
    on with a rubber band that goes through the fuse. As for the stab,
    it too is made in two sections that slide onto small steel rods
    in the fin, but no rubber bands are used to hold it on. You pretty
    much rely on friction between the rod and tube, not to mention the
    force of the air isn't in a direction to pull off the stabs. Luckily,
    I slightly misaligned the two rods, so there's PLENTY of friction
    there. They won't fall off.
       
    By the way, I've seen another plane that's built very similarly
    fly at the Acton field, and it flys just fine. It's a Pilot Harlequin,
    flown by some guy named George. It's actually very heavy, using
    all plywood in the fuse sides, I think; weight is around 40 ounces
    according to the box (I almost bought one). Yet I've watched that
    thing almost thermal out of sight on numerous occasions. And it
    survives all but the most violent landings. Actually, I bought the
    Metrick because it had so many features in common with the Pilot.

    Dave
    

    My TopFlight Wristocrat uses the "tube and wire" attachment method
    for the horizontal stab, two tubes are used, on is the pivot for
    the stabilator, the other is what the control wire rides on to change
    the stab angle.  Works fine, hasn't come off, even though hand launches
    are pretty rough.  Relies on friction to keep it together.

About 18-20 years ago I was involved in building (and trying to fly) RC gliders.
After breaking the fuselage of a "T" tail Nordic 72 in half on its maiden flight
(there were no instructors in the area) and a couple of discouraging subsequent
flights, followed by being told that the Graupner Schleischer (sp?) K-2 that I
later built would make a good slope soarer but was too heavy for anything else,
I sold everything and got into model railroading. 

Now my son, 17, is in the process of ordering, and soon will be building, his
first RC plane, a PT-40. Seeing him getting all excited is stirring me up again
and I'm wondering if I should join him by building a glider again. Where/who can
I talk to to get info/help in the Northboro/Boxboro area on equipment, training,
etc. What would be a good and attractive glider kit to build. How much should it
cost to build the plane (excluding the radio gear)? Is it necessary to use the
new "super" glues (model railroaders refer to them as ACC, but I've heard flyers
refer to them as CA), or can I get by with Franklin's Titebond or something
similar? What are the various launch methods, and what are the pros and cons to 
each? How many channels are necessary/recommended?

About 20 years ago I built a circuit that was described in one of the magazines.
It was a variometer or rate-of-climb indicator, probably similar to the "thermal
sniffer" refered to in a previous note (only a guess). It consisted of two very
small thermistors mounted in line with each other within a narrow tube which was
connected to a 6 oz. bottle. As the bottle was raised, the air inside flowed out
to the lower ambient air pressure, thus cooling one of the thermistors more than
the other. This difference caused an oscillator to change the audio frequency
which was fed to a low power FM transmitter on the broadcast band. The device
was so sensitive that it could actually detect the raising or lowering of the
bottle from the ground to eye level. Would this sort of system be worthwhile to 
include in a glider?

Dave Busch

>< Note 399.47 by BZERKR::DUFRESNE "VAXKLR - You make'em, I break'em" >

>    Carl golberg has 2 nice glider kits. One is called the "GENTLE LADY".
>    The other I think is "SUPER LADY" and is a brand new, 100 inch
>    wingspan.

Close - the Sophisticated Lady is the new one and it is a T-tail pointed nose
version of the Gentle Lady.  Same wing span = 78.25 inches.

SIG makes a Riser and Riser 100 which you may find interesting.

I have a Craft Air Drifter II.

For a first glider to learn on I recommend the Gentle Lady or Sophisticated
Lady.  All the intro 78" gliders come in at around $30 for the kit +
1 to 2 rolls of covering ($10 per roll) + Radio + High Start (30-50 $).

The circuit you described .-2 sounds interesting but there probably won't
be room for it in a 78" glider.  Hope to see you Sunday - there should
be lots of good advice at the competition.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

>< Note 399.46 by OPUS::BUSCH >
...
>Is it necessary to use the new "super" glues (model railroaders refer to them 
>as ACC, but I've heard flyers refer to them as CA), or can I get by with 
>Franklin's Titebond or something similar? 

You can get by with titebond - But I recommend you get three bottles of CA
and one bottle of debonder.  That would be one each 1 oz bottle of
Fast CA, Medium CA and Slow CA.  Brand doesn't matter much as long as you
get it at a hobby shop.  It will cost about $5.00 per bottle.  You won't
use them all up but you need three thicknesses to do things easiest and
most correct.  There are other notes about adhesives in this notes file
and in the old notes file available at K""::RC1.MEM.

>What are the various launch methods, and what are the pros and cons to 
>each? 

1.  High start - that is essentially a catapult action using 30-100 ft
    of surgical tubing and 200-400 ft of 40 lb test fish line.  This is
    the way you will end up launching your plane.
2.  Winch - that is a 12 volt battery and a car starter mounted with a large
    spool of fish line and a pulley system mounted out several hundred feet.
    This you will see at contests and if you become a sophisticated user
    you may migrate to this method.  $200 plus.
3.  Power pod - several kits have directions for building a pod to mount
    on the top of the wing to hold a COX .049 engine.  Lots of folks build
    these and try them - but I don't think the fun/work ratio is high enough
    to bother with.
4.  Hand launch - used with smaller (less than 78") gliders and also for
    slope soaring.  You won't be able to hand launch a Gentle Lady high
    enough to catch a thermal until you are such a good flyer that you
    no longer own Gentle Ladies.

>How many channels are necessary/recommended?

Two are necessary - but I wouldn't recommend any radio with less than 4
channels for a variety of reasons.  If money is no object the best radio
specifically made for sail planes is the Airtronics Modular SP (Sail Plane).
But I recommend at this stage you get a good 4 channel radio that meets
the 1991 specs.  There are lots of notes on this subject.
It is possible to require several channels on complex gliders.
Elevator, Rudder, Ailerons, Flaps, Spoilers, Hook release, etc.

>About 20 years ago I built a circuit that was described in one of the magazines.
>It was a variometer or rate-of-climb indicator, probably similar to the "thermal
>sniffer" refered to in a previous note (only a guess). It consisted of two very
>small thermistors mounted in line with each other within a narrow tube which was
>connected to a 6 oz. bottle. As the bottle was raised, the air inside flowed out
>to the lower ambient air pressure, thus cooling one of the thermistors more than
>the other. This difference caused an oscillator to change the audio frequency
>which was fed to a low power FM transmitter on the broadcast band. The device
>was so sensitive that it could actually detect the raising or lowering of the
>bottle from the ground to eye level. Would this sort of system be worthwhile to 
>include in a glider?
>
>Dave Busch

Could you send me a copy of the schematic and construction article?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

Kay, 

You're the second person interested in the circuit I described. Last night Dan
Miner dropped over to my house and I dragged out the circuit to show to him.
It's been in a box for nearly 20 years and I couldn't find the documentation for
it (it's around SOMEWHERE) but we decided to try it out. We were able to get a
very nice signal out of the sensor as we blew air into one side and then the
other. We also seemed to get a decent RF signal on the FM broadcast band, but
couldn't seem to get the voltage-controlled audio oscillator to work. It's
especially difficult without schematics. However, with todays IC's, it should be
no trouble to rebuild the audio section. If you get a couple of minutes, give me
a call and we can talk. BTW, I don't know what you would have to pay for a unit
like this, but I'm sure it could be built for under $10-$15. 

If it would be of any use a second similar sensor could be built to act as an 
airspeed indicator and the two signals could be mixed and transmitted to the 
ground.

In your reply, you said that you didn' think that this device could be fit into
a glider such as the Sophisticated Lady. Is that because of the size of the air
bottle necessary? When I had the thing working, it was attached to a 6 oz tank.
However, there is no reason why the circuit couldn't be built into a small
package, wrapped in foam rubber for shock protection and sealed into a flat
custom built plastic box which would be installed between the ribs inside the
wing. If more volume is needed, simply add a second box in the opposite wing and
connect them together with a piece of tubing. The foam would not displace enough
air to speak of as long as it is an "open celled" foam. 

Dave 

    You might also consider trying the Goldberg Electra.  Based on the
    Gentle Lady (essentially the same wing and tail feathers, but a
    slightly wider fuse), This is a 78 Inch flat bottom airfoil glider
    with an 05 sized electric motor mounted in the nose (not a powerpod).
    Although heavier than a Gentle Lady, the flight characteristics
    of this plane are quite docile.  I believe that it makes an excellent
    trainer,  and it's quite capable of thermaling.  The big advantage of
    this plane is that you don't need to stake out a highstart or winch,
    and the motor is "no muss, no fuss".  Just walk to the flightline,
    flick the throttle lever on your transmitter, and toss the plane
    into the air.  My Electra typically gave 2 or 3 climbs to 200-300Ft
    altitude per charge.  Average flights lasted about 20 minutes. 
    

I'm currently building the Sophisticated Lady, my first plane, and I've got the
wing and tail section done but not covered and most of the fuselage done. I took
the parts down to the field in Westboro yesterday where they were holding a
small glider contest. I wanted to get a bit of "free" advice before covering up
all my mistakes. 

One of the points mentioned was that the design of the kit calls for a very
pointed nose and I was told that the plane would not be allowed to compete in
any AMA sponsered event unless I rounded up the nose. Is this true? Just what
ARE the regulations, and WHY? (When I got home, I proceded to sand off the sharp
point as suggested.) 

Dave

        I believe the number is 7.5mm. Safety is definitely the reason. In
        the spotlanding task, the practice became to jab the nose in the
        ground, javelin-like. The idea was to keep the model from skidding
        on the grass past the target. Not exactly safe if you accidently
        hit a person instead of the target. It does sometimes get crowded
        there. 

    Yes, according to the International Aeromodeling Rulebook
    compiled from the FAI Sporting Code by the Academy of Model
    Aeronautics (first edition, first printing) 1988, page 57
    describes class F3B.  The characteristics have two parts,
    the common characteristics and the radio.  The common
    characteristics refer to the max surface area, max flying
    mass, loading on the St, and minimum radius of the fuselage
    nose.  The minimum radius is 7.5 mm.
    
    Glenn

    Dan,
    
    I think ANY glider should have wings strong enough to handle a hi
    start. The stress on the wings depends on the strength of the wind,
    the stretch of the high start, and the elevator trim during launch.
    You can always vary the high start tension and elevator trim to
    reduce wing stress. I know you will want to build it light since
    it's an electric, but the wings have to support that much more weight
    due to the batteries, so I figure they still have to be pretty strong.
    
    I think you should buy it. How else will the rest of us know if
    it's any good?
    
    Dave

    re-:62...
    
    Be careful of compensating for anything by trying less tension on
    the high-start.  I've found that the easiest way to roll a sailplane
    on launch (with the usual nose bury in the field routine) is to
    let off on the tension at launch.  Always give a hard launch and
    you'll have the air moving past the wings much faster (or is that
    as soon as needed ;^] ).
    
                             |                      
   \	       	         ____|____                      /   Regards,
    \________________________O_________________________/    Frank.
    

    re: .63
    
    Well, I don't agree 100%. Sure, if there's too little tension the
    launch will be so weak that you never get to a reasonable flying
    height. My point was that on a very windy day, you need less tension
    to achieve the same relative airspeed. For a high start, don't walk
    back as far. When using a power winch, you can modulate the tension 
    by pulsing the motor. When giving a "hard launch" into a stiff wind,
    there's good chance you'll fold the wings. Although I've yet to
    see that happen. I think most of the time you intuitively know how
    hard to launch.
    
    By the way, the only time I rolled a sailplane on launch was when
    there was a heavy crosswind, and I didn't compensate for it quick
    enough. 
    

Speaking of "Glider Guiders" I was attempting to fly at Littleton this afternoon
and I fell off the high start twice.  The only other time I did this was during
the contest I went to last month.  At the time I thought it was just something
dumb that I did on the winch.  Trouble is I'm not sure what it is I'm doing that
causes this.  Seems like it just pulls up and acts as tho I has up elevator in
and flips all the way over and twang the tow line snaps loose.

Along those same lines is seems like I have a tendency to constantly fly
the plane near the stall point.  It just seems unnatural to crank in down
trim.  I keep trying to trim it such that it flies at a point where a touch
of up will stall it.

After the last time I fell off the high start I put a couple of clicks of
down trim in and launched and got my best flight of the day - I forgot about
the two clicks of down trim and therefore didn't take them out after the launch.

Any advice from you guys with experience would be appreciated cause I may not
have any more practice before Sundays competition and it is my goal not to
be dead last in every event this time.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    RE: -.68
    
    Kay-
    
    I've fallen off the high start myself; that quick loop as 30' altitude
    is a real heart racer, isn't it!!!
    
    As far as a tip, I've got only medium experience but something I've
    finally started to do is to move from trying to fly without incident
    to experimenting with manuvers (sp?), etc and finally trying to
    _work_ lift to truly soar, not just glide.  One of the most sensitive
    indicaters of good lift I've been able to find is the sailplane's
    wingtips;  they usually start to get "buffeted" at first lift. 
    If you watch them closely, I think you'll see what I mean... As
    the thermal is entered, the wingtips start to wobble or shudder.
    Wait a moment, to get fully into the thermal and execute a moderately
    tight 360.  With a little practice you'll find that (even without
    any up elevator) the nose will rise and the ship will climb.  Good
    places to look:  a windward slope face- even a sharp rise of 4-5'
    will often generate lift in a descent breeze; another place is over
    an asphalt parking lot that mey be nearby.... experiment!  
                                     
    Also see rambling for an example of _real_ lift I encountered last
    week... scared the hell outa' me! As we get skilled in this area
    of our sport we get to experience what all those power jockeys :^)
    never get...  The graceful relaxation afforded by powerless flight!
    
                             |                      
   \	       	         ____|____                      /   Regards,
    \________________________O_________________________/    Frank.
       

    

I know Kay said a few words about this contest under the "Ramblings" note, but
I'd like to add a few more.

First of all, I've never seen a plane so decimated by pure acceleration as
Kay's was on his first launch. From my perspective it looked like the fuse was
shot from a cannon, leaving the wings far behind. I wondered who the poor pilot
was, then I saw Kay lower his head, shut off his transmitter, and start
walking out to pick up the pieces. What's more amazing is that he had it back
up and flying again in just an hour or so. 

I'm convinced the winch was evil. I've never seen so many botched launches,
and many by very experienced pilots. The most common problem was the plane
releasing from the line early, which caused a huge number of low scores. Out of
6 launches, I only had two that were reasonable. A few of us speculated that
the retriever line was causing enough drag to allow the plane to come off the
ring. It was very hard to judge how much power you needed from the winch
(controlled by tapping the foot pedal).

I'm also convinced that Mother Nature is evil. I've NEVER seen the wind shift
around like it did Sunday. I think it was partly caused by the location of the
trees and hills surrounding us. Matter of fact, it was so bad that we saw a
small twister whip up at the edge of the field, throw lots of grass into the
air, then disappear into the tree line.  I had one near disasterous landing
where my plane was a good 20 feet in the air and just dropped like a stone. It
almost took out 3 other planes on the ground. Another pilot watching me said it
must have been a massive wind shift because up until that moment I was in good
shape. At first I thought about interference, but an immediate check of the
controls ruled that out. Oh, well, nothing damaged.

All in all, it was very enjoyable, and a real challenge. I think the next time
I fly I will practice timed flights and spot landings because that's where you
really find out how well you can control the plane.

Dave Walter


    

    Does anyone have any experience/suggestions about mixing(electrically)
    elevator and spoiler signals.  I would like to have up elevator
    come on when spoilers are deployed to prevent excessive nose pitching.

Well, the time has come. Last night I finished the final task on my
"Sophisticated Lady" and now it's time to get out to the field and cra...er...
that is, learn to fly. That task was to balance the ship with lead in the nose.
Not having had any experience, I wonder how critically the balance has to be 
done. With a couple of dowels for support under the wing where the instructions
indicate I added lead and epoxy to the nose 'till the stab (and wing) were
almost level. Actually, I think there is a bit of down pitch. 

Question: if the balance is not exactly right, what would be the consequences.
Is it better to err in favor of too much or too little weight in the nose? I've 
often heard of needing to add lead to the nose to increase penetration on windy 
days.

Anybody with glider experience going to be out at the CMRCM field in Westboro 
this week after work?

Dave

    From what I've heard, err on the side of more nose weight. If you
    have too little nose weight (CG too far back) the plane gets difficult
    to control.
    

    I cast my lot totally with the opinion in .80.  In _ANY_ fixed-wing
    application (I know nada of whirly-birds) it's _ALWAYS_ better to
    err on the nose-heavy side!!  In answer to yer' question, C.G. is
    "_THE_" most important/critical aspect of setting an aircraft up
    for flight.  Next is wing-straightness, i.e. absence of warps, but
    that's another subject altogether and, usually, a warp won't cause
    a catastrophic situation where a bad C.G. definitely WILL!
    
    Tail-heavy aircraft are verrrry pitch sensitive and tend to tip-stall
    (snap roll) far too easily.  I'd hazard a guess that over 50% of
    all 1st-flight crashes are the result of tail-heaviness.  There's
    no such thing as _close enough_ where C.G. is concerned...when
    suspended from the point indicated on the plans, make sure the nose
    is slightly down and you'll be safe; balancing slightly ahead of
    the recommended C.G. is good insurance!!    

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    re .81
    
    Well Al, here's one 'whirly-bird' driver that prefers a slightly
    nose-heavy ship. My rationalle is simple -- I'd rather have a copter
    that 'tended' to go forward from a hover than go backward! Besides,
    slight trimming of the cyclic (elevator) will zero it all out dependant
    upon the fuel load.
    
    I suspect that some more experienced "ground frighteners" may disagree
    with me, as I have heard that copters are better set-up slightly
    tail heavy for aerobatic flight...
    
    Jimi.

    Jimi,
    
    Evidently, more similarities exist between fixed and rotary wing
    ships than I might've guessed.
    
    Strangely, a _slightly_ aft C.G. also contributes to increased
    maneuverability with a fixed-wing but this is for the experienced
    hands *_ONLY_* as it's the kiss-of-death for the tyro R/Cer!!
    
    BTW, hope you or any of the other chopper-drivers took no offense
    at my "ground frightening" remark as none was intended.  I still
    look at choppers in wonderment; even though I fully understand
    the aerodynamics of why they can, I'm still awestruck that they
    fly at all.  A-mazing!!       

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

			---<First date with the "Squaw">--

Well, we didn't get to "go all the way" on our first date but things are looking
good. Mike Hoefler called at the last minute because something came up but said 
we could get together tomorrow instead. I went down to the Westboro field with 
my son and our planes hoping to get some advice and help, me with my glider and 
my son with his PT-40. There were a number of guys there in spite of the wet 
conditions, and after a while, someone with glider experience came over to help 
me get started. He checked my balance and did a general pre-flight check and 
then, with him at the controls, he had me give it a hand launch towards the tall
wet grass. All went well and we landed in the grass on the other side of the
field. 

Then I went out to retrieve the plane and launch it towards my instructor
(Jack Buckly? I can't remember his last name). It was then that I discovered
my first construction error. As I launched the still wet plane my hand slipped 
forward and, just as I released, I heard the click of the receiver switch. Ouch!
I gritted my teeth as I watched Jack trying to work the controls as the plane 
headed for him in the pit. Fortunately, things were well balanced and very 
little trim was needed, and the plane went nice and straight and landed with a 
slightly nose down attitude...no harm done. Just a little embarrassment, like 
the time I tried to take off in a (real) Cesna 150 before removing the chocks.
After adding a bit more "up" elevator trim we did half a dozen more flights, 
including my first solo launch/flight. After that I decided to "quit while I was
ahead". Nothing fantastic, but not bad for a first date. Tomorrow, we try for a 
high-start.

Dave

Now about that CG question.
Everybody agrees it is best to error on the side of nose heavy.
I over heard several expert glider guiders say that they prefered
their planes to be nose heavy cause they thought they flew better.

BUT...

as regards adding ballast for better penetration - do that at the CG.

============================================================================

New topic - I went to Rapids N.Y. over the weekend to a glider contest at
a turf farm.  Neat location.  There were two classes - Standard and Open.
There were 3 rounds.  The task was thermal duration of 3 minutes for the
first round and 7 minutes for the last two rounds.  On my first flight
I actually got a max - in fact I even earned penalty points because I went
over time.  The scoring was a little different than what I was used to.

They gave a point per second up to the max then subtracted points.  There
was a 50 point bonus for landing within a 50 foot circle.  BUT...  The
points were not linear - it was a step function.  After 1 minute you get
60 points.  If you had a 59 second flight - that is 0.  At 2 minutes you get
another 60 points - etc up to the last minute - then you start earning a point
per second linearly.  After the max then the points count down - first you 
loose a point - then 2 then 2 then 5 points per second down to when you
are 20 seconds late then you loose 1 point per second till you are 30 seconds
over time - then you get a 0 for the entire flight - not counting the landing
bonus.  In other words there is a big penalty for being late - it is better
to be early and get the landing bonus.

There were some great gliders there - took lots of pictures.

In mid afternoon there was zilch thermal activity - then this lonely little
dark cloud came by and one guy was sucked up towards it.  After that there
was a chain of glider guiders following him up.  Unfortunately they
were calling the launch order and the cloud was long gone before I was
up next.  

They were running 3 winches in parallel.  There was two spot landing targets.
You could land in which ever one you wanted.  One guy hit the first landing
target and bounced up and made a good landing in the other target.  They
gave him a 0 for the landing - sorta like calling pool shots.

On August 20th and 21th the Rochester RC club is sponcering a sailplane
meet.  This one will be at the Northampton Park Ski Lodge.  Suppose to
be the highest point in upstate N.Y. and always windy.

In case your wondering - it was a 10 hour drive to get there.  Well I cheated
and went past a ways to Niagara Falls Ontario to stay.  Went to a great show
with an Elvis impersonator in Niagara.

I placed 11th of 22 and 10th of 17 - good for me and the scores are helping
earn my LSF lever II.

=============================================================================

The day before yesterday we were at the Orange airport and I finally got in
one of my 15 minute thermal durations and one spot landing.  My spot landings
are becoming a joke.  I hit one once in a while just by random chance.  
This time I actually hit the towel that I was using for a target so we had
this discussion as to where to measure from - eithor way was within the 1.5 
meters (4.92 feet).  But the goal was not to fly the glider that day but
rather the Aeromaster - more on that in another note.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

>    ship and boy do you need the spoilers. Sean tended to use the "finger"
>    type, about six each wing. I also remember a lot of closed loop
...
Please tell us more about finger type spoilers - never heard of them.
...
>    Southampton. Hope I didn't ramble too much?.
...
The rambling was great - please add more in this topic.
...
>    Regards Eric Henderson

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

To comment on Scott Cronk's question from 239.937:

Being a beginner in gliding I have nothing to compare to but I found the CG 
Sophisticated Lady a very nice kit to assemble. I've been told that it has the 
same wing design as the Gentle Lady but the fuse and cockpit are more attractive
and prototypic. The kit went together easily and from the folks who have flown 
my plane for me in the beginning, and those who have seen my attempts to fly it,
the opinion is that it flies beautifully. Last Saturday I got in another three 
flights and for the first time, I was able to do more than just go up and then 
land. I actually had time and the presense of mind to adjust some trim at the 
start of the flight and THEN, I actually found a bit of lift. Now I've got to 
practice circling so I can stay in the lift for more than a few seconds. 
Saturday mornings sure are a lot nicer and relaxed than trying to glide among 
the hornets nest that one finds at the field after dinner on weekdays.

Dave

    re .- a few: What's a zoom launch??
    
    Btw, I was told in no uncertain terms by my instructor to get that
    glider of mine built and fast !!!. So, we have set a target of Sept
    15 for a test launch..
    
    md

    Somebody asked what a zoom launch is.  What you do is launch the
    plane normally via the winch. As the plane reaches the peak altitude,
    which is when the tow line is almost vertical, you push the nose
    down and give the winch a solid blip of power. This gives the
    plane a lot more speed. You then shut off the winch and pull the 
    glider up into a sharp climb, leveling out when it's lost most of
    the speed. At least, this is how I understand it. Done right, you
    get more altitude than if you had just drifted off the tow line.
    Done wrong, you end up stalling or looping and lose the precious
    altitude you gained. (This is how I usually do it.) Done REALLY wrong...
    it's an opportunity to rip your wing in two.
    
    About using the Bose mountain to slope soar. I've flown there once,
    and it's a bit unnerving. If your plane get below the level of the
    mountain top (which is flat), there's nowhere to land. Except for
    some woods, some buildings, etc. But I guess if you're confident
    you can land on the mountain it'll be alright.
    
    Dave Walter
    

>< Note 399.100 by IGUANO::WALTER >
>    About using the Bose mountain to slope soar. I've flown there once,
>    and it's a bit unnerving. If your plane get below the level of the
>    mountain top (which is flat), there's nowhere to land. Except for
>    some woods, some buildings, etc. But I guess if you're confident
>    you can land on the mountain it'll be alright.

So Dave - where is this place?

re 239.937 the question about what glider for a beginner.

>    I would like to have your opinion on some gliders, or anyones opinion
>    actually!  I have been looking at three specific: the SIG Riser
>    100, Goldberg sophisticated lady, and elctra deluxe.  What would
>    you guys suggest of these, if not these, give me some specs on some
>    others.

In the latest issue of Model Builder there is an article about
what glider for beginners - worth reading if your starting.

The recommended beginners gliders are all simple 2 channel 2 meter 
flat bottom wing gliders like 
	1. Carl Goldberg Gentle Lady
	2. SIG Riser (That's what Dave Walter loaned me last weekend)
        3. Craft-Air Drifter II
	4. etc.

So you can bias your choice by emotion if you like.
The Sophisticated Lady should build about as easy and fly about the
same as a Gentle Lady.

The Electra Deluxe is actually a Gentle Lady modified to carry the
motor and battery.  I would advise against this until you have had
some stick time on real gliders.  Beginners have trouble with electrics
because they are usually marginally powered and stall real easy.

In any case if this is your first plane - don't start without an
instructor and DON'T attempt to fly the first time unless there
is NO wind.  

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    Regarding what is a good first glider, my experience is a 2.5 or
    3 meter "floater" flys much better than a 2 meter floater.  The
    larger gliders are easier to handle on the high start and are much
    easier to fly in wind.  My recommendation would be the Airtronics
    Oly II or the Sig Riser 100".  
    
    Jim Blum

< Note 399.93 by IGUANO::WALTER >

<    Hey! I might be the guy launching the plane in the Middlesex News!
<    I remember seeing the humongous maw of a superlong lens out of the
<    corner of my eye just as I launched, then I forgot about it as I
<    concentrated on the plane. 

Sorry Dave, according to the caption, "Chris Schuch of Weston keeps a close eye
on his radio-controlled glider as Framingham's Chris Pappas, and Anker
Berg-Sonne look on". The other photo shows "Clark Smiley of Newmarket, NH.,
letting loose his radio-controlled glider, allowing a special winch to lift it
to a set height". 

BTW Anker, that Sprite you're holding sure looks refreshing. If anyone wants a 
Xerox � copy, send me mail at OPUS::BUSCH.

Dave

Well - I finally talked my wife into going out flying with me.
Actually I just went to trim out the Drifter II after reconstructing
a new nose in it after my last wing fold.  Wouldn't you know it on my
second flight I parked it in a tree.  Just as I hit the tree a farmer
comes by with a tractor with a large wagon behind and a bucket loader.
I asked him if he could park the wagon by the tree so I could reach the
plane and he said hop in the bucked - that is one slick way to get
planes out of trees.  Anyway the drifter flew a little awkward with the
new nose - it looks more like a B66 bomber nose than glider.

Sunday we went to the sailplane contest in Bloomfield CT.  It was cold
in the morning and warmed up to about 72 by afternoon.  It was as windy
as I can ever remember flying a glider - wow.  Everybody was installing
lead and I had a couple of small pieces so I added them to the nose - 
paying no attention to the CG cause I have found from experience with
the Drifter II that getting nose heavy doesn't change it much at all.

Usually I have been saying that these were pilot days and my equipment
was not a limitation.  Yesterday it was so windy that I had to abort out
of two good thermals because of the drifters inability to penetrate
well.

Anyway my goal was to earn enough points to finish off LSF level 2.
For level 2 you need one third place or (3000 points in 6 contests).
Since I can enter a 2 meter glider in standard class (100 inch) and
unlimited as well then I can pack in 3 LSF contests at one meet.
Anyway - I needed two scores around 500.  Nearing the end I knew I had
decent scores so was hoping the winners scores were not too high.
The formula is your score divided by the winners score times 100 times
(the number of contestants you beat plus one).  

Most had a hard time finding thermals - tho a few kept popping up.
We were on the down wind side of a mountain so frequently when the wind
really blew there were some very short flights.  1 and 2 minute flights
were not uncommon even amongst the experts.  Landing was very
challenging not only to hit the target but to land right side up.

One guy launched a plane that hadn't been flown in quite some time and
it didn't have enough up elevator.  He went straight down the winch
gaining only 50 feet or so and trying desperately to get it back.  As he
banked left it would drop so he made a wide arc around the field and
eventually went in over a flock of sheep - hitting a couple.  Then as
the sheep tried to run one of them stepped on his wing.  It was pretty
funny to see and the guy was working on repairs in the parking lot so
the damage wasn't too bad.

During one flight Chris Schuch went up about a minute before me and I
launched into sink air.  About 30 seconds later I'm about 50 feet up
directly over the landing spots and so is Chris.  He is a very good
flyer so I started following him.  We were circling above our heads at
about 50 feet for another minute then all of a sudden the thermal broke
loose and boom - up they went.  Chris bailed out a minute before me
cause we were flying a 6 minute thermal duration contest and he made
a landing before the first mark on the tape.  It has numbers every
3 inches from 100 to 0.  So he ended up with a perfect score 6'0""
plus 100 bonus points.  I was listening to this as I attempted my
landing and I went 20 seconds over time (penalty points) and missed
the landing entirely - rats.  The CD had his picture taken with
Chris for some paper.  

I made most of my landings and two even were close enough to get them 
signed off for my LSF 2 (even got a 97 on one).

All in all it was a lot of fun and I ended up getting 3rd place in
the Standard class plus enough points.

What a thrill to be in the winners circle the first time.

The CD shook my hand and gave me a nice plaque as he announced
the winner of 3rd place was "JAY" Fisher.

Oh well - can't win them all.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    
    It all started in October when I realized that the old Gentle Lady
    was not going to cut it.  I was searching for a bigger glider with
    a glass fuse.  A few people mention Cumic Plus's, Quasoars, Gemmini
    MTS's and LJMP Pantera's (Larry Jolly Model Products).
    
    We tried to get some Pantera's and waited a couple months for Larry
    to say that he doesnt have any kitted up yet.  I happened to find
    one through Gary Anderson of American Sailplane Designs and ordered
    it.  I started building and within no time, Oct to Mar (oh well)
    Last night it was ready to fly!!!!!!!
    
    As we got to the field last night I thought you know I have spent
    6 months building this Sailplane and it could be destroyed in less
    that 15 secs.  Nah I dont wont to fly it.  I'll just hang it from
    the ceiling and say YUP I built DAT.
    Well I guess the 2 guys that were with me Bob Page and Ron Watts
    would not let me get away with that so I had Ron, who had just flown
    his new Pantera the week before and has flown larger ships(see side
    note) give it the first handtoss.  Oh no it goes up and then left
    and down and right and back up and left and thud it hits the ground.
    OK guys lets go its getting late and it flew. NOPE, We handtossed
    it again and it climbed a little and I flattened it out and it glided
    out majesticly and ended up about 100 yards from where we started.
     OK guys you may now smash my gentle lady this Pantera is the ticket!!
    
    We hook it up to the winch and again I have Ron run the whinch and
    throw the bird whilst I wiggle the sticks. Up it goes and then heads
    off to the left on a 90degree angle.  I crank it back and it starts
    heading for the the clear blue.  I got a pretty good launch and
    I try flying around a little and get it trimed out and had real
    trouble turning it and wanting to stall, when Bob and Ron yell "Its
    not a Gentle lady, let her fly and easy on the Stick" Ok I settle
    down a little and its OK and I land.  A 2:30 minute flight.  
    
    Ok lets send her up again.  This time Bob proclaims "I want to launch
    it" What did you say.  Thats my trophy winner you are talking about!!!
    Anyway I give in and say well what the heck.  Bob mashes the winch
    peddle and when the motor starts to groan he give it the old javelin
    throw (notice I didnt say toss).  The thing goes up like a rocket
    and I can still hear the winch saying "Hey lead foot let up OK"
    and it is groaning and I am yelling let up let up the wings are
    bending and Bob says "Full speed ahead the wings look fine..." We
    come off the launch and things are looking 200% better already,
    gentle on the sticks and let her fly with plenty of speed.  I let
    Bob try the sticks a little.  We even cranked in some down trim
    to see how fast she would fly and it does move out pretty good.
    I made some more turns and landed. A 3:30 flight.  A 3:30 flight
    just goofing off late in the day...Alright!!!
    
    I know I am going to enjoy this plane and boy did I feel bad unloading
    my gentle lady out of the car, with her 3 different colors of monokote
    in all different places, with the yellowing of epoxy around her
    tail feathers and the fraying of monokote around her sides and the
    rubber bands around her nose that are used to hold her tattered
    wings on.  As I pick her fuselage up out of the car I notice that
    she feels a little light compared to the pantera, and she feels
    a little puitrid.  I'll miss you Old Girl....sniff....sniff...I
    used to fly you all over the field and I loved those 2 min precision
    duration as I would wait until 1:30 and then hold full rudder and
    1/2 elevator and watch her come screaming and spiraling out of the
    skys, she did shudder and wobble as I brought her out of this manuever
    but she held on.  Yes Old Gentle Lady...I WILL miss your....
    
    Oh back to the Pantera, Now I have to work on my javelin style launches
    (you cant hold on underneath the wings) and get to where I know
    my capabilites with the plane and then I will be set.  Look at F3b
    I am on my way!!!
    
    
    Side note:  The Pikes Peak Soaring society under the direction of
    master F3b'er Randy Reynolds has 11 people building LJMP Panteras.
    The people range from guys like me who are looking for that next
    step and want to bypass the OLY II category all the way to our Open
    flyers who are looking for a new plane.  This also has a side note,
    every year the Colorado Springs Club and the Denver Club have a
    2 day grudge match and needless to say we are un victorious and
    the panteras are going to give us the edge this year and we are
    going to beat those guys.  So far Ron Watts and I are the only ones
    with our Panteras done, next in line should be Bob Page (all three
    of us are DECIES).  
    
 
    
 
  

    Mark,
    
    Congratulations, the Pantera sounds like a great flying glider!
    The Eppler 205 airfoil definitely requires different stick tech-
    nique than the high lift/high drag Gentle Lady airfoil.  I also
    found this out when I moved from an OLY 650 to a 2 meter Sagitta.
    The full flying stab definitely takes some getting used to.  The
    205 does not like to fly slowly and will quickly drop a tip to tell
    you so.  The LJMP Meteor is an extremely popular glider on the contest
    scene here in upstate New York, however I have only seen one Pantera.
    There is also a 178" LJMP Comet owned by the President of the Buffalo,
    N.Y. soaring club.  Larry obviously likes the Eppler 205 as it is
    employed on his Pantera, Comet, and Meteor.  If I ever get my Algebra
    done which uses the Selig 3021 Airfoil, I will write a comparision
    of the two airfoils in this file.  Michael Selig claims the 3021
    is an "optimized" Eppler 205.  He claims the speed range is greater
    (ie able to fly more slowly, while maintaining excellent penetration
    capabilities).  My personal feeling is the 205 is good as long as
    it is flown fairly fast, it has a tremendous contest record which
    is tough to argue with.  Good luck with your Pantera, keep us informed
    of contest results and your overall impression of the ship.
    
    Regards,
    
    Jim

Since I was glider guiding yesterday and since this has been on my mind for
such a long time and since at least one expert attempted to tell me I was
crazy yesterday I thought now is the time for some aeronautical engineering
controversy.

Here's the beef:

It is my observation that polyhedral gliders (my drifter II anyway) when
making turns (left turns anyway) tend to self center on thermals.

That is if I hit a thermal and just start making tight circles with no
thought as to where I am relative to the thermal I can ALWAYS take the
elevator to the top floor.  That is if I am able to stay in the thermal
at all (for the first 1 minute) then I can usually stay in it till
I have to bail out cause I can't see the plane anymore.

Now I'd like you aeronautical engineers to explain to me why gliders
would self center on thermals.

Maybe hawks aren't as smart as we thought - maybe they just have a better 
mechanism for self centering on thermals?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    All thermals have two things in common, rising air(by definition)
    and they all move down wind.  Usually when I encounter a thermal
    one of my wing tips deflects upward, thus pushing the glider away
    from the thermal.  By turning the glider in the direction of the
    deflected wing tip you will be entering it, whereas if you turn
    the other way you generally will fly out of the thermal.  Once in
    the thermal, the natural tendency is for the ship to drift downwind
    with the thermal, unless the pilot fly out of it.  I have seen many
    local contests won by pilots who are able to ride thermals downwind
    and then be able to penetrate back to the field to land.  The high
    lift/high drag airfoils(ie Gentle Lady's, Oly 650, Drifter, etc)
    are not good penetrators, hence have a difficult time getting back
    upwind.  Thermals vary tremendously in strength, shape, and duration.
    Some are very narrow and powerful, requiring tight circling to remain
    in the lift.  Others are very wide and more gentle, referred to
    as "wave" lift.  Any glider in wave lift will go up.  A glider left
    unattended will tend to drift downwind with any encountered thermals,
    which could be called self-centering, I guess.  The wing configuration
    would have nothing to do with this however, a polyhedral wing allows
    a novice to circle tighter than if he was flying straight wings
    with ailerons which are much more susceptible to tip stall.  
    
    Regards,
    
    Jim

No real controversy yet - let me try this one on you.

Most thermals (not all) are spinning bodies of air.
Some (Maybe most) spin counterclockwise as looking at the
earth from space.

If I always make turns to port (I almost always do) and if I am on
the edge of a thermal my starboard wing would hit the thermal wind
and it would tend to cause a yawl to starboard.  Therefore making
my circles elongated and forcing me into the thermal more and more.
As soon as I start to exit the thermal during my circles my next
circle would have the outboard wing tip hit the thermal again and keep
deflecting my ship back into the thermal.

Anybody buy this theory?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

Kay, I think you may be on to something here...

> Most thermals (not all) are spinning bodies of air.
> Some (Maybe most) spin counterclockwise as looking at the
> earth from space.

I can buy this.  Low pressure areas in the Northern hemisphere spin
counterclockwise.  (The base of a thermal is a local low pressure area.) 
Note that the Southern hemisphere is opposite.

> If I always make turns to port (I almost always do) and if I am on
>      ...
> deflecting my ship back into the thermal.

I can't quite follow you here.  Maybe if you try to explain again. 
Also, for those of us that were never in the Navy, please use "left" and
"right".  :-)

Isn't it true that eagles and hawks ALWAYS circle in a thermal in the
same direction?  If so, is this clockwise or counterclockwise?  Maybe
those birds HAVE learned a trick or two over the centuries...

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

    Here's another theory (or maybe what Kay was saying?):

    First, assume that the thermal in question is a spiraling type
    thermal that is rotating counterclockwise when looking down on the
    earth.  Also assume that the center is rotating the fastest and the
    rotating speed slows down the further you are from the center. 
    (Think of the way water goes down the drain - the center rotates
    fastest.  Or, more accurately, think of a spinning tornado.)  The
    center will also be rising the fastest.

    If you enter the thermal on the right side of the thermal, the
    "wind" generated by the spiral will be coming from behind you and
    will be strongest on the left wing (towards the center of the
    thermal).  The airspeed of the left wing will be less than the
    airspeed of the right wing.  So, the right wing generates more lift
    and bingo - you turn towards the center of the thermal.

    At the same time, the air is rising faster under the left wing and
    tends to turn the plane out of the thermal.  So, when you enter a
    thermal from the right side, these 2 effects work against each
    other.  Which one is stronger?  I have no idea...

    But, what happens when you enter the thermal from the LEFT side? 
    Now the right wing is closer to the center and the spiral wind is
    coming from the front.  The airspeed of the right wing is faster and
    the lift under the right wing is greater.  Both of these effects add
    up and fight to toss you out of the thermal.

    My conclusion after all this confusion is that there may (or may
    not) be a force to make you find the center, but if you make circles
    to the left, you have a better chance to stay in a thermal you
    happen to find.

    Anyone else care to add fuel to the fire at the base of the thermal?

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

        Re:< Note 399.118 by RVAX::SMITH >

        Kay,
        
                I buy  it, hook, line and sinker.  The conclusion is that
        it would make sense to build asymmetric gliders.
        
                What makes this really interesting is that it contradicts
        normal wisdom, which it always to turn into a wing getting pushed
        up.  The revised wisdom  seems  to be to allow the glider to turn
        left but fight right turns and  actally  do  a  270 turn when the
        left wing kicks up.
        
                I'm going to have to watch those hawks carefully.
        
                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

>                What makes this really interesting is that it contradicts
>        normal wisdom, which it always to turn into a wing getting pushed
>        up.  The revised wisdom  seems  to be to allow the glider to turn
>        left but fight right turns and  actally  do  a  270 turn when the
>        left wing kicks up.
         ^^^^ 
Anker -  I'm sure you meant right here.

This is sorta how I fly - cause I can make better left circles with the
drifter I usually make a 270 into the circle or at least a sharp 90 to
starboard then wait a few seconds then start circles to port (left Dan).
       
>                I'm going to have to watch those hawks carefully.

I still think in the long run that hawks are probably dumb.
Maybe they just know if they are high enough to make their short
sited destination.  If they are not high enough they circle to rise.
If they don't rise they flap their wings and fly towards their destination
and occasionally take a break and circle some more.  They probably never
find thermals - but rather thermals find them and suck them in to them.

My observation remains the same - if I circle and I am at or near a thermal
I go up and I never fall out.  I don't make any keen observations about
being in the center or at the edge - just circle and every so often ask
myself - am I higher or am I lower.

Summary - I believe my Drifter II self centers in thermals when I circle
to port.  Unlike Dan (and most of the spectators who watch professional
wrestling) - I don't believe that the toilet spirals clockwise in Australia
and counter clockwise here.  I think there are probably also clockwise
thermals - tho perhaps not as many and perhaps not as large.

Dan - do you believe that those charity penny funnels will only work 
counter clockwise is the states?  Eric's Panic makes tighter spins to
starboard down under!

Now were talking - plenty of controversy.

Keep the thermal/hawk theories coming.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    	I have my own theory about why your Drifter seems to center in
    thermals.  Before I get into that theory, I'd like to say something
    about thermals. 
    	A thermal is a mass of warm rising air.  It is seldom that a
    thermal rotates as it rises.  Here in the New England area, a typical
    thermal will rise at an absolute rate of approximately 500 feet
    per minute at sea level, decreasing with altitude to zero ft/min.  
    The maximum rate in this area is about 1500 ft/min. on a really
    strong day.  The maximum vertical rate is observed at about 2000-3000
    ft above ground.  Max height for a thermal (in New England) is about
    8000 ft above ground on a good day.  Generally it's a lot less.
     	Thermals are turbulent near their edge.  You can mentally view
    a thermal by looking down from space on a donut lying flat on a
    table.  The hole in the donut is the core.  The body of the donut
    is the mass of turbulent air.  Thermals seldom rise perfectly straight.
    They usually rise at a 60 - 80 deg angle on calm days and a 30 deg
    angle on a strong day.  The climb angle of a thermal is controlled
    mainly by the velocity of the winds at the altitude of the thermal.
    Therefore, a thermal will ususally leave the ground going straight
    up and accelerating.  At about 2-3000 ft, it will lose some of it's
    vertical speed and start to drift with the wind. The wind often
    changes direction with altitude so staying with a thermal is a real
    challange.
    
    	There is such a thing as a rotating thermal.  It's called a
    Dust Devil.  In the Northern Hemisphere they rotate in a
    counterclockwise direction, and in the opposite direction for you guys
    south of the equator.  The direction of rotation is a direct result
    of the corellis effect.
    
    	Now, why does your glider self center in a thermal??  The Drifter
    has a polyhedral wing for straight line stability.  To effect a
    stable turn, the glider should have some washout in th ewing tips
    or opposite rudder will backed.  Slow flying trainer type gliders
    have washout.  F3 gliders fly with some opposite rudder in a turn.
    	What I suspect is happening is that your glider DOES stabilize
    in a turn, and probably in just one direction.   This would be cause
    by different amount of washout in each wing tip.  Too little washout
    and you'll tip stall in a tight turn (slow speed, small radius turn)
    Too much washout and it'll be difficult to turn gracefully.  Use
    the good turning side of your glider as a reference and adjust to
    opposite wing to match.  
    	Another possible cause of the seemingly strange behavior of
    your glider if that the wing may not be balanced.  Take the wing
    off the glider and put it on a table.  If it tips to one side, tape
    a penny or dime to the other wing to see how far out of balance
    it is.  It should balance within a penny.  If not, you may have
    a difference in left/right turning ability.             
       	
    	Someone mentioned getting bounced out of a thermal....a wing picks
    up and throw you out of a thermal.  This is very common, especially
    if you are flying slowly.  When that happens, it's usually easiest
    to turn 270 deg to enter the thermal.  During the turn try to pick
    up a bit of speed before re-entering the thermal....you'll need
    the speed for manuvering thru any turbulance before reaching the
    core of the thermal.  
    
    	I could go one for another couple hundred lines talking about
    thermals and such, but I have to do some work.
    
    					regards
    
    						Bob
    	
                                                

	From the description of the way the glider flies, it's possible that 
the thrust line of the motor is set too high.  

	Before changing anything on the A/C, note how it flies without power.
Does it still drop a tip in turns?  Does it fly near stall speed??  You should
have a smooth flying A/C before working on motor induced problems.   Also,
you haven't mentioned A/C weight. How heavy is it?  It could be that your 
wingloading is excessive for the motor/prop combo.  
	
	Assuming everything is OK, take a good look at the thrustline of the 
motor.  If it's too high(up thrust), the A/C will "hang on the prop" at near 
stall speed--the climb rate will be poor, and the A/C will be stalled when the 
motor is initally stopped.  Generally, the motor should be mounted such that 
it is pulling the nose of the A/C slightly down(Downthrust).  The reason for 
this is that you want to motor to move to A/C thru the air as easily as 
possible(read that as "as fast as possible").  Pulling the A/C slightly down 
will accomplish this.  By producing more speed for the given amount of 
power, you will produce more lift and the A/C will gain altitude.  If the 
thrustline is too high, the motor will be lifting the nose of the A/C and
the wing will be closer to stall--that means more drag and less performance.
This proble is not very apparent in powered gas engine A/C because of their
lower power loading(more horsepower per pound of model).  However electric 
gliders are very sensitive to thrustline variations.

	Another possibility is the incidence(angle) of the stabilizer.  
Usually the incidence of the stabilizer and wing are measured relative to a 
datum line that runs the length of the fuselage.  Very few models allow you to 
adjust either incidence value.  The correct amount is built into the fuse during
assembly.  Go back to your plans and reread every assembly step for the wing, 
stabalizer and fuselage.  Look at the plans...then think about how you built 
the model.  Did you follow the plans exactly??  Did you sand too much wood 
off the stab mounting area?  Or use a different thickness wood than called 
out on the plans.   The stabalizer should be mounted almost parallel to the 
lower surface of the wing(assuming you have a flat lower surface airfoil).
The incidence angle varies among A/C, but is usually +/- 2 deg relative to the 
chord of the wing

	If all else fails, install an Astro Cobalt 60 and a couple hundred 
batteries.  Then you can lease the A/C to NASA for launching satallities.

	Hope this helps...let us know what you find out and what the fix is.

					regards

					Bob

        Re:< Note 399.123 by RVAX::SMITH >
        
                I looked  at  it  at the field and have a few comments on
        it.

>    - slow climb rate 
        
                Probably underpowered.   This is very typical of electric
        ARF kits.  Another problem could be pilot training.  On electrics
        you have to let it pick up airspeed and not try to hang it on the
        prop.

>    - seemed as if it were always flying close to stall speed
        
                Any plane will fly fast when either pointed earthwards or
        when sufficient power is applied.

>    - rudder was not very effective - could give full rudder and it
>    would take 3 or 4 seconds for anything to happen.  Then, when it did
>    begin to turn, it responded quickly (as would be expected for full
>    rudder.)
       
                The rudder was much too small.  I advised Steve to extend
        the rudder, which helped.

>    - Ask what the dihedral should be.  (Maybe the rudder problems are
>    due to insufficient dihedral???)
        
                There was less dihedral than I think  is  necessary.  The
        center dihedral was minimal and the wing tip sections were pretty
        small.
        
                With too  little rudder and not enough dihedral turns are
        going to be very painful.

>    - When making a steep bank (about 30 to 40 degrees) it was too easy
>    to stall - the lower wing tended to stall first causing a snap roll
        
                Flying at too slow a speed will cause this.

>    - the difference between stall speed and flying full power was very
>    small.  In other words, if stall speed is (for example) 15 mph, then
>    full power straight and level flight is only 17 mph instead of a
>    more reasonable 25 or 30 mph.  This made it very easy to stall.
>      *** NOTE: numbers are for example only.  Actual values unknown.
        
                I am convinced this is caused by too little power.

>    - Seemed to be flying nose high.  We suspected it was tail heavy
>    (even though balanced according to plans 95mm = 3.74 inches).  When
>    the C.G. was moved forward by 3/8 inch, most of the bad
>    characteristics were improved but not eliminated.
        
                Its hard for a power plane pilot to force himself to keep
        the nose down on an electric. Possibly too much up elevator.

    I would agree with most (if not all) of what you said Anker. 
    However, it was ME at the controls so I would like to think that it
    wasn't pilot error.  :-)

    The comments that Steve posted were also mine.  I've flown a few
    different electric gliders and this one's got me puzzled.

    I will agree that I may have been using too much up elevator, but I
    don't think I was.  At least, I was very aware of this and tried to
    avoid it...  

    I'm still reviewing the flights in my mind...

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

>    I would agree with most (if not all) of what you said Anker. 
>    However, it was ME at the controls so I would like to think that it
>    wasn't pilot error.  :-)

Easy to find fault when your not the one on the sticks.
I also thought it just needed lots more down elevator.
Gliders only fly when the nose is down - not natural to beginners at
all - to make it worse the floater types fly OK with the fuselage
level - BUT - they will actually fly better if you force the nose down.

You have to keep the air speed up and let the airfoil provide the lift.
You will only be able to climb with a positive angle of attack if you
have a power house of an engine and light weight.  It's hard to be
light with batteries on board and I doubt if this glider had a cobalt
engine.

Sluggish rudder response is one sure indicator that your at or near
stall - God's way of forcing you to have air speed (straight down).

Before you flame me - I'm not at all convinced that I could have
done a better job - just an interested observer.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

RE:< Note 399.128 by 22094::HENDERSON "Mode-1 for Ever" >
    
>    Dan flew it fine but it was close to stall a lot due to what I saw
>    as tail heaviness. This could of course be the result of an error
>    in incidences. 

Thanks, Eric.  I was beginning to talk myself into it being 100% pilot
error.  ;-)  I agree that it's probably tailheavy and/or wrong wing
incidence.  Of course, I am NOT ruling out a heavy thumbed elevator yet
either.  (Although I think I did OK.)

Steve, I just thought of something that will eliminate some more of the
variables and I would feel more comfortable as pilot:  I would like to
try flying it strictly as a glider from a hill (as apposed to the 3
second flights we got from Eric's nice hand tosses at the field).  In
doing this, I can get some more flight time on it in an environment that
I'm comfortable with.  At the field, I didn't feel comfortable since it
didn't climb well and as a result, was always too near the ground.  I
know the perfect place, it's about 2 miles from the HLO plant.  (Note
for you would-be slope soarers: NO it's not good for slope soaring...)

>    And last but not least you might find that the rudder angle is not
>    steep enough. I did observe the nose come up when rudder was applied.

This could have been me yanking on the elevator to keep it from tucking
under on the turns.  I can't remember this part too well.

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

    Steve, I'd reposition the batteries/radio if this is an option before
    adding any weight to correct the CG. A rearward CG should make the
    controll surfaces more responsive but also make the airframe more
    critical to stall.
    
    I haven't been following this note so please bare with me. Is this
    an ARF or a kit? I can't beleave your having such a hard time with
    what should be a proven design seeing as it's on the market.
    
    How about telling them it's a piece of SH*T and saying that you'll
    send it back for a reembursement of what you payed for it??
    
    I once bought an EZ lazer and got a half filled box. I was pissed.I
    called and they wanted me to send it back and they would send me
    a new kit. I was then even more pissed. I then ask for and spoke
    to a manager and this got me nowhere but more pissed. I finally
    demamded to talk to the Pres. of the company and gave him a rash
    of sh*t until I felt better. I demanded my money back and UPS to
    pick up the box. I further threatened to write and call every Mag.
    I could think of. What i got was UPS picking up the box the next
    day and leaving me a reciept. Two days latter in the mail I got
    a letter with a check. I kept the check. I threw the letter away.
    
    
    Tom 

    Here's another suggestion.    Without knowing the design and
    construction details, I don't know if this is easy to do but..can
    you reposition the wing back 1 inch??  Yes you lose some control
    responsiveness, but it might be the easiest way out of the problem.
    
    Who is the maker of this kit??  I'd like to avoid them on my next
    purchase.

ONE INCH OFF!!!!  I'm truely AMAZED that the Swallow is not a little
pile of balsa splinters at the moment.  After hearing this, I feel like
I should be given the "Chuck Yeager Test Pilot of the Year Award".  :-) :-)
(Dan Snow too, since he got the first "test flight".)

Seriously, if the CG is that far back, that would explain EVERYTHING.

Fix the CG and we'll try it again.

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

More on the Drifter II self centering in thermals...

Try this theory on for size.

If I make fast tight circles (I was yelled at last Monday for
circling to fast and tight - "Flatten that out and you would be
twice as high up by now!") and if you filmed it and went home
and watched the video.

Now speed it up 10 to 100 times and watch.  What you see is a
cone shaped GREEN blur.  Since it has polyhedral it is not a
pure cone - but if it was a Windsong or some straight wing
F3B ship and had a long (120") wing span - it would look just
like an empty snow cone.

Now picture this - we are in a stable platform above the earth
(ala Buck Rodgers back pack).  Below us to our right is a booming
thermal.  To our left is sink air.  We are exactly in the middle.

We just finish up eating our snow cone and drop the empty cup
down towards the earth.  What does it do?  It self centers on the
thermal (one of those non spinning ones) cause the up air pushes
the top of the cone away and the point then swerves towards the
thermal.  As the cone descends it follows it's point.

Soooooooooo

Gliders that make steep tight turns act like empty snow cone cups
and self center on thermals.

The tipping of the cone is the equivalent of changing my circles into
crooked loops.  Some times I have had my circles suddenly turn
into wild gyrations - then I usually level out the wings myself
cause it doesn't seem to die down by itself.

Opinions?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

Steve, I don't know what the Swallow glider looks like, but you
did say that you added some area to the rudder...I'd remove that
area, since it had nothing to do with your problem (the aft CG)
and try to re-balance.

My HOB 2x4 glider had a bad tail heavy condition and I would up
taking apart and butcherinng the tail as was suggested earlier.
When that didn't get rid of all the weight I added some length to
the nose.   We'll see what that does next time it goes up.

Also, I moved the electronics forward -- you'll probably have to
re-engineer the control linkage as I had to.  But I found the
gain from this to be scarcely worth the trouble.  This may have
been because when I did this I took out my standard radio and
installed the Tower micro system.

The singlemost significant mod that I made was in butchering the
tailfeathers, and I'd suggest you start there.  I did all this on
the 2x4 because I wanted the experience...but the fact is that
I'm trying to make a silk purse out of a sow's ear, and I'll
still have a second rate glider when I'm done.

Steve, much as I like pure gliders - if I were you I would stick with
what you have.  Do the least to change it and still get the CG where you
want it.  Most kits (with the exception of scale) if build as specified will 
end up with the CG right on.  Take the previous advise and trim the tail back
to what it originally was.  Then move the battery forward.  In order to do 
this - take the pack apart and re-solder them in a pattern that will let
them fit in the nose the way you want.  Space left in the very front is good
cause that is where you add lead.  

With the CG right - it will probably be a terrific plane.  Although at this
stage you have to be real careful with weight you will be surprised at
how much weight you can add to the nose and still fly well.  Did you
see my drifter II at the fun fly (the one with the green wings) - it has
lots and lots of lead and epoxy and plywood in the front that was not there
when the plane was brand new.

Right now you only have one problem - CG.  Just fix that and try again.
I'll bet you will be happy you did.  You can always turn it back into
a pure glider later if you want.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    I will take advantage of the recent activity in this note to ask
    about possible designs for my next building project.  I would like
    to build a straight wing ship with ailerons, spoilers, flaps, in
    the 100"-120" range.  To my knowledge the only ships that fit this
    description are Airtronics Adante and Top Flight Antares.  I have
    never seen either of these ships fly and know nothing about them.
    It really seems that not much is offered in this size range.  I
    would appreciate any suggestions about the fore mentioned designs,
    or any other viable designs anyone is familiar with,
    
    Thanks,
    
    Jim

    I have seen an Antares fly and it it is quite a ship!!!!!!!
    
    The person flying it was a club member names John Kappas who lives
    in boulder.  The other neat thing that this plane has is "Electro
    Static Stabilization"  Which means it has four sensors, nose, tail
    and each wing tip.  It then measures the capacitance difference
    between each of these sensors and makes the necessary changes to
    keep the plane wings level and at the right pitch.   The concept
    is that the atmosphear acts as a capacitor and the difference or
    can be measure acuratly enough to tell if one wing tip is lower
    than the other.  This was developed by a fellow named Maynard Hill
    at least I think that is his name.  He is from back east.  The system
    also uses PULODIUM in the sensors to help IONIZE the air to help
    in measuring the Capacitance.
    
    Any way the Antares does a good job.  The only thing that I didnt
    like about it was that the pushrods for the flaps and ailerons exited
    the top of the wing and ran back to the surface.  But oh well. 
    Good luck Jim, keep us posted.
    
    I am working on a Sagitta 600 that will be flat winged with ailerons
    and flaps.  Kinda a minney F3b ship.  Hope to have fun with it.
    
    Went out to the Thermal site this morning and flew my Pantera and
    a Bob Martin Talon (60" Aileron Slope plane that just happens to
    have a tow hook in the bottom).  The Talon was a ball.  You would
    only get a 2 min flight but you could have all the fun you wanted
    with it.  I am going to fly it in our slope contest Sunday Morning.
    
  

    I guess this is as good a place as any...
    
    I called Dodgson Designs friday and asked about their 2meter,standard
    and unlimited class ships. I was trying to get s better price. I'm
    interested in picking up their 2 meter ship and their standard class
    ship to take adventage of some contests in my area. So here's what
    I got...
    
    Lovewing		Retail	229.00	Less	10% =206.10
    Camano			170.00		    =153.00
    K-Minnow			160		    =144.00
    
    Not cheap by any means... but they do fly well.
    
    I don't know if this includes shipping so I doubt it does.
    
    I'm going to order a Camano this week. If anybodies interested
    let me know here.
    
    Tom

        Re:< Note 399.136 by K::FISHER "Stop and Smell the Balsa!" >

                I'm not finished with self-centering thermals.
        
                In  any  fluid  environment  where  you  draw  the  fluid
        towards a drain  there will be rotation inside the drain.  That's
        simply because any effective  rotation in the body, no matter how
        small will be amplified.
        
                So I contend that ALL  thermals  rotate.  Dust devils are
        simply thermals that rotate real fast.   And  tornados  are  ones
        that rotate like crazy.  But show me  a  thermal, and I will show
        you a rotating mass of air.
        
                The  next  question is whether they rotate anticlockwise.
        The coriolus effect will make them rotate more often aniclockwise
        than clockwise.   Assuming  that  all  other  motions are random.
        Now, I don't know whether more often is real close to always, but
        judging from the real, real  BIG  ones,  hurricanes, it cartainly
        looks like biggies DO and somehow that will scale downwards.
        
        QED!
        
                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

    Steve,
    	I wouldn't worry about oversizing the rudder.  I've seldom seen one
    that was too effective.  The only disadvantage is that it will add to
    the nose heavy problem to add weight at the rudder.
    
    Charlie
    

    RE: .145

    Steve, you now know that you need to treat those little blades with
    a LOT of respect.  I hope the cut in your leg isn't too severe...

    Let me know when the Swallow's ready again...


    RE: .146

    Anker, generally I agree that most steady thermals rotate.  However,
    some thermals do not form a steady column of rising air (analogous
    to the fluid down the drain).  Sometimes, the analogy is more like
    an air bubble coming up through water.  Thermals do sometimes
    bubble.  Have you ever experienced FANTASTIC lift one second only to
    loose it the next second?  That's a bubble of lift.  (Or you flew
    THROUGH a thermal...)

    I doubt that these bubble-type thermals rotate.  But then again, it
    doesn't really matter since they don't stay around long enough for
    you to get centered in them anyway.

    BTW - when I was still a high school kid, I spent every summer
    hanging out at an airport with lots of full scale gliders (my dad
    worked there).  I even took 2 lessons and a bunch of rides.  (Not to
    mention hours of "hanger flying").  I never remember anyone talking
    about self-centering in a thermal.

    Also, I looked in my glider instruction manual last night and they
    do not mention self centering of thermals but rather, go on at great
    lengths to explain how much effort is required to find and stay in
    the center.  

    But than again, this book was written many years ago and maybe we
    (in the notes file) are coming up with a new theory!  Let's keep
    those ideas coming!!!

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

    Kay:
    I just read note 399.45 where you talk about the LSF. You said you
    were unsure about getting enough contest action for level II in
    one summer.  Perhaps we could compete by mail. I am sure some of the
    CXO guys would be agreeable. I don't know if this is legal for LSF
    or not, but we could set a task and give it a try. Weather  conditions
    may vary from your area to ours, but ours change every hour anyway.
    We would have to think about the events, perhaps a 15 min. Add-Em-Up
    or a simple thermal duration with a spot landing 4 min. Any way it
    might be fun to give it try. We would need a least 5 people to enter.
     You could fly the event any time you went out and judged the weather
    to be appropriate (no test flying to that monster thermal and ten
    declaring you entry). We could specify a date. We would have to think
     out the rules and see if it's achievable. Let me know what you think.
    

>    I just read note 399.45 where you talk about the LSF. You said you
>    were unsure about getting enough contest action for level II in
>    one summer.  Perhaps we could compete by mail. I am sure some of the

I was premature - as it turned out there are plenty of contests around
you just have to expand the area that you are willing to travel and
also they all don't appear in the AMA magazine first thing in the spring.

That is as the summer rolls along more contests are announced with each
issue of MA.

I finished level II - now on to level III. 

The 1st glider contest out here is in Sidney Maine (where ever that is)
on 21-May-1989 - I hope to have my Sagitta ready in time.

Next is 4-Jun-1989 in Simsbury Connecticut (a long drive - but I went last
year) but that is in conflict with a scale fly in at Hadley Massachusetts
(very near home).

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    I just read the Jan/Feb issue of the National Soaring Society
    newsletter/magazine.  There was an interesting opinion on airfoil
    construction considerations.  The author felt that the probability
    of two builders, each building the same undercambered airfoil, coming
    out with anything close to the same was remote.  He feels that using
    conventional built up construction, one should steer away from
    difficult undercambered airfoils, with razor sharp trailing edges
    (ie Quaback, certain Eppler, and Selig 4233).  The simpler Eppler
    205 and Selig 3021 were highly recommended.  My father has built
    several of these difficult airfoils, and despite careful construction,
    those razor sharp trailing edges air impossible to keep straight!
    Conclusion:  The only way to insure a "true" undercambered airfoil
    is with foam or similar techniques.  Built up wing sections work
    best with flat bottomed airfoils.
    
    Regards,
    
    Jim

    Having noticed that many contributors to the glider notes are also
    power flyers, I was wondering if you fly your gliders at the same
    fields you fly your power planes?  I am always checking out new
    flying sights which inevitably are almost exclusively used by power
    flyers.  I get the impression that they are not interested in gliders
    being allowed to fly even if flown completely out of the way of
    the power planes.  I currently am building my first power plane
    and probably could back door my way into one of the local clubs
    as long as they didn't know I also had gliders!  How do you
    power/glider pilots coexist?
    
    Regards,
    
    Jim

        Re:< Note 399.153 by USRCV1::BLUMJ >

        Jim,
        
                At CRRC we  mix  power and gliders at the same field with
        no problem.  We also got ourselves a glider only field.

                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

>< Note 399.154 by CURIE::ANKER "Anker Berg-Sonne" >
...
>                At CRRC we  mix  power and gliders at the same field with
>        no problem.  We also got ourselves a glider only field.

Tell me (us) more about this glider only field - I never heard of it and
it isn't used for the glider competition that Fritz Bien hosts every year?
Is this new?  Where is it?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    I assisted my father in flying two new scratch-built ships this
    weekend.  The first was the "Thermal Queen" which is a constant
    chord 144" wing, using the highly undercambered Eppler 385 airfoil.
    This is an early 70's Lorber design that my father wanted for evening,
    minimum sink flying.  This ship makes a Gentle Lady seem like a
    hot ship, it is really slow, despite it 10 oz. wing loading.  The
    second ship was Bruce Abell's "Scimitar", which is a very unusual
    looking design with forward swept wings.  It has 118" polydihedral,
    undercambered wings of Abell's own design.  The CG was way off on
    the test flight resulting in an extremely fast flight.  By removing
    nose weight a little at a time we were getting the ship in proper
    trim, unfortunately a hard landing damaged the stab before we were
    able to get it right.  This looks like a promising ship!
    
    Regards,
    
    Jim

    To liven up this highly inactive conference, lets discuss the results
    of the first and recent National invitation only Thermal Duaration
    Soaring Masters Competition.  All the magazines have had articles
    about this event, but if you didn't read about it, I will describe
    it:  The organizers wanted to hold a thermal duaration type contest
    with the best flyers in the country.  To enter the competition required
    at a minimum LSFIV status or a win at a major event(ie "The Nats").
    The contest was held in California, there were 23 entrants, many
    were internationally known F3b competitors(Larry Jolly, Rich Spicer).
    RCSD dexcribed the contest as follows: "Lift was everywhere, so
    it essentially became a landing contest."  The ships entered ranged
    from 2-meter, 2-channel balsa to full blown composite construction
    f3b style gliders.  As one magazine described the landing technique
    used by the top finishers-"It sounded like a little league baseball
    game, when an aluminum bat makes contact with the ball, it could
    be heard throughout the valley."  The technique used by the top
    finishers was to fly their blue foam/composite ship 10-15 feet over
    the landing circle then dive vertically, spearing the ship on the
    mark.  The nose of the ship was literally stuck in the ground! 
    Obviously this technique would destroy and conventionally built
    balsa ship.  These super ships were able to land in this fashion
    all day, which certainly is a tribute to the high tech construction.
    This method of flying/landing sort of violates my sense of what
    gliding is all about.  It puts a premium on building a crash resistant
    ship.  I would like to see the time limit extended, with greater
    penalties for undertime, and less points for spot landing.  These
    "super" ship require super winches to launch them, super radios
    to fly them, and space age materials to allow them to use the spear
    landing technique.  All this is fine, but better left to f3b
    competitions.  Somehow zoom launching a glider to 1000 feet with
    a very expensive winch, and watching it spear into the ground 7
    minutes later violates my sense of "thermal duration".  Take away
    the super winch and many of these ships won't be able to meet an
    extended time limit-say 10 minutes.  Comments?
    
    Regards,
    
    Jim

    How about "spearing" being ruled as a crash rather than a
    landing. Landings could be defined as contact with the ground
    where by the plane comes to rest on tera firma but is not
    "Impaled".
    
    I've seen windsongs come in steep with flaps and spoilers
    deplayed but then landed. Not impaling themselves into the earth.
    
    
    
    Tom (Just my opinion)

I used to have this feeling that I was alone in my opinion
that my glider self centered.  Kind of like believing that we are
the only intelligent life forms.  WE ARE NOT ALONE!

OK - I'm back.  Admittedly my Sagitta don't self center as good
as my Drifter II (rip) did - but here's some more fuel to the
controversy.  In the August issue of "Model Builder" in the Free
Flight column by Bob Stalick there is a discussion about why
"models do seem to end up centered in a thermal at times".

This is good for about two columns of text on page 59.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

This just in from a full size competition sailplane pilot - Mike Newman
from Marlboro who owns and flys a Ventus Bt - whatever that is.

>Real gliders self center in thermals with the proper combination of wing
>dihedral, bank angle, thermal size etc. I imagine it is the same for scale.
>In real gliders there are several models well known to have better self
>centering characteristics: the Libelle is one.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    How about making "spearing" illegal, then mark the center of balance
    on each glider.   The rules could require that the winner have the
    center of balance as close to the mark on the ground as possible.
    Directly over it would be best.
    
    This would make the landings more traditional, the "tough construction"
    less important, but still require extreme accuracy which is measureable.
    
    Glenn

>                 -< Spearing is a technique for marshmallows >-

I think spearing on landing is perfectly reasonable.

Consider the effects of scale.  Real gliders have 6 inches of so of
clearance between their bottom and their wheel.  RC gliders have maybe
an inch from their skid to the top of their canopy.  When you land in
grass fields (don't we always) you can't expect to make scale landings.

I made several divots this last weekend and don't feel a bit guilty about
it.  Unless we have golf course greens to land on and fly scale ships
with landing wheels or skids and as long as the target is worth
some points then we should expect spearing - and welcome it and it
adds to the spectator aspect of the sport.  Now launches and landings
are fun to do and fun to watch.

             _____
Bye          ==+==
Kay R. Fisher  |
               0
_______________O_______________
---------------O---------------
            \  0  /
             \ v /
================================================================================

    I don't know Kay, I don't think I can agree with ya on this
    one. It might be somewhat thrilling for spectators to watch
    gliders crash into the ground, but from a competition standpoint
    I don't think it takes very much skill. As a matter of fact, I'd
    be willing to stick my neck out far enough to say that although
    I've never flown in a glider competition before, I'll bet ya I
    can get pretty decent landing scores using that method. It's much
    more difficult, (higher skill level) to land near the spot in a
    normal manner.
    
    Steve

    It seems to me that under the current rules, the USA thermal duration
    contest has become nothing more than a landing contest.  I agree
    that it doesn't take much skill to spear a glider, only the money
    to purchase one that can take this abuse.  Gliders both RC and full
    scale have never attracted much attention in America and probably
    never will.  There is an elegant beauty in unpowered flight that
    few appreciate.  Why must we resort to "smashing" our equipment
    to attract "demolition derby" mentality fans, who don't understand
    anything about flying anyway?  The original thermal duration rules
    established in the era of less efficient gliders and weaker winches
    needs to be modified to put the challenge back into flying, rather
    than landing.  I propose a 10 minute limit rather than the current
    6 or 7 minute limit, with landing bonus reduced.
    
    Regards,
    
    Jim

I'd like to comment on .174.  But first let me admit that while I
belong to a glider club, and enjoy soaring, I am an outsider to
contest flying.  To me glider flying is just plain relaxing fun.

>    to purchase one that can take this abuse.  Gliders both RC and full
>    scale have never attracted much attention in America and probably
>    never will.  There is an elegant beauty in unpowered flight that

When I attended the '84 Nats in Reno, one thing impressed me; the
large number of glider guiders that entered.  I think that they
were the largest single contest group there, and I believe that
this is typical.  I know that the local turnout that I've seen at
the glider club contests puts our power club to shame, though the
glider club is smaller.  So lets say that they may not be as
large in numbers, but they make up for that in participation.
And I think the numbers of glider pilots could well equal the
power guys, and maybe exceed them, on a national level.  They are
active if nothing else.

On the comment that glider contests have become a landing contest
rather than a flying contest.  I've said before that the glider
guiders have created their own stressful contests from something
that is really laid back, but Jim, I think you've put your finger
on it.  They have this weird fascination with hitting the landing
mark, on target, and on a specified time, to the point where its
not a part of the task, it IS the task. But landing is only a
part of flying, why is it so important?

There's this strange bunch of landing rules about hitting on the
exact time, or on the duration time...with penalties for
deviation.  I sailed boats with a stopwatch -- ever seen how
pretty they are out there on the water?  -- Let me tell you, it
ain't pretty on the boat!  I'll bet that at a hot contest there's
an equal bunch of "glider lawyers" as there are "sea lawyers".
The glider guys have this same way of making the stopwatch the
crux of their contests, making something -- can we call it
"exciting" -- out of something that is inherently very relaxing.
A return to strict thermal duration seems to me a good start to
make glider contests reflect the true spirit of flying gliders. 

    When I was in CXO back in 85 and flew gliders I noticed that the
    practice session were layed back and fun. You were trying to get
    the longest flights you could and make the prettiest landing possible.
    
    At the contest the stopwatch came into play. But then again that's
    the nature of the beast. 
    
    My thoughts are that that's what the LSF is all about. As you strive
    to attain the lower levels you do so for the most part outside of
    the contest format. As you progress and your skill gets better then
    you strive for a different level of excellence. 
    
    
    The bottom line ( and one I've only come to with the last days)
    is that there are those individuals that will take up this hobby
    and strive to get good. There are those that take up the hobby
    to take part in the hobby and then there are those who are driven
    to compete. 
    
    I think (being one of the driven) that those who are the driven
    loose sight of the facts that there are some who don't wish to compete.
    We seem to think that competing is what is the name of the game
    because it is the name of the game for us. We are not the majority.
    
    You need to classify yourself at this time. Are you a striver?
    							a competitor?
    							a partaker?
                                                                  
    
    Whatever one, you and a RC Hobbist.
    
    
    Tom

>    It seems to me that under the current rules, the USA thermal duration
>    contest has become nothing more than a landing contest.  I agree

Not out here Jim.  Where R U?  The expert flyers win by finding good 
thermals and staying in them and also by good landings.  Nobody breaks 
their plane spearing it in and gentle ladies and Oly II's and Sagitta 
650's do just fine in landing.

Spearing happens some times - seldom really on purpose - usually the pilot
just thought he could come down a little faster and a little steeper than
he really could.

I defend spear landings because I don't think it detracts from the
competition and given the choice I would always want less rules
than more.  Shedding parts and flipping over are not subjective.
Spearing is.  When is a spear a spear.  Does it have to stick?
Does the stuck glider have to have the tail so many inches in the air?
If so what about short gliders or flying wings?
If it doesn't have to stick is there a divot rule?
Do you measure divots by area, weight, volume?
Maybe you just want to measure time of flight.  Does that end
when the glider touches ground?  Which bounce?  Tall grass?
Short bushes?  Trees?  Can you catch yours to terminate the landing?

The rules have been developed over many years and they are PERFECT
(my opinion).  Contests are great fun and well attended.  Gliders are selling
like hotcakes and the new electric gliders are bringing a new dimension
to the sport.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    I would ask all who have entered an opinion on "spearing" to please
    read note 399.166, which was the note I entered to initiate this
    discussion.  The conversation is getting away from the original
    point I was attempting to make.  To restate my position:  the best
    flyers(like the ones that attended the inivitation only Masters
    Thermal Duration Contest) will not find staying aloft for 7 minutes
    a difficult task, especially with the winches available today. 
    Hence, for good flyers, the contest essentially becomes a landing
    contest, since everyone is able to stay up the required time.  I
    do not want to change a lot of rules about what type of landing
    is acceptable.  I simply would like the required time extended from
    the current 6-7minutes to 10 minutes, with any style of landing
    acceptable as long as the ship is flyable.  My reasoning behind
    this is the 6-7 minute limit was established when sailplane designs
    were less efficient as were the winches to launch them.  I would
    like to make it a greater challenge to stay up the required time
    which would lessen the value of the spot landing but not eliminate
    it.  
    
    regards,
    
    Jim

Personally, I believe that no matter how you change the competition rules, the
best flyers will always win or place high. They win BECAUSE they are good 
pilots. At least at the level of competition I've been involved in, the best
pilots always seem to max out and then score high landing points WITHOUT 
"spearing". 

I think that raising the duration time from 7 minutes to 10 minutes will simply
widen the points gap between the expert flyers and the sport flyers. The best
pilots seem to be able to keep the plane up at will. I have to agree with Kay,
most spearing I've seen has been unintentional, the pilot just brought it in
too high and decided to sacrifice the nose in the interest of points. If 
spearing is done as a matter of course at the high competition levels, then
the plane has to be designed better, or heavier, to withstand it, and that
penalizes the plane in the air.

So where am I going with this argument (he asks himself)? I guess I've never
felt that the rules favor one flyer over another, because the best always adapt.
And I've always thoroughly enjoyed myself at the contests, even as I was being
wupped by the experts.

Dave

I attended the Farmington CT Summer Soar In Saturday and placed
21st of 26.  They flew two 3 minute rounds, two 5 minute rounds
and two 7 minute rounds.  On the first launch against my better judgment
I was directed to the weakest winch and about 1/3 way up the Sagitta
just out ran the winch - not really a pop off but the same results.

On the first 7 minute round I winched directly into the sun and they
had just put a fresh battery on the winch (the hot one) so I didn't dare 
keep on the switch.  So after a long "where is it?" session I saw it and 
fell of the winch line - again not a real pop off but the same results.

They didn't allow relaunches for pop offs at this contest (which
I think is a good idea).  There were great thermals all day long
and almost everyone had no problem getting maxes except me.  I'm beginning
to loose faith in the Sagitta.  Either I have to strip down the fuselage
and sand it till it's lighter or I have to learn to fly it with less
down trim or something.  In good thermals I can just hold my own while
all the other gliders are going up around me.  Given the same circumstance
I would expect my old Drifter II to go out of sight.  I have compared
the weight (by hand comparison) with two other Sagitta 600s and one
was about the same but the other was significantly lighter.  I think
when I was rushing to finish it and epoxied the tail I created a monster.

Opinions?


Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

One thing that I did in the past was to swiss cheese the sheeting on a heavy 
fuselag. This was done by cutting out circles in the big empty areas and then
recovering over the empty areas. I used silkspan on a heavy sealed and painted
one and then refinished. It allows you to keep the strength of the glue joints
in the structure while reducing the weight of a heavy finishing job. With the
long moment arm of a glider it should be reasonable to save on nose weight (if
you had to add some) by lightening the tail boom. Or lighten the nose and move
the battery farther forward.

Might not be able to spear it in anymore ;^)

>One thing that I did in the past was to swiss cheese the sheeting on a heavy 
>fuselag. This was done by cutting out circles in the big empty areas and then

I'm really glad I asked and didn't get restless and start sanding already.
I completely forgot to even consider cutting holes.  I'll bet I can drill
a few strategic holes in the fin and pull a ton of weight out of the nose.

I had it balanced on the front wing rod and was shocked to see how much
change I got when I added a decal to the tail.  Being lazy I will probably
first drill the holes and fly it before I cover them and re-paint.

This notes file is great!

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    Kay,
    
    For the sake of comparison, my Sagitta weighs about 39oz.  Which
    corresponds to a wing loading of approx. 9oz/sq ft.  Mine also 
    requires a lot of lead in the nose to get it to balance.
    
    Regards,
    
    Jim

>    For the sake of comparison, my Sagitta weighs about 39oz.  Which
>    corresponds to a wing loading of approx. 9oz/sq ft.  Mine also 
>    requires a lot of lead in the nose to get it to balance.

Jim - that's another thing I have never done right.  How in the world
do I weight it accurately - I wish I had a scale that was accurate to
.1 oz from 0 to 200 pounds.

What did you weigh yours with?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    Kay,

    Well, I'm not the one you asked the question to, but...

    I went to a department store and bought 2 food scales: one that
    weighs from 0 to 16 ounces in 1/4 oz. increments; and one that
    weighs from 0 to 10 pounds in 1 oz. increments.

    Someone else in the CRRC club bought a digital fisherman's scale (0
    to 10 pounds) that is very simple to operate: Hold the scale in your
    hand (it's the size and shape of a pocket calculator), attach your
    plane to the metal hook hanging from the bottom, press a button and
    read the weight on the LCD display.

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

    Kay,
    
    I use a mail scale to weigh my gliders.
    
    Regards,
    
    Jim

>    I use a mail scale to weigh my gliders.

Jim - your own mail scale or do you go to the post office?
If it is yours - how high does it go and where did you get it
and how much do they cost?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    Kay,
    
    The scale is actually owned by my father, who used to have a business.
    Hence, he needed the scale to determine postage prices.  I believe
    you can buy one at a stationary or office supply store, but have
    no idea what they cost.  An interesting note about Sagittas:
    Mike Reed of the Pikes Peak Soaring Club(LSF Level V) achieved all
    the LSF requirements using a Sagitta 900.  He claims that Sagitta's
    do not perform well at wing loadings below 10oz/sq ft.  In fact
    he feels that they perform the best at 12oz and up wing loadings.
    
    Regards,
    
    Jim

>    no idea what they cost.  An interesting note about Sagittas:
>    Mike Reed of the Pikes Peak Soaring Club(LSF Level V) achieved all
>    the LSF requirements using a Sagitta 900.  He claims that Sagitta's
>    do not perform well at wing loadings below 10oz/sq ft.  In fact
>    he feels that they perform the best at 12oz and up wing loadings.

Wow - I am convinced that in the wind I can't be beat (well not
my Sagitta anyhow).  But on nice calm days when floaters go up I'm in
trouble.  Could be me not flying correctly.

I attempted to weight it last night.  First on my K-Mart 1 pound scale.
It seemed to bottom out with good authority.  Next I took it up stairs
to our bathroom scale.

We have one of those digital talking scales.  So I got on without
Sagitta and got off again then got on with the Sagitta Fuselage
without wings and without stabilator and stabilator rods but with
the main wing rods and without the canopy.  The scale said I gained
3 pounds.

No figure the scale doesn't know about fractions that probably means
the fuselage is between 2.5 and 3.49 pounds.  Assume the best at 2.5
that is 40 oz without the wings.  I weighted one wing on the K-Mart scale
and it was 7 oz so add 14 to my 40 and I'm at 54 oz without the stabilator
and canopy.  And that assumes all the error on the bathroom scale is in
my favor.  I have this compelling desire to drill holes but I would like
to actually find an accurate method of measurement first so I can tell
how well I am doing.

While I was going upstairs to the bathroom scale (wasn't smart enough to 
bring the scale to the workshop!)  I weighted the Berliner-Joyce and 
my Aeromaster.  The BJ was 9 pounds and the Aeromaster 10 pounds.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

        Re:          <<< Note 399.189 by K::FISHER "Stop and Smell the Balsa!" >>>

        Kay,
        
                What does  the bathroom scale say you weigh?  250 lbs?  I
        refuse to believe  that your Aeromaster weighs 10 lbs.  Mine may,
        but definitely not yours.

                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

Kay,

I've picked up your Sagitta. I should think that sled could be weighed on
a truck scale.

Seriously, I once compared it to my Metric and it felt substantially heavier. 
The Metric comes in at 35 oz. so I'll bet it's up around 42-45 oz. (Hey, we
could start a pool here...guess the weight of Kay's glider).

    RE: Scales
    
    One of my co-workers is heavy into Bass fishing so I asked him what
    was available for weighing fish. He pointed out an electronic scale
    made by Normark. The scale is a handheld unit for $30 that goes
    up to ten pounds and is in accurate within 2 oz. The scale is available
    from Bass Pro Shops at 1-800-227-776. According to the chart, for
    a $30 item, shipping will run $4.35 and insurance is $.60. All the
    usual disclaimers apply about me not benifiting in any way from
    this.
    
    Another possibility is the scale that was a construction article
    in RCM a couple of months back. Its cheaper, handles heavier loads
    and I seem to recall it being accurate down to 1/2 ounce.
    
    Dan Eaton

Glider rambling - part 1.

I copied this story out of the book called "Collected Classics
of Soaring" by Trish Durbin.  Published by and available from

	Arizona Soaring Association
	P.O. Box 11214
	Phoenix, AZ. 85061

Having given credit I'm sure they won't mind a little free advertising.

I'll try and set the stage a little first.
This story is from a chapter on Crewing.  Crewing to full scale glider
pilots is not unlike crewing for Hot Air Balloons.  The crews job is to
retrieve the pilot and plane from where ever he lands.  Frequently on 
cross country trips they land out and have to walk to the nearest
phone and give directions.  The crew usually stays at the starting
airport until they have some radio message (usually relayed) that tells
them where to go.  Sometimes they anticipate an out landing and travel
some distance just to find that the pilot then caught a boomer and
made it back to the airport.  Anyway...

Sweet Revenge by Paul Dickerson.

   This is the story of a truly wonderful joke played on a pilot who had
landed out by his crew.  The pilot in this case was Bob Gravance and the 
crew chief getting even with him for unknown past sins was his son, Jack.

   The setting is the El Mirage high desert area in the early 70's.  Bob
Gravance was on a long cross country in the hottest period of the high
desert summer, mid August, when he hit the ground at Darwin which is truly 
one of the garden spots of the Death Valley area.  It is rumored that there
was at one time two live plants in the city of Darwin.  Inspection today,
however, does not reveal any evidence to substantiate this.

   Bob landed his ASW-12 on the local strip and through the usual comedy of
errors and bad communications managed to establish a link with his ground crew
who was back at El Mirage in the swimming pool.  Now I'm sure it's not true, but
the story was told that the pilot was surly as he addressed his crew, wondering
why they were standing there in their wet bathing suits while he was suffering
from beer withdrawal in Darwin, some 3 to 4 hours away.

   Well, as it happened, in his younger days as a crew chief, Jack Gravance
suffered many of the defects that our own modern day crew chiefs suffer from,
and that is a lack of proper humility, a lack of understanding of the agitation
a pilot feels when he lands out, and a sensitivity to being yelled at.  It's
unreasonable that they should act that way but it's reality and one needs to
address reality.

   Bob, however, failed to address reality and Jack and his friends hatched
a plan to get even.  They launched immediately from El Mirage in their old 
pick up truck with the ASW-12 trailer.  However, rather than the usual arrival
at the airport, beer in hand, trailer behind, ready to retrieve pilot and 
aircraft, they stopped about 5 miles from the airport, disconnected the trailer
and left it in a parking lot.  Thus when they arrived at the airport to retrieve
the now-steaming pilot, they did not have the trailer with them.

   As they rolled to a stop, an agitated Bob Gravance launched out from the
shade beneath his airplane wing which was the only shade within 150 miles of
Darwin.  Jack had an open can of beer, frosty and cold, hanging out the window
ready to hand to his father, when his father said,

   "Expletive Deleted, you forgot the trailer!"

   So in mock surprise, horror on his face, Jack said,

   "My Gosh!  You're right.  I'll go get it.  Stand by."  So he took the beer
back inside the car, rolled up the window, made a dusty 180 Degree turn and 
roared off in the direction he had come, leaving his father agitated because 
not only did he now have a 6 hour wait for the trailer to get back, he still
didn't have a cold beer.

   With some difficulty, the crew managed to keep the car on the road and
disappeared into the distance at high speed.  As soon as they were out of sight
they pulled off the side of the road until they recovered their composure
sufficiently to safely drive an automobile.  After a further mile or two, they
recovered the glider trailer, and returned to the airport to recover a 
properly humiliated hot and thirsty pilot.

===============================================================================

So whatcha think - I've got a couple more I'm willing to type in.
Anybody want to see these or am I just filling the notes file with
junk that nobody cares about?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

>< Note 399.183 by USRCV1::BLUMJ >
>                              -< Sagitta weight >-
>
>    Kay,
>    
>    For the sake of comparison, my Sagitta weighs about 39oz.  Which
>    corresponds to a wing loading of approx. 9oz/sq ft.  Mine also 
>    requires a lot of lead in the nose to get it to balance.
>    
>    Regards,
>    
>    Jim

Finally got some scales.  Mine weights 40.5 oz.  I assume Jim that you
would not consider yours or mine to be a lead sled in that case.

So why do you suppose I don't seem to be able to thermal?  My first guess 
is that I've screwed up the airfoil.  When I added the carbon fibers to 
the airfoil I ended up adding a small area to the bottom of the airfoil.  
I covered with Micro-fill and sanded but the true flat bottom wasn't perfectly 
true anymore.  Now if you assume the worst case and say the flat bottom has
a lump in it (so small in reality that you probably couldn't detect it)
then maybe I am approaching a symmetrical airfoil.

Anyway the plane really likes to fly fast - guess I just have to start
slowing it up a bit and get more practice.

As if I haven't learned my lesson I added carbon fiber to the bottom spar
of my new Thermal Charger last night.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

        Re:          <<< Note 399.195 by K::FISHER "Stop and Smell the Balsa!" >>>

        Kay,
        
                I think  your  problem  is  one  of  two:  Kay - yes you,
        flying it too  fast  and  not  letting  it slow down, or that the
        plane is too tail heavy, which causes it to accellerate when left
        alone.
        
                I have watched you fly  both  the  Sagitta and your other
        gliders and you tend to be  very heavy on the sticks, so my guess
        it that that's your problem.  Why  don't you go to Callahan State
        Park some lovely weekend and let Lincoln Ross  take  your Sagitta
        up. He is as good on a Sagitta as anybody I have seen.
        
                You  can also try to add a tad more  lead  in  the  nose.
        This should cause the nose to pitch up if the plane ends up going
        too fast, thus slowing it automatically.
        
                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

                I still  think  40 oz is awfully heavy for a 2M ship.  My
        Riser weighs 28  and  the  Song  Bird that I almost have finished
        will end up pretty close to that, and its 95 inches wingspan!
                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

    As long as were on this subject, is there any rule of thumb for
    gliders and wing loading. Meaning, if I have a 2 meter glider (72")
    and a wing area of aprox. 770 sq. inches, should my wing loading
    be in the area of ?????? My glider (as described above) also weighs
    in at about 40 ozs. and has a wing loading of aprox. 19.? per square
    inch. That seems mighty heavy to me. Is it?????
    
    
    Steve

        Re:                       <<< Note 399.198 by RVAX::SMITH >>>


>    in at about 40 ozs. and has a wing loading of aprox. 19.? per square

                That's the "wing" loading of a lead pipe!
        
                I am sure you meant 19.? per square FOOT.
        
                Seriously.  That's on the heavy side, but not outrageous.
        Its amazing how  heavy gliders can be and still thermal well.  My
        Airtronics Eclipse electric glider  thermals  beautifully,  but I
        would hate to have to put it on a hi-start!
                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

    Square inch......Square foot.......the damn thing doesn't fly any
    better either way.
    
    Where I'm not sure I'm figuring wing loading correctly, can someone
    give me the formula, or tell me what the wing loading would be on
    a 2 meter (72") wing span glider....540 sq. inches that weighs 40
    ozs.
    
    For those of you not familiar with this lame duck, it was previously
    an electric that flew like a bullet riddled goose. I have since
    removed all of the electrics, closed up the nose, and made it into
    a plain old drag it up into the air glider. The problem is, I had
    to add a considerable amount of weight to make up for the missing
    electrics and it sits at about 2 1/4 to 2 1/2 pounds. It has a very
    high stall speed, which I attribute to a high wing loading, and
    for a glider, tucks it's nose and snaps like you wouldn't believe.
    
    I'm just not sure what constitutes a heavy glider and what doesn't.
    My next step will be to open up the nose again, and extend the nose
    mement in order to get rid of a bunch of weight. I'm determined
    to get this Albatross to fly.
    
    Steve

    To figure the wing loading of a glider in oz./sq. ft., divide the
    wing area by 144, then divide the weight of the glider by the quotient.
    So for your glider, 540 sq. in. divided by 144 equals 3.75.  Dividing
    40 oz. by 3.75 = 10.67.  Hence the wing loading of your glider is
    10.67 oz. per square foot, which is heavy by "floater" standards,
    but relatively light by high performance standards.
    
    Kay,
    
    I flew my 39oz., 2-meter Sagitta this weekend from both high start
    and slope and it flew very well.  Assuming the CG is set per the
    plans(as mine is), the only other problem I can think of is the
    the wing decalage.  It might be worth checking this against the
    plan also.  
    
    Regards,
    
    Jim

I'm sure the designer shortened it from the original when he decided to install
that brick up there. The longer the moment arm the less the weight.

Another thing that might help would be to warp some washout into the tips to
ease up the snap/stall characteristics. I'm pretty sure that's been covered in 
here before (but I haven't got time right now to search). Anyone got a quick 
pointer?

    Here's how to coumpute wing loading:

            ( # sq. inches / 144 = sq. feet )

    So,   540 sq. in. / 144 = 3.75 sq. ft.

    40 oz. / 3.75 sq.ft. = 10.67 oz. per sq. ft.

    This is a very good number for a glider.  I'm not a glider guider
    guru, but from all I've heard (& read) 8 to 12 oz. per sq.ft. is a
    good range for a glider.

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

On wing loading:

	The calculation is easy. It's 40 oz/ (540 sq in/ 144 sq in per sq ft)
	=10.7 oz per sq ft.

My electric (the one that has the motor controller you sold me!) weighs in at
47 oz, so with 600 sq in of wing, it comes in at 11.3 oz per sq ft. And it
flies just like you describe: high stall speed, fast sink. It thermals fine
IF there's good strong lift (Anker).

After flying the electric Saturday, I put the Metric up. That's a regular glider
that weighs in at 35 oz, 8.4 oz per sq ft. What a difference! In comparison 
with the electric, it was effortless flight. It seemed to stay up forever, and
that was when there was essentially no lift. My Riser glider (which I plan to 
sell at the CRRC auction) is lighter still at 28 oz, and as broken and warped
as it is, I still got two contest trophies with it. It just doesn't take much to
keep it in the air.

As for your defanged electric, I'd say try moving the battery, receiver, and
servos as far forward as possible, with the battery closest to the nose. If
that doesn't help, you got a lead sled. You should go to the auction. Have I
got a glider for you...

Dave

        Re:                     <<< Note 399.204 by IGUANO::WALTER >>>

        Dave,
                
                You'll have  competition.    I'm  also  selling my Riser.
        Never crashed (other  than  pinned to a tree by wind).  Its going
        to be interesting to see how much we get for them.
                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

                This weekend  I  had  a  bad  case of "lets get this bird
        finished".  The  bird in question is the SongBird 100 glider that
        I bought quite a  while  ago.    The Songbird is really different
        looking - 96 inch very  high  aspect ratio wings with a NACA 2412
        airfoil at the center section and a flatter one at the tips.  The
        fuse is really short and the wing  is  attached to a saddle below
        the fuse. Definitely not a "run of the mill" glider.
        
                Saturday was spent getting it flyable.  Most  of the time
        getting the wire pull-pull linkages set up right.   The plans and
        instructions have a really compligated linkage between the rudder
        and ailerons.    I had opted to have separate servos and run them
        off a Y-connector  and  put the aileron servo in the wing.  Apart
        from the usual problems fitting everything into too small a space
        it worked out well.  Another modification was to add spoilers.  I
        had considered converting part of the  ailerons  into  flaps  and
        decided against it, mainly because I don't have a fancy radio for
        mixing.  Anyway, late in the day it  was done, but it was way too
        windy to have virgin flights.
        
                Sunday  morning it was relatively calm, and there clearly
        was  a  change  in  the  weather, so I gambled and  set  off  for
        Callahan State Park.
        
                Warning  sign  one  was  that  I  was the only one there!
        Warning sign two was that it was blowing a lot more than  when  I
        set  off.    Anyway, I decided to give it a few hand launches  in
        spite of  the  stern  warnings in the book against doing it.  The
        first launch was hairy because I had way too much elevator.  This
        thing is really touchy!  The next were OK, but I couls understand
        why the designer warns against  hand  launches because of the low
        wing and the relatively slow speed  you  can launch at.  The ship
        is really light, somewhere around 32 ounces - which is incredibly
        light for 96 inches. See this Kay?!
        
                So I decided to set the hi-start up  and wait for a lull.
        With about a 50/50 concentration of adrenalin I launched  it on a
        partially  extended  histart.   To my enormous relief it launched
        well and  remained in control all the way up.  Even my incredibly
        wimpy, 2 year  old  rubbler,  partially extended hi-start gave it
        good altitude - light  weight  and long wings help a lot.  Off th
        hi-start it unfortunately was too  windy  to  check  out  CG  and
        stalls, but it was possible to  control  it  and turns seemed OK.
        The  next  knee-knocker  was  the landing.   I  have  never  ever
        deployed  spoilers,  but  I could see I would  really  need  them
        because of the wind and turbulence.  Boy, did they work!  As soon
        as  I  deployed  them  the  nose  came  down then it  fortunately
        remained in control. I really like spoilers!
        
                After waiting a long-long time for another lull to launch
        in, I simply couldn't wait any longer.  This time the wind was so
        strong that the plane went backwards stretching the hi-start, but
        the slipperyness alowwed it  to advance forward at the top of the
        launch.  I had visions  of  flying  a kite until the wind died or
        the radio ran out of juice.   The wind was also so strong that in
        the  unballasted  state the glider had a  little  trouble  moving
        upwind.  In the middle of the flight a swirl  caught  it  and  it
        went  barreling  downwind, I think upside down, but I'm not sure.
        At  that point I decided I had had enough, deployed the spoilers,
        brought it down and packed up.
        
                I hop to try it out again late this afternoon.

                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

    Anker...Please change that anchor to a tow hook now!!!!!  Let us know
    how the Pantera comes out.  I launched my Stretched Pantera about 1.5
    weeks ago and it did just what the others had done.  With in the first
    2.5 seconds it was upside down and only about 15' of alt.  It demolised
    it pretty good but within 6 days it was going again.  
    
    I believe the problem is in building in putting the polyhedral angle in
    it has you block down the outer panel and raise the inboard panel to
    the set height.  Well with the stretched wing it increases the angle at
    the Poly joint.  Mine turned out to be 7" from the bench to the wing
    tip.  I think this translates to about 15degrees which in my mind
    (because everyone had this has done the old roll over and die on launch
    trick) is TOO much.  So in the rebuild I flattened it down to 4.5" from
    the bench which is about the 10degrees the plans call for.
    
    Keep us posted

    Mark is right! The poly break with the streched wing must be 8 to 10
    degrees for best results. Anker, you mentioned flying the songbird in
    the wind. This week our contest was called off due to 40MPH gusts and a
    constant 20-25 MPH wind. All the Panteras flew in this condition well.
    I had mine ballested to 102 oz and did a faily aggressive launch. No
    wing strengh problems. I did pop off once and relaunced with much
    better results and a trim adjustment. Landings were tricky however.
     Ask Mark Antry who was ahead when we quit.

                I    read        through       the    thick    pile    of
        instructions/modifications  to  the  Pantera  and  now  that  the
        SongBird  is  flying  I   will  start  work  on  it,  slowly  and
        deliberately.
        
                I would like to ask  you  guys  what  you think about the
        following:  I am very tempted  to  stretch  the wing 12 inches to
        get the wing loading into the "ideal"  range.  I would do that by
        stretching all panels 3 inches.  I would  also  like to build the
        wing as an aileron/flap wing and reduce the polyhedral  to slmost
        nothing,  just leaving roughly 3 degrees.  In addition, it  would
        seem  to make sense to sheet the whole wing.  From  what  I  have
        read  the increase in weight is by far outweighed by the increase
        in aerodynamic  quality.    I am also tired of Monokote and would
        like to try  some  other  covering,  and  would  not  want  to be
        restricted to heat shrinkable covering.
        
                I have an Adjusto-jig  and  plan to build the wing on the
        jig and not take it  off  before its completely sheeted.  The jig
        is also great for building dihedrals  and ensures that the angles
        of incidence and alignments are perfect.
        
                Something  I  found with the SongBird is  that  the  very
        small dihedral angle makes it very hard to determine the attitude
        of the plane.  Twice I have been in  doubt  whether the plane was
        right side up or upside down.
        
                Yesterday  was    picture  perfect  with  ZERO  wind  and
        (unfortunately) no lift.   But I was able to put something like 5
        or 6 flights on  the SongBird and take it through its paces.  The
        stall characteristics are more benign than I had feared.  It does
        drop a wing and the nose,  but it is very clear that its about to
        do it because you cann see its  flying  slow  and  in  a  nose-up
        attitude.  It speeds up like a rocket  when  the  nose is pointed
        slightly down and because of my balancing it keeps  going  at the
        high  speed,  so the speed is controlled with elevator.   Just  a
        single click makes a big difference.
        
                It  looks absolutely fantastic in the air and I hope that
        it will be a while before I damage it.
        
                Flying an  aileron  ship  is very different from flying a
        polyhedral, and I like it.  It is amazing how flat and smooth its
        possible to turn.
        
                Its funny, I had  thought about changing the logo myself.
        This is not the final version, but the prop came off!

                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

    Ron and I could always cut you a set of foam cores with what ever hots
    totsy airfoil you wanted and then you have 4 choices in covering them:
    1. Econokote over the foam (Not recomended)
    2. Balsa sheeting either applied with transfer tape or expoxy and
    vacumn bagged or weighted.
    3. Glass and epoxy vacumn bagged.
    4. Hardwood veneer expoxied and either weighted or vacumned bagged.

Don't forget contact cement for either balsa or veneer. I've had good luck with
Sig Core-Bond and generic woodworking contact adhesive. Three points about 
contact adhesive to remember:

1) Put the covering in the right place the FIRST time.

2) putting down an edge of the sheeting and then bowing the rest on in a rolling
motion will improve contour following.

3) Don't forget #1 for a second ;^)

        Re:                     <<< Note 399.210 by CSC32::M_ANTRY >>>

                That would be absolutely fantastic.  I'd be interested in
        one of the  Selig  airfoils  that  responds  well  to aleron/flap
        reflexing. My preference would be 3 (glass and epoxy bagging).
        
                I'm not an airfoil wiz, but the work done by Selig really
        impresses me.
        
        Anker

    
    
    In fact a few of us have been toying around with the idea of cutting
    foam as a service to fellow noters.  If you are interested in getting
    some foam cut drop a note to either Ron at GENRAL::WATTS, BoB at
    CSC32::PAGE or myself CSC32::M_ANTRY and we can discuss it.  These
    cores are all cut hands off and we have cut several sets and I know
    how it goes with other foam cutting projects the "KEEP" ratio is around
    50%.  We cut these cores entirely hands off and have not cut a bad core
    yet(I swear!)  Airfoils that we have ready to go are but are not
    limited to are:
    S3021 8" and 10"
    RG15 10" and 7"
    RG12A 10" and 7" (the new improved RG15)
    
    NACA63009 5" and 4"
    
    Foam would be 2 pound pink extruded closed cell.  The only that scares
    us is shipping.  
    
    Drop us a line if your interested.
    

    re: Anker..
    
    We have the S3021 10"/8" and the RG15 10"/7" would be really good ones
    Bob Page is just about ready to cut the ailerons out of his S3021's
    that he will put on his Pantera, Ron Watts is ready to put the servos
    in his RG15's that he will put on his Pantera.  My Pantera, well I'm to
    busy cutting foam for these guys but mine will be RG15's also.
    
    Let us know.
    
    PS:  The prices will be almost cut in half if we can use templates we
    already have in place..  I guarantee we will beat any of the other
    custom cutting places.
    
    (Hear that John, Foam and Cardboard!!!!!!)
    

    
    Where do you get your foam from??  What size are the blanks you are 
    using??  Tom T. and I have been working on a possible solution to
    every foam core enthusiast's dream...  A good supply of foam...  The
    pieces that we are getting are 3" x 15" x 35"...  And to make it great,
    these are production waste, ie they are being thrown out!!
    
    We are working our first delivery now, about a dozen pieces...  If it
    works well, perhaps DECRCM would like to officially offer to DEC that
    we will dispose of the foam for them...
    
    (ADD moderator hat)
    
    Reminder...  please be careful about soliciting personal business in
    DEC notes conferences...  I don't know if you guys are intending to
    make a profit from cutting wings, but if you are, DEC policy prohibits
    you from advertising for it here...
    
    (DELETE moderator hat)
    
    If people are interested in obtaining these foam blanks, let me know
    and if there is enough interest, I will work with the BOD to make a
    formal proposal...
    
    cheers,
    jeff
    

    Jeff: Any profits from the foam cutting would go to support the PPSS
    F3B efforts. Also Mark and I don't arn't sure there be any anyway. 
    
    As for the foam, we are currently buying it locally. We use 1.5 or 2.0
    lb. density extruded polystryene. depending on the application. The 
    expanded bead board (stryofoam) just dosen't do what we want when vacuum 
    bagged with epoxy and glass. It absorbs too much epoxy. If your not
    going to use epoxy as an adhesive, it will work fine. The only problem
    I see is the length. 35 inches is a little short unless you are going to
    glue panels together. I don't think glueing the panels together is a
    big deal however, especially if the materal is no cost.   
    
    
    Ron Watts
    

Glider rambling - part 2.

I received several personal mail messages asking for more of these 
glider rambling stories so I finally got a free minute.

I copied this story out of the book called "Collected Classics
of Soaring" by Trish Durbin.  Published by and available from

	Arizona Soaring Association
	P.O. Box 11214
	Phoenix, AZ. 85061

Having given credit I'm sure they won't mind a little free advertising.

This one is called "The Chinese Finger Lock" by Charley Spratt
and was first published in "Sailplane Racing News".

   Now here's a good one!  Seems that a chap wanted to increase his
personal duration in his 1-26.  Like his bladder was not large enough
for hours in the sky.  He designed a relief tube to extend along his
left and down the bottom of the fuselage next to the 1-26 wheel.  The
upper end was attached to a condom, so that he was "plumbed in" all
the time.

   The test flight was OK but the landing was another matter.  The tube 
near the wheel caught in the axle which began winding the tube.  The 
condom acted like a Chinese finger lock.  Your eyes should be watering 
about now.  They say his certainly were!

   After the rollout, he did not jump out of the cockpit.  Friends went
over to help him push the bird off the runway.  They opened the cockpit
and the pilot weakly said, "Could you roll it back a bit?"  They say he
couldn't stand for a week.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

                Friday I  fixed up the SongBird.  I used some inner Nyrod
        cores  as sheaths  for  the  pul-pull  wires  and  squirted  some
        polyurethane foam into the  front  of the tail.  That stuff takes
        forever to harden, but the  nd  result  was  great and all of the
        wires were able to move.   For the time being I just poured a bit
        of epoxy into the cracks in the fuse.
        
                Next order of action was to move  the CG forward a tad by
        converting my flat Futaba battepack into a square  one.    That's
        really  easily done if you can solder.  Cut  both  sides  of  the
        plastic covering between the two middle cells and break the  back
        over.   The foil connecting these two cells will break from  this
        treatment, but just solder a piece of wire between them.  Then  I
        wrap the  entire  pack  in take, and voila!  The entire operation
        takes about 15 minutes.
        
                Finally  I  decided   to  change  the  incidence  of  the
        wingtips.  One had  clearly  too much and was causing enough drag
        to force a noticable offset  with  rudder and aileron, more drag.
        The bad wingtip was half sawed  off  and  the reepoxied on again.
        The other one could be heated and bent a little bit.
        
                Saturday was the test to see if all of it worked.  What a
        difference!  The rudder is pointing straight back  and  the plane
        has  lost  its  tendency to accellerate faster and faster.    The
        first flight was a 13 minuter and by the end  of  the  day  I was
        consistently  getting  3-4    minutes    on  the  short  flights.
        Unfortunately it was very  crowded  at the Drop Zone, so I didn't
        get to fly as much as I wanted.
        
                Sunday Chris Schuck, Fritz Bien  and I went to Lincoln to
        check out a field on conservation  land  that we probably will be
        able to get as a glider and  electric  only  field.   It is about
        2000 feet long by 800 feet, mostly covered  by  a  hayfield,  but
        what a wonderful field!  West of it is  a small hill which should
        give some slope effect in strong winds.  Once again, the SongBird
        performed really well.
        
                Sunday  evening I got started on the Pantera.  After much
        soul searching  I  have  decided  to build the first set of wings
        stock, mainly to  allow  it  to  be flown in standard class.  The
        next set of wings  are going to be a lot fancier.  The Pantera is
        a really, really nice kit  and  looks  like it will be abreeze to
        build.
        
                      _ 
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           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

The Sagitta saga continues.

Saturday I flew it for the first time with the Vision SP radio
as the transmitter.  Same old 6 channel FM PPM receiver it always
had.  The first flight was short because I had to retrim and the elevator
needed a lot of up (so I didn't get a very good launch off the high start).

Landing was not good cause this was the first time I ever had the
elevator coupled with the spoilers - floated too much and I had
to dial in less compensation.

2nd flight was better but on landing the spoilers were still floating
too much so I in less compensation (again).

3rd flight was a charm - I used the launch mode switch to step in
some up elevator for the launch and caught some thermals and spend
15 minutes up in 4 to 5 different thermals.  I was never able to go
out of site cause we were at the airport and I kept diving out of the
sky to keep out of the path of full scale planes.

Now for some true glider theory.

I have a couple of observations and invite you to speculate on them.

1st I've heard it said (I think by either Chris Schuck and/or Lincoln
Ross) that one way to detect thermals is to watch for the nose to pitch
down.  At first this seems counter intuitive but they argue that what
happens is the plane is sailing along in calm air when a blast of rising
air hits it from below so it just re-orients itself with the new air stream.

Sounds plausible - BUT...

My observation with the Sagitta is that this does not happen.
Maybe a reason it doesn't happen to the Sagitta is because it is so fast.
In fact I haven't seen any glider at thermal contests as fast as my Sagitta.
That is they may be faster but they don't fly them faster than I usually do.
Double - In fact - this weekend at the airport I was very comfortable
being up in the thermals because when my spotters (Kevin Ladd and Charley
Nelson) spotted full scale planes closing on me I could move out of the
path in no time.  Something I felt helpless about with the Drifter II.

Anyway - when the Sagitta hits a thermal it does not drop the nose.

The second observation I would like to hear comments on is this:
When circling in a thermal I have a built in thermal intensity gauge
on my transmitter - THE ELEVATOR STICK.  If I make nice even constant
size and constant speed circles I have to pull in more and more up
stick to slow the plane down.  If I drop out of the thermal I start
to stall and porpoise.  The question is why - what aerodynamic theories
can you use to justify this behavior?  I can't swear that the Drifter II
ever did this but it sure seems part and parcel to the Sagitta.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Let me admit right up front that I know next to nothing about gliders,
    but...
    
    If you are holding the glider at a point that is close to a stall,
    and the air flow is suddenly supplemented by rising air, the
    vector sum may be beyond the stall angle of the airfoil, so you
    get turbulence and lose lift.  If you fly fast, with the nose down,
    you are not so close to stall angle, and the rising air has a smaller
    effect on the aggregate air flow over the airfoil anyway.
    
    Any corrections to my intuition are welcome learning experiences...

I still have problems identifying when I've hit lift. Like, when one wing
suddenly lifts, I turn to enter that airspace and as often as not there's no
thermal there. And I've ofter heard Fritz Bien (who's an expert sailplane
pilot) say that the speed of the plane increases when it's in a thermal, but
I have yet to notice that. The one thing I have noticed when I'm in a thermal
is this: the plane circles very smoothly, with little need for me to input
corrections. I hold the stick in one position and pretty much leave it there.
If I'm not in a thermal, I'm constantly feeding in corrections to keep it
from being blown downwind. 

Any comments?

Dave

                I agree with both Kay and Dave.  First, I have never seen
        the nose pitch  down when entering a thermal.  I have noticed the
        effect that Kay describes.    Namely  that  in a good thermal you
        don't have to do anything  to  avoid  stalls  and  speedups.  Its
        probably all virtual.  My guess is that if you fly as well in the
        thermal as outside it you get maximum  effect.    Once inside you
        can make mistakes without being punished severely for them.
        
                I  spent a good time Sunday with Fritz  and  here  is  my
        thermal-seeking routine.  I fly stright and level with  the plane
        a good distance from me.  Sometimes the plane just plain goes up.
        Those are the easy ones and I just turn and try  to keep it going
        up.  Other times I see what Walter describes.  A wing gets pushed
        up by the edge of a thermal.  Now here is the new  stuff:  If the
        plane  is  hard  to  turn  into the wing that went up, then there
        probably is  a  good  solid  thermal.    If  it  turns easily, it
        probably was just a bubble or turbulence.
        
                      _ 
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           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

    I also use my elevator stick to see if I am in a thermal.  If I can
    pull the stick back to where it would normaly stall and it doesnt I am
    in a thermal.  With my old Ragidy Gentle Lady I could just put the
    stick in one of the lower corners and watch it go up. (If I was in a
    thermal) If it stalled and porpoised NO THERMAL.

        Re thermal entry/full size;
        
        The way  I  was  taught  back  in the early 60s (at Portmoak in
        Scotland), was if  the wing lifted hard, continue S&L for three
        seconds and then begin a  thermal  turn  towards the lift.  The
        theory was that if you turned  in  as  soon as you detected the
        lift, then you would actually fly through  and  out  of it, and
        your centre would be well away from the  thermal's  centre.  By
        waiting, the turn is more likely to put you  closer  to centre,
        such that you can more easily tune your rate of  turn  for best
        gain.
        
        Andy
        

>    I also use my elevator stick to see if I am in a thermal.  If I can
>    pull the stick back to where it would normaly stall and it doesnt I am
>    in a thermal.  With my old Ragidy Gentle Lady I could just put the
>    stick in one of the lower corners and watch it go up. (If I was in a
>    thermal) If it stalled and porpoised NO THERMAL.

Exactly - now aerodynamic experts - why does this happen?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

                I was home sick yesterday with a lingering cold, and what
        better way to  recuperate  than  to  work  on a kit.  So I put in
        about 6 hours on the Pantera wings.
        
                These wings are going to be strongest I have ever seen in
        my life.  The shear webbing in the main wing panel is incredible.
        It  consists  of  3/8 balsa that  fits  snugly  between  the  two
        hardwoos spars.  The innter braces are almost a foot long plywood
        and the outer panels have shear webbing too.
        
                I  never  follow  instructions, so things started getting
        really  interesting.   I started putting all of the  ribs  on  my
        adjusto-jig  and  gluing spars and leading/trailing edge on them.
        Then I  had  to start cutting ribs in order to get the ply braces
        in, but at  least  the wing will be straight and true.  Following
        the original instructions makes the inner rib bays hard to build.
        
                I may have mentioned  this  before,  but this kit has the
        best quality wood I have  ever  seen in a glider kit.  Everything
        is perfect.  I'm especially happy  with the leading edge hardwood
        stock.  Its going to be a  breeze  to shape this wing.  If things
        keep going as well as they have up  till  now  I should have this
        bird flying by Thanksgiving.
        
                      _ 
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           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

                I have  learned  so much about gliders the last couple of
        years that is  non-intuitive  that  I  think  its  a good idea to
        document  them  in a  form  that  hopefully  can  communicate  my
        experiences effectively.
        
                The scenario I will go through is the pilot showing up at
        the field with a brand new glider.  I will decribe what I believe
        is the appropriate way to trim and get comfortable with the bird.
        Unfortunately  with  gliders  the difference between a dog and  a
        super plane is very subtle.
        
                I  assume  that  the plane has been built right.   It  is
        reasonably light, all spars are true and have the right amount of
        dihedral, washout,  etc..    I also assume the control throws are
        close to those  suggested  in  the kit.  This is very important -
        the control throws may  look  wierd, like almost no elevator, but
        lots  of  rudder,  but do  yourself  a  favor  and  set  them  as
        suggested.
        
                Balancing is incredibly important.  Every  glider  has to
        be balanced dynamically, but to do so, you have to start with the
        static balance as suggested by the kit manufacturer.  DO NOT move
        the CG further forward.  You may end up  with a pile of sticks if
        you do. Put it right there!
        
                I  also assume that there is either no wind or  a  steady
        breeze with minimal turbulence.
        
                Now set the trims so that the rudder points straight back
        and the elevator is close to neutral.  On must gliders this  will
        be  too  much  up,  but I prefer a bit too much up on  the  first
        launch.
        
                The next  step  is  to hand launch the glider.  Give it a
        steady horizontal throw.    There is no need to heave it or point
        it up.  In  must  cases  the  glider  will tend to balloon, so be
        ready to feed in down elevator.  Set the elevator trim so that it
        maintains steady speed and then work  on the rudder trim.  It may
        take a couple of hand launches to get everything right.
        
                If the trims are roughly where you started out you may go
        to the next step.  If they are  way off, fix the problem.  Rudder
        off is probably a warped wing.  Take it  home  and  straighten it
        out.  A lot of up or down is probably  CG  way  off.  Recheck and
        fix it.
        
                Now  you  are  ready  to  launch the plane on a hi-start.
        Pull it out close to the maximum.  It is very dangerous to launch
        with too little pull.  You may stall out or fly off the  hi-start
        prematurely. Brace yourself and let it go!
        
                Once  you  have reached altitude  retrim  the  plane  for
        steady  speed.    Don't  go  too  slow.    If  you  have  trouble
        maintaining speed you probably have the CG  off.    Now  give the
        plane a bit of down elevator, release the  sick  and  watch  what
        happens.
        
                If  the  plane  lifts  the nose, stalls, drops the  nose,
        picks up speed, lifts the nose and stalls again, ...    then  you
        have  the  CG  too far forward.  If the gyrations get  worse  and
        worse  you  have  a real problem, try to get the plane down right
        away.   Move  the CG a little bit.  I would suggest removing lead
        about a 1/4 ounce at a time.  You should just be able to see that
        the CG moved.
        
                If the plane keeps  accellerating earthwards you have the
        CG too far back.   The  plane  is  going to be impossible to find
        thermals with. Take it down and move the CG forward.
        
                Keep  rebalancing the ship until the  forward  stick  and
        then release causes it to pick up  speed, gradually lift the nose
        and then settle down to the original cruising  speed.    Once you
        have done this you will be able to hunt  for  thermals and adjust
        the speed of the glider with a click or two on the trim.
        
                Next step is to check the stall characteristics.  Feed in
        a bit of up and hold it there until the plane  gently stalls.  If
        it  drops a wing and ends up in a vertical dive you  have  a  bad
        case  of  tip stalling.  Take the plane home and fix the problem.
        Usually by  putting  a bit of washout in the tips.  A more subtle
        cause of violent stalls is having too sharp a leading edge.  Make
        sure its rounded EXACTLY  as  in  the plans.  If you have trouble
        curing the stall put a  stall  strip  close to the wing roots.  A
        stall strip is an intentionally sharp leading edge.
        
                We  almost  have a beautifully flying  ship  now.    Many
        people fly with ships set up as  we are now and never go further.
        I recommend a couple of further steps.
        
                Watch the plane on the hi-start.  If  you have to feed in
        up elevator to get it to launch properly you  have  the  tow hook
        too far forward.  If it keeps popping off you either have the tow
        hook too far back or its bent so that the ring  slips  off  under
        tension, You can bend the tow hook so that it has a  low point in
        front.  Keep moving the tow hook until the plane will launch well
        without any application of elevator.
        
                Another step is to loop the plane.  Feed in down elevator
        until it is  moving  really  well  and  then pull full up.  If it
        corkscrews you have a  wing  warp.  It should make a perfect loop
        without any rudder control.  If  the  wing  is straight, then you
        may have a wing balancing problem.   Check that the wing balances
        perfectly.
        
                Try to make a smooth  flat  thermal  turn.  If you have a
        polyhedral ship and it tends to bank too  hard, then you have too
        much  dihedral.    If  it  yaws,  but doesn't like to  turn,  you
        probably  have  too little dihedral.  You can change the dihedral
        effect with  tip  plates.    This  is a science that I don't know
        enough about.  With an aileron ship too steep turns are caused by
        too much aileron coupled  with  too  little rudder.  Yawing bu ny
        turning is caused by too much rudder and too little aileron.
        
                Now for a little flying  technique.  Beginners often have
        too  much  up  elevator  trim  and    the   plane  mushes  along.
        Unfortunately this causes you to lose altitude like crazy.  I see
        a lot of beginners with less than one  minute flights.  Any plane
        should have a still air time in excess of two minutes from a good
        launch.    A rea floater like an Olympic II can have  up  towards
        four  and  five  minutes still air time from a high launch!   The
        plane should fly with good control authority and feel steady as a
        rock.
        
                To find  thermals  you  need  to  be able to see how they
        affect the plane.   Fly a pattern far away from yourself, usually
        at the edges of  the  field.   In still air it should just cruise
        along.  When it hits  a  thermal it should either rise noticably,
        or you see a wing kick  up.    If  it  rises you probably hit the
        thermal at right angles.  If it kicks a wing up the thermal is on
        the side that came up.  Thermals are very narrow at low altitudes
        and get wider and wider.  They also tend  to  build  and stick at
        the downwind side of a piece of ground warmer than  the  average.
        Your  flying  field in summer will often be a good place to  look
        for thermals in  the  downwind  corners.   Another indicator of a
        thermal is the plane  picking  up  speed  and  then slowing down.
        This is often useful when hunting downwind.  When circling in the
        thermal the plane will often stay in it and drift downwind.  Hang
        in there until you get so far  downwind  that you are getting out
        of range and may have difficulty getting back.
        
                Slope is also good for increasing flight duration.    The
        stronger  the  wind,  the  smaller the object that will  generate
        slope.  Three lines are good in a solid breeze.    Try not to get
        too  far  downwind.    The  so-called  rotor  can  be vicious and
        literally slam  your  ship into the ground.  To maintain position
        in the slope  cruise  back and forth along the upwind edge of the
        object creating the slope.
        
                Now for landing.   I  have  seen  an  awful lot of damage
        caused  by  stalling  at  low  altitude.    Keep  the  speed  up,
        especially in turns, and make your  final  approach in a straight
        run.  If you have spoilers, apply them to come down, but be ready
        to apply up elevator to keep the nose up.
        
                So  that's  pretty  much what I have learned.    Hope  it
        proves  helpful.   I don't have a problem if  you  guys  disagree
        violently.
        
                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

    
    Very helpful information Anker, I have a Wanderer ready for its
    maiden flight and although I've been around Rubber, and R/C for
    longer than I care to admit, R/C Sailplanes is a new area to me
    and I can see already that some of my misconceptions could well
    get me into a "heap".  I had one occasion recently when a friend
    (with a glider peacefully soaring overhead) handed me the sticks.
    "Sure, says I, "Piece-O-Cake" - lemme at it.  Boy did I pull some
    unexplained maneuvers!  Lots of stalls, and a cartwheel landing.
    
    I am humbled!           Many thanks for the good tips.
    
    john
                 

    Yes, Thank you Anker...  I am the new owner of Jerry Evers' Drifter II
    and Al is almost done with his Gantle Lady...  This will help us
    tremendously...
    
    Thanks!
    jeff
    

>< Note 399.231 by HOLL22::ANKER "Anker Berg-Sonne" >

>                So  that's  pretty  much what I have learned.    Hope  it
>        proves  helpful.   I don't have a problem if  you  guys  disagree
>        violently.

Glad you said that.  I am hardly an expert tho I do love controversy.
I disagree with several of your points but don't want to just
disagree - I would like others to voice their opinion.  Where I'm
wrong - please tell me and I will learn something in the process.

>                Now set the trims so that the rudder points straight back
>        and the elevator is close to neutral.  On must gliders this  will
>        be  too  much  up,  but I prefer a bit too much up on  the  first
>        launch.

I would prefer too much down.  Too much up causes stalls and porpoising.
At hand launch altitude the stall sends you home for repairs.
        
>                The next  step  is  to hand launch the glider.  Give it a
>        steady horizontal throw.    There is no need to heave it or point
>        it up.  In  must  cases  the  glider  will tend to balloon, so be
>        ready to feed in down elevator.  Set the elevator trim so that it
>        maintains steady speed and then work  on the rudder trim.  It may
>        take a couple of hand launches to get everything right.

I recommend 10 to 20 hand launches if you new to this.  By the 20th one
you should be able to make a circle back to yourself and save considerable
walking.
        
>                Now  you  are  ready  to  launch the plane on a hi-start.
>        Pull it out close to the maximum.  It is very dangerous to launch
>        with too little pull.  You may stall out or fly off the  hi-start
>        prematurely. Brace yourself and let it go!

Here I disagree.  It still isn't trimmed yet even tho you have made
some success at hand launches.  Just pull the high start out about 10 to
20 paces of stretch.  Then carefully (straight and level - not at those
up angles you have seen others launch at) do another hand launch but
in this case the high start is going to help you.  Do it again.  Then
after you are confident that this isn't going to crash your plane make
each launch have a few more paces of stretch on the high start.  Say 15
paces, 15 paces, 25 paces, 35 paces, 45 paces, 50 paces (on a new heavy
duty high start).  Depending on the high start don't stretch too far.
Most recommend that the rubber can stretch out 4 to 5 times it's length.
It will but that will be much too much pull for a new glider especially
on a new high start.  At max launch from 3 times the length of the rubber.
Just count the paces of the rubber when you string it out in the first
place.
        
>                If  the  plane  lifts  the nose, stalls, drops the  nose,
>        picks up speed, lifts the nose and stalls again, ...    then  you
>        have  the  CG  too far forward.  If the gyrations get  worse  and
>        worse  you  have  a real problem, try to get the plane down right
>        away.   Move  the CG a little bit.  I would suggest removing lead
>        about a 1/4 ounce at a time.  You should just be able to see that
>        the CG moved.
>        
>                If the plane keeps  accellerating earthwards you have the
>        CG too far back.   The  plane  is  going to be impossible to find
>        thermals with. Take it down and move the CG forward.

I believe the porpoising will be caused by CG too far aft.  I'm not sure
what the symptoms are of the CG too far forward?  Your explanation
of the aft CG causing "acceleration earthward" is not very informative.
Exactly what do you think the plane will do.  Rocks accelerate earthward.
        
>                Watch the plane on the hi-start.  If  you have to feed in
>        up elevator to get it to launch properly you  have  the  tow hook
>        too far forward.  If it keeps popping off you either have the tow
>        hook too far back or its bent so that the ring  slips  off  under
>        tension, You can bend the tow hook so that it has a  low point in
>        front.  Keep moving the tow hook until the plane will launch well
>        without any application of elevator.

I agree but if you have to feed in a little UP that's OK - just feed it
in.  On windy days you won't have to and if you ever get the hook too far
back you will be in for a real surprise.  It will get real hairy on the
launch and zig zag when you first release.  If you don't get on the stick
quick and correct with rudder it can go right into the ground.
        
>                Another step is to loop the plane.  Feed in down elevator
>        until it is  moving  really  well  and  then pull full up.  If it
>        corkscrews you have a  wing  warp.  It should make a perfect loop
>        without any rudder control.  If  the  wing  is straight, then you
>        may have a wing balancing problem.   Check that the wing balances
>        perfectly.

Be very careful...  gliders going really well the pull "FULL" up will
break wings.  Remember the world R/C speed record is held by a glider.
Second only to folding wings on winches the next most common cause for 
folding wings on a glider is building up too much speed then the application
of up elevator doesn't loop - it snaps the wing in half.  The most common
cause is you get in a booming thermal and can't spiral down so you panic
and just dive out.  Just then you think you have it licked you let off the
down elevator and POW!  The day will come soon enough when you get almost
out of site and want to come down and start to worry.  Perform any gyration
you want to get out but don't just dive without becoming concerned on
how you will bleed off that speed gently!  Depending on the plane they
all have a different interesting way of getting out of boomers.  My Drifter II
could usually just spiral out but if it was a really good one I flew out
inverted.
        
>                Try to make a smooth  flat  thermal  turn.  If you have a

I don't think flat turns are "thermal turns".  It would seem logical that
if you can make flat turns that you are flying more efficiently for getting
max benefit from the thermal but in practice it doesn't work out that way.
Witness real gliders.  There turns in thermals are usually far from flat.
Also some gliders self center and flat turns takes that away.

>        polyhedral ship and it tends to bank too  hard, then you have too
>        much  dihedral.    If  it  yaws,  but doesn't like to  turn,  you
>        probably  have  too little dihedral.  You can change the dihedral
>        effect with  tip  plates.    This  is a science that I don't know
>        enough about.  With an aileron ship too steep turns are caused by
>        too much aileron coupled  with  too  little rudder.  Yawing bu ny
>        turning is caused by too much rudder and too little aileron.

And then there is the amount of aileron differential...
        
>                Slope is also good for increasing flight duration.    The
>        stronger  the  wind,  the  smaller the object that will  generate
>        slope.  Three lines are good in a solid breeze.    Try not to get

Tree lines are good in a hurricane.  Otherwise at best on windy days they
produce just enough kick to entice you into trying to fly the ridge.  This
gets you flying near trees and ultimately causes many trips to the forest
to retrieve gliders.  At the drop zone (where Anker flys a lot) there are 
trees in ideal spots for this kind of lift.  Every time there is a glider
contest there several (beginners and experts alike) glider pilots end up
in the trees.

OK - how about some feedback - I'm ready to apologize after you pick
my comments apart.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

        Re:          <<< Note 399.234 by K::FISHER "Stop and Smell the Balsa!" >>>

                I love  it,  I  love  it, I love it.  I was really hoping
        someone would pick  up  the  challenge, and I was pretty sure you
        would, Kay.  A lot of what you said was preference, but there are
        a few real disagreements there.    I  hope one of the Pike's Peak
        guys pipes up soon.
        
>I would prefer too much down.  Too much up causes stalls and porpoising.
>At hand launch altitude the stall sends you home for repairs.
        
                I  have  personally  hand  launched  gliders   that  went
        straight earthwards because of too much down.  I guess it depends
        what you best recover from.

>Here I disagree.  It still isn't trimmed yet even tho you have made
>some success at hand launches.  Just pull the high start out about 10 to
>20 paces of stretch.  Then carefully (straight and level - not at those
>up angles you have seen others launch at) do another hand launch but
>in this case the high start is going to help you.  Do it again.  Then
>after you are confident that this isn't going to crash your plane make
>each launch have a few more paces of stretch on the high start.  Say 15
>paces, 15 paces, 25 paces, 35 paces, 45 paces, 50 paces (on a new heavy
>duty high start).  Depending on the high start don't stretch too far.
>Most recommend that the rubber can stretch out 4 to 5 times it's length.
>It will but that will be much too much pull for a new glider especially
>on a new high start.  At max launch from 3 times the length of the rubber.
>Just count the paces of the rubber when you string it out in the first
>place.
        
                My theory is that you are better off  with some altitude.
        This  is pure personal feeling, but I believe that  the  hi-start
        assisted hand launch is liable to pull the plane up  into  a nose
        high position and then drop it close to the ground.
        
>I believe the porpoising will be caused by CG too far aft.  I'm not sure
>what the symptoms are of the CG too far forward?  Your explanation
>of the aft CG causing "acceleration earthward" is not very informative.
>Exactly what do you think the plane will do.  Rocks accelerate earthward.
        
                AHA!  Here we go.  With the CG too far  forward  you have
        to keep the plane level with a bit of up elevator.   As the plane
        goes  into  a dive the up elevator you fed will lift the nose  as
        the plane  picks  up  speed and you will get the popising effect.
        Tail heavy is  compensated with down elevator, which becomes more
        effective at speed, drops  the  nose  a  bit, which increases the
        speed, etc ad infinitum.   This  is totally counterintuitive, but
        easy enough to verify at the field
        
>I agree but if you have to feed in a little UP that's OK - just feed it
>in.  On windy days you won't have to and if you ever get the hook too far
>back you will be in for a real surprise.  It will get real hairy on the
>launch and zig zag when you first release.  If you don't get on the stick
>quick and correct with rudder it can go right into the ground.

        
                When I put a mechanical tow  hook release in the Oly II I
        discovered how much elevator one gives even when one thinks "just
        a little".  I would have sworn I  only  gave it a tweensy, little
        bit of up, but the darn release kept opening,  which it only does
        on full up!  I moved the tow hook back  and not it doesn't happen
        any  more.  You are absolutely right about the danger of  getting
        it too far back. Excitement city!
        
>Be very careful...  gliders going really well the pull "FULL" up will
>break wings.  Remember the world R/C speed record is held by a glider.
>Second only to folding wings on winches the next most common cause for 
>folding wings on a glider is building up too much speed then the application
>of up elevator doesn't loop - it snaps the wing in half.  The most common
>cause is you get in a booming thermal and can't spiral down so you panic
>and just dive out.  Just then you think you have it licked you let off the
>down elevator and POW!  The day will come soon enough when you get almost
>out of site and want to come down and start to worry.  Perform any gyration
>you want to get out but don't just dive without becoming concerned on
>how you will bleed off that speed gently!  Depending on the plane they
>all have a different interesting way of getting out of boomers.  My Drifter II
>could usually just spiral out but if it was a really good one I flew out
>inverted.
        
                I  should  have  been more specific.  I meant to just put
        enough speed  on  the plane to ensure that it will fly though the
        top of the loop.
        
>I don't think flat turns are "thermal turns".  It would seem logical that
>if you can make flat turns that you are flying more efficiently for getting
>max benefit from the thermal but in practice it doesn't work out that way.
>Witness real gliders.  There turns in thermals are usually far from flat.
>Also some gliders self center and flat turns takes that away.
        
                In a small,  strong  thermal  you  turn tight.  In a big,
        weak thermal you turn  as  flat  as  you can because you fly more
        efficiently.


                The aileron differential is a  story  to  itself, but the
        same theory applies to power planes, so I didn't include it here.
        
                A  final  piece  of  advice that  I  omitted:    Build  a
        polyhedral ship as your first glider.  Don't try an aileron ship.
        Boy can you get into real trouble fast with them.
        
                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

    Ok a Pikes peak guy..not to mention the PRESIDENT SPEAKS!!!!!
    
    (insert disclaimer here)
    
    I would perfer more down than up on a hand launch.  Remember once it
    stalls it ain't flying no more!!!!  If it is heading to the ground up
    elevator will have an effect, its just will it be in time.  But the 
    plane is aerodynamically flying, just going the wrong direction.
    
    
    I would recommend a winch launch when it comes time to launch, the
    reason being that once you let go of the high start it is going to pull
    until the stretch is gone.  I would also recommend that you not try to 
    launch the thing too whimpy on the high start.  One of the big reasons
    for failure on the high start is insufficient airspeed.  Imagine this,
    you let go of the glider and it goes 20feet up and runs out of
    airspeed, it stalls just happens to tip stall and now its pointed about
    45 degrees for horizontal (read that headed for the ground) and now the
    pressure against the highstart is relieved (from the stall) and it
    decides to pull again and you are still connected to the thing.  This
    is called High Starting it right into the ground.  This is why it is
    critical to give a hefty toss on the high start almost to the point
    that when your hand lets go it is up to flying speed and heading in the
    right direction.
    
    Also I highly recomend having the pilot hold the radio while someone
    hand tosses the plane. 
    
    Well there is the PPSS perspective
    

    I like Anker's idea and I wished I did it more about thourghly checking
    the plane and after doing so you should know at that point if it will
    fly or not.  Our Club resident, Randy Reynolds, just build two high
    performance v-tail, swept back wing planes of his own design to include
    handcrafted fiberglass fuse and all and he just checks em out on the
    bench and puts them on the winch.
    
    You know a hand launch is only saying, I am not sure if this is built
    straight and will even fly.
    

    I agree with almost everything Anker said, except the part about
    an aft CG being hard to thermal. With an aft CG the plane will react
    more noticeably when encountering a thermal and what you do with
    that reaction is of course dependent on pilot skill, etc. Recall
    that earlier we were discussing holding more and more up elevator
    and watching the plane climb better and better, until the thermal
    was exited, and then of course,STALL CITY. Aft CG makes all of that
    easier to happen, the trick is to not over do it.
    
    Concerning hand launches I have good luck by running and then throwing,
    to insure max airspeed. The purpose of hand launching from my view
    is to ensure it will fly straight and level with neutral trim settings.
    Two or three tosses are all thats needed between clevis tweaks.
    It's no fun to come off the hi-start and discover that you need
    up elev. on the stick on top of full up trim just to maintain level
    flight.

This is great. I love opinion arguments where there is never really a "right"
answer.

First, I'll assume that Anker's original note was to help beginners; those of
us who have flown gliders a few years can do things whatever way is most 
comfortable.

That being said, my opinion  on hand launches is that's when I did at least
half the damage on my glider when learning. There's a lot of opportunity to 
screw up, and there's no altitude to recover. So my feeling is you do 1 or 3
hand launches, straight and level (don't try to circle back to yourself),
to get the trims set up reasonably well. The problem with circling back to
yourself is that except for a windless day, it forces you to fly downwind either
on the launch (a major no-no), or to make a low level down-wind turn (another
no-no).  Better to have too much down trim than too much up (within reason).
Do all the rest of the trimming at high altitude.

Now you head for the high start. And I mean specifically "high start". I 
disagree strongly about starting out on a winch. Putting a beginner on a winch
is like asking a 17 year old who just got his license to drive a funny car. 
You KNOW he's going to floor the winch and off go the wings (ask Kay what 
happened to his Drifter on the winch the first couple contests). It takes a lot
of coordination to run the winch AND fly the plane. However, I'll back off on 
this providing that someone experienced runs the winch. On the high start, I
believe in giving a firm launch: not so wimpy you only get 50 feet, not so
strong you can barely hang on to the plane. And if you get into zig-zag trouble 
on the high start, remember to feed in down trim to increase airspeed to get
stability back. I find the high start much more smooth and controllable than
a winch (I don't think I've ever seen a wing fold on a high start, but I've
seen many cleaved by a winch).

On final trimming, I tend to agree with Anker. I tried that trim technique
after reading the instructions for my Prophet 941 (which I haven't even built
yet). It seems to work pretty well, but I think that the optimum setup for 
the plane is not necessarily good for a beginner. That's kind of personal 
preference for the particular pilot.

I want to add my own point on airfoils. For the rank beginner, stick with a 
light plane (Riser, Gentle Lady, Drifter) with a flat bottom wing (is that a 
Clark Y???). It's a lot more forgiving than the faster airfoils. I had a
tough time getting used to the Metric with the Eppler 205; I dinged it up 
many times during low altitude maneuvers that were no problem for the Riser.

Finally, on landing, until you get good, don't try to land it right at your 
feet. Just make a nice flat landing into the wind. So what if you have to walk
50 yards? Takes less time than reattaching the stab. The other half of my
crashes were caused by "going around one more time" so I could land it right
in front of me.

That's my story and I'm sticking to it.

Dave

        Re:          <<< Note 399.240 by K::FISHER "Stop and Smell the Balsa!" >>>

                This has  been  really  great.    Apart  from a couple of
        really minor issues, like how far to stretch the hi-start, we are
        in  total agreement.   I'll  take  what  has  come  out  of  this
        discussion and write a small  flyer  that  I'll  send a couple of
        places, because all of this informations came my way in dribs and
        drabs.    As  a  beginner, what I  found  more  frustrating  than
        anything else was to have an experienced glider  pilot next to me
        say.  NOW, see that lift, OH, you just  got into sink, TURN LEFT,
        here we go, STAY IN THAT LIFT.  Not a  word  about  what  he  was
        observing, just telling you what a klunk I was.  The  other thing
        is that I did everything wrong.  I have several witnesses who can
        testify.   A  week  before  the  big  CRRC  ESL contest I started
        building a Metric,  of  course,  went out early on the day of the
        contest, threw it a couple of times, put it up in a hi-start once
        and then proceeded to compete with a lot of help from experienced
        gliders stepping on the winch and  coaching me.  Needless to say,
        I  crashed  the  plane twice that weekend  -  launched  with  the
        reciever  off  and landed into a lawn chair  -  very  unglorious.
        When  the  Metrick finally was crashed beyond repair I  bought  a
        Riser, which actually taught me something.
        
                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

                           So you wanna fly gliders!!
                           ==========================

                That's a wonderful  decision.   Gliders can be realtively
        inexpensive, can be wonderful  planes  to  learn to fly with, and
        will continue to challenge even the most accomplished pilot.  You
        can also fly many places from  which  power  planes are, or would
        be, banned.
        
                I assume you are new to gliders.    My suggestion is that
        you purchase a flat-bottomed trainer, such as a  Gentle Lady, Sig
        Riser, or an Olympic II.  All of these  ships are very forgiving,
        are floaters (meaning that you will have long flights if you  fly
        them right), and are capable of winning contests.
        
                Because  you  are  dependent   on  lift  and  aerodynamic
        capability it is very important  that you build your glider well.
        All wings and stabs must be absolutely true and all surfaces must
        be sanded to the EXACT contour given  in  the  plans.   More than
        anything, make sure you build it light, especially  the  tail.  A
        heavy  tail  needs an inordinate amount of lead in  the  nose  to
        balance.

                Before  you  go  to  the field check that all throws  are
        exactly  as in the plans.  This is very important -  the  control
        throws  may  look  wierd,  like  almost  no elevator, but lots of
        rudder, but do yourself a favor and set them as suggested.
        
                Balancing is incredibly important.  Every  glider  has to
        be balanced dynamically, but to do so, you have to start with the
        static balance as suggested by the kit manufacturer.  DO NOT move
        the CG further forward.  You may end up  with a pile of sticks if
        you do. Put it right there!
        
                I  also assume that there is either no wind or  a  steady
        breeze with minimal turbulence.
        
                Now set the trims so that the rudder points straight back
        and the  elevator  is close to neutral.  Trim the elevator a hair
        down from neutral.
        
                The next  step  is  to hand launch the glider.  Give it a
        steady horizontal throw.    There is no need to heave it or point
        it up.  In  most  cases  the  glider  will tend to balloon, so be
        ready to feed in down elevator.  Set the elevator trim so that it
        maintains steady speed and then work  on the rudder trim.  It may
        take  a couple of hand launches to  get  everything  right.    Be
        careful not to give the plane so much up that it stalls.  At this
        altitude you are probably too low to pull out of the dive and may
        damage your beautiful new plane.   Just fly straight out and make
        sure you have several hundred feet  of empty ground ahead of you.
        You will be surprised at how far  your  plane will go from a hand
        launch.
        
                If the trims are roughly where you started out you may go
        to the next step.  If they are  way off, fix the problem.  Rudder
        off is probably a warped wing.  Take it  home  and  straighten it
        out.  A lot of up or down is probably  CG  way  off.  Recheck and
        fix it.
        
                Now  you  are  ready  to  launch the plane on a hi-start.
        Pull it out close to the maximum.  It is very dangerous to launch
        with too little pull.  You may stall out or fly off the  hi-start
        prematurely.    Brace yourself, point the nose up at a 45  degree
        angle,  and  let  it go!  Try to keep it going straight  up  with
        rudder control.  Easy gentle movements will keep it on track.  If
        you  don't point the nose up on  release,  your  plane  may  have
        picked up enough speed to shed its wings  when you panic and pull
        up elevator.
        
                You may want to  ask someone else to launch the plane for
        you, so that you have both hands on the transmitter.
        
                If you club uses a winch let someone else run  the  winch
        for you.  Beginners often winch in too hard and rip the wings off
        their planes.
        
                Once you have reached altitude and flown off the hi-start
        retrim the plane for  steady  speed.   Don't go too slow.  If you
        have trouble maintaining speed you probably have the CG off.  Now
        give the plane a bit of  down  elevator,  release  the  stick and
        watch what happens.
        
                The  plane  may atrt lifting the nose, stalling, dropping
        the nose, pickicking  up  speed, etc.  etc..  This is a sign that
        you have the  CG  too  far forward.  Sounds counterintuitive, but
        its easy to explain:   If the plane is nose heavy it will need up
        elevator to fly straight and  level,  as the plane picks up speed
        the elevator pushes harder and harder  down,  and  will  lift the
        nose up.  If the gyrations get  worse  and  worse you have a real
        problem, try to get the plane down right  away.    Move  the CG a
        little bit.  I would suggest removing lead about a 1/4 ounce at a
        time.  You should just be able to see that the CG moved.
        
                If the plane keeps  accellerating earthwards you have the
        CG too far back.  This is because you have  to  compensate  for a
        heavy  tail  with  down  elevator.   It becomes more effective at
        higher speeds and will literally push the nose down.  This can be
        just as scary as the continuous stalling caused by the CG too far
        forward.  The plane  is  going  to be impossible to find thermals
        with  because you will continually  have  to  feed  up  and  down
        elevator  to  maintain speed.  Take  it  down  and  move  the  CG
        forward.
        
                Keep rebalancing the ship until you can  move  the  stick
        forward,  pick  up  speed,  then  release  it  and have the plane
        gradually lift the nose to  finally  settle  down to the original
        cruising speed.  Once you have done this you will be able to hunt
        for thermals and adjust the speed of  the  glider with a click or
        two on the trim.
        
                Next step is to check the stall characteristics.  Feed in
        a bit of up and hold it there until the plane  gently stalls.  If
        it  drops a wing and ends up in a vertical dive you  have  a  bad
        case of tip stalling.  Take the plane  home  and fix the problem,
        usually by putting a bit of washout in the  tips.   A more subtle
        cause of violent stalls is having too sharp a leading edge.  Make
        sure  its rounded EXACTLY as in the plans.  If you  have  trouble
        curing  the stall put a stall strip close to the wing roots.    A
        stall strip is an intentionally sharp leading edge.
        
                We  almost  have a beautifully flying  ship  now.    Many
        people fly with ships set up as  we are now and never go further.
        I recommend a couple of further steps.
        
                Watch the plane on the hi-start.  If  you have to feed in
        up elevator to get it to launch properly you  have  the  tow hook
        too far forward.  If it keeps popping off you either have the tow
        hook too far back or its bent so that the ring  slips  off  under
        tension, You can bend the tow hook so that it has a  low point in
        front.  Keep moving the tow hook until the plane will launch well
        without any application  of  elevator.  Some people prefer to set
        the tow hook a  little  forward  of this point and either trim or
        hold up elevator.
        
                Until you have a lot  of experience let the plane fly off
        the hi-start.  You will see  the  experts  zoom  off  winches and
        hi-starts and gain a lot of extra  altitude.   First of all, your
        trainer may not be able to handle the  stress, secondly a perfect
        zoom is difficult to execute.
        
                Another step is to loop the plane.  Feed in down elevator
        until it is moving well enough to have some  airspeed left at the
        top  of  the  loop, and then pull full up.  If it corkscrews  you
        have a  wing  warp.    It  should make a perfect loop without any
        rudder control.   If  the  wing  is straight, then you may have a
        wing balancing problem.  Check that the wing balances perfectly.
        
                Try to make a smooth flat turn.  If you have a polyhedral
        ship and  it  tends  to  bank  too  hard,  then you have too much
        dihedral.  If  it  yaws,  but  doesn't like to turn, you probably
        have too little dihedral.    You  can  change the dihedral effect
        with tip plates.  This  is  a  science  that  I don't know enough
        about.  With an aileron ship  too  steep  turns are caused by too
        much aileron, coupled with  too  little  rudder.    Yawing but no
        turning is caused by too much rudder and too little aileron.
        
                Now for a little flying  technique.  Beginners often have
        too  much  up  elevator  trim  and    the   plane  mushes  along.
        Unfortunately this causes you to lose altitude like crazy.  I see
        a lot of beginners with less than one  minute flights.  Any plane
        should have a still air time in excess of two minutes from a good
        launch.  A real floater like an Olympic  II  can  have up towards
        four and five minutes still air time from a  high  launch!    The
        plane should fly with good control authority and feel steady as a
        rock.  It seems counterintuitive,  but  you  travel  the furthest
        distance by increasing the speed of  the plane.  Your airtime may
        descrease, but the distance covered increases.   This  is  useful
        knowledge when you are running out of airspace  and are afraid of
        not making it back to the field.  Tell  yourself  NOT  to give up
        elevator. Give it some down and let the speed increase.
        
                To find  thermals  you  need  to  be able to see how they
        affect the plane.   Fly a pattern far away from yourself, usually
        at the edges of  the  field.   In still air it should just cruise
        along.  When it hits  a  thermal it should either rise noticably,
        or you see a wing kick  up.    If  it  rises you probably hit the
        thermal right inthe center.  If it kicks a wing up the thermal is
        on  the  side  that  came  up.  Thermals are very narrow  at  low
        altitudes  and get wider and wider.  They also tend to build  and
        stick  at  the downwind side of a piece of ground warmer than the
        average.   Your flying field in summer will often be a good place
        to look for  thermals in the downwind corners.  Another indicator
        of a thermal is the plane picking up speed and then slowing down.
        This is often useful when hunting downwind.  When circling in the
        thermal the plane will often stay in it and drift downwind.  Hang
        in there until you get so far  downwind  that you are getting out
        of range and may have difficulty getting back.    Once you are in
        the thermal you will find that you can feed  a  lot of up without
        stalling.  I don't know why.  If the plane  then  suddenly stalls
        its a good sign that you came out of the thermal.
        
                Slope is also good for increasing flight duration.    The
        stronger  the  wind,  the  smaller the object that will  generate
        slope.  Tree  lines  are  good in a solid breeze.  Try not to get
        too  far downwind.   The  so-called  rotor  can  be  vicious  and
        literally slam your ship into  the  ground.  To maintain position
        in the slope cruise back and  forth  along the upwind edge of the
        object creating the slope.
        
                Now for landing.   I  have  seen  an  awful lot of damage
        caused  by  stalling  at  low  altitude.    Keep  the  speed  up,
        especially in turns, and make your  final  approach in a straight
        run.  If you have spoilers, apply them to come down, but be ready
        to apply up elevator to keep the nose  up.    Don't  try  to land
        right at your feet, just find a convenient spot  that  the  plane
        can settle into without any damage. Walking is healthy.
        
        Good luck!

Glider rambling - part 3.

I received several personal mail messages asking for more of these 
glider rambling stories so I finally got a free minute.

I copied this story out of the book called "Collected Classics
of Soaring" by Trish Durbin.  Published by and available from

	Arizona Soaring Association
	P.O. Box 11214
	Phoenix, AZ. 85061

Having given credit I'm sure they won't mind a little free advertising.

This one is part of a very long but interesting chapter on the history
of the Arizona Soaring Association (ASA).

   At the end of the year, 1965, the ASA-ers certainly did get cracking.
More new ships appeared.  Don Santee brought his Ka-8 over from Oregon,
and covered it in Bob Wister's workshop.  Bill Ordway flew his new BG-12 
for the first time that October.  And Robbie Roe bought Bob Sparling's
old Laister-Kaufmann, its fabric crisp and tattered from ten years of 
neglect, that was to make him famous in soaring before he even got it 
off the ground.

   According to Joe Lincoln in his Arizona Highways article in July 1967, 
Robbie Roe was a highly experienced instrument pilot and had done some towing
at Harris Hill in Elmira.  Robbie began work on his "new" LK and was
fortunate enough to have assistance from Dr. James Turnbow, called "Doc" 
by his friends, an engineering professor at ASU.  "In mid-May, 1966," 
wrote Joe, enjoying himself immensely, "the wings of this LK were moved 
into the living room of the Roe house in Paradise Valley.  A new era in 
Arizona soaring was then born.

   The presence of those wings in the living room had a strange and 
unpredictable effect upon guests of the Roes' and over the whole neighborhood.
Cars were seen to drive by very slowly; then, after disappearing down
the street, they would turn around and drive by the house again, even slower 
then before.  The postman, who always previously had been content to put his
mail in the mailbox out on the road, came up to the house one day and rang 
the bell.  "I keep thinking that's an airplane in there.  Is it?" he asked
Robbie's wife, Chashie.

   "One of the sheriff's cars was seen going by the house with steadily 
increasing frequency.  Each time it went by it seemed to be moving slower
than the time before.  Finally the car nosed rather timidly into the driveway,
where the deputy parked and turned his radio up to a volume that could be
heard a mile away.  The deputy walked up to the Roes' front door.  "I thought 
there was an airplane in there.  Then I saw the N numbers on it, and was 
almost sure, but I wanted to make real sure.  Is that really what it is?"

   Work on the carried on through the hot summer months.  The young Roes
were always playing Tijuana Taxi (on their record player).  Rob Roe had
planned on calling his new bird some elegant name like "Gull" or "Cirrus",
a moniker that would signify the lonely grandeur and exaltation of the sky.
But, as the summer wore on, the vague apprehension grew.  His beautiful 
sailplane has picked up the name of Tijuana Taxi.

   "People kept dropping in - some to help; some to be astonished; some to
admire; some to be appalled.  Gallons and gallons of iced tea were served.
The aircooled atmosphere was a pleasant mixture of conversation, the unending
strains of Tijuana Taxi and the mixed smells of glue, airplane dope, iced tea, 
lacquer thinner and sawdust.

   "This whole plan was really very practical," explained Rob Roe in the calm
didactic tones of an engineer.  "We had a very good temperature and humidity
control."  His wife was not quite so enthusiastic.  "The air conditioning 
system also did a great job of wafting the scent of lacquer thinner all through
the house," commented Chashie.

   "Late one night Chashie came staggering out of the bedroom, pretty mad.
"Stop that smell," she demanded.  Rob apologized and excused himself by
explaining he'd thought she was asleep.  Later that same night, Bob Roe Jr.
came out of his bedroom, a little red-eyed and gray.  "Dad, will you please 
stop that drill.  I've got to get some sleep!"

   "The work went on happily.  In mid-August the wings were removed from the
living room and the fuselage moved in.  "In September the fuselage was moved
into the living room," said Mrs Roe.

   "Yes, I had it here for a little while, but then in late September, we
took the fuselage over to Harry's place, where it was sprayed along with the
wings," Mr Roe said.

   "It came back into the living room in early December," said Mrs Roe.

   "Yes, we had it back here for some final work.  It was just a little while."

   "It stayed through Christmas."

   "At last the work was done," ended Joe in a congratulatory tone.  "Rob Roe
had one triumphant comment about his experience:

   "A new precedent has been set.  No longer is it necessary for a man to
freeze in winter and boil in summer, working on his sailplane out in the 
garage."  Thus Rob Roe became the first man in Arizona to become famous in 
soaring before really getting airborne.  He had a sailplane in his living
room for 7 months and he is still married.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

================================================================================
Note 399.223               So you wanna fly gliders...                223 of 242
K::FISHER "Stop and Smell the Balsa!"                56 lines  30-OCT-1989 16:05
                               -< Soaring along >-
--------------------------------------------------------------------------------
RE 399.223
    
>Now for some true glider theory.

>I have a couple of observations and invite you to speculate on them.

>1st I've heard it said (I think by either Chris Schuck and/or Lincoln
>Ross) that one way to detect thermals is to watch for the nose to pitch
>down.  At first this seems counter intuitive but they argue that what
>happens is the plane is sailing along in calm air when a blast of rising
>air hits it from below so it just re-orients itself with the new air stream.

>Sounds plausible - BUT...

	This doesn't sound quite right.  To my way of thinking, getting hit 
with an air stream thats rising from below will momentarily increase the angle 
of attack, which will raise the nose till the A/C slows down, which will cause
a stall, which will lower the nose and cause the A/C to speed up until its
in a state of equilibrium.  I believe the A/C should momentairly pitch up and
slow down when entering the rising column of air.
	

>My observation with the Sagitta is that this does not happen.
>Maybe a reason it doesn't happen to the Sagitta is because it is so fast.
>In fact I haven't seen any glider at thermal contests as fast as my Sagitta.
>That is they may be faster but they don't fly them faster than I usually do.
>Double - In fact - this weekend at the airport I was very comfortable
>being up in the thermals because when my spotters (Kevin Ladd and Charley
>Nelson) spotted full scale planes closing on me I could move out of the
>path in no time.  Something I felt helpless about with the Drifter II.

>Anyway - when the Sagitta hits a thermal it does not drop the nose.

>Bye          --+--
>Kay R. Fisher  |
---------------O---------------

Kay.....

	Thought I'd try to answer your questions.  The question about the nose 
of the A/C dropping while entering(actually before entering) a thermal is, in 
my experience, true..well, maybe it's true....some of the time......Here's what 
I believe happens:

	Usually, the thermal is not just a smooth rising column of air.  There's
an awfull lot of turbulance around a thermal, and it's not uncommon to hit 
sinking air just before entering a thermal.  As your A/C entered this sinking 
air, the Angle of attack of the wing will be momentairly changed(decreased) 
resulting in the A/C trying to regain it's former trim state by lowering it's 
nose and accelerating until it was at the same angle of attack as before it 
entered the sinking air.  Your Sagita may not exhibit this behavior because I 
believe that you are flying it VERY fast and therefore wouldn't notice the 
change in speed and attitude.  Try flying at 0.1 mph above stall and then 
enter a thermal and you'll see the nose drop in the sinking air that usually 
surrounds a thermal.

	>The second observation I would like to hear comments on is this:
>When circling in a thermal I have a built in thermal intensity gauge
>on my transmitter - THE ELEVATOR STICK.  If I make nice even constant
>size and constant speed circles I have to pull in more and more up
>stick to slow the plane down.  If I drop out of the thermal I start
>to stall and porpoise.  The question is why - what aerodynamic theories
>can you use to justify this behavior?  I can't swear that the Drifter II
>ever did this but it sure seems part and parcel to the Sagitta.

	Here I think that you are flying fast and once in a thermal, you're
doing what all good thermal pilots would do.  You're slowing the A/C back to 
0.1 MPH above stall speed to minimize the sink rate.  Another way to look at 
this is you should go fast between thermals by flying at best L/D...cover the 
most ground for every foot of altitude lost...then, when you are in a thermal, 
slow down to the minimum sink rate so that you can climb as high as possible 
as quickly as possible.  
	
	As a side note, when you "fall out the back" of a thermal while at 
minimum sink attitude, guess what happens?....you're in a stall, the 
nose goes down until the A/C builds up speed and recovers.  If you are still 
holding some up elevator, the A/C will stall again and repeat the cycle.  
This stall/porpoise is a great visual indication that you are no longer 
thermalling.  Give it some nose down, build up speed and do a 270 degree turn
and you're back in it.

	Opposing views and opinions are welcome. :*)

							Bob

From: [email protected] (LTH network news server)
Subject: Re: Stall speed, minimum sink, best glide.
Date: 7 Nov 89 10:29:54 GMT
 
In article <[email protected]> [email protected] (David F. Kurth) writes:
>Assume the following typical polar plot.  Air speed
>is on the horizontal axis and sink rate is on
>the vertical.  I'm looking a 3 points of interest.
>
>
>                    Air Speed
>  0 ------------------------------------------>
>  ^                                           
>S |                                           
>I |                                           
>N |             B                             
>K |          ..:''::..    C                   
>  |         /         ''::.                  
>R |        /               ':.                
>A |       A                   :               
>T |                            :              
>E |                             :             
>  |                              :            
>
>... Point C is 
>point where a line drawn from the origin (0,0) is
>tangent to the curve.  This is the airspeed of best glide 
>and where the best L/D is found.
>... Do I have the right idea about Point C?
 
Yes, assuming the air is still.  If you fly through sink, you should 
draw a line from (0,v), where `v' is the sink rate of the air.  The
effect is that you fly faster through sinking air (makes sense, right?).
 
Similarly, if you're in a thermal you should draw a line starting below
the origin (0,0) to compensate for the rising air, so you fly slower.
 
Glider pilots are sometimes fortunate to hit a stretch of thermals, in
which case it's reasonable to fly straight on at relatively slow speed.
Circling in a thermal, speed of minimum sink is a better choice.  When
you hit a stretch of sink (much too common!) you really have to hit
the accelerator to get out, taking into account the risk of flying
into a thermal -- at 100 mph it can be quite ``noticeable.''
 
Dag Michael Bruck

        Re:          <<< Note 399.245 by K::FISHER "Stop and Smell the Balsa!" >>>

        More, more, more!
        
                I love  that plot.  Where can I find out more about them.
        I would like  to  see a typical plot for a floater like an OLY II
        and another for an F3B ship and compare them.
        
                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

    I just read the latest review of the Klingberg Wing in Model
    Airplane News.  I have toyed with the idea of building this
    but two other unfavorable building reviews have dampened my
    enthusiasm.  Does anyone have any experience with this
    design?
    
    Thanks,
    
    Jim 

Mark Triebes' Slope Soaring column in the December MA has some
interesting comments on design differences as related to the
SD6060 section and wing planform.  This section begins on pg.
160, but he also makes some remarks earlier in the column. 

Basically, the author comments that high performance design
techniques are more of a function of the experts that implement
them than of the techniques themselves (if you can understand
this long sentence!).

Also be careful of MAN, they don't print anything they can't
sell.  

A guy I saw at the flying field recently mentioned he was working on a 
Klingberg wing, and said it was pretty complicated. He claims the time he
has spent just on the wing is longer than he spent on whole planes. He also
mentioned that the instructions for building the wing include some clever
techniques of cutting up the kit box (!) to create alignment jigs. Can't
remember the name of the guy I talked to.

Dave

Glider rambling - part 4.

Again - I copied this story out of the book called "Collected Classics
of Soaring" by Trish Durbin.  Published by and available from

	Arizona Soaring Association
	P.O. Box 11214
	Phoenix, AZ. 85061

Having given credit I'm sure they won't mind a little free advertising.

This one is part of a chapter called "Other People's Stories".

THE LONG TOW by Ken Bradford.  From Zero Sink, Orange County Soaring Assoc.

   Last month we reported that when accepting delivery of the Club's new 2-33,
Dave and Karl Jessop left some parts on the runway at Tehachapi.  This month 
they left a while glider - including the pilot.

   As the story goes, the brothers happily took off from Orange County Airport
for Tehachapi to tow in Karl's brand new 2-33 with Dave's 172.  And in due time
arrived (110 miles).  After the check out, and amid happy good byes, they 
saddled up for the long tow home,  Karl comfortable in the glider on his donut 
cushion, Dave in the Cessna.  Come the takeoff and Karl was just wobbling down 
the runway when all bedlam broke loose - it sounded like his brand new glider 
was falling apart.  Was the wheel gone?  Was a strut dragging?  Karl didn't 
look.  He released fast and pulled off.

   After his heart got back in place, he climbed out to survey the wreckage as
everybody rushed up.  Look they did, and found - nothing.  It seems the rear 
window was not secured before takeoff and started banging the wing.  With a 
few choice words, Karl locked and taped the latch and saddled up again.

   But where was brother Dave?  Nobody told him about the unhook, and by this
time he was a speck on the horizon doing a masterful job of pulling the tow rope
all the way to Elsinore (125 miles) while brother Karl had fits in Tehachapi.

   After he recovered, Karl placed a call to Florence at Skylark Field, asking 
her to break the news to Dave when he arrived - which he did after two hours at 
60 mph.  He rolled up to the gas pump, got out and scanned around for Karl, with
that, "Now what the H---'s he up to" expression.

   At this point, Florence walked up - grinning - to give him the jolt and broke
up completely - as Dave gasped and staggered back against the Cessna.  And made 
a few remarks reserved for mashed fingers or barked shins.  We can't print it 
here.  But it was too late to go back for Karl so he flew to Orange County and 
tied down.

   Meanwhile, back at the glider factory, Karl had calmed down long enough to
take a tow to 2000, found a good one, and was soon at 10,000 - headed for home.
After all, he thought, it had been done.  And he would "have" brother Dave from 
then on.

   But Karl ran out of day around El Mirage so put in for the night.  Placed 
some calls for Dave, who by this time was on the job taking care of his air
conditioner business.  So dawned a new day and Dave lit out as soon as he could
and flew back to Tehachapi (110 miles).  When they told him where Karl was, his
hat really hit the ground - so hard the boys at 4000 feet felt it.  So it was 
back in the Cessna where he firewalled everything and got the STOL out of there 
for 60 miles to El Mirage.  Where brother Karl was looking in the wrong 
direction and didn't see him come in.

   So, the brothers were reunited and after they stopped yelling at each other,
Karl settled on his donut ready to go again.  So did the brothers hook up and go
peacefully fading off into the sky?  Was this the end of their problems?  Not 
yet!

   Karl was ready to go but Dave was there jumping up and down.  He didn't
have time to make the long tow... he had to get back on the job... his customers
were sweating!

   So Karl climbed wearily out and it was full bore back to Orange County (70 
miles) where Dave got out and on the job while Karl flew over to Skylark (35
miles), picked up Ray Brown (a real tow pilot), and then back to El Mirage (75
miles) where, after carefully adjusting the rear view mirror, they towed off for
Skylark (75 miles) and arrived late Thursday.  Whereupon the '33 was tied down
and Karl flew the Cessna 172 back to Orange County (35 miles).  Wheuuu!

   This adds up to 730 airline miles of flying to get the new bird 110 miles and
qualifies them for the Royal Order of the Cast Iron Tow Rope.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Were it not for Kays' efforts this note is in danger of becoming
    totally quiescent. To avoid that let me pass on an experience at
    my favorite local hobby shop. Last sat. I stopped by to buy two
    Airtronics 401 servos that I'm installing in the wing for aileron
    control on a new foam/fiberglass multi-task glider currently under
    construction (no name selected yet). He only had one in stock and
    offered to order another one for me . He looked up the price in
    the latest wholesale catalog and discovered the retail price would
    be $30 higher than his current price of $34.95. This was a shock
    to all concerned. This helps explain why Vision radio prices have
    gone up about $60 in the latest Tower catalog. So, fair warning
    to everone to buy now or suffer later. I wound up buying a JR micro
    servo for $42.95 and of course have to change the plug. 
    
    Our Dec. soaring contest was snowed out, of all things, the first
    precipitation we've had in Albq. since Oct. The next day, 17th,
    we flew with 2-3 in. on the ground, my first experience with snow
    landings. Not a cloud in the sky and absolutely the deadest, calmest
    air I've ever experinced in RC soaring. Max Mills was getting 4
    min. flights with the latest version of his "Westwind", an excellent
    multi task design for $120. I was getting 3+ min. flights with my
    Pulsar until I landed going backwards and snagged an aileron on
    a grass tuft, ripping the iron on hinge right down the seam.
    Repairs with vinly tape gave insufficient aileron throw on one side
    resulting in a rather spectacular flat spin from 100 ft. alt. 
    No damage though and I quit while I was ahead.
    
    Glider guiders aren't wimpoids so don't let a little winter stop
    you.
    
    
       Terry
    

Re: -.1   Yeah, the glider topic has been way too quiet lately. And I'd LOVE
to continue getting flights in but it isn't too fun in 10 to 15 degree weather
with 20 MPH winds... that's what we've had on the weekends.


Here's a topic for discussion:

	I'm currently building a Prophet 941 sailplane that has a polyhedral
wing design. The instructions in the kit INSIST that you build in 1/2" of
washout in the tips. They stress it several times, and explain that it's 
absolutely necessary for quick response. I don't understand. I've heard that
washout is used to help prevent tip stalls, but how does it improve the 
responsiveness of the glider?

OK guys, jump in...

Dave

    I agree with Erics' explanation. Poly wings don't normally need
    washout to cope with tip stalls in straight ahead flight. In a turn
    though, you are concerned with rudder response. Since the Prophet
    is not a particularly high speed ship, the reduction in overall
    wing efficiency caused by the washout probably won't be noticeable,
    therefore I vote for the washout.
    
    10-15 degrees ! I hear you Dave. The last time daytime temps reached
    that around here (1971) the entire city was immobilized!
    
    Terry
    

    Tom:
    
    I am interested in hearing more about your foam/fiberglass MTS ship. We
    here in the PPSS are also building some foam/glass ships for F3B and MTS
    work. We have even scheduled monthly (Saturday) competitions to rotate 
    between Denver and Colorado Springs. Being in Albq. maybe you would like 
    to come and fly with us. 
    
    What airfoil are you using? We're using an RG15 and shooting for a wing
    loading 10-14 Oz. sq.ft. I am flying an experimental set of wings now
    with 14.4 Oz./ft. and beleave it or not, its great.   
    
    Ron

    Ron:
    
    My MTS bird will be pretty straightforward. You might call it a
    "poor mans' Falcon 880". It has very close to the same wing plan
    form, S3021 airfoil- I've had excellent results with the 3021 on
    my Pulsar- and uses the same tip-hedral on the outbd. 10" because
    I'm curious to see what that will buy me, if anything. It has a
    SD 8020 stab 'foil or as close as I'm capable of building one with
    open frame and balsa sheeting. The fuse. is fiberglass, one of
    Jerry Slates' "Smoothie" models (Viking Models USA).
    
    It looks like I'll wind up with around 850-860 sq. ins. when all
    the trimming, slicing, and sanding is done. Will use one servo per
    aileron, but a common flap servo mounted in the fuse. The only "exotic"
    features will be Kevlar pull-pull cord for rudder actuation and
    carbon fiber rods for both stab pivot and wing rods. These also
    work well on my Pulsar, but can't be justified on a cost basis.
    I can't see why this thing wont' come in at less than 60 oz. which
    would keep it right around 10 oz. sq. ft. We don't fly in high wind
    very much so I don't have much incentive for higher loadings, but
    I can well believe your getting good performance on around 15 oz.
    You guys have reputations of being virtual wind-lords up there,
    but if we cancel all flying weekends with winds over 15-18 mph down
    here, we'd only lose a few weekends per year , of course not counting
    the spring time 40-50 mph 12 hour blows.
    Some of us from Albq. Soaring Assoc. talked about going up to the
    springs last summer, so maybe we'll talk more seriously about next
    summer. I think you guys fly mainly off that sod farm east of town,
    we fly mostly in town , although we have a sod farm out east too,
    use 5 or 6 times during the summer. I'd be interested in hearing
    more about your activities up there, and can pass them along to
    the club.
    
    Terry
    

    Dave,
    
    Tell me more about the Prophet 941. What prompted you to build this
    ship?  What airfoil does it use?  I have seen pictures of this ship
    in catalogs/magazines, but never seen one fly?
    
    Regards,
    
    Jim

    Terry: 
    We would love to have you guys fly any time. I'll send you a contest
    schedule as soon as I get one for next year. Our normal club contest
    is on the third Sunday of the month at the sod farm east of town.
    
    Do you know Ed Whitehouse?. He was a PPSS member and is now in Ablq. 
    He comes up once in a while and flys with us. Also several of us are
    going to car pool to the South West Regionals in Az. in mid Feb.
    Anybody down your way going?
    
    As for SMT and F3B activty, we are developing a plane we call the
    ICON. The wings I mentioned previously are prototypes for this ship. As
    I stated the wings are RG15, build without spares or wood leading
    edges. The wings are vacuum bagged using unidirectional glass and a
    white Hexcel epoxy. Strength appears to be excellent. Our concept is 
    to keep things cheap, minimize building efforts, and treat these things
    like they are golf balls. If you loose one you just replace it. We have 
    also standardized parts so they are interchangeable. This should help a 
    lot in practice and competition.
    
    Regards 
    Ron
                                    

    Ron,
    
    I'll be at the Southwest Regionals at the oldtimer/antique venue. 
    Probably be visiting my ol' C.A.F. buddy and avid oldtimer, Gerald 
    Martin and, barring a miracle, probably _not_ flying as my oldtimer 
    is still a good ways off from airworthy and the engine requires a 
    lengthy break-in which I haven't even begun yet. 
    
    The meet will be held at a small airport just north of town a few miles
    and my understanding is that, unlike the past coupla' years, all but
    the U-control events will be held at the same site so look me up if you
    can.  I'll have my mini-motorhome parked somewhere nearby next to
    Gerald's and we'll likely be the ones "having the best time" as we
    party pretty good during that meet.   

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    Ron:
    Yeah, I'll be looking forward to receiving that contest schedule.
    I'm sure we can get 3 or 4 guys together to make the trip.
    We fly off a 6 acre soccer field about 3 miles due east of the DEC
    plant. We get to use it during every other 3 month block, Dec-Feb
    and Jun-Aug. Soccer leagues use it at the other times. On our "off"
    season we fly on the open prarie, actually right on the city limits,
    about 5 miles n.e. of the Dec plant.
    I don't think I know Ed at least not by name, although a lot of
    guys come by the field and fly without introducing themselves.
    Your ICON sounds like the way to go. Getting away from an internal
    spar structure can sure save a lot of time.
    
    I've gotten one wing on my new bird sheeted now, my best effort
    yet if I do say so. Had to walk around the house last night swinging
    the wing in arcs to "test the lift" until I begin to receive the
    usual pitying looks from family members. It's a conventional spruce/
    ply box spare on inbd. 30" with laminated balsa/spruce leading edge
    to minimize dings when landing in the cholla, prickly pear, masquite,
    and assorted horned toad colonies.
    
    I'm afraid I won't make it to the SW regs. As I mentioned to Al
    earlier, I'm planning to be in Tucson and Phoenix around the middle
    of Mar. Maybe in 91.
    
    You guys have a good Christmas, and get that Mig done next week
    Al.
    
    Terry
    

    Al:
     I'll be sure and look you up at the SWR in Feb. I'm really looking
    forward to the event. I've never been to a really big contest before.
    I'll fly in the soaring event and try to watch what happens in the other
    events too. I think there will be six or seven PPSS members car pooling
    down. We will being staying at a Best Western in Eloy. 
    
    What can we expect for weather that time of year? Any wind? 
    
    Terry:
    
    Let me know what your contest schedule is too. I'm sure I could get
    some people to drive down. We talked about it last year, but didn't
     do it. Also do you guy's have a newsletter?
    
    Ron
    

This is reply to .251 BLUMJ:

Why did I choose to build the Prophet? Well, I currently own a 2 meter Metric,
and I used to have a 2 meter Riser. The Riser was the plane I learned on, and
it's so beat up repairs just wouldn't last. When I built the Metric I figured
it would blow away the Riser, but it's a heavier ship, and I actually had better
luck in contests with the Riser. So after I sold the Riser, I decided I wanted
another floater, light wing loading, but capable of decent speed when balasted
for those windy days. I also wanted a 100" so I could compete in Standard class
on equal ground.

This plane is flown by Tom Keisling, a young guy who racked up a record number
of contest points in the Eastern Soaring League last year (he just made Expert
class). I checked out his plane and liked the features. The wing is polyhedral
and very strong, and comes in two pieces attached with a steel wingrod. The 
plans include spoilers (which I am including) and 2 different means of 
attachment to the fuse (rubber bands or bolt and dowel). The stab is full flying
which has worked very well on the Metric; it keeps the stab away from the
ground on landings. Oh, yes, the wing airfoil is Eppler 193.

This plane has a relatively short tail moment. According to the instructions,
it makes it react quicker, but for stability the tail section needs to have
slightly more area than normal. The nose is very long; I can easily put the
battery, receiver and all servos ahead of the wing. That leaves the entire
wing compartment space for ballast weights. Easy to locate them under the
CG.

At 940 sq. in. and about 41 oz., the wing loading comes in at about 6.2 oz/sq.
ft. Supposedly it can fly in around 20 MPH winds unballested, and 35 MPH winds
when ballested to 10 oz/sq.ft. 

We'll see. I have most of the structure finished now, and it's time to do lots
of sanding. Can't wait to get it up in the air!

Dave

    Ok, I think you guys have convinced me to change my plans and attend
    the SWR rather than attend the Phoenix G.P. in Mar. I would rather
    be out there competing and buying the farm in a big way in the winter
    vacation paradise of Eloy, instead of rubbing shoulders with the
    wordly sophisticates of Phoenix while watching emotionally erratic
    European bon vivants hurl incredibly noisy little autos around an
    arbitrarily designated ribbon of asphalt.
    Now I must dig out the entry form from one of my magazines and send
    it in. Probably would'nt hurt to note the date when this shindig
    is coming off, too.
    
    Ron, We don't have a club newsletter worthy of the name, just a
    computer printed postcard listing the upcoming contests and monthly
    meeting. We have one contest per month during each 3 month period
    that we have the soccer field and on an irregular basis when we
    fly off the prarie site. Jun.Jul.Aug. is the best time to come down
    here . More entries, predictable weather, and thats the period we
    have our MTS events. We normally use electric winches only for the
    MTS events but it's not required to use them as there are only about
    6 or 8 of us who feel comfortable using them although that's slowly
    changing, as the 20th century gradually creeps up on us.
    
    This past weekend saw good flying weather here so I got in a few
    flights with the Pulsar as well as video taping the initial flights
    of Max Mills' newest design, the Northwind. He had it flying with
    the production fuselage, balsa & ply, a generic design that he uses
    for all his 'wind versions. The prototype Northwind used an aluminum
    ski pole for the aft portion of the fuse. but that was impractical
    from a cost and interchangeability standpoint for the kit (soon
    to be) version. Also he's now using the Quabeck 2.5/10 airfoil and
    I must say it is a very impressive flyer. He's using full span camber
    control of course and in dead air off a medium hi-start could get
    consisten 6+ min. flights. Drooping the ailerons and cracking just
    a tad of flaps transforms it into a tight, flat turning, floater
    (relatvily speaking) able to put G.Ls. , Olys, and that crowd to
    shame and then clean it up and go streaking across the sky to a
    whole new thermal ballgame while everbody is standing around saying
    "duhhh.." The upshot of this is that I and another club member get
    free kits from Max to build so that he can get more examples in
    the air quickly, and see how different building techniques affect
    performnce, hopefully not at all. So, I either stop my present project
    immediately, and start on the Northwind or it won't be ready in
    time for the SWR and that would be without any time to parctice
    with it at best. I'll probably finish up my "Vibaro del Cielo"-
    Viper of the Sky- and take that to the SWR. In the meantime my
    oldtimer project gets pushed further back, and there's still a
    Dodgson Orbiter in it's box from last spring.....whats a body
    to do?
    
    Terry
    

    Terry:
    
    Great, I'm glad your going to the SWR. The dates are Feb. 10 and 11. I
    have the info. at home. I'll bring it in and send you the details. Our
    group will be driving through Albq., do you want to car pool or are you
    making a real vacation out of it? I'll check on the room in the car if
    you want. The Northwind sounds really great. I'm looking forward to
    seeing it. I think you can count on some of us coming down for a
    contest, particularly the MTS. Will this include F3B? Some of our
    planes are on the heavy side.
    
    Regards
    Ron
    
    Ron

    Ron; Thanks for the ride offer but I'll be staying in Tucson for
    about a week so will take my own car. Also, I called the CD in Tempe
    last night and an entry blank is on its' way.
    
    Our MTS contests don't include honest to gosh full bore F3B events
    but we do have a speed run around a measured course, two poles set
    about 80 meters apart as well as a max number of laps event around
    the same course, and the usual thermal duration with spot landing
    event.
    
    I'm going to distribute entry blanks for the SWR at the next club
    meeting and as club V.P. will exert massive arm twisting to insure
    we have a good local contingent down there.
    
    Now let's hope for good weather, Feb. in So. Az. can be in 70's
    and not a cloud in the sky, but can also be 50's , overcast and
    rain, on the wrong side of the jet stream. The former is the rule,
    luckily.
    
    Terry
    

Dan Eaton sent me this in the mail.
Sounds really neat.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################
    
               <<< DECWET::DOCD$:[NOTES$LIBRARY]PHYSICS.NOTE;1 >>>
                   -< On the existance of Schrodinger's Cat >-
================================================================================
Note 59.78               birds, and newtonian mechanics                 78 of 78
SSDEVO::EGGERS "Anybody can fly with an engine."    122 lines  10-DEC-1989 18:08
                   -< Dynamic Soaring: an authority's view >-
--------------------------------------------------------------------------------

    Follow-up on notes .31 and .37:
    
    The following excerpt is taken from "Cross-Country Soaring" by Helmut
    Reichmann (PhD thesis at Karlsruhe: "On the Problem of Airspeed
    Optimization in Cross-Country Soaring Flight").  He was a German
    soaring champion in 1965, 1968, 1971, and 1973; and a world champion in
    1970, 1974, and 1978.

    DYNAMIC SOARING

    Inspired by the splendid flight performance of the Albatross, a large
    sea bird whose refined use of horizontal wind shear near the surface
    allows it to cross entire oceans without updrafts, several theoretical
    explanations have been advanced in the last decades which have
    attempted to make these sources of lift available to sailplanes as
    well.  Since these have remained only theoretical until now, many of
    the hypotheses have gotten the reputation of pointless physical and
    mathematical problems with no practical application.

    However, Ingo Renner,  World Standard Class Champion in 1976, has
    actually made dynamic soaring flights, thus proving that long flights
    are possible even without lift as we know it [ridge, mountain wave, and
    thermal], as long as a wind shear of sufficient strength exists.

    The Principle

    Let us imagine that a sailplane flying in still air at a speed of
    200km/h  decreases it's speed to 100km/h.  This will result in a
    certain gain in altitude, let us assume 50m.  Overall, no energy has
    been gained; kinetic energy has merely been converted to potential
    energy. In fact, some energy will have been lost due to air friction. 
    In an actual maneuver of this sort, the total-energy variometer will
    reflect this as a "down" indication.

    However, if the air layer entered during the pullup is not still, but
    has a wind of 100km/h blowing opposite to the sailplane's direction,
    the speeds would be additive: the sailplane has its residual airspeed
    of 100km/h, as in the first case, and an additional 100km/h gained from
    the headwind.  The airspeed indicator would show 200km/h once again,
    and the total-energy variometer would reflect the gain in height as an
    energy increase ("up").

    A PULLUP AGAINST A WIND SHEAR RESULTS IN INCREASED TOTAL ENERGY.

    In the same manner, a sailplane flying in the region of higher wind
    speed can  gain energy by flying downwind and descending into a layer
    of lower wind speed.

    A DESCENT WITH A WIND SHEAR ALSO RESULTS IN INCREASED TOTAL ENERGY.

    Dynamic soaring is based on the technique of combining such ascending
    flight paths into the wind shear with descending paths away from the
    wind shear.  This can take the forms of ovals tilted obliquely into the
    wind shear, figure eights, or zigzags.

    Practical Application

    Natural wind shears are hardly ever so abrupt as in the above example,
    but even weaker shears can result in sufficient gain in energy to
    cancel out the sailplane's friction losses and allow cross-country
    flights. Strong shears are found in the region of the jet stream, but
    also near the surface and in the  region of temperature inversions.

    The Albatross, a bird with narrow wings of some 3 meters span and a
    very high wing loading, performs its maneuvers in the lower 50 meters
    above the ocean surface. As it climbs against the wind, it reduces its
    airspeed distinctly, turns back at a very low airspeed, and continues
    to dive downward with  constantly increasing airspeed. Directly above
    the water, it turns once again at high airspeed and high g-loading, in
    order to climb upwind once again.

    For the sailplane pilot, such aerobatics so close to the ground can be 
    considered out of the question. Dismissing for the present the wind
    shears near  the jet stream, we are left with those in regions of
    temperature inversion.

    Our current sailplanes have a sufficiently wide speed-range
    (80-250km/h) in  which their performance is adequate for the required
    flight maneuvers. The sailplanes of the new racing class appear to be
    particularly well suited due to their high maneuverability.

    Renner began his research with a flapped H301 "Libelle".  According to
    his reports, the wind was almost calm on the surface at Tocumwal,
    Australia, the morning of October 24, 1974. After takeoff, the
    sailplane and towplane penetrated an inversion (clearly visible due to
    the top of the haze layer) at an altitude of some 300m.  Above the
    inversion the wind was strong; sailplane and towplane were able to fly
    upwind only slowly, and Ingo Renner estimates the wind speed at 40 kt.
    (!) At a position about 3km upwind of the airfield, Renner turned
    downwind from an altitude of about 350m and began a steep dive through
    the inversion. At an altitude of about 250m, with an airspeed of
    200km/h, he started a steep 180 degree turn (acceleration: 3g) and
    climbed at the same angle (30 degrees) as his initial dive, headed
    upwind. He re-attained his original altitude, made a second 180 degree
    turn at low airspeed and g-load, and started the process again. In this
    manner he was able to  maintain altitude for about 20 minutes, but the
    wind drifted him downwind so far  that he finally had to abandon the
    flight in order to be able to land at the airport. During later flights
    with a PIK 20 he gradually gained sufficient proficiency to be able to
    continually work his way upwind and remain over the airport.

    If the energy increase is large enough, one can vary the climb and dive
    angles  together either toward or away from the wind to allow for
    crosswind motion; flying zigzags ... allows sideward translation as
    well.

    Wind shears of the strength reported by Renner in Australia may well be
    a  specialty of that particular continent. If the wind changes 40kt
    over a vertical distance of 100m, the wind gradient is about 0.2m/sec
    per meter altitude. Dr. Trommsdorf and Dipl. Ing. Wedekind at Aachen
    have calculated that even a seventh of this value--i.e. a wind gradient
    of only 0.03m/sec/m--would be sufficient for a Nimbus or similar
    sailplane.

    Perhaps in European countries, a Foehn that does not continue all the
    way to the surface would be ideal for such flights, When the
    high-altitude winds pass over a cold airmass lying in the bottom of a
    valley, one might try one's luck at dynamic soaring instead of a wave
    flight. The aero tow above the valley inversion would be a fairly major
    commitment [i.e., expensive] to make, but the eventual successful
    dynamic flight would be far more  interesting than an altitude diamond
    [award for an altitude gain of 5000m].
    
================================================================================

So what do you think.  Can we scale this down.  We sure have lots
of wind shear everywhere I fly.  Typically the wind over the trees blows
pretty hard but down near our little Massachusetts landing strips it is
fairly calm.  So should we be able to climb up into the wind shear over
the trees and then dive back down towards the landing zone and back up
again - over and over?  Certainly not the kind of thing that is intuitively
obvious.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    This is some really interesting info, Kay. I had read about albatrosses
    being able to dynamically soar long distances but thought it had
    to do with their being able to sense and use slight water temperature
    diferentials. The wind shear explanation makes more sense.
    
    If I understand this correctly, dynamic soaring in a sailplane requires
    being able to change the location of the plane very rapidly from
    an area of lower potential energy to an area of higher potential
    energy, and the wind shear provides the only practical conditions
    where this transfer can occur quickly enough.
    
    Considering your example of Mass. wind conditions, it would be my
    guess (based on my vast experience i.e. 2 weeks in Westfield in
    Aug. 87) that the wind velocity difference is caused by the low
    altitude retarding action of the dense forests surrounding the flying
    fields and not a true shearing action between two discontiguous
    (whatever that means !) layers of air. I suspect that the energy
    level gradient from low to high, would be too gradual while at the
    same time being too variable, to be of practical use to RC soaring.
    
    The observations about inversion layers are another matter. Here
    in Albq. we fly in inversion layer conditions quite a bit especially
    in the winter. Cold air from the nearby 10,600+ ft. mountains flows
    down into the valley in the early morning and over the top of the
    warmer valley air, which is then trapped until later in the day
    when sufficient heat is available for it to break through. The layer
    being quite visible as a haze or brown cloud depending on severity.
    Our flying fields are at about 5500 ft. and 5700 ft while the valley
    to the west is at about 4900-5100. The inversion layer extends up
    to about 6000-6500 ft typically, meaning that we can sometimes break
    thru the ceiling on a good launch and suddenly the "whole sky is
    up". There is no real wind shear associated with this, total speed
    differential between the southerly flowing air above the layer and
    northly flow, if any, below is no more than 15-20 mph. However
    this gives rise to the phenomenom known as the "Albuquerque Box"
    which is used by hot air balloonists to fly up and down the valley
    and still return to their launch point.
    
    6 or 8 years ago we had a spate of x-c soaring, in the summer, using
    old 12 ft. Soarcraft designs, and a few of the then new Sagiita
    x-cs'. A few of the guys encountered what we thought at the time
    were verticle wind shears, sufficent to rip a wing off. Since they
    were flying at near the limits of visibility at the time, they could
    have actually entered a high speed horizontal shear.
    
    We also encounter slope lift on level ground when flying 100-200
    yrds. down wind from several arroyos (narrow dry stream beds with
    steep, nearly vertical banks) that cause enough upward component
    to sustain flight in a floater type glider within a narrow band
    parallel to the arroyo and sometimes as high as 200ft.
    
    To bad that soaring is not a path to fame and fortune or there would
    be somebody out there right now doing research on all this stuff.
    
    Terry
    

        Re:         <<< Note 399.268 by ELMAGO::TTOMBAUGH "High Plains Drifter" >>>

        Fascinating,
        
                The instructions  for  my SongBird 100 included advice to
        fly in exactly this kind of pattern in strong winds.  I could for
        the life of me not figure out how it worked, but that explanation
        made me understand.  It  seem  an  ideal  place  to practice this
        would be at the upwind edge  of  a  field  surrounded  by  trees.
        Below  the tree line its calm, above  it  will  be  blowing  like
        stink.  I would think you need a  fairly large, heavy glider with
        good penetration.
        
                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

                I have signed up to CD a F3F(un) glider  competition  for
        CRRC on February 10.  I would like your ideas  for  making it fun
        and interesting for both novices and experts.
        
                My thoughts are to split  the flyers into groups based on
        their planes.  One group would  be flat-bottomed polyhedral ships
        like  Gentle  Ladies.    The  other  for  planes  with  high-tech
        airfoils.  The events could be patterned after  F3B.  It could be
        a lot of fun to try a speed event.
        
                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

    Re .270
    
    Anker,
    
    Your ideas on contest structure sound entirely feasible to me. Not
    having the FIA rule book in front of me, I can't recall exactly
    what the F3F events are or even what type of glider competes in
    them. Aside from that, here's my observations based on helping to
    run and competing in our club contests.
    
    Splitting the entrants into skill levels such as beginer, intermediate,
    and advanced usually works well if you have a fairly large number
    of pilots, and it encourages newcomers to try their hand at contest
    flying. Sandbagging by experienced pilots trying to enter novice
    events has'nt been a problem with us. Also your idea of classifying
    by aircraft type is often realized by this scheme too, since beginners
    most often use flat bottom polys and experts usually use more advanced
    types.
    
    A speed event is the key to having a memorable event, in more ways
    than one. One point to consider; don't use the full 150 meter F3B
    length for the speed course. It's too far for the average sport
    plane and pilot and causes too many landings on course with the
    resultant 0 points, I'm assuming the usual 2 lap, or 4 leg event.
    We use about a 60 to 80 meter course, my estimate, I've never heard
    the actual distance stated, best times are in the 13-15 sec. range.
    We've tried having the course both parallel and perpendicular to
    the wind. Parallel is more fun. One fine point that can cause grief
    if overlooked: always enter the speed run going downwind and exit
    going upwind, leaving plenty of room for landing immediately after
    exiting. You're going to have to have turn callers and an audible
    method of signaling to the pilot when to turn. Flags will work but
    only if you have a spotter standing next to the pilot to call the
    turn for him. We don't have that much manpower available so our
    turn sighter sits on the sidelines sighting across the turnpoint
    pole and bangs on a metal soccer goal post with a hammer to signal
    the turn to the pilot.
    
    Flying a duration event around the speed course is very popular.
    We give a 2 minute time after launch release to enter the course,
    and then it's the max number of laps completed in a 4 minute working
    time.
    
    I'm sure you already know about the various options for the straight
    thermal duration and spot landing events.
    
    Sounds like fun except for the Feb. 10th date. You guys are rugged!
    
    Some of us will be basking in the warm (I hope) AZ. sun on that
    date. 
    
    Let us know how things go. Good luck !
    
    Terry
    

    Gee, I don't know about F3F either. I have flowen in some distance and
    a couple of speed events however. They're a lot of fun. I think it's
    important that the distance event by man on man and not just the most laps
    wins. The conditions at the time of round can make a big difference.
    
    As for coures, we've always used 150 meter distance between pylons for
    both speed and distance. Also everybody needs to help in flaging and
    timing. This could be planed out to make it smooth and go quickly.
    I've seen some problems develop around  equipment failure, ie. winch
    line breaks causing rounds to be re-flowen. I think the ground rules must
    be layed out from the beginning. Winch line breaks or timer issues  are 
    the responsibility of the pilot and are his problem. I have see one
    person intentionally break the winch line when he didn't think
    launching was to his advantage, even though others had already launched.
    This caused the entire group to land and refly. This same person as also
    had timer problems when things aren't going well for him again causing
    a reflight in man-on-man. The point is think about how to handle these 
    occasions, accidental or intentional. 
    
    Another thing that worked well for the novices in speed was a cap on the 
    max time. In our case we used 35 sec. Any pilot that took longer then
    that was scored 35 sec. Thus nobody went right in the toilet due to a
    poor speed run. I have also heard of a low cap, ie. 25 sec. This takes
    the advandage away from the hard core F3B guys. 
    
    Have fun 
    Ron
    
    

    Ron/Terry,
    
    Sorry to have to tell ya's that the soaring and oltimer venues will NOT
    be at the same location at the S.W.R. in February as I'd previously
    guessed.
    
    R/C Oldtimer will be held at the Eloy Airport and Freeflight & R/C
    soaring will be held about 10-miles to the south...the same as it was
    last year.  This'll make it more difficult for us to meet but, maybe...    

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    Welcome back Al, from where ever it is that people go when they're
    on vacation. I would'nt know about those things, har-har.
    
    I got the contest fliers form the C.D., and we'll definitely have
    to make special arrangements to get together. Got any idea what
    that soaring site is like? I know it will be flat, but just dirt
    or maybe one of those old aux. asphalt fields? 
    
    I know for sure that we'll have two more entries from Albq.,
    Max Mills and Tom Thompson ('87 F3B team mechanic) and after I
    distribute the fliers at the club meeting next week we may pick
    up a few more entrants.
    
    Concerning what F3F is, I believe thats the FIA slope racing event.
    They run only one plane at a time, against the clock, unlike the
    more macho American method of having multiple planes on the course
    at the same time, with the inevitable mid-airs. Which is a perfect
    segue into my latest war story.
    Sunday was clear and cold here with a light breeze. By 11 AM the
    thermals were beginning to pop and I was on my third flight with
    the Pulsar and had just hooked into a pretty good one on the N.W.
    end of the field. I was doing 30 ft. circles and drifting slightly
    south when Lucas Jones launched his Sagitta 600 into the prevailing
    wind from the N.W. Just when he had reached max. launch height and
    was about 5 sec. from release, I circled around on the downwind
    side of my circle at what I THOUGHT was about 30 ft. higher than
    Lucas. But noooo... we met head on, my left wing contacting his
    left wing, both at about 50% out from the fuse. I was in a left
    bank so my fuse. passed over his without contact. The impact sheared
    the outbd. half of my wing completely off taking the flaperon with
    it, the servo stayed behind in the inbd. half. I noticed out of
    one eye that Lucas was continuing on and did a normal release staying
    straight and level. This was surprising since my airplane is larger
    and heavier but he was carrying the greater inertia of having the
    weight of some of the hi-start rubber being lifted off the ground
    at the end of the launch. Also later post mortems were to reveal
    that it had hit exactly at the weakest point on my wing, right in
    line with the inbd. end of the flaperon, and the servo cavity.
    In the meantime I was in a steep left spiral with just enough altitude
    to try a few things. Full right stick would result in a straight
    ahead dive with even a little right turn, since I still had right
    flaperon control as well as rudder (coupled). However, the 70 degree
    dive angle didn't bode well for the future and any up elevator caused
    an instant snap spin to the left. It was apparent that impacting
    while spinning was the lesse of all evils. It hit fairly flat between
    a small pine tree and the chain link fence bordering the field.
    The bad wing caught the top of the fence ripping the remainder from
    the fuse, but the right wing came thru unscathed and the fuse. suffered
    to small cracks on the top seam, both easily repairable. So, the
    Pulsar will live to fly again, although I'll make two new wings
    rather than try to match the new half to the old.
    Meantime back to poor old Lucas; he had sufferd some sort of damage
    since he could make only gentle left hand turns, but this was
    sufficient to allow an off field landing without further damage.
    The impact hadn't damaged the wing noticeably other than a rip in
    the top covering but the force had been transferrd to the fuse.
    causing a full depth vertical split 4 in. behind the rt. wing and
    a horz. split running 5 in. toward the tail. This resulted in so
    much empennage flexibilty that he lost almost all rudder control.
    He also hand a 2 in. chunk missing out of the left fuse. side just
    forward of the wing trailing edge. Further inspection revealed many
    more little fractures in the left wing.
    So, my first mid-air and it could have been worse but it was DUMB.
    
    My "Vibaro" will inherit one of the servos, giving me full, independent
    flap and aileron control as well as full crow capability for the
    first time, and yet more program settings to fiddle with on my Vision.
    The Vibaro will be ready to go by the end of next week. I was hoping
    to have the Pulsar as a back up at Eloy but will most likely not
    have time to repair it before then.
    
    
    Terry
    

    Terry,
    
    The free-flight/soaring facility is nothing more than an _enormous_
    open field.  The area used for launching/recovering is a very large
    clear area right in the middle of everything and the remainder has
    sparse desert brush, i.e. tumbleweeds, etc. on it.  No hazards or
    obstructions save for high-line wires to the east and north but well
    away from the area in use.  Overall, a good facility _but_ pray for no
    wind; two years ago, the entire S.W.R. was held at this facility and,
    unfortunately, high winds prevailed all weekend which blew gritty dust
    into every nook-and-cranny of yer' equipment, not to mention yer' bod!
    
    Too bad they couldn't save last weekend and reuse it for the contest;
    it was GORGEOUS!  Keep yer' fingers crossed for contest weekend.    

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    Another great flying weather weekend here. Sat. morning I stopped
    by the field sans equipment, being in the throes of a shopping spree.
    While standing around being unproductive, I had an xmtr. thrust
    into my hand and was told to fly his airplane while Max went off
    to flight-ready another one.
    
    Looking up, I saw I was in command of a stock Southwind (poly wing,
    flaps only) cruising at about 800 ft. Very narrow, "stove pipe"
    thermals were fairly numerous so had no trouble cycling from 300
    to 800 ft. several times over the course of 10-15 min. A Riser 100
    at about half my altitude, repeatedly tried to claw his way up,
    but being no match for the Southwinds' tight turning ability, kept
    getting spit out the side. 
    
    Finally Max came back and said I'd better land pretty soon because
    there was only a 250 mil battery on board and he wasn't sure how
    much was left. I immediately thrust the xmtr. upon him, being
    personally terrified of flying with less than 800 mil rcvr pack.
    
    Less than a minute after walking away, I heard several of the dreaded
    crys of "oh no !" and turning, saw Maxs' plane in a vertical dive,
    which carried neatly through the left wing of the Riser which happened
    to be in the wrong part of his circle at the wrong time. After reaching
    about 100 ft. alt. Maxs' rcvr. decided it still had enough juice
    to pull in the now-strengthened signal and Max was able to recover
    and make an immediate and normal landing.
    
    Meantime the Riser bought the soccer field, and Max, myself, and
    the Riser pilot each converged on the wreckage. Peering down on
    it we realized something was missing, and looking up saw the severed
    wing section still in good lift but gradually fluttering down.
    
    Maxs' wing suffered two small dents in the l.e. The Riser is
    essentially a write-off except for one wing.
    
    If this weather holds none of us will have anything flyable beyond
    the end of the month, except myself, who just bought an already
    completed Italian F3B ship. But more on that later when I find out
    more about it.
    
    Terry
    

    re: .276
    
    This past weekend I bought a 2 year old Italian glider, from a club
    member, complete with 4 Futaba servos. All I need to do is pop in
    my rcvr, batt. and fly. It's in perfect shape, as he didn't fly
    it a lot recently and then only on grass. 
    
    It's balanced simply by sticking in a 1200 mil rcvr pack, no additional
    lead needed.
    
    The model is a "Super Rieti", by Avio Modelli of Cremona. The specs
    are in Italian but wasn't difficult to determine that it's a 2.84
    meter span (~112") with an E-205 airfoil and a Ritz 13010 symettrical
    'foil on the stabilator. Haven't measured the root & tip chords
    yet so don't know the area or loading but would guess it's about
    800-840 sq. in. a little smaller than is currently fashionable,
    but it's surprisingly light so doubt it will be much over 10 oz./ft.
    
    The fuse. is "Duraplex" plastic, appears to be some type of
    polyethelene, and noticebly less "flexy" when squeezed unlike the
    late model Graupner plastic fuselages, but not as stiff as the earlier
    Graupner ABS plastic ones.
    
    The wing is foam sheeted with Obechi wood, about 1/50" thick, and
    Frank wisely didn't cover it with anything prefering to let the
    natural color make it's own fashion statement. He did seal it with
    several wipe on coats of clear matt urethane furniture finish.
    
    It's set up with flaps, ailerons, rud, and elev. , flown with a
    basic 4 channel unmixed radio. The hardware is very trick and allows
    all this without a mechanical nightmare. It uses arrow shaft style
    flap hinges, which Frank engineered himself, and it's such a beautiful
    job that it almost restores my belief in that type of hinge. He
    used alum. bushings inside of a micarta shaft, eliminating the thermal
    binding problems often found in arrow shaft hinges. Also incorporatd
    a slick set-screw method of attaching and re moving the flaps.
    
    This weekend I'll be trying 'er out myself, weather permitting,
    and will post results in note 771, which I had previously thought
    to be merely the rantings of a bunch of party goers and general
    carousers....sorry.
    
    Terry
    

    I heard at the club meeting last night that PPSS had lost the use
    of their sod farm as a flying site. Can anyone confirm this and
    provide more details and alternatives, if true?
    
    Terry
    

    Terry:
    I am afarid you are correct. We no longer have access to the old farm.
     We have been scrambling to find a new site, which was beginning to get
    real depressing. Then thee owners of the old site gave us another sod farm
    . Are they nice
    or what? We really appreciate there efforts, especially when they don't
    benefit in any way. They are just very gracious people.
    
    Ron 

Anybody have something to say about the Airtronics Adante?

I've never seen one.

How about some feedback.  If you have never owned one or flown
one has anybody seen one from 50 feet?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Kay,
    
    One of our club members has one and have seen it fly quite a few
    times. I guess he built it in a stock configuration; if so its
    a flat wing aileron bird, with a balsa fuselage and a sheeted, built
    up wing, ie open structure covered with balsa sheet then Monokoted
    on top of that. It's fairly fast and looks like it would make a
    good general purpose slope ship. I'm not at all impressed with its
    thermalling ability as compared to other contemporary designs.
    
    I get the impression that it was sort of a prototype or at least
    a forerunner of the Sagitta. I don't know exactly where it fell
    in Lee Renauds schedule of designs or what its avowed purpose was
    in the Airtronics stable. In short, the Sagitta does it better.
    
    Terry
    

>         <<< Note 399.281 by ELMAGO::TTOMBAUGH "High Plains Drifter" >>>
>                      -< Adante...not terribly impressed >-
>    a flat wing aileron bird, with a balsa fuselage and a sheeted, built
>    up wing, ie open structure covered with balsa sheet then Monokoted

Terry - The only thing I have seen is an two year old Tower add and picture
and it lists it as a fiberglass fuselage and foam wing.  I think
it is now discontinued but I can't imagine what other Airtronics
plane you could be getting it confused with... Perhaps a Top Flight Aquilla?
It (the Adante) is flat wing, flaps, ailerons and spoilers.  I think it has 
an eppler 205.

Maybe your not confused - maybe I am.  Anybody else think they
have seen one?  Sure hate to order a fiber and foam plane and receive
a box of balsa!

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################
    

    The Airtronics Adante is a 2.5m, foam and glass glider.  I don't
    know the airfoil, it is designed to use 5 function control.  I have
    seen it available mailorder from Sheldon's for $142.
    
    Regards,
    
    Jim

    
    
    The Adante is a foam and fiberglass milti-task ship. The controls
    are ailerons, elevator, rudder, flaps, and spoilers. It has a wingspan
    of 99 inches and requires a 4-5 channel radio.  The add mentions
    an Eppler 205 airfoil but it's not clear if it's talking about the
    Adante or the Cumic Plus.
    
    Price for the Adante was $124.95
    
    Steve

    re last few:
    
    I stand corrected on the Adante. I got my info from the owner. Wonder
    now what he actually has.
    
    Kay, since your in that price range already, you might be interested
    in Bob Sealys kits, the 99" Pulsar and the 124" Laser. Pulsar has
    been $150, not sure about the Laser price. These are similar to
    Dodgsons designs, the Pulsar has a wider speed range than the Camano
    for example, and Sealys kits are simpler to build than Dodgsons,
    and use full fiberglass fuselages. The Pulsar can be built with
    poly wing and flaps or flat wing with flaps/ailerons. I built mine
    with flaperons and it worked ok but would go with separate controls
    if I did it again. Being a cottage industry, Bobs' kits require
    a little more custom design and fabrication on the part of the builder
    as compared to Airtronics, but again, less than Dodgson. They're
    available from American Sailplane Designs in San Diego. They advertize
    in Model Builder. What happened to your Windsong project?
    
    Terry
    

>    in Model Builder. What happened to your Windsong project?

I glued the spars into the Lovesong wings last night.  It has
been a fun kit so far - instructions have a few kinks but I'm preparing
a feedback memo to send Bob Dodgson so he can correct (and enhance) the next 
printing.  Mostly obvious were caused by the switch from Windsong spar 
structures to Lovesong spar structures and from the old manual drawings to 
the new CAD drawings.

Sorry for causing needless traffic in the notes file.

I read all the adds on the Adante - I just would like to have
seen one or hear second hand from someone who had.  I'm not actually
in the $130 market for one but might be able to pick one up cheap ($93).
I had not previously been thinking about it at all.  As it stands
I think I will wait and someday get a Camano.  Hard to believe what appears
to have been one of Airtronics top of the line planes is just dying
of atrophy.

Anybody seen an Airtronics Adante?
Anybody got an old list of finishers in NATs events and their planes?
Could be we would see some contest standings with Adante's.
I know usually contest standing says a whole lot more about the pilot
than the plane but at least is would show what the leading pilots
liked to fly.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Since our thoughts seem to be drifting toward new kits to build
    for the upcoming season, I'll throw out a few more examples that
    I'm familiar with (hopefully more so than the Adante !)
    
    Southwind - 99" poly wing, built up, with flaps. A good choice for
    a step up from the Oly/Riser class. Good thermal duration contest
    ship. E-193 airfoil. Uses basic radio, 3-4 chan.  $75 kit.
    
    Westwind - 99" flat wing, foam/balsa sheet. Designed for Sportsman
    F3B and multitask competition. Flaps and ailerons. S3021 airfoil.
    Needs 5 chan. basic radio. Best with mixable or programmable radio.
    $120.
    
    Northwind - 108" flat wing, as above. The only serious attempt at
    a "poor mans" F3B plane on the American market, that I'm aware of.
    Quabek 2.5/10 airfoil. Needs programmable radio for best results.
    Price TBD but will probably be in $140-160 range.
    
    
    Features common to all three kits: ply/balsa fuselage- gives nothing
    away to glass fuselages in terms of appearance and durability and
    is easier to repair. 
    
    Wing mounting is combination of rubber band (internal) and nylon
    bolts sized to shear on impact. Gives good combination of tight,
    clean installation and crash protection.
    
    
    Two nits I have to pick: wing incidence angle is at 0 degrees with
    reference to fuse. center line. Can't explain my objection, but
    this seems intuitively less than optimum. They use flying stabs
    (stabilators) of course so avoid decalage problems, and they fly
    great so who am I to complain. 
    
    Stabs are built up from 1/4" stock so are essentially flat plate
    airfoils, and I *know* that that is less than optimum. This could
    change in future at least on the Northwind. Look for NACA 0009 or
    SD8020 foam 'foils.
    
    Future additions to the line will include the Crosswind for guess
    what kind of competition; and, if we can talk Max into it, the 
    Breakwind for a TBD type of event.
    
    Terry
    

From this months Model Aviation - Copies of Hans Mueller's glider catalogue
can be had by sending 3 stamps to 
    Byron Blakeslee 
    3134 N. Winnebago Dr.
    Sedalia, CO 80135.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

I found this in the UUCP net.  This has been covered in several
other publications in the past but this is the first instance
of it being in machine readable form so I thought I would bring
it here.  Just in case you have no idea what he is talking about
I will preface it a bit.  A Total-Energy device is something
that full scale gliders use to determine if they are in lift.
They also have regular rate of climb indicators and they are
the moral equivalent of our thermic snifflers.  So the idea
is to modify your thermic sniffler into a total energy device.

Now more to the point.  The problem with rate of climb indicators
and thermic snifflers is that when you wiggle the stick the
output changes.  If you feed in down stick the plane dives and
the rate of climb indicator drops (or the sniffler lowers it's
tone).  If you pull back on the stick the rate of climb indicator
goes up (or the sniffler raises it's tone).  What is wrong is
you are not getting any indication of whether you are in a thermal
or not - you are just hearing stick noise.  Next time you are
at a glider contest find a contestant with a sniffler and listen
in.  You will wonder how they can tell anything because the
tone is changing all the time.  

So what you do is instead of just sensing the barometric pressure
change you run a tube out the airplane into the airstream and
try to sense air speed and compensate with that.  If the plane
is diving the airspeed goes up and with the tube outside with
the holes in the aft part the venturie(sp) effect causes a decrease
in pressure which is opposite the normal increase in barometric
pressure.  If you get luck they are exactly equal and you will
hear no difference in tone.  If airspeed compensation is accurate
then when the tone goes up you are in a thermal.

Now the UUCP net info:

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################
From: [email protected] (~Dave Regis)
Subject: Total Energy Probe
Date: 26 Jan 90 07:38:56 GMT
 
Howdy, 
 
I bought an Ace Thermic Sniffler while at IMS a few weeks
back and have received the information I requested from
them regarding the total-energy tube (seen on x-country
ships in RCM or MA recently).
 
As they suggest:
 
  You need a 4-5" length of 1/8" brass tubing.  Cap the 
  end to be outside of the airplane with hot-glue, solder,
  epoxy (etc).  3/8" below the top, drill two holes 90
  degrees apart from each other with a #79 or #80 drill.
  Make sure the holes are very clean and free of burrs
  inside and out.
 
  A small piece of foam should be inserted in the lower
  end to prevent turbulence generated in the holes from
  reaching the TS.  This is a trial-and-error step according
  to the article, sorry.  They do suggest setting it up
  so if you were to draw a vacuum, it would take 1 second
  for the vacuum to decrease by half.
 
  The tube should be situated between the wings so the
  holes are aiming rearward, 45 degrees from spanwise;
  about 2" of the tube should protrude from the fuselage.
  The 2"s is to keep the probes openings out of the 
  boundary layer.  Make certain the holes are located 
  45 degrees either side of the fuse centerline and that
  they are facing aft.  The probe will not work if this
  relationship is not maintained.
 
  Connecting the bottom of the tube to the TS should be
  an appropriate length of fuel tubing.  The article
  suggests chamfering the end connecting to the TS to
  allow it to slip over the intake easier; bond with
  adhesive of your choice being VERY CAREFUL not to allow
  glue to enter the intake orifice.
 
  The article claims the probe will generate less than 2%
  of max drag on planes of about 1000 sq.in.  At max L/D
  the drag is less than 1%.
 
Confused?  It's hard to illustrate with text graphics, so
if you want copies of the info, either email me or talk to
Ace.  The folks there are very willing to help.
 
I haven't had a chance to try the TS out let alone the total
energy system though I might this weekend...reviews to follow.
 
Dave Regis

        Re:         <<< Note 399.289 by K::FISHER "Only 47 Days till Phoenix!" >>>

                I did  it!    Yesterday I stopped by a hardware store and
        bough the right  size  drills.   I had brass tubing.  So when the
        news were over I donned my jeans and went out into the workshop.
        
                I  decided  to put  the  tube  right  behind  the  canopy
        sticking right up.  I  made  it  a  bit  shorter  than suggested,
        simply because I know that the  boundary  layer  isn't two inches
        thick.   The holes were easy enough  to  drill  in  the  tube  by
        holding it in a vice with a couple of lead strips.
        
                The hard part was modifying the sniffler.   First I tried
        to epoxy a piece of brass tubing directly onto  the  outlet.   It
        quickly  became apparent that I would end up filling the  pinhole
        with epoxy, so then I decided to tear the sniffer apart  and  see
        if there was an easier way.  To my pleasant surprise I found that
        they had a short length of fuel tubing connecting the sensor with
        the outlet  nipple.    By  removing  the nipple and interting the
        brass tubing through  the  hole  into  the  fuel  tubing and then
        sealing the hole around  the  brass  tubing  with  epoxy  I  have
        something thats sturdy and leak  proof.   After wedging all of it
        back into the plane I powered the sniffler up and was relieved to
        hear the tone rise and lower as  I  moved  the  plane.  The next,
        really crude, test was to blow on the  tube  sticking  up through
        the fuse and lo, pitch went up, so the  venturi effect was there.
        It  was late at night and the basement is too  small  for  flight
        testing, so I still don't know whether it REALLY works.
        
                It was  amazing  that the whole modification process took
        only about an hour.
        
                Cant wait for the weekend!
        
                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

    I have a few questions for Mark Antry.
    Been meaning to ask you this for a while Mark, but did you buy your
    King from Ben DeMeter ? I saw the list of that bunch of planes that
    he had advertized in RCSD, and I think that a King was among them.
    Incidentally, he bought a German F3B plane that was hanging from
    the ceiling of the local hobby shop for a while. Don't recall
    the type but it included 4 Becker servos and I think the asking
    price was $450.
    
    Also, how is the King for a general purpose sport flier? That is,
    can you launch it with a suitably stout hi-start, or is anything
    less than a winch courting disaster?
    
    I sent for the Mueller catalog from Byron Blakeslee (thanks for
    pointing that out Kay, I'd overlooked that item in MA.)
    So we'll see what he's got. I'm just about burned out on building
    for a while. Can't remember an evening when I wasn't hunched over
    the bench since Oct. Got my new stabs sheeted and weighted down
    in the cores last night. Tonight will slap on l.e. , sand and cover.
    
    Terry
    

    Yes, right now my King is my primary ship and it was Ben DeMeter's old
    plane, I stipped down the Fuse and rebuilt it, patch a couple of dings
    in the wing and its a screamer now.  After flying a plane like that it
    will do anything any other plane will do and I plan on flying it 100%
    of the time until our club finishes our F3b project plane the ICON
    which will have a RG15 airfoil and Mueller comet fuselages made out of
    Kevlar(talk about a nice fuse), then I will be flying that.
    
    The King is a bit heavy to fly in F3b this comming cycle it weighs
    about 100 oz's  I know everyone just let out a big sigh, but I was out
    flying last week with about 3" of snow on the ground and granted it was
    only my 7th or 8th flight and I was getting around 5 min flights
    without trying.  Who says those lead F3b ships wont thermal with the
    polyhedreals.
    
    At 100 oz's I think that answers your High Start Question.  Now you can
    buy those expensive bungie ones but you would probably need help in
    stretching it back.  launching the King I can even stall out our club
    winches, they have a chain drive that goes between the motor and the
    drum shaft and that adds quite a bit of drag.  To Launch the King you
    step up, connect the tow line, lean back holding the King like a
    javelin, hit the winch, let it build up tension until the winch stalls
    and then give it a heave and say "Geeeez look at that thing go!!!!!",
    it is great to fly.  Once you get used to Aileron planes they are so
    much fun to fly, even up there thermaling.    Can you tell I love this
    plane!!!!
    
    
    The King is sure a joy to fly and now I am considering selling my 120"
    LJMP Pantera because I dont really have a desire to fly it
    
    
    Wish I could get out and fly before the SWR......
    

    Thanks for the info Mark.
    At 100oz., that would rule it out for Sportsman F3B events as presently
    constituted, as they specify 75 oz. max, but that's up to local
    discretion sometimes and I'm not sure what AMA multitask rules say
    about max weights. I've seen Steve Works Comet fly so I can agree
    about the flying characteristics of full bore F3B ships. I have
    a high start that can handle 100 oz. okay. Max Mills has a 16 ft.
    scratch built monster, with a fuselage volume large enough to hold
    a cat, litterally. No we haven't tried it ! It weighs about 108
    oz. and my high start is the only thing other than a winch that
    will get it up, trauma free. I don't use it much myself as holding
    on to the darn thing under tension is just too much work.
    Got my new stabs done last. They come out at 5 grams per half lighter
    than the stock stabs, but the amazing thing is that they are only
    .5 grams different in weight between the two. I couldn't get that
    close again in a million years.
    Snow here today, but weekend is looking good for a few test flights.
    
    Terry

Some interesting stuff about Aspect Ratios from the UUCP net.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

From: [email protected] (Wayne Angevine)
Subject: RC Sailplane Aspect Ratio
Date: 1 Feb 90 17:01:45 GMT
Sender: [email protected]
 
I have written this article in response to a question on the soaring
mailing list, but I've also posted it to rec.models.rc and sci.aeronautics.
The sci.aeronautics people may be interested in some of the tradeoffs
that go into the design of an aircraft with this particular set of
constraints, and some of this could even apply to RPVs or other "real
work."  I've taken an exclusively empirical approach, unsullied by
any actual mathematics :-).  I've also tried to look at the whole
system and all aspects (pun intended) of the task.
 
The question was, "What is the maximum practical aspect ratio for a
radio-controlled sailplane?"  The motivation for the question is the
observation that induced drag is inversely proportional to aspect
ratio, all other things being equal.
 
There is a competing school of thought which asks the question,
"What is the *minimum* practical aspect ratio for a radio-controlled
saiplane?"  These people have had some notable successes, particularly
in span-limited classes, but I won't address that in this article.
 
For several reasons, small chords are a problem.  The reasons are:
1) Reynold's number - proportional to chord.  This can have large
   and grossly non-linear effects in the range in which most RC
   sailplanes fly.
2) Thickness - proportional to chord for a given section.  The
   strength of the section is proportional to the square of the
   thickness.
3) Accuracy - it seems to me that the performance impact of 
   inaccuracies in the construction of the wing will increase as
   the chord gets smaller.  I'm talking about errors like waviness
   or simply not having the exact profile on your rib or template.
   The absolute magnitude of the errors will be approximately
   constant, so the magnitude relative to the thickness will be
   greater at smaller chords.  This may be offset to some extent
   by the lower Reynold's number I mentioned above, since errors
   may matter less at lower Reynold's number.  Accuracy is critical
   to the performance of modern laminar-flow airfoils.
 
Given all these difficulties, it seems to me that the minimum practical
chord is six to seven inches.  If so, the maximum practical aspect 
ratio would be 13/1 at two meter span, up to 20/1 at 120" span.
 
Let's look at another question:  If high aspect ratio is so good,
how come you (almost) never see a plane which is outside the "normal"
range?  The "normal" range is from about 8/1 for some 2-meters to
13/1 or so for unlimiteds.
 
RC sailplanes have to do several things besides glide.  In particular,
they also have to launch, land, and be controllable from the ground.  
 
Safe launching depends largely on absolute weight, because the launching 
person and launch equipment have to be able to accelerate the plane to 
safe flying speed before it leaves the launching person's hand.  The
practical limits today seem to be around 12 oz/sq.ft. wing loading
for launching on a "normal" winch, 9 oz/sq.ft. for high-start launches, 
and quite a bit higher for launches on an (old-style) F3B winch with
highly trained crews.
 
High launching, at least as currently practiced, depends on the ability 
to pull many, many Gs during the zoom (ping) phase of the launch.  I 
have heard numbers like 30-40 Gs bandied about, but I've never seen a 
measurement.  It's also handy to be able to handle wind gusts, clumsy 
pedal feet, etc. without blowing the wings off (believe me, I know.)
 
There is a three-way tradeoff between strength, weight, and complexity
in any structure.  The higher the aspect ratio of the wing, the stronger
the structure needs to be.  In practice, this means that, to achieve
the same ability to pull Gs, the wing must be both heavier and more 
complex than a wing of the same area with lower aspect ratio.  By 
"more complex" I mean that it must be made of more exotic materials 
and with more exotic processes.
 
Strength also is important during the landing phase, particularly if
the landing area is not perfectly smooth.  Tearing the wings off by
catching a wingtip is not the way to have a nice day.
 
To control the plane, you must be able to see it.  People I have 
talked to in the RC cross-country game say that chord is more important 
than span for visibility.  The possible loss of performance from poor
ability to control the plane accurately could be quite large.  Furthermore,
a wing of higher aspect ratio requires more precise control, since
the derivative of lift coefficient with angle of attack is steeper.
 
I think another reason we don't see high aspect ratio sailplanes is
that the performance of RC sailplanes today is sufficient for the
tasks we fly.  The only subfield which needs ever-greater plane
performance is F3B, and the primary need there is for speed, not L/D.
In fact, I think that an argument could be made that the improvement
in performance of F3B planes has leveled out in the last several years.
The pilots keep getting better, though.
 
Does anyone have any other thoughts?
 
    Wayne Angevine		[email protected]
    Boulder, Colorado		{uunet,boulder,nbires}!cadnetix!waynea

From: [email protected] (Al Bowers)
Subject: Re: RC Sailplane Aspect Ratio
Date: 2 Feb 90 21:51:22 GMT
Sender: [email protected]
 
In article <[email protected]> [email protected] (Wayne Angevine) writes:
 
>The question was, "What is the maximum practical aspect ratio for a
>radio-controlled sailplane?"  The motivation for the question is the
>observation that induced drag is inversely proportional to aspect
>ratio, all other things being equal.
 
Some years ago I was posed a similar question which went along the
lines of 'what is the optimum airfoil design'?  While at first this
seems some what unrelated in actual fact knowing the minimum Reynold's
number a particular airfoil can stand will indicate the maximum aspect
ratio.  This question was posed by Mr. Christopher Ray of Swarthmore,
PA and I hope he doesn't mind my using his name or my response to his
question.
 
>For several reasons, small chords are a problem.  The reasons are:
>1) Reynold's number - proportional to chord.  This can have large
> and grossly non-linear effects in the range in which most RC
> sailplanes fly.
 
Exactly, once Re drops below 500,000 things can get weird real fast
and once you are below about 100,000 your options are seriously
limited.
 
>2) Thickness - proportional to chord for a given section.  The
> strength of the section is proportional to the square of the
> thickness.
 
>3) Accuracy - it seems to me that the performance impact of 
> inaccuracies in the construction of the wing will increase as
> the chord gets smaller.  I'm talking about errors like waviness
 
Errors of this sort tend not to be as important as profile shape.
Smoothness is not as critical as you might at first expect, shape is.
If the roughness is buried in the boundary layer it tends not to
affect the results.  Also beware of low speed airfoil codes as they
USUALLY require excessive smoothness for analytical performance which
is not required for high performance in flight.  See NASA TM 86035.
E-mail me if you can't get a copy at your library... (Please excuse
my blowing my own horn concerning the report... ;-) ;-) ;-))
 
> may matter less at lower Reynold's number.  Accuracy is critical
> to the performance of modern laminar-flow airfoils.
 
Not quite true.  The major problem at low Renyold's numbers is getting
the boundary layer to become and STAY turbulent.  This is the reason
for turbulator strips proliferating on hand launched RC sailplanes.
 
>Given all these difficulties, it seems to me that the minimum practical
>chord is six to seven inches.  If so, the maximum practical aspect 
>ratio would be 13/1 at two meter span, up to 20/1 at 120" span.
 
This number is very dependent on the airfoil.  I would expect an old
NACA 6-series airfoil (especially a 65- or 66- series) to have major
problems at these chords on a thermal type aircraft. A slope racer
might get away with it.  Some of the newer class of airfoils may be
able to go to slightly smaller chords.  This can also explain how some
of the old favorite airfoils can be made to work reasonably at these
chord lengths.  Witness Mark's Models Windfree, Clark-Y airfoil
(turbulent) and an aspect ratio 18 (chord of 5.6 inches).
 
>There is a three-way tradeoff between strength, weight, and complexity
>in any structure.  The higher the aspect ratio of the wing, the stronger
 
You obviously understand the challenge...
 
>I think another reason we don't see high aspect ratio sailplanes is
>that the performance of RC sailplanes today is sufficient for the
>tasks we fly.  The only subfield which needs ever-greater plane
>performance is F3B, and the primary need there is for speed, not L/D.
 
L/D is speed.  All you need for speed is a higher wing loading, if
you're at the same lift coefficient L/D will be the same to a first
order of magnitude approximation.  Reynold's number will play a part
but will be secondary as long as you aren't operating at the Reynold's
number of an under priviledged butterfly. ;-)
 
Newer airfoils that may assist in this area are from the Eppler and
the Horstmann-Quast series.  Some of the Ritz airfoils may also be of
use.  I wish I could give you a better source but there is a gentleman
at Arnold Engineering Development Center (AEDC) by the name of Chuck
Anderson who has advertised the availability of some of this
information.  I will see if I can contact Mr. Anderson and perhaps
post a followup.
 
--
Albion H. Bowers  [email protected]  ames!elxsi.dfrf.nasa.gov!bowers
         NASA Ames-Dryden Flight Research Facility, Edwards, CA
                  Aerodynamics: The ONLY way to fly!
 
                     Live to ski, ski to live...

    Spent 4-5 hours over the weekend in a tedious trim session with
    the Rieti, my last chance before the SWR. Clear and in 40's, almost
    dead calm and dead air. A bunch of 1-3 minute flights as I experimented
    with flap/elev. mixing trying to get good launches with a medium
    weight hi-start. All launches were sluggish but finally settled
    on 15% flaps and neutral elev., feeding in a slight amount of down
    trim on the last half of the launch. This plane definitly prefers
    winch launches, but once up can hang in with the floaters. With
    a common servo for both ailerons, versatility is less than I prefer
    but the Vision allows for independent up travel volume under such
    conditions, and I cut back on UTV several times before reaching
    a point that minimized dropping the inside wing too much in a turn.
    
    The new gray foam stabs worked ok and look a lot better than the
    stock stabs. Sheeted with 1/32 balsa their weight is within a gram
    of the stock stabs ( white foam sheeted with 1/50 Obechi) and are
    6 sq. in. smaller, so I'm convinced gray foam is feasible for small
    sevices at least, but may be too heavy for wings. The bare cores
    weigh 7-8 grams per half vs. 4-5 grams for identical white foam
    cores.
    
    Needing a back up plane for SWR, I took the old faithful Cirrus
    off the wall and installed my new 6 chan. PCM. Sort of overkill
    since it only has elev., rud., and spoilers. But since the SWR
    has no speed events the Cirrus will hold its own against modern
    stuff, provided the wind doesn't blow next weekend. I might
    even fly it as my primary plane depending on the competition.
    
    Terry
    

    Terry: I may bring my old Cirrus as a back up too! It might even be fun
    to fly.
    
    Ron 

Little Sloper notes from the UUCP net.

Bye          --+--
Kay R. Fisher  |
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From: [email protected] (Dylan McNamee)
Newsgroups: rec.models.rc
Subject: Re: Small slope ships
Date: 8 Feb 90 20:22:07 GMT
Organization: University of Washington, Computer Science, Seattle
 
In article <[email protected]> [email protected] writes:
>this...]
>
>What's the minimum size slope soarer anyone has tried?  I am aware of
>the "pee wee Penetrator" made out on the west coast which has a 28"
>wingspan.  I'm toying around with the idea of converting a F-18
 
At my favorite slope behind Pacifica, (south of SanFrancisco) I saw
a guy slope soaring a TINY Mustang gas plane, from which he removed
the engine.  The winds at this place were very strong (about 30-40 mph)
and this thing was extremely mobile and maneuverable.  The wind was
even strong enough to make my 9 times broken, 5 pound Ridge Rat fly well.
 
>Hornet balsa kit I just picked up to a slope ship (for those interested,
>it's a "Todays Hobbies" kit, 20" span, scale outlines, see the
>December issue of _Model Aviation_ for their ad).  With a 100ma pack,
>2 Futaba S-33 servos, the R/C flight pack should be under 5 ounces.
>I figure thus that I need to keep the airframe weight under 5 ounces
>or so to have a reasonable wing loading.  Am I dreaming?
 
Not at all.  In my experience, with good winds and lift, just about
any plane will glide well.
>
>					Bill Tsang
>					[email protected]
dylan mcnamee
[email protected]

    No one else attending the S.W. regionals has seen fit to enter a
    report so here goes. More may follow time permitting.
    
    First off, I got to meet many of the legends of model aviation there,
    The ol' desert rat hisself of course, Eric Henderson driving a Pontiac
    (nice touch) and the Colo Springs crowd, Mark Antry, Ron Watts,
    and other Deccies and non-Deccies from the Springs.
    
    Weather was absolutely perfect all weekend. Virtually dead calm
    on sat. a little more breeze on sun., still under 10 mph most of
    the time. Flying site resembled a dry lake bed, no obstructions
    within sight. Thermals were present but not real good, certainly
    adequate for 7 minute duration flights if you were an expert pilot
    which of course we all were. I even got a 5+ minute flight on a
    couple of rounds. Some of the C.S. guys were right up there in the
    standings, John ? finished in 2nd on sat. Ben DeMeter was in the
    top 10 (out of 52 on sat. and about 55 on sun.) Ron Watts finished
    well up in the top half, Mark and myself exchanged positions several
    times as the rounds progressed. I wound up in 28th on sat.
    and 42nd on sun. fulfilling my goal of not finishing last.(Aim High)
    Overall winner was Gary Anderson (Amer.Sailplane Design) Flying
    a 3 chan. Pulsar with poly and flaps.
    
    Saw some new high tech fuselages from Ray Olsen, to be marketed
    as the "Spirit", with molded wings later this summer. Seth Dawson
    had a new Muller Comet with Selig airfoil , got some good video
    of his last round flight.
    
    All in all an excellent weekend was had by all and hope some more
    Deccies can plan a winter vacation around the contest. I know
    I'll be there again next Feb.
    
    Terry
    

This funny one from the Flying notes file.

Bye          --+--
Kay R. Fisher  |
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################################################################################
================================================================================
Note 2298.60              In-flight Emergency at Nashua                 60 of 60
CAM::BERMAN "integration or altercation?"            12 lines  13-APR-1989 12:55
                          -< Mind if I play through? >-
--------------------------------------------------------------------------------
    This is getting a little off the subject, but: When I was flying
    gliders in upstate N.Y. I heard a story about a guy who chose a
    golf course as an off-field landing spot during a contest (sailplane
    racing). As some of you may know, a racing sailplane flying at the
    speeds appropriate to short final is a very quiet beast indeed, so
    the golfers on the fairway didn't notice this guy coming down behind
    them. His solution?: He opened up the canopy and yelled FORE!! at
    the top of his lungs and was rewarded with a satisfactory scattering
    of groundhogs.
    
    FWIW,
     - Mark
    Overall winner was Gary 

    I am contemplating building a scale glider, probably a vintage model
    such as a Grunau(sp) Baby.  This is one aspect of this conference
    that no one else seems interested.  Has anybody attempted a scale
    glider project?  I would be curious to hear about the results.
    
    Regards,
    
    Jim

    I think some of us are interested in scale gliders. As for myself,
    I can't seem to spare the time from other projects, that I know
    will have a better chance for success. My last scale attempt 15
    years ago with a Multiplex Ls-1, wasn't too impressive for all the
    predictable reasons.
    
    Jim if your contemplating building a Grunau Baby (is it the Klaus
    Krick kit that Hobby Lobby sells ?) I for one would be real interested
    to hear of your experiences. The old vintage gliders make better
    scale subjects, in terms of a more versatile flight regime, in that
    they are easier to fly on flat land and thermal conditions, whereas
    the more modern fiberglass & composite ships work better on the
    slope. Trying to build an exact scale modern design can be a real
    challenge. The scale wing chord becomes so small that construction
    techniques must be very advanced to achieve any kind of strength,
    while the wing loadings are high and the Reynolds number low.
    Exactly the conditions to guarantee max trauma. That's one of the
    reasons most scale gliders are as large as possible.
    
    There's a guy in Britain, Cliff Charlesworth I believe, who is well
    known for his excellent set of plans for various vintage gliders.
    If you don't mind scratch building, his are as impressive as your're
    likely to see.
    
    Terry
    

    TOM,
    
       I would probably be interested in scratch building my vintage
    glider because I do not want to spend $200+ for plans and balsa
    wood.  I have Cliff Charlesworth's literature, but there are two
    problems with building one of his designs.  The first is the cost
    of the plans which runs in excess of $50 because he requires payment
    in pounds sterling, necessitating a bank draft($15+).  The other
    slight problem is most of Charlesworth's designs are 1/4 scale which
    translates to ships with 12+ foot wingspans and can be hard to launch
    due to the corresponding weight.  I have toyed with the idea of
    building from a 3-view photo, blown up to around 100-120 inches.
    
    
    Regards,
    
    Jim

    A belated thanks to Hartmut for giving us all that information on
    the electric gliders, last month. I for one, didn't expect you to
    go to so much trouble.
    
    But, here's some more questions, that hopefully you can answer without
    so much research:
    
    please confirm or deny the accuracy of the following translations:
    
    Querruder= aileron
    
    Landeklappen= spoilers mounted on top of the wing
    
    Wolbklappen = conventional trailing edge flaps
    
    Storklappen= small flaps that pop up vertically like trailing edge
    spoilers
    
    gleiche Ausfuhrung = ?
    
    Hohlkehle = ?
    
    I have a catalog from Hans Muller, and if and when I ever order
    anything from him, it would be nice to know if some of my translation
    understanding is correct.
    
    My catalog is dated March 89, would you happen to know if his prices
    are still about the same. For example, he lists the lowest price,
    with minimum options, of a Comet at DM 780 and a Cobra T, 3.36 meter,
    at DM 720.
    
    Don't go to a lot of trouble to track this info down.
    Thanks.
    
    Terry
    

     Terry,

     here you go:
    
>    Querruder= aileron          correct

         
>    Landeklappen= spoilers mounted on top of the wing

     No. Landeklappen are control surfaces to make landing (Landen) easier.
     This means that they add lift and drag. They can be made in different
     variations (this means verschiedene Ausf�hrungen). Look (if you have
     a chance) at the FW190 on the January photo of DC aviation calendar. 
     This ship has Spreizklappen, a special version that only deflects on the
     underside of the profile and leaves the topside as it is. 
     In general you can probably say that Landeklappen are what you call 
     'conventional trailing edge flaps'. Note that they are at a 0� angle 
     during normal flight and have usually two down (+) positions to help 
     start and landing.
    
>    Wolbklappen = conventional trailing edge flaps

     mmmmyes. The main difference to Landeklappen is that W�lbklappen are 
     used on sailplanes to adapt the profile. This means there are several
     down (+) positions for thermalling and up (-) positions for speed.
     W�lbklappen function when installed is best working when the ailerons
     are coupled. On real sailplanes this means: If you move the 'W�lbklappen'-
     stick, ailerons and flaps (?) are moving at the same angle. If you move
     the control stick for ailerons, the (2 or 3) trailing edge parts move
     at different angles.     
    
>    Storklappen= small flaps that pop up vertically          yes
>    like trailing edge spoilers                              no

     Storklappen are mounted where the wing is thickest (at the spar). They
     move up vertically. There are versions lying flat in the topside of
     the profile that can rotate, most famous and often used on real sailplanes
     are 'Schempp-Hirth' St�rklappen that are stored vertically in the profile
     and move up. You can even get these in double height, meaning you have
     two sheets (aluminum in most cases) that are stored behind each other
     and, when deployed, one sits over the other. Their job is to disturb
     (= st�ren) the boundary layer, increase the drag and therefore the sink
     rate without rising the airspeed. On some vintage sailplanes they are
     used on both topside and underside of profile, but be aware that they
     are roughly 1/3 as efficient on the underside because of the lower
     boundary layer airspeed.

>    gleiche Ausfuhrung = same type, design, quality, whatever
    
>    Hohlkehle = I'll try to draw it as I don't know how to explain.
     Hohlkehlenscharnier is what is called gapless hinge (I assume).

         _______________ ____
                       //    ---___
             wing      H flap  ___---
         ______________\\____---
                       |
                   Hohlkehle (hollow groove, just found my dictionary)


      Sorry, don't have access to a M�ller catalogue. Nobody here in KBO
      seems to be into F3B. Maybe Hans MUNCSS::Karnitschnik can help you
      here. I would assume that prices grow about 3 to 5 % per year.
      Spielwarenmesse (toy's fair) is just over, so you are probably 
      late if you want to avoid price increase. If you assume that the
      prices are 'about the same', you are probably right. Variations
      in dollar exchange rate are probably higher than price changes
      over a year.

      Hope this helps.

      Regards,
               Hartmut

    Hartmut,
    
    Thanks a lot for your help. This clears up a few points of confusion
    when puzzling out the Mueller catalog.
    
    I have a pair of aluminum Graupner Storklappen that operate just
    like the Schempp-Hirth units that you describe. Graupner also
    makes plastic units that rotate up 90 degrees, driven by a torque
    rod. They call these units 'landeklappen'. In English both units
    would be called spoilers, since they add drag but no lift.
    
    Spreizklappen in English might be called split flaps.
    
    If anyone thinks all this is confusing, try saying "integrated circuit"
    in Navajo.
    
    Terry
    
    

Some modestly interesting stuff from the UUCP net.

Bye          --+--
Kay R. Fisher  |
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Article         2121
From: [email protected] (Steven Philipson)
Newsgroups: rec.models.rc,sci.aeronautics
Subject: Re: RC Sailplane Aspect Ratio
Date: 17 Feb 90 03:01:29 GMT
Sender: [email protected]
 
> > I think another reason we don't see high aspect ratio sailplanes is
> > that the performance of RC sailplanes today is sufficient for the
> > tasks we fly.
 
   Not true.  Competition fliers go to great lengths to maximize the
performance of their aircraft, and technological innovation is a major
part of the game.   If aspect ratio by itself were that important, we'd
be seeing higher aspect ratio aircraft.
 
> 	That seems like the key.  Full-sized sailplanes go to
> 	extreme aspect ratios and high wing loading in order
> 	to optimize cruise performance.  Since an RC sailplane
> 	has to stay local to be seen, it's greatest need is
> 	to work lift rather than to cruise or penetrate sink.
> 	For working lift, sink rate is more important than
> 	glide slope.
 
   I disagree.  First, cruise performance IS important even when
one flies from a fixed location.  Aircraft that attain high L/D at
a high airspeed have a strong advantage in windy conditions (it enables
them to fly further downwind and still be able to return to the field) 
and when there are strong local downdrafts or only isolated spots of 
lift.  Their ability to efficiently move from one thermal to another 
is a big advantage, even when thermals are less than a mile apart.  
"Floaters", i.e. low sink rate, low L/D aircraft, can stay up in very 
light lift, but if they do not launch into lift, they  have trouble 
reaching better conditions (and coming back from there).
 
   Cross-country competition is now the rage in California.  We tend 
to see gliders with slightly higher aspect ratios than for non-X/C 
planes, but they aren't all that much higher.
 
   There are two factors that I believe are responsible for the 
relatively low aspect ratios we see on model sailplanes.  One is
span limitation by contest class.  If a glider is limited to a
relatively small span, it is often more effective to go with a
lower aspect ratio planform than a higher aspect planform of the
same span but with much less wing area, lower Reynolds number, etc.
A higher aspect ratio with the same wing area might be more efficient,
but you can't go to the higher span due to the span limit for the
class.
 
   Second, structural considerations are very important.  The aircraft
has to withstand very heavy launch loads (20 g loads are common), be
resistant to "ground contact", and avoid flutter during both launch and
high speed cruise.  These goals are more difficult to achieve with
high aspect ratio wings.
 
						   Steve
					(the certified flying fanatic)
					    [email protected]

Article         2135
From: [email protected] (Al Bowers)
Newsgroups: rec.models.rc,sci.aeronautics
Subject: Re: RC Sailplane Aspect Ratio
Date: 20 Feb 90 17:05:14 GMT
Sender: [email protected]
Organization: NASA Dryden, Edwards, Cal.
 
In article <[email protected]> [email protected] (Steven Philipson) writes:
 
>> > I think another reason we don't see high aspect ratio sailplanes is
>> > that the performance of RC sailplanes today is sufficient for the
>> > tasks we fly.
 
>   Not true.  Competition fliers go to great lengths to maximize the
>performance of their aircraft, and technological innovation is a major
>part of the game.  If aspect ratio by itself were that important, we'd
>be seeing higher aspect ratio aircraft.
 
I'm afraid I have to disagree.  Aspect ratio is only one part of the
total equation.  If you are flying a slow flying airplane then you
have to balance area (or lift coefficient) against aspect ratio
(induced drag).  This is also true of faster designs.  The trade offs
are well known, and the limits of Reynold's number prevent higher
aspect ratios from being flown in today's 'typical' RC sailplane.
Once Reynold's numbers drop below about 60,000 to 100,000 there just
isn't anything you can do to sustain attached flow over wings.
 
>> 	That seems like the key.  Full-sized sailplanes go to
>> 	extreme aspect ratios and high wing loading in order
>> 	to optimize cruise performance.  Since an RC sailplane
 
.... deleted ...
 
>   Cross-country competition is now the rage in California.  We tend 
>to see gliders with slightly higher aspect ratios than for non-X/C 
>planes, but they aren't all that much higher.
 
>   There are two factors that I believe are responsible for the 
>relatively low aspect ratios we see on model sailplanes.  One is
>span limitation by contest class.  If a glider is limited to a
 
Span is relatively insignificant as a factor.  Construction techniques
can keep wing loadings relatively constant.  The major problem is
Reynold's number.
 
.... deleted ...
 
>   Second, structural considerations are very important.  The aircraft
>has to withstand very heavy launch loads (20 g loads are common), be
 
I must be misunderstanding what you guys are refering to as 'launch
loads'.  I think of loads due to g as acceleration loads, I think what
you are refering to is wing root bending load due to the downward pull
of the high start or winch.  In this case it is an equivalent load.
Static load tests of aricraft are normally done in this manner, but is
not a 20 g load.  A 20 g load would load up the servo and radio pallet
by 20 g's also which this kind of load does not.
 
--
Albion H. Bowers  [email protected]  ames!elxsi.dfrf.nasa.gov!bowers
         NASA Ames-Dryden Flight Research Facility, Edwards, CA
                  Aerodynamics: The ONLY way to fly!
 
                     Live to ski, ski to live...

Article         2137
From: [email protected]
Newsgroups: rec.models.rc,sci.aeronautics
Subject: Re: Towline release stresses (was: RC Sailplane Aspect Ratio)
Date: 21 Feb 90 03:25:52 GMT
Sender: [email protected]
Organization: UC, Santa Barbara. Physics Computer Services
 
-Message-Text-Follows-
In article <[email protected]>, [email protected] (Al Bowers) writes...
>In article <[email protected]> [email protected] (Steven Philipson) writes:
> 
>.... deleted ...
> 
>>   Second, structural considerations are very important.  The aircraft
>>has to withstand very heavy launch loads (20 g loads are common), be
> 
>I must be misunderstanding what you guys are refering to as 'launch
>loads'.  I think of loads due to g as acceleration loads, I think what
>you are refering to is wing root bending load due to the downward pull
>of the high start or winch.  In this case it is an equivalent load.
>Static load tests of aricraft are normally done in this manner, but is
>not a 20 g load.  A 20 g load would load up the servo and radio pallet
>by 20 g's also which this kind of load does not.
> 
 
2c worth from a newcomer to these groups, but a lifelong RC sailplane 
enthusiast .. I suspect Albion Bowers may be misunderstanding the point
here (and perhaps also about the span limitation on contest classes?).
 
Competition fliers have developed a particularly keen trick of using
very high power winches to wind in the model over the second or two
immediately before launch; the loss in potential energy is made good
by both additional kinetic energy over that due to the height loss,
and (I guess) strain energy stored in the bending of the wings.  This
energy is recovered by hitting up elevator sharply just as the plane
is released.  Both the reeling in *and* the sharp change of attitude
involve very high accelerations - they are an essential part of the
trick, the purpose of which is to gain additional altitude.  You stand
no chance at all in international competition unless you use it!
Accelerations of 10-20g associated with this phase are widely quoted.
 
Forgive me if this point is already well known to you!
 
My question: I have never seen any source for these figures, although
back-of-envelope calculations and sight of the planes would support
them - I would be interested to hear of them.
 
Russ Evans, Forth Valley Soarers, Edinburgh UK

    Does anyone have any tricks to keep barn door type spoilers made
    from trailing edge stock down flush?  I am putting the finishing
    touches on a Dynaflite Apogee which uses dacron thread to pull
    the spoilers into the up position.  I have thought about trying
    to use small magnets to hold the spoilers down tight to the wing
    when not in use.
    
    Thanks,
    
    Jim 

    I've used springs made from twisted music wire. They seem to work well.
    It's hard for me to describe , but I'll try. Mount a small dia. tube,
    say 1/16" and 1/2" long on the side ofa rib close to the end of the
    spoiler by. the tube should be parallel with the bottom wing surface
    and half way between the top and bottom skins. The front of the tube
    should angle down slightly. Mount another tube of the same size on the
    underside of the spoiler. This tube is parallel to the other tube, but
    is 1.5 rib bays away. Then bend the music wire so that it looks like
    this...      |                      |
                 |______________________| 
    You then twist the wire so that is looks like this...
    
                 |
                 |______________________
                                        |
                                        |
    
    This gives it some spring tension. Then slip the ends of the wire into
    the tubes you just mount and you have spring loaded spoiler. It may
    take some trial and error to get the tension and location right. 
    
    I' have also used magnets with some success. 
    
    Ron Watts
    

    At the WRAM show, there was a spoiler assembly on display which used
    latex hinges that were self closing.  The spoilers were made of sheet 
    the same thickness as the wing sheeting, and strips of 1/4" wide latex
    were attached to the underside so that opening the spoiler put tension 
    on the hinge.  I think it was at the ACE booth.
    
    
                Sheeting          Spoiler
          __________________ __________________ _________________
          _________________| |________________| |__________________
                    ========----=====
                             |  /
                             |_/- - - - - -  Thread    
                          Control horn
    
             =====  Latex strip bonded to sheet
             -----  Unbonded latex
    
    You might be able to use pieces of ordinary rubber bands, but I really 
    don't know.
    

    Gee, I am surprised Ron would mention the music wire method.  I know he
    is using the magnets on his Pantera as I am. (it was his idea)  I tried
    the Spring method and yes it closes the spoiler just fine the trouble I
    had was that the tension increased as you opened the spoiler to the
    point that I could not get the spoiler to open as far as I would like.
    
    
    The magnets work just fine.   The normal way though was to put a magnet
    on the spoiler and then a pan head screw in the plane.  Ron came up
    with the ingenious idea of why not use two magnets?   Put a magnet on
    the spoiler blade and one inside the spoiler compartment.  Try to get
    the two magnets as close to each other as possible when the spoiler is
    closed and if the two magnets touch all the better.  The magnets give
    you just what you want in a closing mechanisim.  The closer they are
    the stronger the pull, as the servo opens the spoiler the magnets break
    their attraction and it gets less as the spoiler opens.  Its need to
    see the spoiler go closed and then "click" as the magnets go together
    and lock the spoiler down tight.  The attraction of the magnets is not
    enough to even notice as the servo is opening them.  The torsion
    springs on the other hand, some people have wondered if that was too
    much torque to ask for out of a servo.
    
    Any questions just ask
    
    Mark Antry
    

    The latex would work OK but here again, like the torsion springs the
    force increases as you open the spoiler, why bother, use magnets they
    are just the opposite, the force gets stonger as they get closer.  How
    about a picture.
    
    
                  spoiler
    ------------++++++++++++-------------------  top of wing
                       @@@@  magnet
                       @@@@   other magnet
                       ****
                       ****  Shim stock to get the magnets close together
    -------------------------------------------   bottom of wing

For some reason Radio Shack seems to always have a bucket of little magnets
next to the register. I've also seem magnetic sheets that can be cut to shape
with regular scissors in craft stores. You could cut strips from this and
have a longer contact point or several smaller ones...

The problem with magnets is exactly what you think is an advantage.
They will stick too good and you won't be able to open the spoilers
without a POP.  But worse that that.  The reason you want tension on
the spoilers when they are open is so that you can close them.

The Magnets may make sure they go all the way down and make a good seal
but that is only half the problem.  I have seen several gliders go 
completely out of control just off the winch release because the spoiler
popped up and the spin turbulence kept it locked up.  If for some
reason you get a spoiler up and in a spin the wind will push back on
it and you go into a death spiral.  I have never had this happen but
I have seen it happen to some pretty experienced glider pilots.  They
start yelling "I'm getting hit!"  then a few seconds later they
recover and have a normal flight.  

I favor the torque rods but when I put them in the Sagitta I used 1 diameter
too small a rod and after bending the spoiler open too many times
to adjust the string and clean the grass out I bent them so they don't
pull the door shut tight any more.  So I added a rubber band to each
spoiler and they snap shut nice now.

Bottom line - make sure you have something that forces the spoiler
down from it's most extended position - don't assume air flow will help.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Nice try Kay but NO GOOD!!!!!!
    
    Unless you have some nice stretchy cord for your spoiler cord there
    will be no POP, even if the magnets are touching when the spoiler is
    closed.
    
    Also the magnets are heavy enough when the one is attached to the
    spoiler bay that there will be enough force to close them, assuming
    that you are not inverted.
    
    One thing you have to be carefull with is to watch the thickness of the
    tape or other mateireal (sp) that you use to attach the spoiler blade
    to the wing with.  some of the thicker tapes have too much memory in
    them and when the spoiler is bent up in open position there is some
    resistence for it to go back to the closed position just because of the
    tape(this is common with the clear insulation tapes).  I use just plain
    scotch tape and I would imagine monokote would be fine provided you
    dont get alot of stretch accross the joint when you srink it.
    
    GO with the magnets, I've tried both and will never use springs again.
    
    Radio shack part number for the magnets are 64-1880 1/2" Button magnet
    18 cents each

    I went to Radio Shack this morning and purchased a roll of magnetic
    tape which looks like it will work just fine.  The local store only
    had the 1/2" buttons which were to heavy.  Thanks for the information.
    
    Regards,
    
    Jim

        Ron,
        
                I missed  three weekends.  One because of weather and two
        because of vacation.    Anyway,  I need to repair a little bit of
        landing damage at the  wing  rods where they go through the fuse.
        This is only about a 30 minute job.  Then I plan to trip the E204
        wings to see how well that  works and finally when the Airtronics
        Vision SP comes back on a usable  frequency  I'll  install it and
        start flying with the vacum bagged wings again.
        
                I did fly with them one weekend in  windy  conditions and
        with  a  regular 4 channel radio, therefore no mixing.    It  was
        challenging to say the least, so I think I'll put  the foam wings
        on the shelf until the SP in installed.
        
                The  combination  of  E204 and RG15 wings is really neat.
        The E204  wings  have  excellent  sink,  I get about 3 1/2 minute
        still air time.   The only other plane I have that's better is my
        32 ounce Oly II,  which I can hold up for 4 minutes in still air.
        With the RG15 I have  superb penetration.  On the windy day I was
        able to go off the winch  and  then  upwind  to the far side of a
        hill and slope for about 10 minutes.    Forget  that with an Oly.
        The main challenge is to get it down  on the ground in one piece.
        It is HEAVY, I suspect about 70 to 75 ounces!
        
                I plan to cut a set of E216 wings  for 120 inch wingspan.
        With  the  three wings I should have a single plane  for  a  wide
        variety of conditions.
        
        I'm  having  tons  of fun, and one of these days I'll  paint  the
        fuse!
        
                      _ 
                     / |
           _----____/==|
         /__====------- 
             |-          
            /              
           /               
         Hang in there!      
                           
             Anker           

    Well this is the first winter in two years I have not been able
    to fly.  Upstate NY weather can be pretty bad and it has been every
    weekend since November.  I finally finished the 4 meter Algebra
    I purchased 18 mos. ago and am anxious to fly it.  My other ships
    for this year will be a 100" Dynaflite Apogee, my beat up 2-meter
    Sagitta and a Pierce Aero Ridge Rat which won't fly till I pull
    the radio gear out of one of the aforementioned ships.  I would
    be curious to know what gliders other contributors currently are
    flying or have flown.
    
    Regards,
    
    Jim

    re .319
    
    Currently I'm flying an Aviomodelli Super Rieti, an Italian semi-F3B
    108". I've got a "Smoothie" fiberglass fuse. from Viking Models,
    which has flown a few times last month. Currently waiting for new
    120" S4061 cores and obechi sheeting to arrive from Calif. This
    airplane will then become my Nats entry in the unlimited class,
    if I got my entry in, in time to be accepted. They only allow
    10 entries per channel. Sounds like a lot but there were 380+
    entries in glider classes in last years Nats. Won't know if I
    make the cut until May when they start processing entries.
    
    I'll also be entering the hand launch class with a Dodgson Orbiter,
    60" with ailerons, yet to be built.
    
    If Airtronics gets their new Legend 113" on the market by April
    as rumoured and if I can get one right away, then it will be my
    Nats flyer in Open class.
    
    In between all this, I should get my old-timer built, and build
    new wings for the Pulsar, which I already have the cores for, and
    it will be my backup at the Nats, or even my primary if nothing
    else goes according to plan. So I'll be one busy dude.
    
    I'll be interested in hearing how the Algebra flies, Jim. Have
    heard good things about them.
    
    Terry
    

    Another clear, calm weekend , at least on sunday, so our monthly
    club contest attracted 14 entrants and much weirdness was had by
    all. 
    
    Buzz Averill, launching his Southwind (built by someone else)
    had his right wing fold at the root 3/4 of the way up the launch
    on the rather potent club winch. The builder had notched the bottom
    spar in order to get the mounting tube to fit between the spars.
    Lower spar failed in tension.
    
    Charlie, launching his Sophisticated Lady, had it tuck under and
    do 1/2 of an outside loop the instant that he pulsed down elevator
    to drop the line. He had no elevator control at all but the rudder
    was responding normally. He was'nt sure what to do, the S.L. meanwhile
    was circling randomly and stably upside down, while Charlie and
    the rest of us watched bemused. after about a minute it circled
    down for a smooth inverted landing. Not a scratch. The elevator
    nyrod outer housing had popped lose causing the innner rod to jam
    against a bulkhead.
    
    Jim, a new flier here, moving recently from Dayton, brought the
    spirit of Orville and Wilbur with him in the form of a 100" v-tail
    pivot wing of his own design. A slight amount of anhedral didn't
    seem to bode well for future stability. But he put it up on the
    mild winch with no trepidation, its maiden voyage. Avoiding the
    obvious temptation to insert deflowering jokes here, 100 ft. up
    the line he corrected for a slight veer and all h--- broke loose.
    No way I could describe the gyrations. Human reflexes were running
    about 3 minutes behind real time but after it popped off the line
    he momentarily caught the spinning, corkscrew, yaw performance and
    got it into a series of straight ahead deep stalls, missing the
    pits, cars, and soccer goalposts impacting cleanly on the nose,
    snapping the ruddervators off but otherwise little damage.
    
    I don't remember who won the contest. I know it wasn't me.
    
    Terry

    Has anyone flown or seen a House of Balsa Two-Tee fly.  I saw one
    already built for sale at the local hobby shop and really thought it
    was a nice looking ship.  Would appreciate any comments on this model.
    
    Thanks,
    
    Jim

The 2T was my very first rc airplane, complete with home brew
transmitter and receiver!  I only managed to get it to the hand
toss stage, since at the time I didn't have any other facilities
to fly -- such as a high-start.  I did throw it off a few hills,
and crashed it a lot of course since I was trying to teach myself
to fly.

Based on that experience, I'd advise you to do a good job of
putting the stab on the end of the fin; that darn thing falling
off on a hard landing ruined more sessions than anything.  To
this day I pass over any T-tailed airplanes.

Other than that it was a nice airplane, and it flew very well,
though I think the Gentle Lady is far better for the price.  I
should add that I think HOB does a very nice job of kitting.

The 2T's wings still survive as the outer panels in a much
modified HOB 2x4. 

    Well Sunday May 6th was the day for the Annual F3b contest hosted by
    the Rocky Mtn Soaring Assoc in Denver.  Myself and another Pikes Peak
    Soaring Soc. member made the trek north from Colorado Springs.  Last
    year the two of us went up and stole some of their trophies so we
    thought we would give it a try again.  This year it would be a little
    bit different and that this would also be a F3b team trial qualifier,
    meaining:  We send the top three pilots to the World F3b World Champs
    in Holland in 1992.  These three pilots will be chosen this comming
    Labor day at the USA F3b team trials.  In order to make an attempt a
    try at the USA team trials you must first either win a F3b team trial
    or score 90% of the winners score or you can do it by completing the
    absolutes.  The absolutes are 400 pts in FAI duration, 16 laps FAI
    distance, and a 24 sec or better FAI speed run.
    So this being a team trial qualifier it brought in some of the glider
    heavies from around the area to the likes of Seth Dawson, past USA F3b
    team member (finished 7th in the World Champs) up from Phoenix and Mike
    Forester from Salt Lake City who is the designer of the YAHOO that has
    been seen in the model press lately.  Well the day started and it was
    first to be Man on Man thermal duration with a 6 min percision task
    with L4 landing option.  I happend to do pretty well seeing how my
    worst element flying my Mueller King is duration.  I got a 5:56 with a
    60 point landing (100 possible).  This was good enough to win my flight
    group and earn me 1000 pts.  Next up was distance.  I was on the
    distance course with 7 laps complete but was getting low.  I elected to
    abort and relaunch and give it another attempt.  Doing so only got me 7
    laps on my second attempt so I did not win that round.  I should have
    though! darn.  Next was speed.  I launched and entered the course and
    pollished of a 32 sec speed run which was good for my personal best. 
    Some of the heavies like Seth were getting runs in the low 20's.  We
    then did one more round of distance which I won for another 1000
    points.  The final rankings left Seth Dawson in 6th place and I managed
    a 9th.  So did I get the 90% to qualify to attend the USA F3b team
    trials.  NOPE.  My score was 89.13 of the winners.  Dang.  Well it was
    close enough.  There will be more qualifiers before Sept.  So I should
    make it OK.
    
    

               < Explain please, What is a" flying stab" >
    
          I know this is something anyone who understands 
       aerodynamics might take for granted BUT I really do not
       know what is meant by a "flying stabilizer". And while I'm
       asking what is "decalage" and how do flyinig stabs help/or
       prevent or interact with this?. (whatever it is). Since
       gliders have my interest I think I should know a little 
       about this here technical lingo that keeps cropping up.
    
         And if there has ever been a video designed to spark up
       the soaring energies it would be that "Dodgsons Designs" video 
       I just watched! Great to watch and really helps with my
       daydreaming (flights made while hard at work)
    
       kevin p                                

    A flying STAB is one in that the whole surface moves.  This is called a
    STABILATOR meaning that it is a horizontal STAB and a ELEVATOR all in
    one piece.  The other methods would be a seperate Horizontal Stab with
    a small Elevator on the rear of it, Like most planes you see.  one
    other meathod would be a V-tail either in the full flying stab method
    or part fixed and part moving configuration.
    
    A full flying stab (stabilator) is on most fighters, F-4, F-14, F-15,
    and some of the Piper civil aviation planes have STABILATORS.
    
    Hope that helped.
    
    Welcome to the world of Silent flight!!!!!!
    
    Remember, anyone can fly with an engine!!!!!
    
    Mark Antry pres
    Pikes Peak Soaring Society  (RC)

    Kevin,
    
    I seem to re-call Al Casey answering the question of decalage some
    time ago, but here's a re-cap ...
    
    Decalage is the term which describes the difference in angles of
    attack between the main flying planes ( the two wings ) of a bi-plane;
    the top wing may be at 3 degrees, for instance, whilst the lower
    may be at 1 degree; the decalage is 2 degrees.
    
    However, decalage is used more frequently ( and wrongly ) to describe
    the difference in angles of attack between the wing and stab on
    a mono-plane. So the wing may be at an angle of 3 degrees, for
    instance, whilst the stab is often at 0 degrees; the decalage is
    3 degrees.
    
    With a normal stab the stab is fixed, of course, and only the elevator
    hinges.
    
    With a flying stab ( or all fyling stab ) the stab is a single unit
    ( no elevator ) which rotates around a point ( usually at about 25% 
    of chord so that the pivot point is ahead of the mean chord to stop 
    flutter ) so that it changes decalage, and hence lift characteristics, 
    by using the whole of it's surface rather than just the elevator. The
    angle of rotation is, of course, limited to a few degrees. 
       
    I hope this explains ( and is correct?! ;8} )
    
    Brian
    

This weekend I picked up a the Sterling Schweitzer I-34 scale
glider kit at a garage sale -- with an 8-foot wingspan no less!
Anybody have experience with the kit (PPSS members: I know
there's one in the club and I have his name).

I have a Sagitta 600 in the box and I could be persuaded to part
with it...I'm really tickled to get the Schweitzer.

I'll simply comment that it can be built HEAVY ;^)

Very thin wings for a very fat fuselage. You've got enough room to install the 
winch IN the plane ;^)

Mine broke the plywood tongues before ever getting airborne. With the current 
technology, I'd use a lot of carbon fiber on the wing spars and a lot less glue 
(CYA these days) in the fuselage.

The fellow who sold it to me said that the box in the fuse for
the center of the wing should be reenforced with epoxy/glass to
handle the loads from the modern winches.  I'll be sure to check
the one we have up here to see how he did the outer wing panel
joint too.  I've seen the model and it is very pretty in flight.

    It's time to enter a kit review of the Southwind. I've finally
    completed mine and it will be test flown this weekend.
    
    Since this will be my entry in the open class (444) at the Nats,
    I increased the wing span from 99" to 110", and the fuselage length
    by 1", stock is 51". I had Max cut the kit that way so I didn't
    have to hassle with making ribs etc.
    
    As this is an all wood kit, it seemed like a lot of work compared
    to foam/glass but is no worse than others of it's type.
    All wood supplied is good quality and with a little attention to
    matching the sheeting my wings panels came out within 1.3 grams
    of each other.
    
    The fuselage requires a lot of shaping, planing, sanding but comes
    out looking very sleek, and maybe just a little too narrow, as standard
    size servos are out of the question mounted side by side, and even
    my 831s' had to be mounted end to end to avoid servo arm interference.
    
    Stock configuration is poly wing with flaps and one servo for each.
    Plans show alt. setup with one flap servo. I reduced the di- and
    poly- angles by about 1/3 and will have flaperons, simple with the
    Vision.
    
    Plans are very good, instruction manual needs a complete rewrite.
    
    Stock wing mount is by internal rubber bands at L.E. and nylon bolts
    at T.E. This system works well and is recommended  for novices,
    as the bolts shear before wing is damaged. Alternate method recently
    ECO'ed but not included in kit uses bolts fore and aft, eliminates
    rubber bands, looks trick, and was invented by Buzz Averrill because
    he couldn't get his fat fingers inside the fuse. to manipulate
    the rubber bands. I used that method.
    
    Stock stabilator is built up, is strong but is a flat plate. Can't
    accept that so I used gray foam cut to NACA 0009 sheeted with
    obechie. Plenty of road hugging weight in the tail now. 
    
    All up weight is 57 oz. on 901 sq. in. 2-4 oz. of nose weight can
    be eliminated when I go to a sym. airfoil built up stab, next project.
    
    All hardware, horns, control cables, tow hook, etc. are provided.
    
    Next: flight testing.
    
    Terry
    

    
    This weekend was our sod farm fun-fly. One PPSS guy, Pat Haley,
    and his son came down.
    
    Winds from dead calm to 20+ as the dust devils danced in all
    directions. Nearly 90 degrees and shaped up to be great thermals,
    but no, 6 min. was good time.
    
    Got the Southwind in the air for the first time. The first hand
    launch, javelined into the sod 4". Sounds familiar. No damage done,
    dialed in a shade less down trim, and the next attempt was up the
    hi-start for an arrow straight launch. Didn't even need to touch
    the sticks, and the stock tow hook placement allowed max climb
    angle with no yaw. Off the line and the flaperon action was very
    good, almost like regular ailerons, a little unexpected as
    they are only 14" X 1.5" and mounted inbd. Differential was right
    on, I actually didn't even think about checking it. Speed range
    is very good, reflex seemed to powerful, and I kept backing off
    until I was down to 0%, then realized I was forgetting to change
    the elev. compensation and it was actually the elev. causing it
    to dive when the reflex switch was thrown. 
    All in all I was more pleased than expected, and it should be fully
    competitive at the Nats; now if I can just find a pilot who is...
    
    Terry
    

>         <<< Note 399.345 by ELMAGO::TTOMBAUGH "High Plains Drifter" >>>
>                         -< Test flying the Southwind >-

>    they are only 14" X 1.5" and mounted inbd. Differential was right
>    on, I actually didn't even think about checking it. Speed range

How did you know the differential was right on?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    re .346
    
    Because it responded to inputs immediately, held a given turn without
    changing the arc, and didn't wallow or yaw when entering or exiting
    the turn. What else do I want?
    
    Actually I'll be experimenting with diff. settings some more this
    weekend, when I can fly in lighter winds, and will be moving the
    C. G. back a little from its most conservative position.
    
    Terry
    

    Misc. ramblings:
    
    Got a catalog from Windspiel Models in Coeur d'Alene Idaho.
    They import the GLasflugel line of scale sailplanes.
    Beautiful kits, glass/foam, prepainted, brutally expensive,
    $600-$2000 range. If your kids' college fund is burning a hole in
    your pocket.....
    
    Also received two pairs of wing bags from Service Plus in Okla.
    City, an open class size and a hand launch. Good quality material,
    full width velcro closures, full length stab pockets, no color
    choice, but mine are a nice blue/gray. People running it are
    soaring types and seem interested in pleasing the customer.
    
    Started building the Orbiter HL. Interesting engineering. Wing
    spar stops 7" short of the tip. 1/32" shear webs and the L.E. sheeting
    form a monocoque structure. Shear webs are precut,accurately, and
    range down from 1/4" to 1/32". All wing sheeting is 1/32", ribs
    are 1/16" and use 1/32" X 1/8 cap strips. 1/64 ply doublers are
    used on first two root ribs. A whole bag of fiddly bits are provided
    to build a mini version of the A.F.A.R.T.S. system as used in the
    Wind/Lovesongs. I'll be avoiding the by using separate servos for
    the ailerons and xmtr mixing. Stay tuned, I've only got 3 weeks
    to finish this thing, assuming I don't need any practice before
    the Nats, yeah sure.
    
    Terry
    

    The Orbiter is nearly finished. Only have the wing left to cover,
    should be ready for test flight this weekend, 5 days before I leave
    for the Nats.
    
    With 4 servos, ( 2-S133, 1- 401, 1-43?), 270ma rcvr pack, 8 chan.
    pcm rcvr, it now weighs 450 gms, 4 gms less than 1 lb.
    
    Advertized weight is 17 oz. with 3 servos. The weight of Micafilm
    on a 430 sq. in. wing should be ~ 1oz. so total flying weight will
    be right on the nose. Amazingly the 8 chan rcvr fits without chopping
    on anything, and using the Vision results in a flaperon system
    that gives a better range of flap travel than on any of my larger
    ships. Having $150 worth of servos in a handlaunch still makes me
    laugh, or cry, but you can't beat it for sheer ostentation.
    
    An interesting comparision that taught me something:
    The kit comes with two 3/64" music wire pushrods for rudd. &
    elev. They seemed too heavy so I decided to try nyrods, but
    discovered that 3/64 x 36" music wire weighs 7.5 gms and
    36" nyrod (inner tube & outer housing) weighs 9 gms. Also
    The music wire can use z-bends at one end while the nyrods
    require the threaded shaft and clevis. And the music wire
    is stiffer and can be threaded thru tight areas better.
    
    The kit supplies a 1/4 x 20 nylon bolt for wing hold down.
    Talk about over kill. I substituted a 10-32, which is capable
    of withstanding winch launches on my 110 incher, so should
    be adequate on a 60".
    
    The whole thing is covered in Micafilm. The more I use it the better
    I like it. By using a thermometer on the iron and keeping the temp.
    in the specified 20 degree range, the stuff is easier, but more
    time consuming, to work with than Monokote.
    
    Next: Test flying
    
    Terry
    

    I finally finished and test flew my Dynaflight Apogee  this weekend.
    I was not too excited about the construction methods employed with
    this kit, but this did not adversely affect the ship's flight
    capabilities.  The Apogee is a 100" wingspan, Eppler 205 with the
    Schuman planform, polyhedral-3 channel glider, kit cost was $37 through
    Omni Models.  The most striking feature of this ship is the double
    swept back wing planform.  The Schuman planform as it is known, is
    supposed to improve the low speed flight characteristics.  It certainly
    seems to work, I was able to fly this ship nearly as slow as the
    2-meter floaters that were flying that day.  My only other Eppler 205
    experience is with a 2-meter Sagitta which would not fly slow well and
    had a nasty tip stall characteristic.  This kit probably offers the
    best price/performance($37 for a 100" glider!) of any ship I have
    flown.  The kit is not the easiest to build but is easier and cheaper
    than a Sagitta.  The designer(Mark Smith) did very well with this
    ship in last year's Masters Thermal Duration Contest against all types
    of gliders, both modern(epoxy/glass f3b type) and traditional
    (Paragon,etc.), but I guess he's a hell of a flyer anyway!
    
    Regards,
    
    Jim

    The Orbiter had its flight baptism yesterday. A muggy, dead calm,
    high overcast morning, quite similar to Nats weather I suspect.
    Just as it says in the specs, this is not a flip and float type
    of HLG. With the surface travels set to plan specs it is a darting,
    swooping little beast that reacts violently to the slightest lift.
    Just the ticket for competitive HLG work, but flipping on the dual
    rates for elev. and ail. (70%) tamed things quite a bit and I got
    in 12-15 successful flights, reprogrammed ail. differential once,
    and decided that the balance is ok as is, and will still be within
    limits if I substitute a 180 ma pack for the present 270 ma.
    Total weight with 1/2 oz of lead to bring it to the most conservative
    balance point, is 17.98 oz for a loading of 5.99 oz. 
    Flap effect with the outbd. flaperons is mild but 3/16" of reflex
    really moves 'er out quite nicely. Stock elev. throw is way to powerful
    causing porpoising when trying to steady it in turbulance.
    Got in 5-6 winch launches, since I'm planning to enter it in
    the 2 meter class also, if they'll let me sign up on-site, which
    they will, freq. allocations permitting. Several of the winch launches
    were pretty hot, and I noticed two stress cracks in the trailing
    edges, at the same place on both sides. Not surprising since the
    t.e. is hollow, two strips of 1/32".
    Other than that the thing is a lot more robust than I expected,
    surviving several hard landings that would have sent my Flinger
    to the showers. 
    Comparing it to the other HLGs on the field at the same time,
    two Gnomes, Chuparosa, Baby Lady, and Thornburghs' 60" Bird of Time,
    I can say that it's not a floater, is faster than most sport gliders
    up to 100", can turn 180 degrees in its own length, and acts like
    a rat in the jaws of a terrier when encountering lift. Life
    should be interesting next week.
    
    Thornburgh was out tuning up his Nats entrys; 60" BOT for HLG,
    a shrunken Southwind wing on a Doodler style fuselage for 2 meter,
    a stock Southwind for Standard, and a 118" BOT for Open. Be interesting
    to see how this goes over with the foam/glass jet set crew at the
    Nats.
    
    Terry
        
    

As long as the Flinger was mentioned in the previous notes (that's the
one that would have "headed for the shower" on a hard landing) I thought
I'd report on the status of mine.

Briefly, the problem was a weak plywood wing connecting rod, which I 
glued back together, then reinforced with carbon fiber. Working with that
carbon fiber was a real experience. As careful as I was, I still ended up
with tiny black hairs all over the place, on my hands, my clothes, and floating
around in the air. I still don't know if it's strong enough for hand launches
because when attaching the wings to the fuselage, the screw for the wing bolt
came unglued... again. I got so disgusted I just put it down and didn't want
to look at it. As Gilda used to say, "If it ain't one thing, it's another!"

Actually, I'm not optimistic about the fix. I think ultimately I will have to
use some sort of steel rod for the wing joiner, which will boost the weight
a bit. Right now it's sitting at 13.5 oz. I will definitely get some flights
in before the end of the week.

Dave

    

>    Thornburgh was out tuning up his Nats entrys; 60" BOT for HLG,
>    a shrunken Southwind wing on a Doodler style fuselage for 2 meter,
>    a stock Southwind for Standard, and a 118" BOT for Open. Be interesting
>    to see how this goes over with the foam/glass jet set crew at the
>    Nats.

I'm most interested in these other BOTs.  Ray was at the glider contest
in Northboro yesterday with his beautiful BOT that is 4 or 5 years old.

As I understand it the standard BOT is a 100 inch plane - that is the
kit you can purchase from Dynaflite and the plans published (in RCM?).
The mini BOT was a 2 meter I thought.  So that leaves me in a pickle
to identify Thornburgh's 60" and 118" versions.  Can you elaborate?
Did he just shorten the constant cord center section of the 2 meter to
get a 60" and did he just stretch the constant cord center section of
the 100" to get to 118".

As an aside - did you see the picture in the last RCM of the 32 foot
wingspan BOT - AWSOME.  He must winch it up with a MAC truck!

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    I'll call Dave up tonight to verify a few things but I know this
    much now:
    His 60" is scratch built, in 36 hours, and everthing is scaled
    accordingly. He carries everything around in his head, slaps it
    down on paper with a straight edge and French curves and proceeds
    to build it. The 60" is a beautiful flyer. Easily the best floater
    of the HLGs I mentioned.
    
    I think the original BOT was designed as a 118", and that was the
    one appearing in the original RCM article, I'll check this. At
    any rate, several 118 " were built by Steve Work and Dave and 
    taken to France in '77 to compete in the World Soaring Champs.
    One of these is the one he's taking to the Nats. Exactly
    how they compare with the 100" Dynaflite, proportionately,
    I'm not sure. Dave kitted about 200 BOTs himself before
    selling it to Mark Smith. Of the several other kit built BOTs
    flying around here, they are all 118".
    
    I have a 8mm video tape interview with Dave, that I took last fall
    at the field, expounding on the philosophy of the BOT design, complete
    with Eastern mysticism quotes that Dave likes to throw around.
    Unfortunately it's embedded in a tape with a lot of other flying
    nonsense, and I'm not sure how to extract it. I'd be willing to
    loan it to you, after I get it back from my cousin.
    
    Terry
    

>    I have a 8mm video tape interview with Dave, that I took last fall
>    at the field, expounding on the philosophy of the BOT design, complete
>    with Eastern mysticism quotes that Dave likes to throw around.
>    Unfortunately it's embedded in a tape with a lot of other flying
>    nonsense, and I'm not sure how to extract it. I'd be willing to
>    loan it to you, after I get it back from my cousin.
    
Love to see it - as would several others out here I'll bet.
But 8mm is not too convenient.  Could you possibly copy it to VHS?
We could then ask Eric Henderson to splice it on to one of the DECRCM
tapes.  At any rate any form you can send it in I will somehow find
a way to view it.  I'm at LTN1-2/B17.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Ok Kay, I'll send the tape out to you early next month after I get
    back from vacation. It is already copied to VHS. Be forewarned that
    it contains raw flying footage around the Albq. area, gliders and
    old timers only. Not for the faint of heart.
    
    About the various BOTs. Dave didn't know that the Dynaflite BOT
    was 100". He said he built several 100" for his own use years ago
    and liked them better than the 118", but launch heights weren't
    as good so he never kitted them.
    
    He derived the 60" by half-scaling the 118", except he retained
    a 8" root chord by using the #3 or 4 rib from the tapered section
    of the 118" wing. Also the fuselage is about 2-3" longer than half
    scale.
    
    Another thing he told me that cracked me up, was when he was shrinking
    the Southwind to make a two meter he decided to try a V tail. His
    wife, who is an R.N., says, "Don't use a V tail, you'll never have
    time to trim it properly before the Nats." So he was forced to abandon
    the idea and go with a conventional set up.
    
    Terry
    

>    Ok Kay, I'll send the tape out to you early next month after I get
>    back from vacation. It is already copied to VHS. Be forewarned that
>    it contains raw flying footage around the Albq. area, gliders and
>    old timers only. Not for the faint of heart.

Great - looking forward to it.
    
>    About the various BOTs. Dave didn't know that the Dynaflite BOT
>    was 100". He said he built several 100" for his own use years ago
>    and liked them better than the 118", but launch heights weren't
>    as good so he never kitted them.

Don't get me wrong - I only seem to recall that it was 100" - maybe it
in fact is 118".  Since you talk to him regularily - maybe you could 
get us the story behind the story on the 32 foot BOT seen in the August
RCM?
    
>    He derived the 60" by half-scaling the 118", except he retained
>    a 8" root chord by using the #3 or 4 rib from the tapered section
>    of the 118" wing. Also the fuselage is about 2-3" longer than half
>    scale.

So if a mini BOT is 78" then this must be a Micro Bird :-)
    
>    Another thing he told me that cracked me up, was when he was shrinking
>    the Southwind to make a two meter he decided to try a V tail. His
>    wife, who is an R.N., says, "Don't use a V tail, you'll never have
>    time to trim it properly before the Nats." So he was forced to abandon
>    the idea and go with a conventional set up.

I never got my Thermal Charger trimmed properly till I switched to a
Futaba 9VAP - talk about overkill!  I never could get it right on the 
Vision - in hind site my mistake was to think of it as a V-Tail when
in RC Radio language it was actually a Elveron (flying wing setup).

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    I'll ask Dave about the 32' BOT but doubt if he knows anything about
    it. I'd kind of like to be around when that guy tries to fly it.
    
    There is a Bird of daylight savings time, designed by John Lupperger,
    (sp?) who I believe designed the Chuperosa, Dave mentioned it last
    night and implied it was of HLG size, but I've never seen one.
    
    Terry
    

>    There is a Bird of daylight savings time, designed by John Lupperger,
>    (sp?) who I believe designed the Chuperosa, Dave mentioned it last
>    night and implied it was of HLG size, but I've never seen one.
    
Terry - this gets better with every episode.  Where can I read about
the Bird Of Daylight Savings Time (BOdsT)?  Was this published in one
of the magazines?  If so I probably read it and it went right over
my head without me making any connections.  Problem is I never knew
of Dave until he released his book.  I started the hobby after all his
previous articles in Model Builder were published.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################
    

    I don't recall ever seeing any articles on the BODst either. If
    John ever kitted it , it was on a very limited basis. MA, MB, or
    RCM might list it in their plans catalog. I'll check with Dave
    tonight.
    
    Terry
    

Thought I better save these references to the Maynard Hill work
that just came over the usenet.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

Article         2886
From: [email protected] (James Sonnenmeier)
Newsgroups: rec.models.rc
Subject: Re: Wing Leveler
Date: 30 Jul 90 23:01:51 GMT
Sender: [email protected]
Organization: University at Buffalo
 
In article <[email protected]>, [email protected] (Robert Turner) writes...
>In article <[email protected]> [email protected] (Lawrence Curcio) writes:
>>There is a continuing thread on models.rockets concerning the detection
>>of nose-over at apogee. In sci.physics, someone mentioned that atmospheric
>>potential (voltage) sensors have been used as wing-leveling devices in
>>model aircraft. This looks like a good scheme for nose-over detection as well.
> 
>Wasn't this an April Fool Joke?  Yes there is a variation in potential
>but it takes several hundred, if not thousand feet, to measure.  And
>of course once you get a piece of wire that big you can start
>listening to AM Radio Station KBLU broadcasting with 1500 watts of
>power from Yuma Arizona.  (It was 1500 watts when I was growing up).
> 
>Why not look into a fixed wing gyro.  Century Systems had them -
>available from Circus Hobbies Las Vegas about 2 years ago.  Or for
>close to the ground - sonar distance measuring systems as in digital
>tape measures or Polaroid cameras.
> 
>The perputal beginner,
>Robert
 
 
Sorry to disappoint you but it is indeed a method of sensing airplane 
attitude and was developed to a high state of functonality by 
Maynard L. Hill then of the applied physics lab of the Johns Hopkins Univ.
He even marketed the circuitry for awhile on the the name of 
Aeroprobe Technology Corp.
 
I researched the work of Dr. Hill and came up with the following reference 
list which is by no means complete but has most of the major papers 
explaining the phenomenon and the circuitry.
 
Hill, M. L.,"Electrostatic Autopilots. For stabilization of Radio-
Controlled Airplanes",Flying Models, V76 No 2, Feb 1973 pp 20-29
 
Hill, M. L.,"Introducing the Electrostatic Autopilot",Astronautics
and Aeronautics, V10 No 1, Nov.  1972.,pp 22-31.
 
Hill, M.L.,"Designing a Mini-RPV for a World Endurance Record",Astronautics
and Aeronautics ,V20 No 11, Nov. 1982,pp 47-54.
 
Markson, R.,"Practical Aspects of Electrostatic Stabilization", Astronautics
and Aeronautics, V12, No 4, April 1974,pp 44-49.
 
Hill, M. L.,"R.C. Soaring - Electrostatic Autopilot Update",Aeroprobe
Technology Corp., 2001 Norvale Road, Silver Spring, MD 20906, (301)598-6264
(address information as of August 1986)
 
Jim
==========================================================================
Jim Sonnenmeier                  !
[email protected]  : BITNET    !    :-)
[72361,2133]  : CompuServe       !    I like to think that time and space
University at Buffalo            !    are ours to use :) ... The sky is my
Department of Mechanical/        !    joy, the wind is my lift.
Aerospace Engineering            !  
==========================================================================

Article         2893
From: [email protected] (Joe Pfeiffer)
Newsgroups: rec.models.rockets,rec.models.rc,sci.physics
Subject: Electrostatic altitude sensing
Date: 31 Jul 90 19:10:42 GMT
Sender: [email protected]
Organization: NMSU Computer Science
 
I'm posting this to all these groups because there are currently
relevant threads in all three.  I looked up the 1972 Hill paper, and
found a schematic!
 
The sensor is incredibly -- I'm tempted to say unbelievably -- simple.
For a roll sensor, all he did was hook up some 500 microcurie polonium
patches (Staticmaster u 500) to coax, running into two Fairchild ua740
op amps configured as a differential amp!
 
To get a two-axis sensor, he used three polonium patches.  The wing
tip sensors are hooked up to a differential amp to get roll, and are
averaged with the resulting signal put against a differential amp
against the signal from the tail sensor.  He calls this a ``triangle
circuit'' for obvious reasons.  The roll amp here is also trivial; he
used 2N3823 FETs as inputs to a 747 op amp!
 
The telemetry downlink was laughable.  He hooked the sensor output up
to a VCO and listened... the article talks about ``tone variations
were small,'' ``a low groaning sound accompanied a steep left turn,''
and other great lines.  Doesn't the American Institute of Aeronautics
and Astronautics referee their house journal?
 
The 1974 paper (don't remember the author) mentions some problems with
the scheme.  Basically, in inclement conditions -- snow, rain,
excessive dust, etc -- the conductivity of the atmosphere increases to
the point that the field breaks down.  This isn't a serious concern
for the RC and rocket people, however...
 
Anybody know where I can get some polonium?  Who is Staticmaster, anyway?
 
-Joe.

Article         2895
From: [email protected] (Lawrence Curcio)
Newsgroups: rec.models.rc,sci.physics,rec.models.rockets
Subject: Re: Electrostatic altitude sensing
Date: 1 Aug 90 01:58:16 GMT
Organization: School of Urban and Public Affairs, Carnegie Mellon, Pittsburgh, PA
 
I haven't checked the references on the wing leveler, but the polonium is
evidently there to keep the sensor in equilibrium with the ambient
potential. The only commercial source of the stuff that I know of is
cheap smoke detectors. Sounds a bit expensive for a hobby application
though.
 
-Larry C.

    Staticmaster is the name of a lens cleaning brush that prevents
    build-up of static electricity on the lens when you brush it. Static
    electricity buildup attracts dust, which defeats the purpose of
    cleaning the lens.
    
    ajai

    Just a comment on Maynard Hill's electomagnet auto pilot; this is
    anything but a new system.  It's probably been around as many as
    20-years and it _does_ work.  Hard as it is to believe, there's enough
    difference in electromagnetic levels, even with minute deviations in pitch 
    or roll, that the Hill system detects and corrects for it.  I saw it
    demo'd once quite a few years back and was amazed at how well it
    worked.
						 __
				|      |        / |\	   	       
      	         \|/		|______|__(o/--/  | \	   	       
      | |        00	       <|  ~~~  ____ 04 ---- | --------------------
    |_|_|        (O>o		|\)____/___|\_____|_/	   Adios amigos, Al
      |     \__(O_\_	        |	  |___/	 o	   (The Desert Rat)

Article         2900
From: [email protected] (Jeffrey L Bromberger)
Newsgroups: rec.models.rc,sci.physics,rec.models.rockets
Subject: Re: Electrostatic altitude sensing
Date: 1 Aug 90 14:19:49 GMT
Organization: City College of New York - Science Computing Facility
 
In article <[email protected]> [email protected] (Lawrence Curcio) writes:
>The only commercial source of the stuff that I know of is
>cheap smoke detectors.
 
The isotope found in smoke detectors is Americium, not Polonium.
As for Polonium, you have to be careful.  If I'm reading the CRC
Handbook correctly, it's not very safe.  It does mention the film
negative cleaning use, but recommends the use of other stuff.
The alpha particles emitted are very powerful (about 5 times that
of P-32).  It has to be used as a sealed source - weight for weight,
it is listed as being 2.5x10^11 times as toxic as Hydrocyanic acid (HCN).
Not to mention that the halflives aren't extremely large (Po-209 is
unusual at 103 yrs).  Also, availability is with permit from the AEC.
 
If we really need an alpha emitter, can't we use something a little
more common (Bi-210) ?  Maybe make the circuit work with a beta
emitter like C-14?
 
j
-- 
Jeffrey L. Bromberger
System Operator---City College of New York---Science Computing Facility
[email protected]			[email protected]
	Anywhere!{cmcl2,philabs,phri}!ccnysci!jeffrey

Date:	3-AUG-1990 00:00:55.54
From:	TALLIS::FISHER       "Stop and smell the balsa!"
To:	FISHER
CC:	
Subj:	rec.models.rc new articles

2902 Re: Electrostatic altitude sensing
2903 Re: Electrostatic altitude sensing
2904 Re: Electrostatic altitude sensing
2905 Re: Electrostatic altitude sensing
2906 Re: Electrostatic altitude sensing
2907 Re: Electrostatic altitude sensing

Article         2902
From: [email protected]
Newsgroups: rec.models.rc
Subject: Re: Electrostatic altitude sensing
Date: 1 Aug 90 15:57:00 GMT
 
 
Back when this was all "hot news", the polonium by Staticmaster was
obtained from the company, or removed from a draftsman's brush, which
Staticmaster marketed.
 
Back when we had draftsmen instead of plotters, they would make their
master drawings on a tracing paper or linen, which was then run through
a blue print machine. Errors on the drawings were corrected by erasing
with an electric or hand eraser. This left a lot of "junk" on the drawing,
so the draftsman would brush off these erasings with a Staticmaster
brush, which picked up all of the dirt. The polonium in the brush
provided the charge to the hair of the brush to cause the erasings
to stick to the brush.
 
If you can find a draftsman supply store, you might still obtain
such a brush.
 
Al Irwin
[email protected]

Article         2903
From: [email protected]
Newsgroups: rec.models.rc,sci.physics,rec.models.rockets
Subject: Re: Electrostatic altitude sensing
Date: 2 Aug 90 19:43:49 GMT
Sender: [email protected] (Mr Background)
Organization: M.I.T. Lab for Nuclear Science
 
-Message-Text-Follows-
In article <[email protected]>, [email protected] (Jeffrey L Bromberger) writes...
>In article <[email protected]> [email protected] (Lawrence Curcio) writes:
>>The only commercial source of the stuff that I know of is
>>cheap smoke detectors.
> 
>The isotope found in smoke detectors is Americium, not Polonium.
>As for Polonium, you have to be careful.  If I'm reading the CRC
>Handbook correctly, it's not very safe.  It does mention the film
>negative cleaning use, but recommends the use of other stuff.
>The alpha particles emitted are very powerful (about 5 times that
>of P-32).  It has to be used as a sealed source - weight for weight,
>it is listed as being 2.5x10^11 times as toxic as Hydrocyanic acid (HCN).
>Not to mention that the halflives aren't extremely large (Po-209 is
>unusual at 103 yrs).  Also, availability is with permit from the AEC.
> 
>If we really need an alpha emitter, can't we use something a little
>more common (Bi-210) ?  Maybe make the circuit work with a beta
>emitter like C-14?
 
  I think you mean C-13, C-14 is stable.
 
  Americium is a good source of ionizing radiation and will work fine,
In smoke detectors it is used for the same purpose to make the air
conductive. The ions produced interact with smoke (sticking to it)
which makes the air less conductive in the presence of smoke.
 
  Another much harder possibility is to build a ion generator, but 
that requires high voltage and sharp points so weight and building
it will be harder. Also you will have to contend with the voltage
and fields from the high voltage source, which is not an easy problem.
 
  I hope the the figure of 500uC was wrong, that is quite a strong 
source and care is needed. Smoke detector sources are more like 1uC.
 
 
				[email protected]

Article         2904
From: [email protected] (Andrew Zimmerman)
Newsgroups: rec.models.rc
Subject: Re: Electrostatic altitude sensing
Date: 2 Aug 90 16:32:41 GMT
Sender: [email protected]
Organization: Stanford University
 
Yet another reference for "Electrostatic Autopilots" is an article in
"Flying Models", February 1973.  What, you don't have a copy of a 17 year
old magizine at home?  Well, if I get time this weekend, I will try
to get postscript versions of the schematics that are given in the
article.  Most of the text is hype, so you won't be missing too much.
 
Andrew
[email protected]

Article         2905
From: [email protected] (Joe Pfeiffer)
Newsgroups: rec.models.rc,sci.physics,rec.models.rockets
Subject: Re: Electrostatic altitude sensing
Date: 2 Aug 90 21:46:54 GMT
Sender: [email protected]
Organization: NMSU Computer Science
 
In article <[email protected]> [email protected] writes:
 
	 I think you mean C-13, C-14 is stable.
 
I couldn't find a carbon isotope that looked useful:  they all were
stable (C13 is stable), almost stable (C14 has a half-life of 5730
years) or have much too short a half-life (C11, the longest half-life
of the remaining isotopes, has one of 20.3 minutes).
 
	 Another much harder possibility is to build a ion generator, but 
   that requires high voltage and sharp points so weight and building
   it will be harder. Also you will have to contend with the voltage
   and fields from the high voltage source, which is not an easy problem.
 
This actually seems like the most likely possibility.
 
	 I hope the the figure of 500uC was wrong, that is quite a strong 
   source and care is needed. Smoke detector sources are more like 1uC.
 
For comparison, the max. allowable body dose of Po is 0.03uC.  But
that is what the article said!  I wonder if he has cancer yet...
 
				   [email protected]

Article         2907
From: [email protected] (John G. DeArmond)
Newsgroups: rec.models.rc,rec.models.rockets
Subject: Re: Electrostatic altitude sensing
Date: 2 Aug 90 23:37:21 GMT
Organization: Radiation Systems, Inc. (a thinktank, motorcycle, car and gun works facility)
 
[email protected] (Jeffrey L Bromberger) writes:
 
>The isotope found in smoke detectors is Americium, not Polonium.
>As for Polonium, you have to be careful.  If I'm reading the CRC
>Handbook correctly, it's not very safe.  It does mention the film
>negative cleaning use, but recommends the use of other stuff.
>The alpha particles emitted are very powerful (about 5 times that
>of P-32).  It has to be used as a sealed source - weight for weight,
>it is listed as being 2.5x10^11 times as toxic as Hydrocyanic acid (HCN).
>Not to mention that the halflives aren't extremely large (Po-209 is
>unusual at 103 yrs).  Also, availability is with permit from the AEC.
 
Po-210 is not nearly the hazard the CRC handbook might indicate, especially
in the encapsulation form presented by the antistatic brushes.
 
>If we really need an alpha emitter, can't we use something a little
>more common (Bi-210) ?  Maybe make the circuit work with a beta
>emitter like C-14?
 
One would have to provide sufficient quantities of Bi-210 to generate
the same number of statcolumbs of charge in order to duplicate the 
performance of a Po-210 source.  That's the big advantage of Po.   It
emits a very high energy alpha, is easily encapsulated, has a high
specific activity (and a corrispondingly short half-life - an advantage
for disposal concerns.) and a high yield.
 
In the staticmaster brush, the Po-210 is encapsulated in a ceramic bead
matrix and then fused to a metal substrate and enclosed in a physical
barrier.  This is a very secure and leak-proof configuration.  I've 
used the cartridges in my lab for years as a source of intense alpha 
particles.  I've NEVER had a leaker.  The only disadvantage is that
the half-life is pretty short.  StaticMaster will put you on a renewal 
list and send you a postcard order form when it's time to renew.
They'll also take the old one back and dispose of it if you so desire.
The refill cartridges are significantly less expensive than the whole
brush assembly.
 
BTW, another non-rocket use of these cartridges is for static dissipation
on a phonograph turntable.  I have several of these units mounted such that
when the cover is down on the turntable, the record is irradiated with
alpha particles.  It will kill the static that holds dust to a record in
seconds.
 
John
 
-- 
John De Armond, WD4OQC  | We can no more blame our loss of freedom on congress
Radiation Systems, Inc. | than we can prostitution on pimps.  Both simply
Atlanta, Ga             | provide broker services for their customers.
{emory,uunet}!rsiatl!jgd|  - Dr. W Williams |                **I am the NRA**  

        Re:         <<< Note 399.365 by KAY::FISHER "Stop and smell the balsa." >>>

                The atmospheric potential buildup is an amazing 100 volts
        PER METER!   Not  difficult to measure!  I'ts caused by ionizaton
        in the upper atmosphere.
        
        Anker

	Thermal experience


	Yesterday Hartmut and me went flying after work with our gliders
	(ASW24 and FIESTA) trying to improve our skills at the winch. The 
	length of the line was 325 m (1065 feet) one way, we should get a 
	hight of maybe 200 m (655 feet).
	My first start was a "@#$%^(*&^" , the line broke after I was 4 meters
	(13 feet)high. Instinctively I pushed the elevator imediatelly forward,
	the ASW24 took the nose down and made a hard landing, no damage. Lucky.

	The next flight was a real shorty, maybe 2-3 minutes. Then Hartmut 
	arrived and after assembling his Fiesta he made his first launch at
	the winch, no problem. His flight duration was not longer, my remark
	"Hartmut, you shouldn't fly with spoilers out" was not that funny in
	his opignion. Then Reinhard arrived, with good advises and a stopwatch,
	telling me that Hartmut was more lucky the next flight than me. I never
	understand why Bussies (nickname for Bussard) always circle when I'm
	not flying and my buddy is close to them. 
	Then Hartmut got a real good thermal, circling upward with our friends,
	the Bussies. I hurried to get my plane up, flying to the same thermal,
	3 minutes after Hartmut took off. I was always looking for our friends'
	circling position, they very slowly moved circling away, my ASW24 right
	under/above them. Hartmut was looking for a new thermal, but after 
	35 minutes he touched down. 
	My neck was hurting meanwhile and my eyes because I had to look 
	into the sun, where the thermal moved to. And my concentration was 
	slowly but surely getting worse, the plane was a simple spot in the 
	air. I was steering my plane back after a while to where I started, 
	trying to get annother one. But there were no Bussies anymore and I
	had problems to get the next thermal centered. I touched down after
	42 minutes, my personal high score in the class : Glider_winch_start_
	blue_thermal_conditions_nowind_noslope_Reinhard_and_Bussie_assistance.

	Trying to disassemble my plane I broke the screw holding the wings
	tied in place. Have you ever tried to get a 138 inch wingspan plane
	into your car without folding the wings ??  Well, fortunatelly my
	last 20 K$ investment made it possible (used VW bus). And then Hartmut
	rolled the tow onto the winch - it took us 30 minutes to unroll it
	again and get all the knots out of the 2130 feet tow !  

                      \\
                       \ \                    __
                        \  \                  \ \
                         \  \                  \ \
                          \  \                / \_\
                           \  \              /LO |
		       .o^^^--------==========___/
		      <      \  \-''
		       '-___-'\  \            
			       \  \
                                \  \          Holm- und Rippenbruch,
                                 \ \
                                  \\                          Bernd

    Where is the field where you guys fly?  It must be very large to
    handle 2000+ ft. of winch line.
    
    
    Regards,
    
    Jim

    re: .368
    
    Jim,
    
    there are several open fields in the area that are large enough (you
    must have at least one for every possible wind direction, right?).
    
    Maybe it's just an advantage of the European Community (there is an
    advantage??). Since the farmer's production is too high to achieve the
    guaranteed prices in a free market, farmers are encouraged (with state
    money) to let a field lie fallow. Others have large meadows to feed
    the grass to their cows (many cows in Bavaria = large meadows). This
    doesn't necessarily mean the cows are out there, often they stay in the
    cowshed and the farmer comes with a tractor twice a day to get fresh
    grass for them. Which means, that the meadows are kept reasonably
    short, too. And one meadow is most often not big enough, but you always
    find places where there are two or more meadows in line with the wind
    direction. And they usually don't have fences to give easy access for
    the tractors.
    
    I must admit, this is the place to fly gliders. The slope where I
    recently flew was about 15 miles away. And with an hours drive, you are
    at the Alps...
    
    Regards,
             Hartmut

Looking for silicon hinge information.

There was an article published in one of the smaller newsletter
type of sailplane publications a few months ago about silicon
hinges.  Sorry but I don't remember the name of which magazine
it was.  

Does anybody have the article - I could really use a copy.  With
or without the details I plan to put silicon hinges on my Lovesong.

Before anybody asks what a silicon hinge is - how about someone
with the article putting in a one page description - that way
we can get straight to the facts.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    I first read about silicon rubber hinges in a RCM construction review
    of Harley Michaelis's Keetah Sailplane.  I think they are available
    through him.  He has had many designs published throughout the years
    and currently his Easy Eagle 2-meter design is being kitted by ACE.
    If I'm not mistaken these hinges are marketed as "Harley's Hinges".
    
    Regards,
    
    Jim

>                      <<< Note 399.375 by USRCV1::BLUMJ >>>
>                             -< "Harley's Hinges" >-

Jim - I know the article you are referring to - that's not what I'm
after.  Those were just long strips of rubber causing a pulling
positive snap to keep the aileron against the trailing edge.

The silicon hinges I'm referring to you make with masking tape
and a caulking gun of silicon - no slots are required.

Anybody else?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    I'm hurrying as fast as I can...pant...
    The article you're referring to appeared in the Feb. '89 RCSD, pg.
    6 and 7. A copy of these pages is on its way via decmail even as
    we speak.
    
    Terry
    

    
    I wanna fly a glider !  (pardon me, I mean BUY a glider)
    I've seen one in the local store named "QUASOAR". Does anybody know
    about this one, or would "LEGEND" or "SENSOR" or any other similar
    plane be more recommented ?  The plane of my idea should be a high 
    performance thermal plane like those F3B ships with glass fuselage
    and solid wings to stand a ZZzzzoooommmm on a winch. I don't know
    the market in this country nor the brands that are offered. The only
    thing I know, the current exchange rate Deutsche Mark to Dollar is DM 1.65 
    for $1.- !
    
    Holm- und Rippenbruch,   Bernd

    The Quasor was designed by Paul Carlson formerly of Off the Ground
    Models.  It is now kitted through ACE I believe.  It has a foam core
    wing of approximately 110" using the Selig 4061 airfoil and can be
    built with flaps.  It does have a glass fuselage, I have never seen
    one fly.  The Legend is Airtronics latest entry into the high
    performance thermal duration market.  It has a kevlar reinforced 
    glass fuselage, wingspan is 110", it is built up construction with
    balsa sheeting on the top.  Uses the Selig 3021 airfoil with winglets
    at the tips.  The Sensor was designed by Mark Smith it has a glass
    fuselage, built up wings of 117" span, don't know the airfoil.  This 
    ship also can be built with flaps for additional landing control.
    Of these three ships, I would think the Quasor would be the most suited
    to f3b type flying.  It sells for around $100 in kit form.
    
    Regards,
    
    Jim

    Bernd,
    
    Of the three kits you mention, my vote would go for the Legend.
    If you have actually seen one of these on the shelf of a store in
    Colorado, grab it, as you would be nearly the first person in the
    U.S. to have one. The 3021 airfoil of the Legend is faster than
    the 4061 of the Quasor, if speed is an important concern. Also,
    Airtronics kits have a reputation for top quality.
    I'm looking forward to meeting you when I come to Colo. for the
    contest.
    Now if I could only get Mark or Ron to tell me where the field is.....
    
    Terry
    

    
    from the raw specs I would have choosen the LEGEND, the main spar looks
    pretty solid to me. The QUASOAR has a foam wing with just an upper and
    a lower spar, but should be sufficiently strong, especially when I would 
    reinforce it with carbon fiber (if Reinhard would give me some).
    But the point is, the QUASOAR is available in the store, the LEGEND 
    don't. And there is that cost difference $115.- for the QUASOAR versus
    $179.- for the LEGEND when mail ordering - and I don't know how long
    it would take to get it. And Jim's preference is the QUASOAR what tells
    me, that at least one would vote for it, it cannot be that bad. 
    
    I hope I meet you all at the competition. Is it the 26th August ?
    If Mark won't come up with the directions to the field, I will ask
    in the local store (Jack) where it is.
    
    
    Holm- und Rippenbruch,   Bernd

    Bernd,
    
    Yes the contest is the 26th. I'm coming up on the 24th, maybe get
    some practice in, on the 25th.
    
    I've seen a completed Quasoar but never saw it fly, or actually
    the owner attempted to fly it but it was severely out of balance
    (tail heavy) and it did a flat spin off the hi-start, landing without
    damage. The embarrassed owner picked it up and rushed off before
    we could help him trim it out. It is a nice looking ship.
    
    The Legend isn't on the market yet in spite of the magazine ads,
    so I suspect you would have an indefinite wait if you tried to mail
    order one.
    
    Hope this rain lets up before the 26th.
    
    Terry
    

    Hi, Bernd, why dont you let us help you with one of our All Composite
    home built ICON's, see me about it and also I will let you try your
    thumbs on it.  We may be able to get you the wings, stabs, rudder
    before you go back to Germany and then you can get a comet fuselage
    from Hans Mueller and assemble it.  Even has a fancy smancy slide on
    nose cone!
    
    If I was going to buy a fast ship with ailerons/flags solid wing etc, I
    would go with a FALCON 880, granted they are not in the stores as off
    the shelf but they can be had mail order and they are pretty good for
    the price.  There is one of them in our club and at least 2 of them
    that I know of flying up in Denver.  The Falcon in our club crashed
    last weekend but only busted the nose off of the fuse, it should be
    flying in time for the contest and I would be willing to bet that one
    of the ones from Denver will be down for the Aug 26th contest, his name
    is Byron Blakeslee, who may sound familiar, he writes the Soaring
    column for Model Aviation.  I also have a Mueller King that I have been
    thinking of selling.
    
    OK Terry, Here are the directions....
    
    Take Highway 94 from north of the Colorado Springs Airport/Petereson
    Airforce base, east 17 miles to the town of Ellicott, in Ellicott turn
    Right on Ellicott Hwy and go 6 miles south to Drennan Road and turn
    right, go 2 miles west and it is on the South East Corner of Drennan Rd
    and Bar 10 road.  If you find out where you are staying, and I really
    dont have any ideas on locations to stay at off hand if you would call
    me either fri or Sat night and tell us where you are at we could give
    you directions from that point.
    
    Bernd, plan on comming over to my house at least once for dinner, say
    one night next week, we could even cut your foam wings for your ICON if
    you wish, bagging them would only take some glass cloth, but that is
    or can be gotten in a few days I believe.
    

	Last Saturday I went to the PPSS flying field to watch a 2 meters
	fun flight event held by the club. Mark Antry told me to ask for
	a guy named Frank Deis, he'd bring his FALCON 880 to the field.
	After a (almost) endless drive I found the field. My thermal_looking
	eyes told me, hu, this area is very uniform, no trees no cornfield
	or anything else that could possibly produce a temperature gradient
	needed to get thermals development. And I know what I'm talking about
	since I've read those books.... 

	There where maybe 10 people with sailplanes, mostly GENTLE LADY kind
	of planes, but real nice built and finished. And there was this sleek
	looking ship lying on the ground, the wings with a slight V and the
	outer 1-1/2 foot with a steeper V, having ailerons and flaps. The guy
	whom this beauty belongs too is Frank Deis. He starts explaining me
	some details, while the other contestants where Hi-starting their 
	Ladies WITH the wind, gaining some feet of altitude and making spot
	landings (assume the wind just turned). The high starts at this point
	of time looked real critical, no so later.

	Well, one of the most interesting details where the way the flaps and 
	ailerons where hinged. He uses an aluminum bow arrow, glued to the 
	control surface. He cut two slots in each for the movement of the 
	control surface. Inside this tube there where two pieces of round 
	aluminum that exactly fit, with a threaded 4-40 hole in it. From
	outside a 4-40 screw was attached through the slot in the tube 
	and srewed into that piece ao aluminum and glued into the wing.
	A perfect hinge, no gap, aerodynamically perfect and  v e r y  stiff
	with no play. Super !  He explained the functions build in the 
	computer TX, I cannot recall all of them. But there was a variety
	of mixing one channel with a certain percentage and differentiated
	to annother one. (example: flaps where mixed to elevator, rudder
	to ailerons, ailerons with flaps and elevator for the craw-manoeuver
	and much more).	

	When the winch and high starts where turned against the wind Frank
	made a flight with the FALCON. WHOW, the winch start was awsome !
	Not to compare with my baby winch what I now believe to have. And
	I was so satisfied with my winch....until you see a better one.
	He then showed me the speed range of his Falcon, to say I would have
	been impressed would be the understatement of the year !  He was
	going very slow with the flaps down, as I'm used to from my Cirrus.
	But with the flaps up coupla degrees it was going fast, like my ASW
	after a 200 meter vertical dive - but it was doing it almost 
	horizontal !  And then the landing aproach, much too high and too close,
	my ASW with spoilers would have made two more turns to land before
	our feet - the FALCON landed with the craw manoeuver right in front
	of us. This made my day finally - does anybody wants to buy a brandnew
	ASW24 (just few flight) out there ?

	The next flight Frank gave me the TX after launching - when grapping
	the TX - "scratch" - I hit one of the mixers, was nervous because I
	didn't know which one and where - my flight for shure was not 
	impressive, it got to much speed when turning (I pulled not enough)
	and so on. This ship needs practice, practice, practice...
	The second flight was a little better since I didn't worry so much
	about the mixers, still not good. Frank did perfect.

	Then I've gotten a flight on annother plane with polyhidreal (sp?)
	wing, 3 meters wingspan and rudder/elevator/spoilers only. I don't
	remember neither the name of the owner not the name of the plane. A real
	thermal spip, nice to fly with slow speed. I got a beautiful thermal.

	I don't know the result of the contest, but it was fun to watch
	bomb dropping, spot landing etc. Because I've never seen RISERS, 
	GENTLE LADIES and such plane flying I really liked their thermaling
	abilities and manoeuverability (this word kills me !). 

	AND there were this strong thermals, that popped off everywhere.
	I think these thermals almost fold your wings when entering them. 
	Where do you get these from and how to order ? TOWER - HOBBY LOBBY 
	or maybe HOBBY SHACK ?  Could you tell me your secret ? My books
	tell me otherwise.


                      \\
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		      <      \  \-''
		       '-___-'\  \            
			       \  \
                                \  \          Holm- und Rippenbruch,
                                 \ \
                                  \\                          Bernd

    Good report Bernd.
    
    Thermals everwhere...you betcha.
    
    Welcome to the high plains.
    
    Terry
    

    Well, last night was the night to have Bernd over for Dinner, its a
    good thing that Bernd's favorite American food was Hamburgers, so we
    fired up the BBQ and cooked some burgers.  After dinner we headed right
    for the workshop downstairs and assembled both my Mueller King and PPSS
    ICON and played with them some.  We then spent the rest of the evening
    talking about composit construction techniques and Bernd even got a
    chance to cut a foam wing panel with my hands off cutter.  Hopefully
    Bernd will be here past the end of August and it will allow him to
    attend the USA F3b team trials in Denver on Labor day weekend.  Also if
    we have the time we are going to make Bernd an ICON before he leaves,
    or at least do the wings, stabs and rudder, then we he gets back to
    Germany he can pick up a COMET fuselage from Muller and slap it all
    together and have a KILLER sailplane!
    
    Yup ole' Bernd is a great guy, really alot of fun to be around, accent
    and all, was quite a fun time, even my wife and 6 year old enjoyed his
    company.  The chuckle of the night though was when we were talking
    about living in large cities in either America or Germany and how Bernd
    does not like all the Auto traffic, "You know" he says, "I don't like
    driving in those traffic SLAMS"  You me traffic JAMS Bernd, YA YA.
    Now all we have to do is get him to get rid of all those planes he has
    with that funny noise maker, gas eater, finger ripper that is on the
    front.  As it has been said before, "Anyone can fly with an engine!"
    

    I forgot to mention that on this Sunday we are dragging Bernd out to
    the PPSS field for our August NSS soar in that we hold every year.  ONe
    of our fellow flyers has a OLY II that we are going to let Bernd fly
    and we will just see how he does!   Looking forward to it.  Bernd did
    stop by our Club meeting on this past Tuesday and I had him talk for
    about 5 mins about flying sailplanes in Germany.  I think everyone
    enjoyed his talk than about all of the other meetings thus far.
    
    
                                        

	Thanks, Mark, it was a fantastic evening and a great dinner. And
	the superb beans your wife cooked I'm still aware of.....

	His planes are really something, the KING and the ICON both high tech
	gliders, with impressive features (not only due to this programmable
	Tx). When I was at evil Eric's house around April this year and he 
	showed me his foam cutting I was impressed. BUT the foam cutting
	quality that Mark showed me yesterday is unbeatable ! YEAH, that's
	the way to cut foam. All you need is some wood, wire, power supply
	clamps, string, wheels, one empty can (to put the lead in), screws,
	nails, a wall, few other items and a good building instruction - 
	(almost) no wizzards and you have a perfect foam cutting machine.

	The next one was the sheeting technic, no balsa at all, but some
	glass and epoxy for covering and mylar foil and a vaccum bag with
	pump. The result is the best trailing edge I've ever seen and a
	surface that comes vey close to absolut perfect. If you're worried
	about pinholes just fill them - there you are. The wing is vey stiff
	and the weigh with 4 servos is 670 grams per winghalf. 

	With the hinging technic Mark uses he gets a high performance 
	wing capable to compete in todays F3B competition. It might only
	depend on the pilot's skills and luck ?

	With the right attitude such a plane is built in two weeks. Attitude ?
	Well, if you like it pretty you could easily spend much more time in
	cosmetics instead of flying.

	Saturday morning Ron will pick me up and we drive together to the field.
	We'll be there around 8:30. Hope Barry has charged the nicads of the
	OLY what is is going to let me fly, I plan to soar for hours in those
	monster thermals out there ... 

	Dress yer warm, Bernd's coming to compete !

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		      <      \  \-''
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                                \  \          Holm- und Rippenbruch,
                                 \ \
                                  \\                          Bernd

    I'm looking to build up my set of tools again now that I have jumped
    back into the hobby. 
    
    Apart from a good compressor/vacuum pump I am hunting around for plans
    for a good "hands off" core cutter. Seems that Mark has got just the beans.
    
    Any chance of a set of drawings, an article, some help, anything on
    setting up a good rig?
    
    	would be very grateful,
    
    	regards  George Frost

    Send me mail with your internal mail address and I will make a copy
    of the plans that are going around with the DECRCM tape...  Neat setup.
    
    Cheers,
    jeff
    

    
    	When I was at Mark's house last Thursday I was impressed with his
    	foam cut setup. He didn't have any plans, I would appreciate if I
    	could have a copy of the plans, too.  My mail adress is 
    	KBO/ Bernd Knoerle
    	
    
    	Holm- und Rippenbruch,  Bernd
    
    	

    Those are the ones to get!!!!
    

    
    
    
        I wrote this reoprt last monday, just forgot to reply in notes -
    	how silly I am ! (I think I'm getting old, senil, debil, 
    	whatever....)   
    
    
	The training with the OLY at Saturday was very good, I've got some
	good flights in the 9-14 minutes range. There was just a little wind,
	no problem for the OLY. But I couldn't get it down in the circle. This
	plane just didn't want to come down. So I figured a good score would 
	only depend on the pilot's skills. My strategy was : stay up 10 minutes
	each flight and come down exactly after 600 second, land right on the
	nail of the landing tape and get the score of 2800 points for 4 flights.

	Sunday morning was calm in Colo Springs, almost blue sky, my strategy
	should apply perfect. Out at the field the wind was blowing quite a bit,
	maybe I wouldn't get all the landing points...

	I met Terry Tombaugh (sp?) out at the field, a very nice guy with great
	planes. I enjoyed talking to him, it's quite an experience when you
	know somebody from the notes and met him personally later.

	Okay, the first round went bad, I didn't come off the hook perfectly
	and touched down after (I hope to  remember right) 3:50 right at the
	edge of the landing tape receiving 35 landing points. Too bad, I didn't
	find THE thermal, just a baby thermal and lots of down.
	In the same round Ron got a flight close to 10 minutes with good landing
	bonus, so did Barry, whose OLY I flew. I don't remember Mark's score.
	My strategy didn't work out perfect at this first round.

	But at round two, I didn't come perfectly off the tow either. There 
	was a thermal I could utilize for coupla minutes, gaining a 5 something
	minutes flight with approx. 75 landing points. It was  getting better,
	the last two rounds with 700 points each should still get me the first
	place in sportsmen.

	The third round my strategy was : wait till the wind calms down, the OLY
	is perfect in calm air. When I went to the winch, the wind was real low.
	The launch was lousy (sp?), I need more practice. When I finally came
	off the tow, the wind picked up enormously. No thermals in this run,
	touch down at 80 landing points after 2 minutes something. The hope of
	the first would have got low, if there wouldn't have been a 4th round.
	With a perfect 700 I still could make it probably.

	Meanwhile two planes unfortunatelly disassembled completely, real scary.
	The first plane was a high performance F3B type of plane, doing stunt
	manoeuvers at the launch. I don't know what caused the trouble but
	I could share the feelings of the pilot, I've been in this situation
	with a bit more luck. Sorry Bruce (name correct ?). The second plane 
	was one of these Gentle Lady - type of plane, maybe an OLY, for shure
	with build-up wings. It just couldn't stand the ZZZOOOOooooommmm. Having
	to watch was no fun at all. Real sorry.

	The last round I went to the launch prepared, Barry would launch his
	OLY and I would be the pilot flying his OLY to all the honors. This
	time the launch was perfect, I was getting heroical feelings when I
	took the transmitter. And there was this real Monster thermal - a real
	inverted one, everywhere. I had to watch the OLY coming down as fast 
	as it would dive straight down. No lift anywhere, just SINK !  
	After 1 minute 30 (was it one minute ?) I got somewhat 80 landing 
	points (I believe), maybe more than for flying. I was smashed down. 

	Terry got his best flight after changing to the VIBARO, he was very
	unlucky with the SOUTHWING coming off the hook twice.

	A total of around 1100 points and the 4th place and still getting a 
	yellow band - I like it. To get a better place would't have been fair,
	the other guys were just better. I'll work on it.

	I don't have the overview of the other classes, maybe Mark will type
	the results.

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		      <      \  \-''
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                                \  \          Holm- und Rippenbruch,
                                 \ \
                                  \\                          Bernd

    You did well. Being he proud owner of a new Oly II, I hope to do
    as good as that. I have spoilers installed in mine which hopefully
    will help get it down. That's assuming, of course, that I manage
    to find any kind of thermal in the first place. There's a glider
    contest at the Central Mass field in another week. I'll let you
    know.
    
    Nice going,
    
    Steve

    
    	Hello Steve,  you will have lotsa fun with your OLY II. It's very
        gently flying with good response. You can make turns almost like a 
    	turntable, if you use rudder and elevator. To find thermals the OLY
    	is easy to watch. Even very light thermals will lift it. 
    	If there's some wind you should use enough lead at the CG,
        otherwise you could get into trouble to land it where you 
    	started. One funny thing I didn't report : When I was trainig on
    	Saturday, I had pretty good lift and maybe 600 feet altitude. I 
    	tried to bring it down somehow, making loopings, flying inverted,
    	dive steep and release slowly (not to build up too much speed nor
    	stress to the wings). Because there was some lift it took me for
    	shure more than 3 minutes to get it down. I tried to stall it,
    	no success. Full rudder and full up elevator resulted a very tight
    	turn with steep banking, but not loosing altitude. This plane is
    	fun to fly !
    
    
    	Holm- und Rippenbruch,  Bernd

    Well the 1991 United States F3b Team has been Decided.  The team 
    trials were held up in Denver the weekend of Sept. 1st, 2nd, and 
    3rd.  The event started out on Friday Aug. 31st with the checking in 
    of pilots at the hotel and the measuring and weighing in of planes 
    and the certification of winches.  At 6:45pm the pilots meeting was 
    held and all of the rules were gone over with any questions being 
    worked out.  Saturday morning started the contest off with the first 
    round of duration starting out about 8:20am.  It was a little windy 
    in the morning so pilots were forced to punch out front and just 
    park until their 6 min precision duration task was finished.  We 
    managed to finish off Saturday with 2 complete rounds being run, 
    each consisting of Duration, Speed, and Distance.  Larry Jolly 
    turned in a record setting 17.1 second speed run in the middle of 
    the day and after Day 1 he had taken the lead and was to never give 
    it up.  Sunday, Day 2 so more of the same events and 2 complete 
    rounds were also completed.  Speed runs were a little slower on 
    Sunday and by mid-day you could see the Colorado thin air and heat 
    starting to wear on the pilots and their teams, I think this contest 
    is also one of attrition, just seeing who can stay on the edge of 
    perfection the longest.  A brief Colorado Thunder shower did delay 
    Sunday afternoon's events by about 1 hour but after the storm blew 
    thru it was back to flying again.  Monday started off a little 
    slower than the previous days and changing winds caused the winches 
    to be moved 3 times throughout the day, whereas on Saturday and 
    Sunday the wind was out of the South in the morning and right about 
    noon it switched to out of the North.  The trials were finished up 
    about 6pm on Monday evening and the final results are listed below.  
    It is interesting that the lowest score is 75% of the highest, so 
    you can see just how close the competition is in a contest like 
    this.
    1	 Jolly	   14855	       12   Spicer    13069
    2	 Perkins   14697	       13   Wyss      13035
    3	 Wurts	   14690	       14   Drake     12599
    4	 Dawson	   14556	       15   Hiner     12495
    5	 Edberg	   14254	       16   Edmonds   12485
    6	 Lewis	   14272	       17   Fredette  12134
    7	 Burnoski  13581	       18   Sasson    12128
    8	 Keer	   13555	       19   Edson     12029
    9	 Hesselius 13481	       20   Phelan    11544
    10	 Tiltman   13206	       21   McCarthy  11242
    11	 Miller	   13081	       22   Corvin    11212
    	 Stroup	   DNF		       	    Burr      DNF
    

    The NSS Soar in was quite the International competition this year as 
    you will see in a minute.  As I left my house the morning of the 
    contest, it looked like it would be a favorable day but upon 
    arriving at the field we had the usual Colorado wind.  The winds 
    were about 10 mph out of the south.  When I got to the field and 
    started the checking it became apparent that there were several 
    people there that I did not know.  I knew that there were going to 
    be two out of towners but we ended up with 5.  There was Bernd 
    Knoerle from West Germany who is working over here for a couple 
    weeks with Digital Equipment and Terry Tombaugh that drove up from 
    Albuquerque NM who works for Digital down there, Phil Shew also 
    drove up from Albuquerque.  Bill Dickey from Topeka KA, and Darrel 
    Calton from LaCompton KA were vacationing in Colorado and decided to 
    arrange it around our contest.  Chuck Anderson was also in Colorado 
    from Tallahoma TN and decided to bring a plane and fly with us.  
    Also Dave Fagan from Morrison Colorado decided to come down and let 
    us be the first glider contest that he entered, congratulations 
    Dave!  Unfortunately the weather wasn't the best that we could of 
    had and it resulted in some lower than normal scores but when the 
    day was all over after 4 rounds of 10 min precision duration the 
    winners were:
    
    	 Open Class		       Sportsman Class
    1	 Dave Kurth	2047	  1    Joel Zellmer   1564
    2	 Ron Watts	1644	  2    Bill Dickey    1452
    3	 Barry Welsh	1586	  3    Pat Haley      1015
    4	 Bob Avery	1540	  4    Bernd Knoerle  1010
    5	 Jack Dech	1314	  5    Phil Shew       963
    6	 Chuck Anderson	1219	  6    Darrel Calton   799
    7	 Mark Antry	1205	  7    Murry Lane      222 DNF
    8	 Terry Tombaugh	 596	  
    9	 Ben Demeter	 555 DNF       Novice Class
    10	 Duane Thomas	 192 DNF  1    Matt Kindle    1112
    	 			  2    Steve Tarcza    942
    DNF = Did not finish	  3    Dave Fagan      437

    Note 399.397 earlier today referred to 399.231 where the dynamic
    balancing technique was described by Anker.

    I have attached the old, terse keyword, "CG", to that note for future
    reference.  Notice that the keyword, CONTROL_TRIMS, is not appropriate,
    since it is not a control that is being adjusted.  (But comments and
    suggestions are welcome.)  

    The technique is simple; even I use it.  And since I have to repair and
    rebuild before each flying day, I use it almost every flying day.

    It was written up in R/C Soaring Digest last spring or winter ---
    complete with diagrams. 

Thanks to Dave Walter, his advice and his hi-start, I was able to put in about
6 flights on the OLY II last night after work. The first flight, I chucked it,
and Dave flew it up the hi-start. Went up nice and straight. After it came off
the line, he handed the radio to me and I began to familiarize myself with
the bird. First flight was fairly short, maybe 2 plus minutes, as I was just
doing trimming and feeling. Second flight, Dave chucked it and I flew it up.
No problems. It again went up nice and straight. This time I did some dynamic
testing and found that I was a little nose heavy. Landed and took out a quarter
ounce of lead. Went up again, this time doing everything myself and found that
it was still just a tad nose heavy. I will take out another quarter ounce of
weight and that should do it. Last night, I just wanted to fly so I didn't
bother opening it up again. The last few flights I concentrated on staying up
and doing landing approaches. I was averaging between 3 and 4 minute flights
with landings within 10 feet of myself. considering the fact that I was doing
nice gentle, pretty landings, being within 10 feet ain't to shabby. In a
contest, I'm sure I could PUT IT DOWN much closer. The last flight of the 
night, I managed to get a 5 minute 45 second flight in virtually dead air. The
way the OLY floats is incredible. It was also fun playing with the spoilers.
I was kicking them in on final about 6/8 feet up. The OLY drops its nose but
doesn't pick up any appreciable air speed. You just compensate with elevator
and you can drop it where ever you want it. Can't wait for the contest
Sunday.

Steve

    
    	congrats, Steve, for your successful first flights. Your report is
    	exactly what I experienced with the OLY I had flown : an
    	outstanding floater. With spoilers the landings should be very
    	predictable, it wouldn't be without. This bird just doesn't want
    	to come down.
    
    	Bernd

For those of you who have read "The Old Buzzard's Guide to Soaring", you might
have noticed a reference by Thornberg to an article in Scientific American on
how birds soar. I had nothing to do one lunchtime so I went to the local library
and badgered a librarian to go down to the dungeon and dig through the archives.
I forgot to note the year and month of the issue (might have been 1963?), but
it's Volume 206, #5, "The Soaring Flight of Birds".

I made a copy of the article. Thornberg must have borrowed heavily from it,
because many of the diagrams show up in his book in a cruder form. The article
briefly explains soaring in wind shear (how sea birds stay aloft without wing
flapping), it spends quite a while on the formation of "thermal shells", and
gets a little into the aerodynamics of birds wings. I can't say I learned
anything radically new, but if you liked the Old Buzzard's book, I think you'll
be interested in this. It mainly covers the same information in more depth, with
nicer diagrams. It even gets a bit into history, how the theory of thermal
behavior was developed. 

If anyone would like a copy, send me E-mail with your mailstop.

Dave

    Heard from my local hobby shop proprietor:
    
    Availability of the Airtronics Legend has been pushed back to some
    indeterminate time. Airtronics can't find anyone to build the fuselages
    for them.
    
    Their three new radios will be introduced between now and next spring,
    including the freq. changing model.
    
    Terry
    

Just got the latest Dodgson Newsletter in the mail last night.

Lots of interesting stuff in this one.

1.  Announcement of the new "Saber".
    121" span
    1030 sq. in.
    70 oz.
    SD7037 Airfoil
    modified Schumann planform
    Kit has completed fuselage (not the typical Dodgson taco shell)
        comes with full size Obechi sheeting (no more sheeting splicing).
        requires computer radio (no AFART linkage supplied).
    
    One goal was to reduce the building time.

    Looks great to me.

2.  They have stopped the Orbiter but offer plans and building instructions
    for $10 plus #3 shipping.

3.  Letter by Micheal Frederic (Kent Washington) recommends machine shop
    Ejector pins for wing rods.  Says they come in most diameters and lengths
    as long as 14" or more.  The outside surface is nitrided to a hardness
    of 65-74 Rc, and liquid honed.  In other words, the pins are very hard on
    the outside surface to give the least possible amount of flexing and yet
    they are softer in the cord so that if they are over stressed they will
    not break off.

    Sounds interesting.

4.  He (Bob Dodgson) took exception to an article published in "The Spoiler"
    (the journal of the Pikes Peak Soaring Society - Feb-1990).  So Bob spent
    over a page (of fine print and figures) flaming the author Randy Reynolds.
    Great reading - an as Bob states in his advertisement -
    "I will consider that I am slipping, if I put out an issue in which I have
    not offended a large segment of the soaring population.  So...if you are
    left deflated by watered down articles on soaring, worded so as not to
    offend anyone, they you too are ready for your SECOND WIND."  The name
    of his news letter.

    It was 10 pages long and cost $2.00 for a one year subscription of the
    bi-annual news letter.  Available from 
        Dodgson Designs
        21230 Damson Rd. 
        Bothell, WA 98021
        phone (206)776-8067


Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################
    
   

    If anyone finds out what the price of the Sabre (note spelling)
    is, please let us know. I fear the worst.
    After using Obechi sheeting on several wings, I've come to the
    conclusion that its' only advantage over balsa is the fact that
    the extra width eliminates the necessity to splice sheets together.
    Otherwise it's more brittle, chips and cracks easily, harder to
    sand, grain requires more sanding/filling, almost mandatory to use
    vacuum bagging rather than weights, very sensitive to moisture,ie,
    no water based contact cements. Harder to repair because of all
    of above; but it doesn't gouge or dent as easily when landing
    in mesquite (puckerbrush), cacti, or prarie dog colonies.
    My next wing will use blue foam skinned with 1/48" birch veneer.
    Now awaiting arrival of cores and vacuum bagging equipment.
    
    Terry
    

>< Note 399.418 by ELMAGO::TTOMBAUGH "High Plains Drifter" >
>
>   If anyone finds out what the price of the Sabre (note spelling)
>   is, please let us know. I fear the worst.

	$295.00 plus $15.00 UPS shipped in 3 boxes. 

	Info from latest Dodgson newsletter.

    Gee, I would really like to see Dodgson's newsletter. Could someone
    send me a copy? I'm at CXO1-1/N15. Did the newsletter include Randy
    Renolds letter or just Dodgson's response?  Also Dodgson's letter was
    first published in the "Spoiler" sans the personal attacks.
     
    
    Ron Watts 
    Editor
    "The Spoiler" The Journal of the Pikes Peak Soaring Society
   

< Note 399.420 by GENRAL::WATTS >
                     -< A Question About the Second Wind >-

>    Gee, I would really like to see Dodgson's newsletter. Could someone
>    send me a copy? I'm at CXO1-1/N15.

     Since I'm going to be in the office tomorrow (which I get into 
     once every week or so whether I want to or not) I'll drop you
     a copy. Please be patient since it has to go by slowwww boat.

     -TomR-
     
   

    Thanks Tom. I'm looking forward to see it.
    
    Ron Watts

	Mark gave me some directions to their slope_soaring_mesa near Monument,
	Colorado. I found one, still not shure if this was the one Mark 
	described, but what a slope !  Approximately 300 - 400 feet high, 
	in the middle of nowhere. Just gras around, should be a good basis for
	good thermals besides the slope lift. If the wind would have been 
	blowing from south or north, it would have been 100% perfect. But
	the wind was blowing from west/south-west instead. And there the range 
	where you could fly was not very wide, but it worked great !  
	I enjoyed 1 hour slope soaring with good wind (15 - 25 knots as the 
	forecast said) and one monsterthermal, that lifted my plane like it 
	was in a high speed lift. 

	Because I was out in the afternoon, I had to look always into the sun
	watching my plane. For landing I had to walk back maybe 150 yards at
	least because there were too many rocks laying around. When walking back
	my plane lost some high, maybe I was not flying at the edge anymore.
	When circling back to where I wanted to land the plane was to low
	to get to the top of the mesa. I tried to fly back to the front edge 
	(where the wind was coming from) because there was no lift anymore 
	the edge where I wanted to land (the wind was blowing parallel - 
	imagine a u-shaped slope) when I got a bad tip stall. This never 
	happened before - SURPRIZE. The ASW24 spiraled into some rocks. 
	The spiral was not to steep, it couldn't built up much speed before it
	crashed. Damage : slight damage at the balsa part of the right wing tip,
	the rudder hinges popped out (they are stucked in a slot), little cracks
	where the rudder control horn comes out, one crack (3 inch) at the fuse,
	servo board broke 3 times and came loose. The whole fuse must have been
	completely bent where the canopy sits, there are bending marks visible.
	Imagine an epoxi fuselage !  There seem to be some advantages of an
	ABS fuse over epoxi fuses - this for shure was one. Under the line :
	minor damage, fixed already.

	In the morning I flew my Ringmaster C/L for the first time. It is 
	powered by a FOX 35 (Bernie, this is the one I bought from you).
	I was not too impressed with the flying characteristics, it was just 
	flying too slow. Is it the altitude ?  I did some stunts, the loops
	where always a risk, I did three belly landings because I missed
	several inches at the bottom. 

	Aileen, my daughter (3 years), helped me to start the plane. The 
	first time she release it before I hold the handle in my hand -
	I got it before the plane took off - uffff, lucky. Silvia, my wife,
	told her, to hold it longer and listen when I say "let it go".
	The second start, she hold the plane. I shouted "okay, Aileen, let
	it go". Because the propeller wind was blowing sand around, she closed
	here eyes and turned here head - away from me. And this muffler on
	the Fox is not a Snuffler. I shouted, cried as loud I could, Aileen
	just didn't hear me. There she was sitting, holding the Ringmaster,
	here I was jumping, waving my arms, shouting " Aiiilllleeeennnnn, let
	it gooooooooooo!" - afaid to move because she could let it go every
	moment - unpredictable. My wife was so badly laughing, since she was 
	further away with Marvin, our son, watching this scene. 

	Well, when the plane finally was airborn, I was doing inverted flight
	maybe 4 feet above ground (luckily) when the elevator (stabilizer) 
	came off. I only broke the needle valve and rudder. The elevator 
	didn't come off the glueing surface, it ribbed off the balsa of the
	fuse which was pretty soft. 


	Oh what a day !


                      \\
                       \ \                    __
                        \  \                  \ \
                         \  \                  \ \
                          \  \                / \_\
                           \  \              /LO |
		       .o^^^--------==========___/
		      <      \  \-''
		       '-___-'\  \            
			       \  \
                                \  \          Holm- und Rippenbruch,
                                 \ \
                                  \\                          Bernd

    Does anybody have the number for Bob Sealy Quality Fiberglass? I know
    he recently moved to Ten. and I want to order a 2 meter Fuse.
    
    Thanks 
    Ron Watts
    

    
    Sealy's address and number is
    
    Bob Sealy Quality Fiberglass
    1941 Dixie Ave.
    Cookeville Tn.  38501
    
    PH. 615-526-4770
    
    

	Now that I've got this ancient computer radio (Multiplex Royal MC)
	and I will be able to do all kind of mixing, how do I setup the
	Quasoar ? 

	For those who don't know how the Quasoar looks like, it has polyhidral
	(sp?) wings with flaps, no ailerons. I will install two servos for the
	flaps, one right and one left and two others, for elevator and rudder.

	Because of all this mixing possibilities, I could have an aileron 
	function on the flaps (coupled with rudder). Would that be recommented
	on this kind of a plane or shouldn't I install aileron function, which
	is probably not very effective because they are not located 
	close to the wingtips ?  Is the aileron function probably eating up
	significant thermal performance that I really like to get out of this
	plane ?  Or is it even more recommented to use just one servo for the
	flaps ?

	I will have flaps coupled to elevator, and on demand vice versa to
	get real manoeuverability.


                      \\
                       \ \                    __
                        \  \                  \ \
                         \  \                  \ \
                          \  \                / \_\
                           \  \              /LO |
		       .o^^^--------==========___/
		      <      \  \-''
		       '-___-'\  \            
			       \  \
                                \  \          Holm- und Rippenbruch,
                                 \ \
                                  \\                          Bernd
	

    I am currently building an Osprey 100" glider (second RC model - and
    the first one is still in one piece!)
    
    I have a question about the use of closed loop rudder controls, as used
    in the Osprey. The books tell me that you should always set up the
    servo arms and control horns to get the correct throw of the control
    surface with the maximum servo travel, so as to obtain the most
    accurate control from the servo. The use of rate switches is a
    "second-best" because you lose servo definition. However, with a closed
    loop system you need to set up the geometry so that servo arm
    connections and control horn connections are the same distance from
    their respective pivot points, to avoid the cables loosening/tightening
    as the servo moves. But this means that you must restrict the servo
    travel using rate switches, in order to set the maximum control surface
    travel, as servo arms and control surface will turn through the same
    angle.
    
    I guess that the geometrical requirements are the most important (and
    anyway, with my current level of flying skill I don't suppose that
    servo positional definition makes much difference!) but I am curious
    from a theoretical point of view how you reconcile these two opposing
    aims. Anyone have any comments?
    
    Anyone else out there fly an Osprey? Does it really perform so well
    that I am going to regret not building spoilers into the wings?! Or
    does the actual performance not quite live up to the kit manufacturer's
    claims :-) !

    re. .434
    
    Bernd, 
    If your radio will support the flaperon function, by all means use
    it. If you retain the stock poly angles, response won't be as quick
    but ailerons will still be useful. I'm using the same set up with
    my Southwind, the one I couldn't keep on the tow line at the NSS
    contest. I reduced the poly angles about 50% and roll response
    is pretty good but the rudder throw has to be used on low rate most
    of the time when using light lift to keep the response down where
    I like it.    
    
    Terry
    
    
    re. 435
    
    I'm using closed loop rudder control with kevlar string on a ~ 120"
    sailplane and it is the best rudder system I've ever tried.
    Don't worry about the theory of angles and all that. Just
    keep as straight a line as possible between the servo arm and rudder
    horn, make sure the cable isn't rubbing on anything, or sleeve it
    if it is, set the string tension equal on both sides of the servo
    arm when the servo is in neutral, and go for it. Of course
    the string will go slack on one side when turning. So what?
    Trying to avoid this won't buy you a thing except wasted time.
    Try it, you'll like it.
    

    Couldn't help noticing, that if the string goes slack on one side, you
    will have "backlash" or sloppy/floppy controls, as the surface won't
    respond going the otherway until the slack is taken up.
    
    Then again, the air pressure on the surface would help move the control
    surface until the slack is gone from the other side.
    
    ajai

    I had this system on my first Panic fuselage. The big problem I ran
    into was that the edges of my exit guide tubes weren't as smooth as
    they should have been and this chewwed on the Kevlar lines over time.
    When I built the second/lighter fuselage, I went with light wire cables 
    to help eliminate the fraying problem. Pull-pull is great and the slack
    is minimal and taken up by ANY air pressure

    Will the flight charactristics still be the same when I reduce the
    angle of the Polys ?  Shouldn't the polys stabilize the plane when
    flying narrow turns in thermals ?  Did you experience any difference
    when reducing that poly angle ?  I rather take personal experiences 
    than theoretics.
    
    Bernd 

    re 437
    
    My statement about slackness has been bothering me all morning while
    I was off doing other things. I didn't mean to imply that the slack
    side of the line was so loose that it was lying on the bottom of
    the fuselage 8^), I meant that it felt looser than the tight side
    when plucked with the finger. This much slack doesn't cause any
    slop in the controls. The Goldberg pull-pull set comes with outer
    ny-rods and metal ferrules to slip over the end of the rods to prevent
    fraying of the kevlar. The eyelets that interface between the kevlar
    and the control horns are larger than necessary though, creating
    a rather clunky appearance. Next time I'll engineer my own setup
    and do away with the eyelets.
    
    
    re. 439
    
    Bernd,
    
    If you reduce your poly angles and then try to make rudder-only
    turns you will notice some skidding. However if you fly with 
    coupled flaperons and rudder then everything will groove nicely
    after a little experimentation to find the optimum rudder travel.
    And sometimes it's nice to be able to skid around a flat turn with
    rudder only. I fly coupled flaperon/rudder 99% of the time on the
    right stick and rudder only on the left stick.
    That Quasors' a nice looking plane. I'll be interested to hear how
    it works.
    
    Terry
    
    

    This seems to be about the best place to ask this:
    
    What are the radio requirements for the standard and open class
    gliders. I've heard varying comments about number of channels and such
    and figured I'd ask here. I'm thinking of adding flaps to my Gentle
    Lady which I'll be building for an expendable (but bigger than the Gnome)
    ship for next year and I didn't want to restrict it from standard class
    competition next year but I've had so much fun with flaps on my Panic
    that I thought it would make a good addition for a "transportable" glider 
    for next season. I'm looking at a 99" model too but the modified Gentle 
    Lady will be my "toss it in the car just in case" glider.

>         -< How many channels/servos/functions for each glider class? >-

My favorite question.

There are presently no restrictions on the number of channels/servos/functions.

There used to be a limit to two channel for Standard Class.  And in fact
one contest here used to run a Standard Class where it was assumed that 
you could not use spoilers or flaps.  However in each case there was a
pilots meeting and it was decided that spoilers and flaps would be allowed.
Those without did not mind those with using them.  In consequent contests
the CD has been careful to call this "Modified Standard" class to be sure
that everyone knows that spoilers/flaps are allowed.  

The original goal was to create a "Standard" class that was affordable by all.  
I just looked through the 1990/1990 regulations and couldn't find any mention of 
this previous limitation.  In fact the leading paragraph to the definition
of sailplane classes says: "The following classes of sailplane shall be allowed
for competition and the number of control functions (servos) are unlimited.

Even at the one contest where they "almost" didn't allow spoilers they
were just asking the pilots to tape their spoilers shut.

Don't worry about it.  If you're building a standard class sailplane
and you want to have spoilers and/or flaps - put them in.  And everybody
uses Gentle Ladies for back up ships - I wish I had one.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    At our club meeting last night, some info was given on the new Roland
    Sommer designed 'Omega' for F3B competition.
    Last weekend Seth Dawson showed up at our sod farm to test fly his
    new Omega. Several of our club members were there (unfortunately
    not me) to witness. 
    Compared to a Mueller Comet it turns much quicker, and tighter.
    It uses a t-tail with separate stab and elevator. Seth was over
    controlling badly until he cut the stab throw down to 1/8", wow.
    Has about 110" span, with the wings of a balsa/glass laminate, top
    and bottom halves molded in an oven then joined in a monocoque
    structure with full depth carbon fiber spar running between them.
    The wing is otherwise completely hollow. Fuselage uses a carbon
    fiber crutch inside a condom style nose cone. Ailerons and flaps
    use some kind of knuckle hinge that results in a completely faired-in
    hinge line, but it's not an arrow shaft system. The whole thing
    comes completly finished with a white gel coat and cutouts for wing
    servos, and alum. access plates.
    Delivered to the U.S. for ~$800 including shipping and duty. (sigh)
    2-3 month delivery at the moment.
    So Buzz ordered two of them ! Gulp, and Phil ordered one, and Seth
    two more !
    So we'll be waiting to see these puppies fly come Jan.
    Almost forgot, they weigh 90 oz. with nose weight and radio,
    with provision for 20 oz. of ballast.
    
    Terry
    

RE: Note 399.443 by ELMAGO::TTOMBAUGH   -< Omega >-

>>    Has about 110" span, with the wings of a balsa/glass laminate, top
>>    and bottom halves molded in an oven then joined in a monocoque
>>    structure with full depth carbon fiber spar running between them.
>>    The wing is otherwise completely hollow. Fuselage uses a carbon

    Could you please explain the hollow wing construction further?  

    Are the top and bottom halves a glass/balsa/glass sandwich or
    balsa/glass/balsa sandwich or are they just glassed on one side?

    What is "monocoque"?  Does this mean just joined at the leading and
    trailing edges?  Exactly how is this process done?

    Does the carbon fiber spar run the full span or just part way?

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Castor Oil!! "    
                      |_____/

    Re: .-1, Dan'l,
    
    I can't speak to the other facets of yer' question but I can explain
    monocoque; this is where the exterior shape is maintained without
    benefit of internal structure.  Most glass fuselages, for example,
    could be considered nearly full monocoque while a fuse with minimal
    internal structure, just enough to shape the balsa (or whatever) skin,
    are more semi-monocoque.  In either of these cases, the majority of the
    stress/flight-load is borne by the skin.  You'll sometimes hear the
    phrase "stressed-skin" used in concert with monocoque due to this
    characteristic.
    
    In the case of a fuse (or other structure) where the internal structure 
    is intended to bear the stress/flight-load (skin strength adding little or 
    nothing to the structural integrity), this type construction is non-
    monocoque.  Most, if not all fabric covered fuses and wings are of non-
    monocoque where all metal fuses, though not necessarily wings, are
    usually at least semi-monocoque.
						 __
				|      |        / |\	   	       
      	         \|/		|______|__(o/--/  | \	   	       
      | |        00	       <|  ~~~  ____ 04 ---- | --------------------
    |_|_|        (O>o		|\)____/___|\_____|_/	   Adios amigos, Al
      |     \__(O_\_	        |	  |___/	 o	   (The Desert Rat)

    Sooo, it seems to me that once you get done building a regular foam
    wing, and glassing it, you just need to dissolve the foam away - by
    pouring petrol/gasoline on it, for instance? Does that getcha a
    monocoque wing?
    
    Boy, I learnt a new word today. Sure would like to know how those
    hollow wings are made.
    
    ajai

    I haven't seen this beast yet so some of my info is relayed from
    others; 
    The wing const. is fiberglass on the outside with balsa as one of
    the inner layers, I don't know how many layers there are, but I'd
    suspect a fg/balsa/fg layup.
    Monocoque is French for "single shell". I first heard it used in
    referring to racing car construction, but it generally refers to
    any type of construction that derives its strength from its outer
    shell with little or no internal framework.
    
    In monocoque glider wings the top and bottom halves are molded
    separately in  female molds, often in autoclaves under controlled
    heat and pressure.
    The two halves are joined only at the le and te, usually by fiberglass
    tape internally, held in place by an air bladder, which is then
    deflated after the epoxy cures, and withdrawn through the root end.
    The whole assembly being held in a jig all the while.
    This is all adapted from full scale glider construction, German
    modellers started doing it first, partly because they have access
    to full scale companies to learn from.
    I don't know exactly how long the Omega spars are. Most monocoque wing
    spars aren't full span. I guess it would depend on how the designer
    expected the plane to be used, and what experimentation showed he
    could get away with.
    Last winter at the  S.W. Regionals in AZ., Ray Olsen showed us some
    female molds he had made from carbon fiber. They were works of art
    in themselves. At first glance they looked like they had been machined
    from a slab of black marble. He also had a custom, computer controlled
    autoclave built for him by a commercial oven company for ~$3000.
    He planned to start production on a high performance thermal duration
    design and market the kits, but the latest word I've heard is that
    it's still not available.
    
    I'll enter more about the Omega as I find out more.
    
    BTW, Rich Spicers' Synergy design uses most of the above technology,
    and he's been advertizing those recently for ~$600. 
    
    Terry
    

    Terry,
    
    	If it isn't too technical, can you explain how the spar is
    attached to the hollow wing and if there is any other reinforcing
    structure involved like some sort of plug at the root that both
    wing halves would connect to.
    
    Steve

    Wonder why no one is buying my dissolve-the-foam idea!
    
    :-(
    
    ajai

    re .448
    
    I've heard of two techniques, there are probably more.
    In one, the spar is slipped in the open root end and CA'ed or epoxyed
    in place, top and bottom. This would probably work if you were'nt
    expecting massive fore/aft loads.
    In the other method the spar is  attached along its length, to the bottom
    wing half, before the top half is joined, using glass cloth or carbon
    fiber, in an 'L' shaped joint. Then the top half is glued over the
    spar where it contacts it. 
    Since we're talking gliders here, each wing panel would plug onto
    the fuselage independently, with a root rib of a glass/c.f./kevlar/
    plywood sandwich. You can buy laminated 6 x 12" panels of this type
    and just saw out the root rib to suit.
    There's usually another rib placed 3-6" outbd. to take the load
    on the outer end of the wing rod which then slips into the tube
    in the fuselage. There are as many ways to engineer this part
    of the construction as there are people doing it.
    The Germans like to use rectangular blade type wing joiners, the
    Yanks prefer tube and rod. Each has its dis/advantages.
    
    Terry
    
    

    Can you explain what is hand towing and what the purpose of the 
    spool??
    

    I'm looking for a shark fishing line with at least 80 lbs and 1000
    yards length (2 x 500 yards will work, too). Does anybody know where I
    could buy this and what price it would be ?  I like the fishing lines
    better than the wooven (sp ?) ones, the last ones tend to burn if two
    lines rub against each other.
    
    Bernd
    

    Has anyone got any experience/opinions on Max Mills' Southwind
    glider kit.  My father is looking for a winter project.  He
    wants a kit with flaps, no ailerons, preferably built up
    construction.  I talked him out of Ace's Easy Eagle.  The
    Southwind is 100" wingspan, eppler 193 airfoil, with rudder
    elevator, flaps.  My father needs a ship with docile handling
    due to very poor eyesight.  
    
    Thanks,
    
    Jim

    Jim,
    We were trying to launch a Gentle Lady. We figured that was the
    best choice for calm conditions. I agree that a winch with a handle
    that allows a straight pull on the line is a necessity. I was having
    a hard time keeping the drum perpendicular to the line, just holding
    it by one side. We may try again when there is a little more wind.
    
    To answer your Southwind question, I built one last summer and flew
    it at the Nats. There are several dozen flying around here, as Max
    used to live in Albuquerque and we were his guinea pigs.
    It's a fairly docile flyer, but faster than an Oly or Riser.
    It needs more flap area if you want to really slow down on landings.
    The stock flaps are intended more for maximizing thermal performance.
    The plans and wood are good, the instruction booklet could stand
    to be rewritten but nothing to give any problems to a resonably
    experienced builder. Dollar for dollar, I'd say it is competitive
    with any other all wood kit on the market. 
    If your dad orders one direct from Max, tell Max that Terry sent
    him. Kick backs and all that, don't 'cha know. ;^).
    
    Terry
    

    Terry,
    
         I thought you built a Westwind.
    
    Regards,
    
    Jim

    Last sat. was the first event of our winter contest season. We decided
    to try the balloon hitting event as described in a recent issue
    of RCSD. With a 3 mph wind blowing and the balloon sinking at a
    typical rate, it was essentially impossible to hit the balloon.
    Nobody managed it. When released at winch launch altitude you had
    time for 3-4 passes. At hi-start altitude, about 2 passes.
    The article recommended 18" streamer length with a paper clip on
    the bottom. We had to shorten the streamer to ~8" to prevent it
    wrapping around the fuselage on launch, and removed the paper clip
    to reduce the sink rate. The consensus was that the balloon is best
    used staked to the ground and used as a spot landing target.
    We may try a helium balloon tethered at 300-400 ft., next time.
    
    At the contest next sun. I will spring the "turn in one direction
    only" event on the unsuspecting membership. They will rue the day
    they elected me president.
    
    Terry
    

    re .472
    
    I haven't built a Westwind, but there are 5-6 flying here now. It
    is much faster and requires flaps and ailerons. Not a good choice
    for really relaxed flying.
    I am finishing up a 124" poly wing with flaps, that was built from
    two sets of Westwind cores. These will go on an old Pulsar fuselage.
    I expect it to be pretty fast for a poly, but flying characteristics
    won't be much like a Westwind. It will be used as a contest backup
    ship, and for spot landing events, as the flaps are going to
    be massively effective, I hope.
    
    Terry
    

Did anyone see RCD's ad in the January issue of "RC Report"? They now have
a 5 channel micro sized FM receiver. It's weight is claimed to be 1 oz., but
the ad doesn't list dimensions of the rcvr or it's price. I could use a
couple of these babies!

-Lamar

><<< Note 399.487 by ESCROW::PHILLIPS "DECtp Engineering TAY1-2  DTN 227-4314" >>>
>                      -< RCD micro 5 channel FM receiver >-

I don't get RC Report magazine but in the Jan-91 issue of RCM they
have a picture of it in an article by George Steiner about his
trip to Korea.  No price or availability.

This is really good news because up till now there has been NO
dual conversion FM micro receiver.

None - Zero - not a one.

Well - I think the Futaba 4 and 5 channel conquest PCM is
but they haven't been cheap and according to Futaba (but not the
usenet) they are not compatible with the 1024 systems.  Besides
the cost is way out of sight - except I just saw an add by Great
Northern Hobbies for a Conquest PCM for $169.  Is this the cheapest
PCM on the market?  

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

I just called RCD and the price will be $79.95 with availabilty towards the
end of January. Not as inexpensive as I would have hoped for, but as Kay
mentioned in .488, at least there is a micro sized FM dual conversion rcvr
available!

-Lamar

    Does anyone know of any sources for 80lb. or greater monofilament 
    fishing line?  I am having problems finding any locally(Rochester,NY).
    
    Thanks,
    
    Jim

    
    	If someone points out a source around here (Worcester MArlboro) I
    can deliver it Monday as I'll be in the REochester Office for a short
    time before going to the Big Yellow Box for two days.

    They've got a pretty good selection at the 'Sports Shop' in the Spag's
    complex. I got my braided "squiding" line for my Upstart there and
    that's the first place I plan on checking. I didn't really look at the
    monofiliment display but they seemed to have a rack full.

    
    	Gee thanks Jim That's my favorite place this time of year.;^)
    
    	Mr Blum how many feet you want 15? 20? 2000?
    
    	Art

    Art,
    
       I think Frank Keitz, who I now work with, knows you.  I appreciate
    your offer to help me.  I would like 1200 ft. of 80lb. or stronger
    monofilament line.  Please call me dtn: 252-7281 or (716)385-7281
    if you need any further information.  I would expect that it would
    be difficult to find 1200 ft. of line but I would be happy to get
    200,300,400,500,600 or whatever I can get.  Thanks again.
    
                                                    Thanks,
    
                                                    Jim Blum
    

    To date the longest line (80lb.) I have been able to find is a spool
    with 140yds.(420ft.).  I would really like to buy a single length of
    a 1000 ft. or more, either monofilament or braided.  Do any of you
    guys who launch with electric winches know where your line came from,
    as I assume it must be fairly long and high test?  I would appreciate
    an address of a source.  
    
                                                    Thanks,
    
                                                     Jim

    Jim,
    I've been meaning to answer this but keep forgetting to call the
    guys who have the info. We (our club) bought ~1000 ft. of 125 lb.
    monofilament last year for one of our winches, it didn't work worth
    beans so we went back to 125 lb. braided. I'm pretty sure both were
    bought locally, so gimme a day or two and I'll make an effort to
    run down the info.
    
    BTW, the monofilament cost ~ $90 !
    
    Terry

What we buy for our club winches is a woven Dacron line that is 200 lb test
and comes on a 1000 yd reel.  It now even comes in Floresent pink color.
The company that we buy this from is back east somewhere and called Gudbrud and
it is marketed as Great White Shark Fishing line.  

Also we have bought 150-200 lb monofilament line for our F3b winches them come
in 400 meter reels.  This line is called Jinkhi line.

You can also go down to the hardware store and buy mason's line which works
pretty good in pretty big rolls.  The advantage of the woven Dacron over the
mason line is thread count, which when used on a winch where it is drug accross
the ground alot really has some advantages.  If it it gets a nick or something
in it then you have a lot of other threads that carry the load.

I believe the cost for either woven or mono is about $50 per reel.

I will post ordering info tomorrow.

Mark

    I fly my stunt kites with Kynar.  It's braided, it's thin (less drag),
    it's wicked strong (in high winds, my kites will almost lift me off the
    ground), it's really light, and it doesn't have a lot of stretch to it. 
    Any decent kite store will stock it (though  I bought mine mailorder
    from a place in CA, who's name and address I can't recall).

    Also, it makes a really cool, high pitched whine when drawn tight in
    strong winds.  Just the thing to impress the crowds.

    Randy

I don't have a need for this stuff so take this information with a grain 
of salt.

I borrowed my co-workers Bass fishing catazlog and found the following.

ANDE MONOFILIAMENT
Tournament Green 1LB Spool
#	test 	yrds
422-207	80	750	$35.97
422-913	130	340	$35.97
Tournament Green 2LB Spool
#	test 	yrds
422-918	50	2000	$71.97
422-258	80	1500	$71.97
422-266	130	680	$71.97

or

GUDEBROD
G-12 GREENSPOT Dacron line
#	test 	yrds
436-308	50	600	$22.99
436-312	80	600	$29.99
436-316	130	600	$37.99

There's a couple of other choices depending on what you want. 
What I've enter here should at least give an idea of whats available.

The company is Bass Pro Shops
1-800-227-7776
they take Visa & MC

 

    OK here are the numbers....
    
    
    for the woven Dacron
    
    Gudebrod INC
    P.O. Box 357
    Pottstown, PA 19464
    (215)327-4050
    
    Order: Planer Board Tow Line    200 lb test 1000yds around $70 per reel
    
    
    
    For the mono:
    
    Janus
    Englewood CA
    (213)678-4821
    1001 yds 150 lb test $94.00 per reel
    Jinkai Mono type
    

    Tell you what, next time you can hold the reel ;^)
    
    BTW: I couldn't fly MY Gnome because the front wing dowel hole in the
    bulkhead became a U instead of an O on my last flight (folded the new
    RG15 wing on the hi-start) and I didn't notice it until I was loading
    the car ;^(

    re: last few
    
    I'm sitting here waiting to be hammered senseless by an approaching
    snow storm and you guys are out wading in a swamp. Some people
    have all the fun.
    
    So Jim, I guess you don't know yet how the RG-15 wing will work
    on the Gnome; an interesting combination. Maybe there should
    be a 2 meter F3B class. Hmmmmm.
    
    Since I'll probably be confined indoors all weekend, there will
    be time to bag my newest wing. This is a sparless design and here's
    what I'll do to make this puppy survive in the real world:
    
    12" X 3/4" X 3/4" spruce box in each wing root to house the 
    12" X 5/16" brass tube for the wing rod. I was able to insert this
    in the blue foam core from the bottom only, leaving the top surface
    untouched for max airfoil integrity.
    
    1.5" strapping tape, full span (60" each half) on the bottom only,
    laid directly against the foam.
    
    1" x 24" X .014" carbon fiber strip (not tow) laid in a shallow
    channel parallel to the l.e. of the spruce box and overlapping the
    outbd. end by ~4", on the bottom only.
    
    2 oz. glass cloth cut to full root chord width (10") and tapering
    out ~8" in a U shape, top surface only, laid against the foam.
    
    8" X 22" CF mat (looks like a very thin black furnance filter)
    laid on top of the glass cloth, from the root outward.
    
    3/4" CF tow, full span on the t.e for stiffness and a sharp
    sanding line. 1" glass tape full span on top of the tow.
    
    Sandwich the whole mess between 1/48" birch veneer and....well,
    we'll see how she turns out. The birch is so smooth that NO suface
    prep is necessary before final finishing which will of course be
    my favorite gloss polyurethane furniture finish, 2 coats brushed
    on, steel wool between coats.
    
    And if the jet stream doesn't swing north pretty quick, I
    won't have a chance for a test flight before arriving at
    the S.W. Regionals, and be forced to violate the AMA rule
    about no-test-flights-during-an-event. The most violated
    rule in the history of human legalism.
    
    Terry

    I do know that it flew much faster than the fattened 205 that the Gnome
    normally has. It seemed to fly pretty well from hand launches but
    didn't survive my 3/16" rubber upstart. My main objective was to
    increase the penetration of the Gnome (which sucks with the thickened
    205) so that I could fly it on the slope at Bose or in windier
    conditions than previous. I hate to admit to it being too windy to fly
    (that's why I was in the swamp ;^)
    
    I haven't had any spare time in my shop to dissect the wing to find out
    what gave but I'll do that over the holiday weekend while I start my
    winter projects. The Gnome is such a nice sized lunchtime ship that I
    don't want to be shutdown by the wind. Besides, I needed an excuse to
    build the automatic foam cutter ;^)

    My father is on his 3rd Gnome(yep trees got the other 2) and it
    really is a nice flying Ship(I have flown it many times).  It
    does not penetrate well, however.  In fact one of the tree incidents
    occurred when trying to get back to the field after following a nice
    thermal.  Originally I think the thickened wing was to accomodate
    zoom contest launches.  I have always wanted to try a different wing
    on this ship and thought the Selig 3021 would be a good candidate.
    While thinner than the E205, it seems to have reasonable flight
    characteristics and better penetration.  Essentially being a flat-
    bottomed airfoil should be relatively easy to build either in foam
    or built-up construction.  I have had good luck with my Dynaflight
    Apogee which is a 100" E205 polydihedral built up wing with Schueman
    style planform.  However I have not flown it in winds over 20mph.  I
    may build another version of this ship with S3021 wings.  I am not
    aware of any kits which use built up S3021 wings, has anyone else
    had any experience with the S3021?
    
    Regards,
    
    Jim

    Keep in mind that the Gnome uses a "modified" 205. The modification was
    to thicken it even more than standard. The Northeast Sailplanes catalog
    has the specs on both the Standard 205 and the Gnome version and it's
    something like 2% thicker (11% vs 9%)
    
    When I was flying regularly with Dave Walter at lunchtime, he
    consistantly hand launched his Flinger (with the standard 205) higher
    than my Gnome. The thicker airfoil made the slow speed characteristics
    better but if the wind got over 10mph, I couldn't afford to turn
    downwind. The thicker airfoil also reduces the terminal velocity of the
    plane so that if I dive to build up speed for some reason, I don't get
    as much return height as I'd expect (or as I've seen others achieve
    with other designs). I'm on my second fuselage and have a 3rd in
    progress but it really is a calm and light conditions plane. The
    different wings are mostly because it's such a nice size to throw into
    the car in the available space when you're going somewhere.
    

    Jim,
    I've had/have three S3021 planes. The first was a Bob Sealy Pulsar,
    100", foam, ailerons. This was a nice flying plane, pretty fast,
    very responsive, could be slowed down in thermals, but not as slowly
    as an S4061.
    The second was a 112" built up wing of my own design that I used
    on an electric glider. I made the leading edge radius much sharper
    than the stock S3021. For some reason this was about the slowest
    plane I've ever had, but was extremely responsive to the lightest
    lift. It could sometimes make a Gentle Lady look like a lead sled.
    No fun at all in wind over 5 mph.
    The third S3021 wing I've just finished, and have flown it only
    once. It's a 125" foam poly with flaps. Actually just two sets
    of Westwind cores cut down and combined. As far as I can tell from
    the one 15 min. flight, it's pretty fast especially with flap reflex,
    and at ~ 2 oz. lighter loading than a stock Pulsar (uses a Pulsar
    fuselage) it's a little better floater than a Pulsar.
    All in all, the S3021 is a pretty versatile airfoil.
    
    Terry

	The Flinger is grounded while the Futaba radio is out for upgrading.
	In the interim, I plan to build another handlaunch (the Flinger is
	getting pretty beat up). This one will be a home design, but nothing
	radical about it. I will increase the wing chord from 6" to 7" to
	get some more area, but leave the span at 59" which is standard HLG.

	In a rare display of openness, Helmut Lelke threw some numbers at me
	during a handlaunch session. He said ".4, and .03". I said, "Huh?".
	He said, "Stab volume and rudder volume". I gather those are the 
	numbers which work well for him, so I'm going to blindly follow them
	in the design of this new thing.

	When I got to airfoil selection, it was between the E205, the S3014,
	and the S3021. So I printed each of them out. Lo and behold, they
	are virtually identical! I mean, the differences are really subliminal,
	and considering I'm doing a built up wing, the final product will be
	very similar to any one of them. Now I see why Selig says you have to
	build to within 1%... the airfoils barely differ by 1%!

	Dave

    The Airtronics Legend kit has finally arrived at our local
    hobby  shops. A few preliminary impressions:
    
    $195.95 is the actual local price. $299.95 is the full retail.
    Kit quality is up to usual Airtronics standards.
    The fuselage is especially nice. A faired in hatch cover, kevlar
    strips embedded in the laminate, not just glued to the inside of
    the fuse.
    'Glass quality is very good.
    Carbon fiber strips are supplied for wing spar reinforcement.
    
    The first production run kits have a Xeroxed,tm, instruction manual
    because they  had a printing hold up on the full glossy manual.
    You can call for the glossy and they will send you one free.
    The manual is about the best I've seen, large print, every step
    covered.
    
    A small bag containing replacement ply root ribs is supplied with
    a note pointing out that the originals were cut wrong.
    
    They've made an effort to produce a kit that will introduce the
    relative novice to high performance sailplanes, and allow them
    to have something competitive without going to foam wings.
    
    I'd advise waiting until their production glitches have settled
    down then spend, spend, spend ! 
                    
    Already there are two on local building boards, no not me, yet.
    
    Terry

    
    I've finally finished my blue foam/birch veneer wings. 122" span,
    945 sq. in.
    Each panel weighs ~640 gms, including servo and wiring. The 12"
    spruce/ply wing tube boxes, with 12" brass tube are overkill, but
    I'll be able to use 24"-26" wing rod for extra ballast if necessary.
    Total weight of the plane is 92 oz. which is getting up into F3B
    wing loading territory, ~ 14oz/sq. ft.
    I could save ~6-8 oz. by going back to the original obechi stabs
    but the new birch stabs are so much heavier, 136 gms vs. 77 gms,
    that I had to add a bunch of nose weight. I think I'll stick to
    obechi or balsa for stab sheeting from now on.
    Now all I need is some decent weather to test fly this brute.
    
    I had another 1 1/2 sets of white foam Westwind cores taking up
    storage space, so they are now being converted into yet another
    set of wings for my Pulsar fuselage. 123" span, ~ 1088 sq. in.
    with a more rational spar structure, obechi on the outbd. panels,
    balsa on the inbds. Flaps and ailerons; a single flap servo in the
    fuse., aileron servos in the wings. I expect total weight to be
    68-70 oz. This will be a good MTS ship, I hope.
    
    Terry

    
    At our club meeting last night, Steve Steidl stopped by to give
    us a look at his new Lobo flying wing (pg. 5, Jan. '91 issue of
    RCSD).
    This is a simple ingeneous design that puts flying wing experience
    in the hands of everyone. He uses blue foam cores, SD7003 airfoil,
    full span spruce spars top and bottom, and covers directly over
    the bare foam with a low temp. film, Superkote. Sheeting over the
    foam could be used for a smoother finish.
    
    There is no reflex built into the cores. He accomplishes the reflex
    function by using anhedral at the tips and cutting the joint at
    an angle to the l.e. It's easier to see how this works in person
    than it is to describe it.
    Control is by 80% span ailerons with small outboard elevators.
    These operate in conventional fashion, no elevons, no mixing, so
    a simple radio can be used, although elevons and mixing could be
    incorporated if you've got the radio.
    
    Servos and rcvr. are in a plastic pod on top of the center section.
    The pod is made of Lexan, Steve heat molds them himself after finding
    out that a plastic company wanted $20 a piece to do the job.
    He is a 99% slope flyer but has hi-start launched the Lobo using
    a single string and tow hook mounted on the aft end of the keel,
    no Y harness is necessary.
    
    He's almost got me convinced to go try sloping again,especially
    since his flying site is free of the ever present lava rock.
    
    Terry

    After reading Martin Simmons article in the latest Radio Control
    Soaring Digest, it sure makes me wonder about the appreciable
    differences between the plethora of "new" airfoils available to
    the Sailplane Modeler.  For those who did not see the article,
    Simmons compares the performance graphs(max l/d, min sink, etc)
    of some of the latest airfoils with the old Clark Y.  There really
    is surprisingly little difference.  It has led me to wonder what
    makes sailplanes fly so differently.  My first ship was an OLY 650
    which has a flat bottom, high lift, high drag airfoil.  I then moved
    to a Sagitta 600 with Eppler 205.  As far as I know the Eppler airfoil
    is thinner, hence less drag.  These two ships fly very differently.
    The OLY is slow and easy to control, but has bad penetration.  The 
    Sagitta is much faster, stalls easier , penetrates better(but not great)
    and just generally flys much differently than the OLY.  Is it possible
    that many of these differneces are not due to the airfoil, but to
    a combination of many other factors.  I guess what I'm wondering is
    if the polars for the various airfoils are not dramatically different,
    why do the ships fly so differently?
    
                                                    Regards,
    
                                                    Jim

    An interesting point Jim.
    It would be interesting for a group of guys to build a series of
    gliders all identical except for the airfoils, and compare the flight
    performances. Perhaps more subjective than wind tunnel tests, but
    would probably yield some surprises.
    
    The Clark Y, NACA 6409 and other 'foils normally thought of as low
    speed, floater types have been used since the early days of R/C
    soaring when virtually all models WERE low speed floaters.
    Therefore even today they are still stuck on models with exposed
    wing dowels, rubber band hold downs, pushrods and horns hanging
    out in the breeze, etc.
    Put them on a slippery 'glass fuse., get the wing loading up over
    10 oz., and you might see quite a different result.
    
    Although I can't back this up with hard evidence I have a gut
    feeling that theoretical airfoil performance figures have a tendency
    to converge toward a smaller window as the Reynolds # gets lower.
    Or to put it another way, the Spirit of St. Louis and the Piper
    Cub (I think) both used the Clark Y to great success, but it would
    be ludicrous to think of the Clark Y on an F-16.
    
    At any rate, the SD8000 has caught my eye as the 'foil on my next
    project, a sort of "poor mans' F3B", to be built around a Jerry
    Slates  'Zen' fuselage.
    
    Terry

    One certain airfoil may penetrate much better than another one. Other
    than that, it doesn't float any better, doesn't thermal any better,
    doesn't do anything any better. But if what you need is penetration
    then that's the performance your looking for.
    
    Steve

	I have a nice comparison of the Clark Y vs.the E205 on my handlaunch.
	There are very easily detectable differences between the two. The Clark
	Y will fly slower, in tighter turns, and thus is easier to catch a
	thermal near the ground. On the other hand, the E205 clearly covers more
	distance and just plain glides better. So the 205 is my choice for the
	slope, and the Clark Y for thermaling.

	I am now building a handlaunch with a S3014 airfoil because I read in
	this conference that it's considered very good for small (handlaunch)
	wings. When I compared the airfoil to the 205, the differences were 
	nearly subliminal!  Less than the thickness of the line output by the
	postscript printer. No way can I build a wing accurately enough to
	distinguish between the two. I find it difficult to believe that the
	flying characteristics will be substantially different, even if built
	accurately.

	Dave

    At last a good flying weather weekend, and I was able to get some
    shake-down flights on my new blue foam/birch veneer sheeted wings.
    
    The SD7032 airfoil seems to work pretty well. It allows good speed,
    necessary to keep 92 oz. in the air. Slowing down to what seemed
    a normal thermal hunting velocity, would result in no tip stalls,
    it would just drop the nose vertically and become a non-aerodynamic
    mass in the sky for 2 seconds until flying speed built up.
    In spite of this the few weak low altitude thermals that were
    around could be ridden at rather steep bank angles, as long as I
    whizzed around in them at about 125% of the velocity of the standard
    class Sagitta that was sharing the sky.
    
    I don't have a clue yet as to how to slow down for spot landings,
    flaperon action hasn't been tested too much at low altitude and
    seems only moderately powerful at higher altitudes which is to be
    expected with outbd. flaperons. The best technique seems to be to
    circle nearly overhead gradually descending, then roll level and
    plop 'er down, sometimes within walking distance.
    
    For launching, my medium hi-start was just adequate for test flights
    but it's time to break out the red rubber heavy duty guy which has
    been languishing in my closet awaiting an airplane worthy
    of it's arm-busting properties.
    
    After some initial caution to worry about the sparless
    wing construction, I found I could lay on the club winch without
    pulsing, all the way up, and nearly stall it on the round-over,
    followed by a line break as a finishing touch. The wings
    would flex noticeable after the break indicating the desirable
    "energy recovery" mode. But after three line breaks I quite
    for the day to allow other people to fly unmolested.
    
    Terry
    

    To continue the discussion on airfoils(after all airfoils are to
    sailplanes what engines are to power planes, right?), I believe
    that Mr. Simmons has stated in previous articles that he feels the
    Reynolds numbers on models are so low as to render much wind tunnel
    testing inconclusive.  In other words how the models actually fly 
    may be quite different from what one would expect from the wind tunnel
    tests.  Case in point, the polar for the Eppler 214 vs. Clark-Y did
    not look great(for the E214), but I've seen some awesome Dodgson
    Windsong flights.  Simmons concluded in the recent RCSD article 
    that the ideal thermal airfoil is not too far from a good f3b airfoil.
    Can we believe the wind tunnel in low reynolds numbers applications?
    
                                               Regards,
    
                                               Jim

    It's been know for quite a while that very little is known about
    airfoil performance at Rn <500,000, and Eppler, Selig and other
    low speed aerodynamcists have been trying to shed some light on
    this area using full scale techniques ie wind tunnel research.
    
    It's my feeling that their results are valid and usable to modelers
    on a general compararision basis as long as we don't try to extrapolate
    downward too far. Building to the required accuracy to even show
    up the very small % differences between some airfoils is virtually
    impossible. 
    
    Agonizing over whether your t.e. is 1/32" thick when it should be
    1/64", is a waste of time.
    Recently I had a otherwise adult research physicist do everything
    but lay down and cry when he discovered I was going to use an SD7032
    rather than an SD7037 because his computer program had "proven"
    that the SD7037 was far superior and I would sure be sorry when
    I saw the miserable performance of my unwise choice, etc. etc.
    
    Terry

The day dawned quit ominously and 14 flyers gather at the PPSS club field a mear
25 miles SE of Colorado Springs, the task 15 min addem up with 3 rounds, the
classes, OPEN, SPORTSMAN, and NOVICE.  We had gentle winds and some pretty good
air the whole morning and when all was said and done it was DEC's own Bernd
Knoerle taking first place in Sportsman with his new QUASOAR that I belive was
only out for its second flying session.  Bernd did a great job with the Quasoar
and put in 3 good rounds except for the one where he lost control of the ship
due to some problem that has not been found and on the way down off the field
happend to brush by a power line. Still though the flight was good for 5 mins
or so and not one to be stopped by a minor problem that he could not find, Bernd
steps up with the Quasoar to fly the next 2 rounds and win the contest.  Bernd
is flying the Quasoar with Flaperons that have an arrowshaft hinge in them
running almost the full length of the trailing edge.  I should have told him
about the F3b pilot in Denver this summer that tangled his F3b plane (with
arrow shaft hinges) with a power line and managed to short out two of the wires
and when the smoke cleared his plane was GONE.

I had a OKAY day, I had gotten my old Saggita 600 back from the guy I sold it 
to and flew it.  Boy sure was different after flying my F3b ship.  1st round
I ended up with 4:18 and no landing, came up short, that E205 just doesnt 
penetrate as good as the RG15 on my F3b ICON.  2nd round I had to get some time
in because no single round can be longer than 7 mins so I caught a boomming 
thermal and at 6 mins I was still spec'd out.  I started to come down but of
course, the thermal just got stronger, I finally put into a steep 90 degree 
bank turn, and got it down to manageable height but was carrying a little too
much speed on landing, and did the classic Polyhedreal waggle landing and ended
up upside down in the middle of the landing circle at 6:50, well no landing 
points on that one.  3rd round and I need less that 4 mins to get my 15 min 
total time and I was able to make that although I landed just a little early
than my target time but did manage a 80point landing so I ended the day with
14:54 and only 80 out of 300 possible landing points which landed me in sixth
place out of 9 OPEN flyers, Oh well.  I am going to drag out my 120" stretched
Pantera which is your basic 3 Channel Thermal hunter/Gentle Lady Killer.  I am
going to try to win some contests this year with it and leave the flying of my
Flatwing, Flap/Aileron, F3b ship to the fun flying sessions.

Congratulations Bernd!!!  When you going to move here for good?

Mark Antry

    Well, the modified Gentle Lady (or as Kay has named it, Rude Bitch) is
    completed and in the car for it's maiden flight at lunch today. I like
    the concept I used but I'm not pleased with the final results (yet) I
    turned out a lot heavier than I had wanted and I came to the
    realization that I needed 4+ oz. of lead in the nose last night to get
    the balance where the plans expected it. There will be another fuselage
    done and this one will have a stretched nose so I can move the radio
    farther forward as neccessary. Here's what I did and why (the why is
    mostly because I can't leave a kit "stock" ;^)
    
    I wanted a 3ch glider with flaps. The Gentle Lady was a cheap kit that
    I could butcher so I got one. I only used the wing out of it because I
    HATE cutting out ribs.
    
    1. The wing was built with the center section having 1.5" trailing edge
    stock as flaps. They are monocoat hinged on the bottom and are
    currently set up for about 5 degrees reflex and 75 degrees deployed.
    The wing senter section is glassed with .6 oz cloth. The wing is
    transparent orange with white flaps. The wing tip panels are removable.
    The wing bolts on with two 4-40 nylon screws into brass inserts in the
    fuselage.
    
    2. The tail was built out of two layers of 3/32" balsa with carbon
    fiber sandwiched between them. The stab is stock size and is bolted on
    so I can pack the fuselage flat for travelling (or replace a broken
    one). The fin was moved forward to allow the stab to come off and the
    rudder was lengthened to be the same width as the stab. The elevator
    rod exits the rear of the fuselage inline with the fuselage and the
    rudder is pull-pull and the exits are built as part of the fin flaring.
    The fuselage is white and the fin and elevator are white with the
    rudder and stab transparent orange. Since they line up it is very
    striking.
    
    3. The fuselage has the same profile as the stock one but was thinned
    to 1.25 wide. The fuselage was contoured to the wing and there are
    fillets around all joints. I used 1/2" tri stock around the edges and
    rounded the fuselage to the point that the rear cross-section is
    elliptical. The wing hold down is a front 1/4" dowel and two 4-40 nylon
    screws into brass inserts at the trailing edge. No rubber bands or
    holes hanging out in the breeze. The Rx antenna is routed through
    straws in the fuselage and exits under the stab. The entire fuselage
    was done in .6 oz glass cloth and then painted white. I finished wet
    sanding with 600 grit and I must say that this is the best finish I
    ever took the time to do.
    
    Now for the reasons there will be another fuselage. It came out at 36
    oz all up. This gives a wing loading of 7.8 oz/sq. ft. Not unreasonable
    but not a floater either. I ended up putting 4+ oz of lead in the nose
    to get it to balance properly. I'm hoping that the flaps will allow me
    to tune the flight characteristics to penetrate well but still thermal
    with partial flaps. Hell, it hope it flies today at lunch ;^)
    

    Well, the maiden flight is over and the results are in...
    
    It went much better than I had expected. The plane does/can fly fast. I
    managed several flights from an upstart that really didn't want to toss
    36 ozs. into the air and managed to try out everything while I was at
    it. I found that it launched higher with about 30 to 45 degrees of flap
    in and it handled quite well. With the flaps up it really covered
    ground but when I lowered them it slowed back down to typical Gentle
    Lady speeds. The wind was mostly calm so I didn't get to check out the
    penetration but I expect that it should be fine. It tracked with
    authority (like it was on rails) and I felt comfortable with it right
    from the start. I couldn't hand launch it like my Gnome but I think it
    will handle the wind MUCH better. With the extra rudder area I was able 
    to put it into 30' diameter flat circles without too much trouble. Didn't 
    notice any snapping tendencies in the stalls and it seemed to stall pretty 
    slow. I think I'll give it a few more flying sessions before I start a new 
    fuselage.

    I won't dwell on contest finishing positions too much except to
    say that Thornburg got 7th overall on the two day combined score,
    out of 50, and several other club members finished in the low 20's.
    Of course I brought up the rear in 45th, muffled snickers, and have
    taken a vow never to go to a contest with a new, unfamiliar plane
    again, a mode that I seem to wallow in. Also a 14 oz. wing loading
    isn't really what you need in nearly dead calm conditions. Not an
    excuse, just an observation. 
    
    The Airtronics team was there with four Legends and the 2nd prototype
    of a new 2 meter kit, the Image 78, to be out at the end of the
    year. The Airtronics guys were letting all comers fly their Legends
    on sat. afternoon after completion of the rounds.
    I got a few minutes stick time on Tim Renauds' yellow #666, the
    Legend that appears in the magazine ads. What can I say except it
    flys well, real responsive on the ailerons, and I kept it high and
    didn't touch any switches on the Infinity 800 that he was flying
    it with.
    The "guest" pilot of another team member lost sight of the airplane
    while taking his turn at the sticks. The Airtronics guy had looked
    away momentarily to talk to someone. Noone could locate it in the
    sky again, so after a few minutes he reluctantly switched off the
    xmtr. About half an hour later, someone decided to patrol the field
    boundaries on his motorcycle, and eureka ! there was the Legend
    about 300 yrds. south with its nose javelined in. Some damage to
    the underwing covering, broken locater pins on the center section,
    and a few cracked ribs. But the fuselage was perfect and the t-tail
    assembly was intact. It was easily repairable for sundays' rounds
    but he elected to fly the Image 78 on sunday to see how it could
    stack up against the big boys. Fairly well I would say as he went
    on to take 1st overall on combined score (precision duration and
    triathlon).
    More on the Image 78. The wing is a small version of the Legend
    wing,same plan form, polyhedral, 3 piece bolt on etc.
    The fuselage is balsa, rather boxy looking behind the wing,
    the nose similar to the Sagitta. Overall construction looks simpler
    than the Sagitta, and it's expected to sell for "slightly more
    than a Sagitta 600", according to Tim.
    It was being flown with 6 servos at the contest, ailerons, separate
    flaps, rud, elev. Weighed 46 oz. The production version may have
    the option of common flaps, to reduce the servo count.
    Performance was outstanding, especially the launches. The wing
    was designed to take full power winch launches to get around the
    problem of lower launch heights with small airplanes. It was zooming
    right up there with the Muellers and Falcon 880s.
    
    When it came time for the raffle drawing, I was standing there with
    my puny 8 tickets, some people had bought dozens if not hundreds.
    First I win a copy of Daves' book, of course I already had one.
    Then they get down to raffling the kits. A Sagitta, Apogee,
    and two Algebra 2.5 meters, a $175 British kit. Wouldn't you know
    it, I won one of the Algebras. A lot envious glances.
    I've started building the Algebra of course. A beautiful kit,
    presheeted obechi wings, gel coated glass fuse. More on it as
    it progresses.
    All in all a worth while weekend.
    
    Terry
    

    Terry,
    
         Even if the contest didn't go that well for you, winning the
    Algebra should dull the pain some.  I built the 4-meter Algebra
    last year and it is a great sailplane.  Did your kit come with
    the Selig 3021 or Eppler 392 Airfoil?  Let me know your impressions
    of this kit as ther building progresses.  Also are you going to
    build it with ailerons or polyhedral.  I built mine with a poly-
    hedral wing, and it is incredibly responsive, especially considering
    it has a 151" wing.  Good luck!
    
                                                   Regards,
    
                                                   Jim

    Jim
    The kit is the S3021 with ailerons version. I'm building with the
    straight wing and stock 8 degree dihedral since that is the angle
    that the wing rods are pre bent to. The only changes I'm doing is
    using foam stab cores rather than the solid 1/4" slabs that they
    give you to carve, sand and more sanding into stab halves. The rudder
    will be built up, rather than the slab etc...
    The ailerons will be either the foam pieces cut out and faced, or
    pre shaped t.e. stock. The kit gives you 1" slabs to carve, etc.
    
    It's supposed to weigh ~ 60 oz. with 4 servos, but weighing all
    the parts in their raw form gives me a total weight of 36.8 oz.
    and I can't see where covering and radio is going to be 20+ oz.
    So this should be pretty light for a 99+ ". 
    The wing ballast tube is suitable for a flag pole, I won't be using
    it.
    I like the gel-coat fuselage but its laid up with polyester resin
    which means I can't use epoxy to glue the servo rails. I ordered
    some of that P.F.M. stuff to do the job. 
    
    One neat feature is running the aileron servo wires in a routed
    out channel in the rear of the l.e. strip. This prevents having
    to cut another slot in the bottom of the wing. I'll use that idea
    on my next scratch project.
    
    The stab pushrod is a piece of spruce with the threaded wire wrapped
    and glued on each end. I've got a hollow carbon fiber 1/4" rod that
    I never could find a use for that I'll substitute. It weighs about
    1/3 as much.
    
    Terry
    

    An excellent day of flying yesterday. Stayed up until 2:30 AM getting
    the Algebra 2.5 ready.
    Two hand launches and it was ready for the winch. Climbed out at
    a conservative angle, the long nose was very noticeable, reminded
    me of a submarine broaching the surface during an emergency ascent.
    But the long moment arm meant that I only needed one oz. of nose
    weight to balance.
    It tracks in the turns better than another flat wing/aileron glider
    I've flown. Speed, with the S3021 'foil, is good. Overall low drag
    characteristics, nearly dead silent high speed, low altitude passes.
    Roll rate is startling, and I will explore the world of multiple
    axial rolls more thoroughly after I put a little more friction in
    the stab wires. I'm a little afraid of slinging them right off
    from centrifugal force.
    
    52.5 oz. with 4 servos and 800 mah batt. 748 sq.in., 10.1 oz/sq.ft.
    
    Terry
    

    After reading the latest Model Builder I noticed that Paul Carlson
    placed first in the 2-meter NATS flying the Great Planes Spirit. Paul
    is obviously a tremendous flyer, but then again so were his competitors
    whichs is encouraging to low budget,low tech flyers.  The Spirit is
    available mail order for $35 and should be easy enough for most novices
    to build.  At the other end of the spectrum is the Mariah which costs
    5 times as much and is apparently rather difficult to construct(a
    cnstruction video is available to assist the builder).  Lets face it
    most of the contests(at least at the highest levels) are being won by
    high-tech foam and composite ships, its nice to see that a competent
    flyer can still compete with a built up balsa ship!  Comments?
    
    
                                                     Regards,
    
                                                     Jim

    Terry,
    
         Sounds like the Algebra is going to be a nice ship.  Could you
    elaborate a liitle more on how you built the ship, especially aileron
    and spoiler linkages,servo placement,wing covering material and overall
    flight characteristics of the ship.  I built the polyhedral 4-meter
    Algebra.
    
                                                     Thanks,
    
                                                     Jim

>>> Lets face it
>>> most of the contests(at least at the highest levels) are being won by
>>> high-tech foam and composite ships, its nice to see that a competent
>>> flyer can still compete with a built up balsa ship!  Comments?
    
Well, I've never been to a high level contest, but at the local level I've 
noted that the winner is ALWAYS a competent flyer, regardless of what he 
flies. (Real deep observation, huh?) Case in point is Helmut Lelke, who
did very well at the NATS in '85 (?). He routinely wins contests with the 
scummiest 2 meter you've ever seen. Bent wing, holes patched with strapping
tape and "happy face" stickers, unpainted fuse. A real horror show. But he
KNOWS that plane inside and out, he's flown it for years. Matter of fact, he
flew one contest this year with his hi-tech, electrostatic stabilized thing
(same one he flew at the NATS) and he did relatively poorly. Probably because
he hadn't flown it in a while.

These comments apply for thermal duration. For speed and distance, I can see
how the high tech composite sleds have a distinct advantage. But you still
need a good pilot who's very familiar with the plane.

Dave

    Jim,
    The Spirit was lost in the shuffle at the Nats, while everyone
    was ogling the Mariahs (there were a bunch there). The Mariah
    is simply too ugly for my tastes.
    Paul won with consistent flying and nailing all his landings.
    Speed, camber changing, those things that the Mariah has an advantage
    in, simply weren't a factor. No matter how hard people try to change
    it, it's still a fact that virtually any higher level contest
    is won on landing points.
    
    I didn't put spoilers on the Algebra. I used JR 305 servos in each
    wing for ailerons, mounted about 1/3 of the way out from the inbd.
    end of the ailerons. Stab and rudder are driven by Airtronics 102s
    mounted in-line, very close to the position shown on the plans.
    
    Since I'm using a Vision radio, it was simple to set it up for
    flaperon action. With about 1/2" reflex, it comes down like it had
    spoilers. Flap action isn't as effective, but ~3\4" down will slow
    it up enough to be reasonably useful in landing.
    Wings and stab covered in Oracover. I like it for sheeted surfaces.
    Prefer Monokote for open structure.
    Stab is blue foam SD8020, cut to stock planform.
    Rudder built up from 1/16" sheet with internal ribs.
    Ailerons hinged with silicon caulk.
    After several tries at shaping the wing tips to suit me, total wing
    area is 748" sq. for a loading of 10.1 oz.
    
    It's the best flying kit plane that I've had. Better than a Pulsar.
    Extremely low drag, very good aileron response for axial rolls with
    the coupled rudder switched off, but not overly sensitive around
    neutral, when trying to dawdle in a narrow thermal.
    
    I'm so impressed that I'm going to look into current prices and
    availability of the 3 and 4 meter versions. Any current info on
    those?
    
    Terry
    

    NorthEast Sailplanes in Vermont has the entire Algebra family listed in
    their catalog. They're listed in each Model Aviation among others.
    
    They were out of stock on Flingers when a friend called (unable to get
    them for the last 6 months) but it's probably worth a call to check
    availability.

    I purchased my 4 meter Algebra directly from Edmonds Model Products 
    in England.  It was $141 US dollars and arrived at my doorstep within
    2 weeks of ordering.  Edmonds accepts VISA which is what I used to pay
    for mine.  I can provide the address and telephone number if anyone is
    interested.  I concur with Terry's assessment of this Sailplane, it is
    a real nice flyer, and a good kit, in fact It is the best kit for the
    money that I have ever seen.  
    
    Terry, do the aileron servo arms stick through your Algebra's wings and
    then connect with metal rods to control horns attached to the Ailerons?
    If so are the control horns mounted on the top or bottom of the
    ailerons?  Did you use the pull-pull rudder control system?  
    
    Regarding the thermal duration contest being nothing more than a 
    landing contest, This makes Carlson's win with the Spirit even more
    impressive.  Normally a rugged ship(ie composite construction) that
    can do the "crow" landing will get the most landing points than a
    3 channel balsa ship with spoilers.  I realize that these contests
    can be extremely close, with one botched landing costing you several
    spots, but it does prove that a good flyer can win with relatively
    low-tech equipment.  I would be interested in hearing any details
    you coul provide about the NATS.
    
                                                  Thanks,
    
                                                  Jim

    Thanks to the two Jims for your info. I happened to see a '90 NSP
    catalog at our club meeting last night and they are selling 4 meter
    Algebras for ~ $212. $141 sounds a lot better, but recent exchange
    rates may have changed that. I've sent for a '91 NSP catalog, an
    excellent source of info.
    
    The aileron arms extend about 1/4" below the bottom surface of the
    wing, and use regular metal pushrods, ~ 4" long. Metal clevis at
    the servo end, Z bend at the aileron horn. The horns are cut from
    printed circuit board stock, the stuff that is left over after the
    boards are sheared in the wave solder process. Oops, I meant "servo
    arm" at the beginning of this paragraph.
    The horns are epoxied into slots cut in the bottom of the alierons.
    Much stronger than nylon horns, and you avoid using the screws and
    plates.
    
    After experimenting with a variety of servo mounting schemes, this
    time I simply glued the servos to a 1/32" ply plate using that PFM
    adhesive, a la Al's suggestion, and it works great. They can be
    pulled loose if needed, without problems, but are tight in use.
    I install the servos before covering the wing, then cut out small
    slots in the covering, for arm clearence, then put clear vinyl tape
    over the slot for stiffness around the edges, then cut a matching
    slot in the vinyl. 
    This semms to match my "big 3" requirements of durability, simplicity,\
    ease of building.
    
    Terry

    Terry,
    
          With your ailerons directly connected to servos in the wings,
    are you able to get differential throw.  If so, how?
    
    
                                                    Thanks,
    
                                                    Jim

    Jim,
    Differential is programmable from the transmitter in 1% increments.
    I think I have it set at 50%, ie twice as much up travel as down.
    It's been my experience that the rule-of-thumb 4:1 ratio is a little
    conservative for gliders, or maybe I just like snappier aileron
    response than some people.
    
    Terry

    This is the winter that I am resurecting two of my older damaged ships.
    I had intended as usual to build a kit this winter, but when I noticed
    that I had two perfect set of wings from earlier projects(Sagitta 600
    and Paragon) I decided to scratch build new fuselages for these ships
    adding my own changes.  Both these fuselages had broken several times
    at bulkhead joints where the lite ply met the bulkhead.  I have never
    really liked lite ply, so these new fuselages are built by laminating
    a piece of 1/64" birch plywood to 3/16" balsa for the Paragon and a
    piece of 3/32" birch ply to 1/8" balsa for the Sagitta.  The bottom
    fore sheeting will be 1/16" birch ply laminated to balsa.  The
    fuselages will be covered with .6oz/sq.ft. fiberglass bonded with light 
    CA.  I am hoping the 3 ply birch laminated with balsa,fiberglass, and
    CA will be stronger than the traditonal lite ply.  Has anyone ever
    tried this or a similar method?
    
                                                   Regards,
    
                                                   Jim

    Hi Jim,
    
    I totally agree with you and even though my Gentle Lady (modified for
    flaps) was a slimmed down version using most of the techniques you
    mention. The big difference was that I used K&B finishing resin on the
    cloth and Al's toilet paper method to apply it. I should have extended
    the nose since I needed 4oz of lead to balance it and I would have
    preferred to just move the gear farther forward.
    
    I told you that to tell you that I recently had a bad upstart launch (a
    roll induced by the monocoat ripping off the underside of an inboard
    panel) which caught the line in my removable tip joint and before I
    could head back upwind, the line yanked mme nose down and tent pegged
    me from about 50'. The only damage was the wing holddown bolts and
    dowel (which ripped the top off the bulkhead) and one servo pulled it's
    rails loose. We had had a thaw and the ground was sponge but I had to
    pull about 3 inches of nose out of the ground (it was standing vertical
    with the upstart still stretched ;^) It may be heavy, but it takes a
    LOT of abuse!
    
    Sounds like you method should work fine but watch the tail weight or
    extend the nose to move the radio forward more.
    
    Jim

    I've used the 1/64" ply laminate on fuselages from the wing t.e,
    forward and it worked fine. 3/32" ply laminate sounds like a little
    overkill, but it would definitely be strong. The best way to keep
    weight down in the rear, is to run two strips of ~3/4" CF tow from
    the wing t.e. back to the stab. Use CA or epoxy to stick it down,
    and you'll have all the empanage strength you'll need, minus the
    weight.
    
    Terry

    Terry,
    
    Do you run the CF on the inside while building or the outside after the
    fueslage is assembled (I would think inside but sometimes it's hard
    with the formers and such to be glued down)

    I run the CF down the inside of the fuse. Formers for strength are
    totally redundant once you have the CF in there. If you need them
    for pushrod housing support, then just notch the former to fit over
    the CF, or use a half-former that doesn't extend down to the CF.
    CF works best when the fuselage depth is fairly small, usually
    the case on gliders. If you have a lot of bare balsa area above
    and below the CF, then obviously that portion can still break,
    but you'll still gain a lot of lateral rigidity.
    
    Terry
    

You know how gasoline eats foam.

Does any petroleum based product?

For instance - what if you coated some push rod music wire
with grease and built a fuselage around it.  Then you fill
the aft section with instant foam out of a can.  Wouldn't
the push rods (with the help of the grease) create their own
tunnels though the new foam such that you would gain
tail strength but not gum up the push rods?  If not grease
then there must be something that can give similar results?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    I use bicycle bearing grease to coat tubes/rods/wires that I don't
    want to stick, when glueing things in or around foam, and I've never
    noticed the slightest reaction between the grease and foam, but
    I always wipe the grease off after the process is complete.
    I suspect that coating wire with grease and then leaving it in contact
    with foam for long periods, would gradually soften the foam as the
    grease seeps into the pores, elongating the holes and causing slop.
    In that application I'd be likely to try rubbing the wires with
    paraffin (sealing wax, to you British speakers) and I'd be even
    more likely to run the wire inside of a stationary housing first
    so that there is no friction at all against the foam.
    
    Terry

    Kay,
    
    If I understand your reasoning, you want a foam filled tail with free
    pushrod movement? Once the coating on the pushrods attacks the foam so
    that it retreats from contact, what's going to tell the chemical
    retreating on the surface of the foam to stop attacking it?
    
    The only way I can think of doing this would be to use wire
    pushrodsenclosed in GoldenRod type cases. The foam would support the
    outer tube to prevent flexing and the solid wire wouldn't
    expand/contract like the nylon inner sleeves tend to.

    I believe the foam that squirts as a liquid from a can is polyurethane
    and resistant to petroleum.  The white foam we typically use for wings 
    is styrofoam and sometimes polystyrene and always vulnerable.  As
    Lambie says about styrofoam, "just about anything but water and epoxy
    will dissolve it."

    Nonetheless, I would use a plastic sheath tube before adding the foam.

    17 entrants showed up for our monthly contest on saturday. Not too
    bad for an overcast day, punctuated by no great occurances but a
    random collection of silliness.
    
    Howard leads off with his Gentle Lady, in the first of three rounds
    of 2 minute precision landing, knock over the beer can and collect
    the $.25 per person pot.
    Pops off 50 ft. up, does a loop, Howard looks befuddled. Can it
    be? Yes! The classic receiver turned off ploy ! And dad burned it,
    if he'd had just 6" more altitude he could have completed the loop
    too.
    Thornburgh launches his 2 meter orange thing that he flew at the
    Nats, hits the 2 minutes, the spot, the beer can, collects the pot.
    Sigh.
    Taylor, having retired his Lovesong, lost his Westwind far to the
    south a few weeks ago, is reduced to flying a 99" ARF foam Big Wing
    flying wing. Clever in concept, impossibly crude in application,
    it nevertheless flys far better than it has any right to and causes
    us to shuffle around wondering if we could copy the planform and
    cut some proper cores.
    I managed to get the Algebra back to the field all three rounds
    and was even seen to head toward the landing circle once.
    
    The second contest was a three round, 15 minute add 'em up with
    spot landing.
    Taylor made 3 perfect one minute flights, consistancy far beyond
    my wildest dreams.
    An OLy II landed in a tree 50 ft. up then proceededto slither down
    through the branches just to a reacheable height. Not a scratch.
    Dave flew his orange thing to a 1050 out of 1200 point win.
    I got the Algebra in the circle once for 6 points, and ~ 12 minute
    total. 
    Then some of us went downtown to the SSA convention, and sport show
    and watched a squirrel water ski behind an electric R/C boat.
    
    Terry

    If any of you glider guiders are in the Nashua area, be sure to stop
    by Hobbies Plus on Rt 101A in Nashua.  The owner is an avid glider
    person and has a really impressive variety of gliders built and hanging
    from the ceiling.
    
    Everything from a V-tail HLG to unlimited class ships.  He has one
    fiberglass fuse/foam-fiberglass wing that was built in germany and
    (supposedly) used by some top pilot.  They said he had it up to 120mph!
    
    The covering jobs are also very good..  Most ships are done in Ora-cote
    (or is it oracover?) with one flourescent color on one side and another
    color on the other...  Sharp looking with BRIGHT green and BRIGHT
    orange.
    
    Preston buys all of these ships prebuilt.  Whomever he gets to build
    them does a really nice job.
    
    Worth the stop if you are in the area...
    
    Cheers,
    jeff
    

    Re: 1298.9
    
    Brian,
    
         I would like to hear more about your Osprey, both ease of building
    and specific flying characteristics.  I nearly bought one a year ago
    but was apprehensive about it because it looked like a difficult ship
    to put spoilers in, due to the 2 piece rubber band attached wing.  The
    hobby shop I frequent has one for sale.  The eppler 176 is not a common
    airfoil on this side of the Atlantic.  Will the ship slow up acceptably
    to land without spoilers?  Is the wing sufficiently strong enough to
    dethermal without spoilers?  How does it fly?  Would you build another?
    Thanks for any info you can provide on this ship.
    
                                               Thanks,
    
                                               Jim

    Re: .-1 (Osprey comments)
    
    I have to say a few words about myself first to put my comments into
    context - I have been flying for little more than a year, with
    virtually no tuition in that time. I almost always fly alone, from a
    50m bungee. I have now progressed to the stage (with relatively little
    damage to airframes, considering my DIY learning approach - both my
    first two gliders are still flyable!) where I can safely launch, circle
    around, and land, usually within 100m and about half the time within
    50m of myself. I am now at the stage where I need to actively go out
    and look for thermals, and then make use of them. I was flying last
    Saturday, and I could see and feel from the Osprey's behaviour in the
    air that there was plenty of thermal activity, but I was just not able
    to catch one. Please remember my lack of experience when interpreting
    my comments below.
    
    Please - this is not a recommendation that anyone should just go out
    and believe that they can fly RC by themselves from scratch. It is
    _not_ easy!
    
    So, after some background and the mandatory warning, back to the
    Osprey!
    
    I wanted something with a little more performance than my "trainer" 2m,
    but nothing too extreme. I am very pleased with the Osprey in this
    respect. It was straightforward to build, with balsa/ply fuselage,
    builtup polyhedral wings (two webbed spruce spars inboard, and I think
    balsa spars on the outboard sections), built-up flat tailplane and
    sheet fin. I am sure that the wood in the kit could have been better
    selected, but I have learnt a lot from that experience (like picking
    out matching wood for both wings before starting to build!). Diecutting
    was OK, no particular problems getting out clean ribs from the sheet,
    etc. I would happily build another one, or recommend it to others
    looking for a good middle-of-the-road 100S class sport glider.
    
    Spoilers - I built without, after some soul-searching. As far as
    landing is concerned, I do not think that speeds are too high for
    safety. With care, it will flare out to a reasonably slow touchdown,
    although I get it right rather less than 100% of the time :-). A better
    guide perhaps is that I fly in a relatively small field (about 1�
    football pitches wide by 2� long, but encumbered by football posts,
    metal posts with attached wires around the cricket wicket, children's
    play area, and a wooden shed). I very seldom hit anything on landing
    (famous last words!) but don't ask me about the times when I did :-).
    In a modest breeze, I have achieved a landing at little under normal
    flying (air) speed with a descent angle of around 45�. Gentlest landing I
    ever made! So, for landing, spoilers don't seem essential. 
    
    The wings and their attachment are a small problem. In flight, I have
    had no problem, but the vibration of sliding across the grass on a
    faster than planned landing causes the wings to slide apart and drop
    the wingtips on the ground as the joining rods rotate (dihedral angle
    supplied by bent joining rods). You then have to unhitch the rubber
    bands and reseat the wing. No structural damage, but when flight times
    are as short as mine you seem to spend forever refastening the wings!
    However, the method does have its advantages on a really bad landing.
    If a wingtip hits the ground, the whole wing rotates and the bands pop
    off easily. This has happened a couple of times. This wing does seem to
    be pretty strong. I have not yet damaged a wing, apart from peeling
    back the solarfilm at the polyhedral joint where it rubs on the ground.
    Anyone know a good fix for that, apart from doing the whole lower
    surface of the wing in one piece? Dethermalling without spoilers - I
    believe that the wing is significantly stronger than the rubber bands
    and is unlikely to fail, but there might be problems with the
    attachment (wing position shifting, maybe, or lifting at the LE) if you
    try anything extreme. I am considering a stronger method of attachment
    (nylon bolt and peg, maybe) but I am unwilling to give up the
    designed-in weakness of rubber bands at my present stage of landing
    skill!
    
    Eppler 176? I remember it saying "modified E205", but I could well be
    mistaken there. It certainly says "modified". That probably just means
    that they have straightened out the very slight undercamber towards
    the TE. I do not think that my building techniques are accurate enough
    to really tell much difference. Is the design section supposed to be at
    the rib position, or where the solarfilm pulls tight between the ribs?
    We all make ribs to the design airfoil section, and end up with wings
    where most the area is anything but!
    
    Performance in the air - it does what I originally wanted, which was to
    fly steadily and smoothly, with no obvious vices. I have no reason to
    disbelieve the manufacturer's claims for its performance, but I yet to
    develop the skill to really test them! I trimmed it from the board with
    the CG about 4-5mm forward of the design CG (as recommended in the
    instructions). Since then, I have taken an ounce or two of lead out of
    the nose with no harmful effects, and I guess that the CG is somewhere
    back to the drawing position by now. I believe that my inability to
    thermal at present is indeed my inability, not that of the design. I
    can circle reasonably tightly, but never manage to achieve that
    immediately after detecting a thermal! However, I do not really know
    just how tight/flat a good thermal turn should be. I've never seen one.

    Brian,
    
         Regarding finding your first thermal, my father and I had the
    same problem the first year we flew.  No matter what we could never
    stay up more than 4-5 minutes max.  Of course a lot of this was
    due to our poor technique, but two things come to mind that
    dramatically increased the number of thermals we were able to find.
    The first was the flying site itself, we flew at a high school located
    in a valley.  By moving to fields out of the valley, thermal activity
    was much more prevalent.  The second thing was our fear of flying to
    far away from the original launch site.  We tended to want to stay 
    up wind all the time.  Obviously you must know your glider's pen-
    etration ability before straying too far down wind, but it seems that
    flight times increased as my ability to fly further from the field
    increased.  Good Luck!
    
                                                    Regards,
    
                                                    Jim

    If you get a chance, borrow/buy and read the Old Buzzard's Soaring
    book. This will really help you picture the "river of air" and how to
    hunt thermals. Lots of simple things that add up to good success. The
    thermal will get blown downwind, to stay in it you need to allow the
    plane to drift downwind as you circle. Your search pattern upwind
    should be back and forth crosswind while always turning upwind (this is
    diagrammed in the book and avoids you checking the same air twice) If
    you make a rectangular search, you cross the same air on your downwind
    crosswind leg as the upwind one since both you and it have moved
    downwind together. If you turn upwind, you'll cross fresh (unchecked)
    air. I caught my first thermal since getting back into gliders by
    circling under a hawk ;^)
    
    As the Ol' Buzzard says:
    
    May you screw up every flight! Right into the clouds ;^)

    I doubt if The Old Buzzard has made it to Britain yet, but it will
    help you with your thermaling technique.
    
    To keep you wing rods from rotating on landing, the only permanent
    solution is to glue them in the fuselage.
    
    A strip of vinyl tape over the Solarfilm seam can help keep
    it from peeling back, or run a thin bead of instant CA along the
    seam. When I use Solarfilm I always put a coat of Balsarite on the
    bare wood before covering, everywhere I know a seam will be. Solarfilm
    is noted for it's low adhesive strength.
    .......................................................................
    
    After watching Wings last night, a surpressed urge to build a flying
    wing finally burst forth, so this morning I sent off to Western
    Plan Service for the plans for the Blackbird 2M that is featured
    in the Mar. RCSD. This looks like a quick, simple way to experiment
    with flying wings. We'll see.
    
    The Chuperosa fuselage is complete. A vanguard 6 ch. PCM rcvr and
    two s-33s fit ok, with a 270ma batt. I changed the rudder to pull-pull
    cord actuation, and the stock sheet stab is just a little too funky,
    so I'll build a white foam/ 1/32" balsa sheeted stab, SD8020 'foil
    also and see which one works best. Might have this baby flying in
    1-2 weeks.
    
    Terry

>>> So, for landing, spoilers don't seem essential. 
.
.
>>> Dethermalling without spoilers - I
>>> believe that the wing is significantly stronger than the rubber bands
>>> and is unlikely to fail, but there might be problems with the
>>> attachment (wing position shifting, maybe, or lifting at the LE) if you
>>> try anything extreme. 

Spoilers aren't required for landing, but they sure come in handy, especially
for spot landings in contests. When you're learning to fly, best not to use
spoilers on landing because it's just anothing thing to screw up. Once you are 
comfortable with landings, you can use the spoilers (or flaps) to control the
rate of descent without picking up tremendous speed.

As for dethermaling, I can think of a few instances where I was real glad to
have the spoilers. When the plane is a mere spec, and you're afraid of losing
it, it's real easy to come down TOO fast. It's difficult to see the plane's
speed when it's up that high.  There's a danger not only of folding
the wing, but also of picking up flutter in the tail which can destroy it (I've
seen this happen). Of course, I did a lot of flying before I had one of those
climb-til-it's-invisible flights, so again spoilers aren't really required for
beginners. You can always build the spoilers in and tape them down til you
feel ready to use them.

By the way, I also endorse running a little thin CA on seams to seal them down.
Works pretty well. It's especially worthwhile on power planes where the fuel
can get on the seam.

Dave

    Spoilers - I agree, not necessary, but probably desirable. At my stage
    of progress, I was looking for simplicity, not complications. I am also
    building a Wristocrat HLG with flaps option, though, just for fun!
    
    I have seen Old Buzzard's book mentioned a few times in this notesfile,
    but I have never seen it in the UK. I have copies of George
    Stringwell's book "Thermal Soaring", and another by Dave Hughes (two
    well-known UK authors on the subject), which between them have taught
    me just about all I know - or at least, enough to start me "learning by
    doing!" The chapters on hunting thermals in both books are very well
    thumbed! If I ever manage another US trip, I will try to look out a
    copy, maybe.
    
    I think my local terrain is probably OK for thermals. It is fairly open
    to S and W, where our prevailing wind comes from, and has a few
    irregularities (hedges and so on) which I understand are good for
    triggering thermals. There are even a couple of tarmac tennis courts,
    which may provide good thermal hunting grounds come the summer.
    However, the field is too small for a full length 150m bungee, and I
    could only use my 100m line if the wind is in just the right direction,
    hence my use of a 50m line. This gives an inexperienced pilot
    relatively little time to go hunting :-(.
    
    I will try putting a strip of vinyl tape around the polyhedral joints
    on the Osprey, as the problem there is not only the Solarfilm lifting,
    but also straightforward abrasion. 

    Al Ryder contacted me off-line to ask about the methods I used to
    install pull-pull cables in my Chup HLG. I'll answer here as it
    may be useful to a wider audience, and also I can't connect to
    Al's node right now.
    
    I used the kevlar cord that comes in one of the Sullivan or Goldberg
    packages. I glued ~ 1" lengths of the small diameter yellow nylon
    guide tube, supplied in the Chup kit, inplace to serve as lead-throughs
    whereever the cord passed through the bulkheads. I also glued two
    pieces to the rear longerons where the cord exits the fuselage.
    I threaded the cord through the tubing and got all the
    lengths,clevises,etc. adjusted before covering. This is a pretty
    straight-forward job, and to save weight I don't use adjustable
    clevises at either end. Just stick the kevlar cord into the clevis,
    push the end of a toothpick tightly into the clevis from the front,
    hit it with a drop of instant CA, then cut the excess length of
    toothpick off. 
    
    If you're using the vinyl coated kevlar then you don't need the
    lead-through tubing in the fuselage, except at the rear exit points.
    
    In a narrow fuselage such as the Chup, it's usually easier to mount
    the rudder servo ahead of the elev. servo. and have both cords pass
    by the elev. servo, keeping the elev. cable in the center.
    
    In general, kevlar cord works much better than 1/32" wire cable
    in pull-pull applications, especially in tight installations such
    as the Chup. Much more forgiving as to routing, flex, binding, etc.
    
    $ 7.00 for 20 ft. of the 85 lb. test vinyl coated kevlar cord from
    Aerospace Composite Supply is the cheapest way to go.
    
    Terry

    You might try spectra in pull-pull cables. Spectra is a long chain
    polyethylene that has similar characteristics to kevlar, but with two
    distinct advantages:
    
    o Spectra is slippery while Kevlar is highly abrasive.
    
    o Spectra doesn't deteriorate as quickly with exposure to ultra-violet
      light as Kevlar does.
    
    Braided spectra can be purchased from kite stores. The last I checked
    you could buy 135 feet of 80 pound for less than $15.
    
    	Marty Sasaki

    the only concern/question I have is if it stretches.
    
    The uncoated kevlar tends to fray in normal use (rubbing over time
    produces a fuzzball) I had given up on it and gone over to fishing
    leader (wire). Haven't seen much coated kevlar out east yet.
    
    Keep contributing Marty, you've got different sources than many of us
    (guess it's time for a road trip to the kite store ;^)

    I've never had problems with kevlar fraying as long as it isn't
    allowed to rub against anything. The coated version eliminates that
    problem.
    
    I sent for a catalog from the kite store in Colo. that Marty gave
    the address for. Haven't received it yet.
    
    If Spectra is made out of polypropylene fibers, rather than
    polyethelene, then it should work very well. They use polypropylene
    tow lines in full scale soaring and it doesn't stretch, abrade.
    Polyethelene sounds ok though, if CA glue will stick to it and it
    is available in small diameters, ~ .050-.060 ".
    
    Terry

    Spectra is stronger in tension than Kevlar (for a given weight) and it
    either has the same stretch characteristics as Kevlar (spectra 900) or
    stretches less (spectra 1000). Now that Terry brings it up, I'm not 
    sure if it is a polyethelene or a polypropylene. CA glue does stick to
    it, although I'm not sure how good the bond is.
    
    I'll measure the diameter tonight, if I remember. The fibers are
    smaller in diameter than Kevlar, at least in the braided state, ie, a
    150 pound piece of Kevlar is larger in diameter than a 150 pound piece
    of Spectra.
    
    	Marty

    Finally got a chance to fly this weekend.  On Saturday flying my
    father's 2-meter Chuperosa, 3 of us were able to hand the transmitter
    back and forth for a 40 min flight.  Keeping the ship in sight was
    a real consideration.  March thermals have always proved the strongest
    in my 4 years of flying.  We lauched using the hand tow method with
    a turnaround spool.  I was then able to stand next to the pilot
    launching the ship, eliminating any false launches.  We attempted 
    a downwind launch just to see if it would work at all.  It did not,
    even with a 2-to-1 pulley system and a 24 oz. glider and me running 
    strongly, the launch was weak and low.  Not adviseable!  Sunday 
    brought 25 mph winds and cold temperatures.  I flew my elektro-uhu,
    but was unable to stay up.  Another flyer warned that the fuselage 
    was particularly vulnerable to damage in cold temperatures, so I
    quite while I was ahead.  Really looking forward to some nice weather
    and more comfortable flying.
    
                                              Regards,
    
                                              Jim

    I too flew this weekend. I finished a S3014 wing for my Gnome HLG and
    couldn't resist taking it to the slope. I was very pleased with the new
    wing and was able to fly inverted with it (which the stock wouldn't
    allow) The penetration was greatly improved over the fattened E205 in
    the stock wing and I was very pleased. I also played with the elevator
    mixing with the flaps on my modified Gentle Lady and got this sorted
    out. Two hours at Bose only stopping because the snow was stinging my
    eyes so that they were watering and I was loosing the plane
    periodically.

    A mild cloudy day yesterday. We flew only three rounds of our monthly
    contest before increasing winds wimped us out. The Algebra handled
    the wind better than most. Now, a few more people are interested
    in getting one.
    
    I'm ready to start on the Chup wings. They should go quickly compared
    to the relatively fussy fuselage.
    I picked up a Lobo foam flying wing kit, prepratory to trying some
    slope flying. It will be stock, with separate ailerons and elev.
    and will probably use my old AM Conquest. I'll save the fancier
    mixing stuff for the built up Blackbird wing.
    
    I ordered some fiberglass tubing from the kite store in Colo., some
    .248" for pushrods, and some .505" for possible fuselage booms.
    
    Found some Spectra line locally. 175 ft. of 80lb. for $5. It looks
    like it will make good control surface line.
    
    Terry

The other day I saw an add in some magazine for some zig-zag trip tape.
I was planning on placing an order but now I can't locate the add.

Anybody know where I seen it?  Is should have been in RCM or Model Builder
or Model Aviation - but I must admit I stick my nose in any publication with
airplanes involved.

I'm usually pretty good at filing and cross referencing things but I blew
this one.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Hobby Lobby sells zig-zag trip tape, look for their ad. I saw it
    too, in more than one ad.
    
    Terry

>         <<< Note 399.583 by ELMAGO::TTOMBAUGH "A Fistful of Epoxy" >>>
>                                -< Hobby Lobby >-
>
>    Hobby Lobby sells zig-zag trip tape, look for their ad. I saw it
>    too, in more than one ad.
>    
>    Terry

Great - just checked RCM and Model Builder (there latest add doesn't
show it) will check Model Aviation and others (including their catalogue)
tonight.  I do remember reading the add though and I have another question.
It doesn't say how thick it is.  Has anybody seen this stuff?  The problem
with most tapes is that it is not thick enough.  We've been encouraging
them to make thin tape for decorative trim for years now we want thick
stuff - it can't be found.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Not that it would be pretty...
    
    The cloth electrical tape is thicker and has texture. It will also rip
    along it's lengthh into strips.
    
    Jim (still haven't tried tripping an airfoil yet)

    The zig-zag tape that H.L. sells is from Germany and is specifically
    made for wing trips. It is thick like the zig-zag sold in fabric
    stores, but with an adhesive backing. I recently read somewhere
    why zig-zag is better aerodynamically than straight-edge tape, can't
    remember the details.
    
    Terry

    What is the lowest cost radio outfit which will allow differential
    aileron mixing for micro servos installed directly in the wings of
    a glider. 
    
                                                        Thanks,
    
                                                        Jim

>                      <<< Note 399.587 by USRCV1::BLUMJ >>>
>                           -< Aileron mixing radios >-
>
>    What is the lowest cost radio outfit which will allow differential
>    aileron mixing for micro servos installed directly in the wings of
>    a glider. 
>    
>                                                        Thanks,
>    
>                                                        Jim

This answer doesn't count - I'll let someone else give you the answer you
want to hear - but...

$0.00 is the answer.  Use Y connectors to the micro servos and just select
a strategic hole in the control horn for the amount of differential you
desire.  Normal servos rotate 90 degrees.  Normally you set the neutral
setting of your control surface such that the control rod goes into a
hole in the control arm at the exact side and as the arm rotates it goes
45 degrees in each direction.  If you pick a hole offset from the center
in either direction you get differential (+ or -).

If you leave access to the control horn you can adjust it by
selecting different holes and moving the horn on the spline.

There is one thing to be careful of - make darn sure that the servos
turn the ailerons in opposite directions.  Your servo reversing switch
won't help you a bit if both ailerons go up together.

But you probably already know this and want to do it electronically such
that you can adjust it with a radio button.  In which case someone else
will have to tell you the lowest cost radio.  

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Kay's method works fine as long as you leave yourself plenty of
    adjustment points ie clevises on the aileron pushrod as well as
    at the servo end, as you will need to do a fair amount of
    fiddling/adjusting to get everything right.
    
    You're looking at $400+ to get a radio that will have programmable
    differential. $520 is the cheapest price I've seen on the Vision.
    $400-$425 for the JR X-347, and at least that much for a similar
    Futaba.
    Come to think of it, an Infinity 600 is <$400, but they are still
    not available, from what I've heard lately.
    
    Terry

    I had recently bought a used House of Balsa 2x4 glider that seemed in
    rather good shape; the only visible structural damage/repair had been
    to the fuselage where it had broken completely off just in front of the
    tail assembly.  The repair was neatly done although I didn't know at
    the time that it was quite weak.  The design of this glider is heavy,
    and the builder exacerbated the condition, albeit his workmanship was
    good.  I removed some minor structures and, like John Tavares,
    relocated the radio gear further forward.  [The design puts one servo
    behind the CG, etc.]  The ready-to-fly weight came to 20 ounces plus
    0.7 ounces of lead in the nose.  This is for a plane with 20% less
    wingspan than a typical hand launch glider.

    Yesterday morning I did the trimming hand launches in my field.  It
    flew as good as it looked --- quite well.  Two of the six landings were
    hard and the last, without much justification, broke the fuselage at
    the old wound.  My repair isn't as pretty as the first, but it does
    have carbon fiber tape and is now known from experience to be strong.

    At noon I went to the club field for a dozen hi-start launches.  On one
    of my launches I forgot to turn on my transmitter, and the launch
    became a spectator sport.  Up like a rocket for a hundred feet then a
    180 turn and straight in.  Whack!  Then, without dignity, to be dragged
    upside down by the still attached hi-start.  The fuse is still intact. 
    The only damage was to my self esteem and a minor split in the hatch
    cover.  The sturdy design and construction had been redeemed.

    This bird is a reasonable trainer for a glider beginner.  It would have
    been easy to build and is quite roomy inside.  (But I would recommend
    carbon strips along the fuse before assembly.)  The low aspect ratio
    wing should take cartwheels and other abuse.  The wing attachment and
    saddle arrangement is good, and easier to use than that of the Gentle
    Lady.  The Gentle Lady is a better thermalling sailplane, but the 2x4
    should be more fun on a slope and on windy days.  If I put a finger
    hole in the belly, I can use it as a hand launch bird.
    
    p.s.  I did realize during the wing-over that the transmitter must be
    off.  Without taking my eyes off the bird I pushed the switch forward
    and pulled full up.  But what I had pushed forward was the elevator
    trim, not the power switch.  Besides, I should have pulled full left,
    not up; it was still on the hi-start and could not have responded safely.

    In regards to using my Futaba Conquest to provide differential aileron
    mixing, I am not sure how this works.  I have done this with strip
    ailerons connected to a common servo, but I don't see how it would
    work with separate servos.  For example if I attach the control rod
    to provide more upward throw on the left wing and the other control
    rod to simultaneously provide more downward throw  on the right wing,
    how could this situation be reversed without reconnecting the rods
    to different control horn holes?  Hence the proper differential would
    only be applied when turning in one direction.  Am I missing something,
    or is it not possible to get differential throw in both directions?
    
                                                   Thanks,
    
                                                   Jim

    The angle between the control rod and the servo arm isn't 90 degrees.
    Since the linear component of the motion is reduced as you get away
    from perpendicular, you put the "larger" throw os that it passes
    through center in it's travel. In simpler terms, you offset the arm so
    that it isn't sticking straight out from the servo when you hook it up.
    The earlier part about the two servo approace is that you might find
    that you need to put the rod on the opposite/same side when running two
    servos off the Y connector. The offset from center would be in the same
    direction on both servos if both aileron horns are on the same side of
    the surface.
    
    If your horns are on the bottom of the ailerons and you want more down
    than up, you make the servo arm be offset so that is is closer to the
    surface when centered. Thus pulling will go through center and give you
    more linear travel in the down position than the push to make it go up
    (which is trying to go around the bend sideways) With the surface in
    the 12 position, you want the arm either at the 10 or 2 o'clock
    position. to get more down throw

    Obviously, it must be unique to sailplanes but, WHAT TH' HECK IS
    ZIG-ZAG TRIP TAPE.....?????????
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				|      |        / |\	   	       
      	         \|/		|______|__(o/--/  | \	   	       
      | |        00	       <|  ~~~  ____ 04 ---- | --------------------
    |_|_|        (O>o		|\)____/___|\_____|_/	   Adios amigos, Al
      |     \__(O_\_	        |	  |___/	 o	   (The Desert Rat)

RE: Note 399.593 by UPWARD::CASEYA
>>WHAT TH' HECK IS ZIG-ZAG TRIP TAPE.....?????????

    Well, it is a roll of tape that has zig-zag edges instead of
    straight edges.  Simple, huh?  :-)

    "All right wiseguy, why would a modeler want some???"

    Well, _there's_ the real question...  In the wind tunnel studies
    that have been done by NACA/NASA, the University at Stutgart (sp?),
    Princeton University (Seileg, Donovan and Fraiser) and others; it
    has been determined that if the airfoil is made too smooth, the
    laminar airflow separates from the airfoil and forms a "bubble" of
    stagnant air.  (This is especially true for airfoils at typical
    Reynolds numbers of models.)

    This bubble greatly increases the drag.  If the leading portion of
    the airfoil is "roughened-up" then the laminar airflow is "tripped"
    into turbulent airflow earlier and the bubble is burst thus reducing
    the overall drag.

    Seems counter intuitive at first, but think of it this way.  With a
    very smooth airfoil, you have VERY low drag for the first 30-50% of
    the airfoil but then the air separates and forms a drag bubble that
    causes LOTS of drag.  However with a rough (or "tripped") airfoil,
    there is slightly more drag in the first 30-50% but the bubble is
    gone (or greatly reduced) so the overall drag is greatly reduced.

    So by giving up a little bit of drag on the leading half of the
    wing, you can greatly reduce the drag on the last half of the wing.

    Now back to the zig-zag trip tape.  Experimentation has shown that a
    "too smooth" airfoil can be sufficiently "roughened up" by simply
    adding a piece of tape along the span (going from root to tip)
    somewhere between the 30% and 50% point of the airfoil.  Normal
    "straight" tape works here, but the zig-zag tape usually works
    better.  Why?  Well, does anyone _really_ know how planes fly?  :-)

    DISCLAIMER: I ain't no aeronautical engineer.  All of the above
    could be complete hogwash, but it's the best I've been able to
    understand from all the books I've been reading lately and I beleive
    it to be accurate.

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Castor Oil!! "    
                      |_____/

><<< Note 399.594 by RGB::MINER "Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11)" >>>
>           -< More than you wanted to know about zig-zag trip tape >-

And the only place that sells the stuff (somebody tell me if I'm wrong)
is Hobby Lobby.  The darn stuff costs $5.45 for a heaping 47 inches of
trip tape.  There is some gap sealing/trip stuff packed along with it
that I would throw away.

Now I need 136 inches for my Lovesong and after you add shipping I'm
looking at $20 for my trip.

If you seen the total cost for my Lovesong you would understand my
sudden reluctance to blow another $20.

Looks like a scouting trip to the notions store is in order - maybe
they have colored zig-zag bias tape with adhesive on it?

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Dan's explanation is pretty darn good actually. Last night I saw
    a version of the zig-zag tape that Hobby Lobby sells that is about
    1" wide, zig-zag on the leading edge and straight on the trailing
    edge. It's applied right over the aileron hinge line so that the
    aft portion seals the hinge gap, while the front zig-zag portion
    trips the flow over the control surface thereby increasing its
    effectiveness. The rear portion flexes with up control movement.
    
    While I'm at it,this was seen at a friends house where I had gone
    to trade/buy kits. He has the biggest collection of unbuilt German
    scale kits that I've ever seen, period. He was also finishing up
    a 4 meter Multiplex ASW-24. It is fabulous. If he had entered it
    in the Nats in scale glider events last year, it would have won
    the static judging hands down. I didn't see anything at the Nats
    that even came close. Full cockpit detail, map pockets with maps
    that fold out (he told me the source of the maps but don't remember),
    rearview mirror, retractable machined aluminum landing gear with
    bungee cord gear door actuation, just like the full scale. etc.
    It blew me away.
    
    Anyway I wound up trading him my Graupner Cirrus plus $150 for a
    Multiplex Cortina flying wing, still in the box. If I want to
    get the flying wing bug out of my system this baby should do it.
    If my metric conversions are correct the specs. are:
    
    Span: 137", 18 degree sweep
    
    Wt: 116 oz.
    
    Wing area: 1472 sq. in.
    
    Wing loading: 11.4 os./sq. ft.
    
    The fuselage pod is teardrop shaped, 31" long. The wings plug in
    on steel blades into brass boxes in a conventional manner. Controls
    are separate ailerons and flaps, 4 surfaces, with aluminum scissors
    spoilers already mounted in the wings, although they have to be
    removed to hook up the linkage. White foam presheeted with obechi.
    The German kit manufacturers must have a lock on the worlds prettiest
    supplies of obechi. The stuff I order is never that good looking.
    Control surfaces are precut, but you need to face the edges. Servo
    cutouts are made and tubes for control rods are in. I'll remove
    the rods and use the channels to run the servo wires.
    The wings use bolt-on ~ 8in. winglets on the tips.
    The fuse. pod has a blue tinted canopy plus an access hatch between
    the wing roots. The wings are held on with a 2" steel turnbuckle.
    
    I can understand why Hobby Lobby was getting ~$400 for these things
    2-3 years ago, before they went out of production.
    
    He has other Multiplex kits, and after my tax refund comes back
    I might just relieve him of a 3.2 - 3.8 meter (removable tip
    extensions, a la full scale version) of a DG-600.
    
    It looks like the Legend project will take a back seat while I build
    the Cortina. Should be just in time for the sod farm flying season.
    I'd be afraid to familiarize myself with it, too close to civilization.
    
    Terry

    Kay,
    
    While you're at the notions store, check out the pinking shears (I
    think that's the name). My wife has a pair in her sewing stuff. Nice
    zig-zag shears that you can cut the material of your choice with. As
    I've found out with other "borrowed" sewing items, buy your own or
    don't get caught!
    
    You could probably use rubber cement on the zig-zag cloth trim to stick
    it down or really go back to the roots of modelling and stick it down
    with clear dope. You can get rubber cement in jars with brush caps.

    Really, Jim,
    
    You should have asked me before entering your note 20 minutes prior!
    Yer' note echoes my thoughts 100%...
    
    I was thinking of pinking shears as I read Dan's note. Kay should be
    able to get one for less than $20 in the fabric section of any dept
    store...
    
    ajai
    
    

    But you can get pinking tape already "pinked" in the fabric store.
    No need for the expensive scissors. I think I'd use RC-56 to glue
    it down. Removable without causing damage to the covering, and plenty
    strong enough in that application.
    
    Terry

    Sorry Ajai. It would have taken me longer if I had entered YOUR typical
    100+ line message ;^)

    At the risk of starting a huge debate, what is the best way to get
    started flying ? Should I start on a powered trainer or try a
    sailplane. It appears different skill are needed down the road but I
    just thought to learn rudder/elevaitor skill would seem easier on a
    beginner sailplane.
    Thanks
    Walt

    
    I'm in the process of building a Pulsar 100" sailplane.  I want to
    install a flap servo in the fuse.  To do so and have the flap actuated 
    by a cable requires tha I cut two holes in the center seam of the
    fiberglas fuse. The holes would be 1/8" in diameter.  Does anyone see
    any issue (structurally) with doing this?  These two holes would be
    app. 1/2 and 3/4" behind the joiner rod.
    
    Tom

    Tom,
    
    Another alternative would be the Dodgeson design described in 399.540
    I'm currently installing this in a standard class glider and it allows
    for easy plug-in wing removal without disconnecting the servo linkage.
    I can't picture the Pulsar design so I'm not sure if this is truely an
    option for you.

>    fiberglas fuse. The holes would be 1/8" in diameter.  Does anyone see
>    any issue (structurally) with doing this?  These two holes would be
>    app. 1/2 and 3/4" behind the joiner rod.
    
No problem Tom, Most fiberglass gliders have holes by the wing rods
for servo wires, spoilers, etc.  Common practice.

As to the beginner who wanted to know about starting with a glider.
You will get mixed answers on this.  More important is where you
live and who your instructor will be.  If you are close to a good club
and your instructor wants you to start with a Gentle lady and a Futaba
4 channel with a trainer cord that that is what you should do.

If your instructor wants you to get a PT40 with an OS 40 and a JR radio
then that is what you should do.

Clearly the light cheap gliders are easier for a beginner to control
but it is harder to accumulate stick time because each flight is only
1-3 minutes long.  Also I think you will have to make too many landings
to get use to the sticks.  There are those who would disagree.  An interesting
compromise is an electric (Goldberg Electra) or the Dynaflite Butterfly
small gas powered (sorta) glider.

But there is a long series of notes addressing beginners and the most
important thing to do first is seek out a club and an instructor.
If you don't get an instructor I guarantee you will wish you would have.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Tom, do you mean by "center seam" the center of the fuselage on
    the bottom, or the center of the molded-in wing root fairing ?
    If the latter, then it's no problem at all. a 1/8" hole won't cause
    any problems in the bottom either, just try to keep it as far forward
    of the wing t.e. as practical. The weakest point on a Pulsar fuselage
    is the area immediately behind the wing root fairing,ie, just behind
    the trailing edge.
    
    Terry

re Note 399.603  by Jim Reith   -< Possibly use the Dodgson mechanism? >-
    
>>    Another alternative would be the Dodgeson design described in 399.540
    
    This has a topic of its own, 1024, pointed to by the keyword, FLAPS.
    
  1024  ZENDIA::REITH        28-JAN-1991    10  flaps for plug-in wings
  1025   BRNIN::SOUTIERE     14-JUN-1989    56  Flaps
  1027    RVAX::SMITH        15-JUN-1989     5  Use of spoilers
    
    Hmmmn.  I'll see if it also has a GLIDER* keyword.

    sorry for the misspoint. I had a reference paper copy in my desk. BTW:
    1/2A nose wheel arms are just right.

Terry,

	The Legend is one of the easiest kits I ever built. It took a month
elapsed time and about 36 hours investment. It's simply a beauty. Get it done!

Anker

    I have a question about mounting aileron servos directly in the
    wing.  Does the output arm of the servo typically protrude through
    the bottom of the wing?  Most of the modern airfoils are quite thin
    and it doesn't appear that the servo could be completely encased
    within the wing.  Also are futaba micro(S133) servos suitable for 
    this application?  What is a good way to secure them in thin foam
    wings?  Do you epoxy in a plywood plate and attach the servo to it?
    
    
                                                     Thanks,
    
                                                     Jim

>    I have a question about mounting aileron servos directly in the
>    wing.  Does the output arm of the servo typically protrude through
>    the bottom of the wing?  Most of the modern airfoils are quite thin

Not on gliders

>    and it doesn't appear that the servo could be completely encased
>    within the wing.  Also are futaba micro(S133) servos suitable for 

Turn them sideways

>    this application?  What is a good way to secure them in thin foam

Yes - but watch for new Futaba micro servos with metal gears.

>    wings?  Do you epoxy in a plywood plate and attach the servo to it?

Silicon.

Save the plywood for a lead sled.    

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    re .608
    
    36 hours to build a Legend !? Good grief, I just spent 47 hours
    to build a Chuperosa. However, Ankers' prodding may push me toward
    building the Legend before the Cortina, then again I was thinking
    of building the Lobo flying wing and doing some sloping. Decisions,
    decisions.
    
    Yesterday was the first flights of the Chup, and it's really great.
    Everyone that saw it fly wanted one. Both handlaunch and hi-start
    were thermally successful. It has much better penetration and neutral
    stability than the Orbiter, and can be racked around in tight turns
    without losing so much altitude. Mine is pretty beefy at 18.7 oz.
    but with a 6 chan. PCM rcvr, and 270ma pack, and 26 grms of nose
    lead, I can't complain too much. The method of securing the t.e.
    of the wing with a piece of tape is so simple and effective. On
    a small airplane it's much better than a nylon bolt. Also, his method
    of gluing a strip of rubber band on the wing saddle works better
    than foam tape. Both techniques allowed me to catch a wing tip on
    landing several times without damage.
    
    re. 609/610
    
    Try to mount your servos so that you have minimal but adequate
    clearance between the pushrod and wing surface at full throw, while
    using as short as control horn on the aileron as practicable.
    If this means that you wind up with a little bit of the servo arm
    projecting out of the wing, don't panic, you won't notice any ill
    effects and it beats having to engineer some sophisticated totally
    hidden system.
    Incidentally, that hidden system that Harvey Michaelis came up with
    and mentions in the latest MA, sounds interesting. I'm going to
    build a mockup to see if I've visualized it correctly, and test
    how easy it would be to install in foam wings.
    
    For mounting servos in wings, silicon is ok as Kay says, but if
    you put a piece of 1/64" ply in the bottom of the servo cut out
    (epoxy or UFO it in place) then you have a better suface to stick
    the servo to, and you don't have to worry about the foam ripping
    loose. Weight is negligeble. I like PFM the best for mounting servos,
    more rigid after it drys, but still easily removeable.
    
    If I could build as fast as I give advice my kit backlog would
    disappear overnight.
    
    Terry

>    Incidentally, that hidden system that Harvey Michaelis came up with
>    and mentions in the latest MA, sounds interesting. I'm going to
>    build a mockup to see if I've visualized it correctly, and test
>    how easy it would be to install in foam wings.

Please let us know in your own words how this works after you build your
mockup.  I couldn't visualize it either.

P.S.  I might have an application for it - TONIGHT!

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    After reading about high tech sailplanes I have figured the cost
    as follows:  1) Low end high tech Sailplane kit =        $200
                 2) Vision radio                    =        $525
                 3) 2 additional micro metal geared servos = $100
                 4) Misc. covering, glue, carbon fiber, etc  $30
                 5) High start(cheaper than winch)           $80
                                                             ----
                                                             $935
    
    Wow!  This hobby isn't cheap, when you get into the high performance
    stuff.  
    
                                                   Regards,
    
                                                   Jim

    You might want to consider the $400 JR X-347 as a substitute for the
    Vision. I'm pretty sure you can program it to do everything and you
    avoid (Kay's favorite) Airtronics micro servos (and his hassles related
    somewhere in here about upgrading them to metal gears)
    
    P.S. I think #4 is about 1/2 what it should be

    Can anyone tell me anything about the Eppler 387 airfoil?  I was
    looking at the Jan. edition of Model Aviation and noticed that this
    airfoil was used on Brian Agnew's new hand launch V-tail glider as
    well as Rudolph Freudenth???(world f3e champ) world class f3e ship.
    It would seem that an airfoil that is used to allow speeds in
    excess of 100mph would not be the best choice for a HLG.  Any ideas/
    comments?
    
                                                       Regards,
    
                                                       Jim

    Ciao Jim: While I can't give you any real techno-facts about this I can
    say that over here (Italy) we are using them in a wide variety of
    planes, from F3E to electric thermal soarers up to 4 mtrs with great success
    although the new foil of choice for the F3E seems to be the DU84-084. I
    think for the glider version of the 387 they increase the thickness to
    12% or so and for the  speed at 9%. No flaps used, spoliers/brakes
    only. A few of the guys make up the foam cores to various profiles,
    thickness and shapes (wash out, tip shape etc) and have fun. From what
    I understand the profiles have to be within 1-2% to be faithful to the
    specs. Also it seems the  low-speed wind tunnel figures go out the
    window as the speed increases (ie the 'specs' indicate this is not a
    good foil for speed but the experience is different); at least this is
    what I understood/translated from one of the 'experts' here (he wins
    many of the contests here) and always builds from scratch. 
    
    I have several configs of this foil and am most pleased with the
    performance envelope (but then again I don't compete much..). It
    appears to stall gently and predictably as well and with minimal lift
    seems to float forever.
    
    Regards, Ed 

Jim,

	The SD3021 that the Legend uses is a 9.5% airfoil and too thin for a
standard servo lying sideways. I first used Futaba S133s and on the first day
managed to strip the aileron servo gears on a zoom launch. The wingtips
fluttered with a horrendous FLRRRRRRRR and the plane flew like s..., but I
managed to get it down thanks to mixing aileron into the flaps and the tiny
bit of polyhedral. My theory is that the ailerons fluttered first, stripped the
servos and then the fluttering ailerons caused the entire tip to flutter.
Haveing learnt my lesson I ordered the new Airtronics 141 servos, which have
brass gears and are a bit bigger than the 133s. Much more confidence inspiring!

	Yes, the arm protudes through a slot in the bottom of the servo hatch.
The servo itself is attached to the hatch, whcih works really well. I hadn't
thought of this possibility.

Anker

    re .615
    
    Quoting from the NSP catalog:
    
    E387 :  Camber: 3.8%, Thickness: 9.06%
    
    This airfoil is under-cambered with less thickness and camber than
    the E214 and was designed to be used without camber changing devices.
    For an under-cambered airfoil the E387 has reasonably low drag at
    mid speed. It consequently has a fair speed range aithough its
    performance envelope is best at low to mid range speeds. Its stall
    characteristics are mild.
    The E387 seems to be a common choice for competition hand launch
    gliders, possibly because of its good speed range and high lift.
    One ship that uses this airfoil is the Pivot. (and Vertigo, as Jim
    says.)
    
    re. 617
    
    The very latest 94141 servos do have all metal gears (metal final
    drive gear). Whether these are actually being sold yet, I don't
    know. The original 141's have a plastic or nylon final drive gear,
    and THEY WILL STRIP! I saw it happen at the regionals, and Tim Renaud
    was quick to jump forward and announce the immanent arrival of the
    improved models. You may have to pull the case off to see what version
    you have.
    
    Terry

    I just received a catalog from Western Plan Service, 5621 Michelle
    Dr., Torrance, Ca. 90503. It's free if you stop by their office,
    or $3.00 by mail.
    
    The catalog has top and side views of all the plans available and
    some photos. I hadn't realized there were so many neat plans available
    for flying wings of every shape and size, also some nice scale birds,
    Schweizer TG-2, D-28 Windspeil, Hortons, etc. A 60" Fieseler Storch
    that looks about right for electric, scale slope Spitfires.
    
    "The time will come when thou shalt lift thine eyes
    to watch a long drawn battle in the skies
    while aged peasants too amazed for words
    stare at the flying fleets of wondrous birds."
    
    Thomas Gray--1737 ( from the cover of the catalog...so now I know;
    I'm an aged peasant)
    
    Terry

    I recently finished scratch building a Ninja. It's pretty stock but I
    added smaller twin fins and did it in a military-like motif. I put a
    towhook on it and test flew it yesterday. I was somewhat surprised by
    what I found and was wondering if there were other Ninja owners out
    there that could offer suggestions/experiences of their own.
    
    I was flying off an upstart and mostly interested in the aerobatic
    handling before I get to a slope (when the winds are next "right"). I
    found that the elevator throw I had was too touchy and I wasn't quite
    pleased with the roll rate but the speed was great. Doing a split S off
    the line gave me plenty of speed but the plane REALLY slowed down when
    I tried my first loop. I think it might have been too tight and the
    elevator drag slowed it down too much. Later on, I got a nice round one
    and I didn't seem to be going any faster at the time (but it was
    bigger). The plane will glide nice and flat if you keep the speed up
    (something I'll have to work on) but it slows way down and muches in
    rather than stalling and snapping. This is my first aileron/no rudder
    upstart launched ship so going up the line did get me out of shape a
    couple of times. Comments?

    Jim,
    What's the weight/wing loading on your Ninja?
    What is the fuselage made of? How rugged is it?
    What is the wing attachment method?
    Is it designed for wing mounted servos? 
    
    You probably couldn't say how well it holds up, landing in volcanic
    rock, but we're always interested in such things around here, as
    our best slope site is carpeted in baseball to basketball size volcanic
    rock. I'm contemplating some slope soaring shortly, and am going
    to try to devise a net catching scheme for landings so that the
    plane doesn't have to touch the ground.
    
    I started on my Lobo flying wing this week, which is primarily a
    slope ship, and will have it done shortly as there isn't much to
    do on it. A good thing too, since the instructions are vague and
    the drawings scarecly better. But they do fly well on the slope,
    and it will take my old Conquest rcvr, and full size servos without
    shoehorning them in. 
    
    Terry

    
    	I've been keeping quiet about this but... I've been building a
    standard class ship as a size project.  I'd competed when I was out
    in CXO in 85 and had wanted to get back to it. So a few weeks ago
    I called NorthEast Sailplanes and ordered a Pulsar.  This design
    was suggested to me by a few of the noters and a good standard class
    thermal duration ship.  My idea is to build it and enter in Std and
    open class using one ship.  Perhaps to add a 2 meter ship later.
    I've been working on a farmer in the area that abutts a water
    filter bed atop a local mountain/hill.  It faces west and usually
    sport a constant breeze.
    
    	Anyways...  To date I've glued the three piece cores together and
    installed the cable jackets into the cores for flaps and ailerons.
    I'll have four servos in the fuse driving ailerons,flaps, elevator
    and rudder. I also plan to use a 1000 or 1200 ma battery pack up front
    in the nose for it's storage capacity and weight.  Hopefully I'll get
    the storage capacity I want without having to add any dead nose weight.
    A fellow noter has agrred to help me with the vacumm bagging of the
    wing cores and this should happen some time in the next two weeks.
    I also have the plug in tubes installed in the stab cores and the
    mounting block for a flying stab glued into the fuse. the only other
    progress in the rudder. It's framed up and ready for covering.  I'm
    using a tape hinge on this. I learned this in CXO. You bevel the rudder
    all to one side. To install you use clear packing tape. Attach a piece
    to the rudder and the fuse side at the rudder post. Then flex the
    rudder until the rudded LE and the rudder post make a flat surface.
    Then add a second piece of tape to the inside of the hinge and your
    done.  I've never seen one fail and it's a completelt sealed hinge
    line. 
    
    Tom

    Re: .621
    
    Well, you really want the WHOLE story huh?
    
    This was built from borrowed plans. If you've seen the single sheet
    that passes for Ninja plans, you'll understand why this is "sorta" a
    Ninja. The majority of the plan is 60% size. Two enlargements at 129%
    give you back a close approximation. The kit comes with lite-ply
    interlocking fuselage sides. I had a standard sheet of 1/8" ply (12x48)
    and cut them from that. I interlocked them since there are no corner
    spars to support them. There are two large oval holes in each side of
    the "tail boom" for lightening (standard) and it has 3/16" sheet tail
    surfaces (I found an incredibly stringy piece of HARD balsa rejected by
    all other modellers at the shop I went to. Perfect! I cut light white
    foam cores and used 3/16" square spruce as the stick barrier/leading
    edge. I used standard servos and a 550ma battery since I expected to be
    tail heavy due to the standard plywood used. I ended up using about 1-2
    oz of lead in the noseblock (firmly fiberglassed onto the plywood) and
    ended up at 2lbs 10ozs with the plans calling to ~2lbs. I'm really
    pleased with it after about 10-15 upstart flights yesterday. The wind
    is strong and from the right direction today for the local slope site
    so I think I'm starting to feel a little sick... ;^)
    
    It's in the car and I'll report more tomorrow

    Terry, (Re: .621)
    
    Little did I know how much experience I'd gain in the structural
    integrity of the plane. I honestly think you could fly this plane just
    about anywhere. The "slope" note has all the gory details of the day
    but after inspecting the plane last night, I wanted to STRONGLY
    recommend it to you. My fuselage was entirely glued with 5 minute epoxy
    and it got bashed pretty hard yesterday without a wimper. To answer
    more of your questions, the wing is held down with a front dowel into
    the bulkhead and a rear bolt. I used a 1/4" dowel and an 8-32 nylon
    bolt. As far as the wing area goes, I'm not exactly sure. It has an 58"
    wingspan and the cores I cut were ~8+" tapered to ~5+" with an
    additional 3/16" leading edge, trailing edge and 1.25" TE stock
    ailerons. There wasn't a dimension box on the main plans. Steve Smith
    might be able to be more specific as he also has one.
    
    It should survive a net catch and does slow down and mush rather than
    stall/snap but you have to understand that at 2+ lbs and the speed it
    likes to fly at, it's not something I'd consider hand catching. Dave 
    got my attention about the crowd behind me when he started warning people 
    that landings in the rotor behind the hill were unpredictable. He also
    commented on how hard I was working the slope and then hit on the true
    incentive, I didn't want to do too many landings ;^)

    So it it looks like you've got ~400 sq. in. area and a wing loading
    of ~15 oz./sq. ft. Just about right for the force 10 gales you guys
    so blithely fly in.
    
    Terry

    I must admit it handled the wind quite well. The only wind related
    problems I had were when I slowed it down too much or let an upwind
    wingtip get too high. In both of these situations it rapidly responded
    to the corrections.
    
    I should explain about Bose a little more so you understand why I built
    this lovable brick sh*thouse... The slope is covered with sumac which
    at this time of year is a bunch of upstretched hands waiting to poke
    holes in anything that ventures too close. The landing area is a rocky
    field that is wet mush right now and on good days, generally occupied
    by kite fliers. If the wind is blowing towards the preferred slope, the
    kite people seem to move closer to the lip to avoid flying out over the
    parking lot. Landings can be interesting and monocoat wings get lots of
    poke holes here. I've had to dump a plane to avoid the people a few
    times and in the wind yesterday, Dave's warning to the spectators was
    warrented. My Panic has wings sheeted in the same manner as the Ninja 
    and has stood the test of time with but a few punctures. The change I 
    made was to add a spruce leading edge to stand up to possible stick 
    impacts without cutting into the wing. So far so good. 
    
    It didn't handle like 15 oz/sq ft off the upstart on wednesday. It has
    a reasonably flat glide as long as you keep the speed up. I think this
    would be nice as a beater/rough field slope ship and I wouldn't try to
    lighten it up too much for fear of reducing the survivability of it.
    The stock lite-ply would probably give you a few ounces for free and
    eliminate some/all the nose weight I added.

    After Jim's description of Bose, I have to relate something that I saw
    once while flying kites there.
    
    The field was covered with a light layer of snow. The folks at Bose had
    inserted those metal poles at the edges of the parking lot so that the
    snow plowing folks would know where the edge was. This was the only
    pole in the entire field (except for the lights).
    
    An unfortunate pilot managed to arrange to have the pole go through is
    wing, right between the ribs. The glider sort of spiraled down the pole
    to a gentle landing. The kite flyers gave the pilot a round of
    applause.
    
    	Marty Sasaki

    One more Ninja note mostly for Terry, and then I'll give it up. The
    advanced/accomplished throws that Steve Smith put in here are just
    about where I like them. This gives the plane good characteristics and
    a good roll rate. I went out at lunch off an upstart at the local
    soccer field and it was very aerobatic. It likes the speed to be kept
    up and likes loops to be big enough so that the elevator doesn't create
    too much drag. Now for Terry, you can use a soccer goal to catch the
    plane with no damage. I don't know if I'd want to do it all the time
    but I got away with it on my last landing. (I also don't think I'd want
    to have to hit the net every flight)

RE: Note 399.628 by ZENDIA::REITH 
>>It likes the speed to be kept up and likes loops to be big enough so
>>that the elevator doesn't create too much drag. 

    When you give it full up elevator, it is probably increasing the
    angle of attack of the wing so much that the wing itself is stalling
    and giving you that high drag "mush".  You're just lucky that the
    Ninja doesn't have a tendency to snap roll.  :-)  

    On an ElectroStreak, if you give it full up, you may very well get a
    snap roll instead of a loop...

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Castor Oil!! "    
                      |_____/

    
    re .628
    
    Jim,
    Thanks for performing the soccer net catch experiment. It WAS an
    experiment wasn't it? ;^).
    All this talk about Ninjas caused me to buy one friday, and then
    I discover over the weekend that several other club members have
    been covertly building them. I saw the bare (gasp) wing of one and
    it looks pretty nice. Now I have to decide where it will fit in
    the building queue.
    I'm thinking of rigging up a net about twice as deep as a volley
    ball net and mounting it on PVC pipe that could be hand carried
    or ground mounted. An assistant could possible make a "butterfly
    catch", and sort of roll with the punch, minimizing the impact.
    
    In the meantime the Lobo flying wing has been sheeted, and is ready
    for the leading edge to be installed. The radio installation has
    been trial fitted and the flap linkage on one side installed.
    One oddity of this design, is that the 7" flaps are mounted outboard,
    with ~26" strip ailerons mounted inboad. Therefore the flap actuating
    tubes run out from the central pod, 8" short of the tip and are
    buried under the top spar which avoids having to cut separate channels.
    He uses Ny-rod in the kit which caused way to much friction, so
    I ran 1/32" cable inside the inner ny-rod and that seems to be pretty
    free moving.
    It has a 5" tip anhedrahl, necessary for stability because he doesn't
    use a reflexed flying wing type airfoil. This will be a durability
    sore point, all the more reason to devise a net catching scheme.
    
    Also in the meantime I soldier on with the Chup and Algebra. 
    Yesterday I noticed that the Chup can hold its own with Thornburgs'
    2 meter quasi-mini Bird of Time that he was hand launching, the
    pilot gap being greater than the design gap.
    Also got in some inverted flying with the Algebra, and watched several
    first timers semi-solo sucessfully with their Spirits and Oly 650s'.
    And of course the inevitable bane of all novices, the Kyosho electric
    ARF Cessna that snap rolled on take-off after actually doing an
    ROG much to my amazement.
    
    Snow saturday morning, 70 degrees yesterday. Ah, spring.
    
    Terry

    Just a mention of something that might have been lost in earlier notes.
    I strongly recommend replacing the leading edge with something more
    substantial. I used spruce and rounded it with a file. You can get
    spruce triangles which would be perfect. Don't hit your catcher, that
    sucker moves right along at speed.
    
    

>         <<< Note 399.612 by KAY::FISHER "Stop and smell the balsa." >>>
>                              -< Hidden Ailerons >-
>
>>    Incidentally, that hidden system that Harvey Michaelis came up with
>>    and mentions in the latest MA, sounds interesting. I'm going to
>>    build a mockup to see if I've visualized it correctly, and test
>>    how easy it would be to install in foam wings.
>
>Please let us know in your own words how this works after you build your
>mockup.  I couldn't visualize it either.
>
>P.S.  I might have an application for it - TONIGHT!

I couldn't wait.  I installed a similar system in the Genesis.
I'll bring it in to the next DECRCM meeting.  It ain't great but
the idea is it (1) saves some weight, and (2) keeps the ailerons in the
wing so that on hard landings when you shear off the wing you don't
mangle up some mechanical linkage.  The disadvantage is that
done my way the servos are a permanent part of the plane and very hard
to remove or maintain.

Anyway - I just mounted the aileron servo at the root rib.  I ran a torque
rod from the servo to the inside of the aileron (two rib bays away).

The torque rod is just light music wire and it goes into the aileron
straight (unlike Harvey's angle and slot).  Then it bends about 60 degrees
(but anything past 45 would be OK) and goes towards the servo.  Then it bends
another 60 degrees and runs parallel to the servo horn (for about 1/2 inch).
Then makes a 90 degree bend into the servo horn.  Now buy itself it won't turn
the aileron until you anchor both ends down to force them to pivot.

I believe it is the lightest way to put Aileron linkage on the Genesis.

Sure hope my untested Airtronics 401's work!

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    I still don't have the confidence to start hacking the beautifully
    presheeted undercambered obechi wings of my Multiplex Fiesta to
    install servos in the wings.  The plan calls for the servos to be
    installed in the fuselage, but this is just not possible.  The design
    was not well thought out.  Anyway, I am thinking of doing what Kay
    mentions in the previos note(similar, if not exactly the same).  That
    is burying the servos in the wing near the root, where hopefully it is
    thick enough to enclose the entire S-133 servo.  The torque rod would
    then run to the already installed bellcrank buried further out on the
    wing.  Is it best to attach the servos directly to the white foam with
    PFM adhesive?  The last time I inquired about this I wasn't clear
    what works the best.  Also since I don't have a computer radio I
    presume that a Y-connector is used to couple the signal to the servo
    in each wing.  Does this mean that one servo must be installed the
    reverse of the other, so one aileron goes up and the other goes down?
    Also off the subject, how many and what type of servos do you get with
    the Vision radio system?   I am just finishing up my Sagitta 600 with
    my own modified fuselage.  It has ailerons, spoilers, elevator, and
    uncoupled rudder.  
    
                                                   Thanks,
    
                                                   Jim   
    
                                             

    Isn't this fun? Trying to picture mechanical concepts from arcane
    verbal descriptions.
    
    Kay, if you can answer a few simple (;^*) questions maybe I can
    grasp the concept.
    
    Is servo mounted its' side?
    Which way does the output shaft point, in relation to the wing trailing
    edge?
    
    Does the torque rod enter the aileron from the inboard end of the
    aileron, ie, parallel to the aileron long axis, or does it enter
    from the leading edge, ie, at right angles to the long axis?
    
    When the rod makes its first 60 degree bend, angling it toward the
    servo, then makes a second 60 degree bend, does this put it back
    on a parallel path? .....   < to servo
                             .
                              .
                               .......> to aileron
    
    There are other questions but this is enough for a first pass.
    
    Terry 

    re .633
    
    Jim, If you have bellcranks already installed in the wings, then
    your idea of mounting the servos further inboard and using a pushrod,
    is probably best. I assume there is also a tube pre-installed in
    the wing to act as a pushrod housing. It sounds similar to my Multiplex
    Cortina.
    
    With the sevos mounted on their sides and the output arm lined up
    with the pushrod, you would have a straight back and forth movement
    between the arm and the bellcrank. The only problem might arise
    at the servo end as the pushrod moved up and down with the rotation
    of the servo arm. You would need sufficient clearence at the point
    where the pushrod exits the foam and enters the servo cavity.
    This should't be much of a problem since radius of the s-133 arm
    is so small; vertical motion will be minimal.
    
    Don't glue the servo directly to the foam. Glue 1/64" ply to the
    foam first, then mount the servo onto the ply. This spreads the
    load, eliminates squirming between the servo and foam, and prevents
    the foam possibly tearing under heavy load.
    
    The Vision normally comes with full size 102 servos (4), the bottom
    of the Airtronics line. There is a more expensive option that comes
    with 748 (?) servos. I don't know anything about that servo.
    At any rate, 102s are too big to fit in most glider wings, but they
    work ok for me as rudder and elevator servos.
    
    Before cutting the obechi, use the servo as a template to determine
    how small of a hole you can get away with. Use a steel straight
    edge and a new single edge razor blade to make the cuts. Use repeated
    light scoring cuts until you've penetrated the obechi on all sides.
    Then pry the obechi off the top of the foam and continue deepening
    the cut around the edges of the cavity until you reach the desired
    depth. Obechi splits VERY easily along the grain.
    This sounds like a very dooable project to me.
    
    Terry

4>    Kay, if you can answer a few simple (;^*) questions maybe I can
>    grasp the concept.

Well - remember first that what I have does NOT match what Harvey described
in Model Aviation.  So the following responses are relative to the way
I did it on the Genesis.
    
>    Is servo mounted its' side?

Yes

>    Which way does the output shaft point, in relation to the wing trailing
>    edge?

The shaft is towards the wind tip.  That is if you took a straight piece
of music wire and put a Z bend in it and stuck it into the servo wheel
it (the wire) would lay straight back towards the trailing edge.
    
>    Does the torque rod enter the aileron from the inboard end of the
>    aileron, ie, parallel to the aileron long axis, or does it enter
>    from the leading edge, ie, at right angles to the long axis?

It enters from the leading edge - straight back.  That is why there is
no need for a slot - just a hole (re-enforced with ZAP).
    
>    When the rod makes its first 60 degree bend, angling it toward the
>    servo, then makes a second 60 degree bend, does this put it back
>    on a parallel path?

Yes
>                       .....   < to servo
>                            .
>                             .
>                              .......> to aileron

No - more like
=========================================Leading Edge=========================
                   +----+ 
                   |    |  
                   |401 | 
                   |    | |
                   |    |-|
                   +----+ H|
Root                       |   < to servo                               Tip
                            .
                                .
                                    .
                                        .
                                            .  V to aileron
                                            |
                                            |
-----------------------------------------------------Trailing Edge------------
                                          ^
                                          Aileron starts about here

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Is the Futaba 7 channel computer radio(7uaps I believe) acceptable
    for use with sailplanes?  This radio is available in fm for $320
    and $369 for the PCM version.  Hence it is considerably cheaper than
    the Airtronics Vision which is about $525.  The fact that the Futaba
    comes with four S-148 is lousy for gliders, but now I understand that
    the Vision also comes with full size servos.  If I have to pay $525
    for the Vision and then invest an additional $200 for four metal
    geared micros, I think I might have to stay out of the high performance
    sailplanes.  That is why I am wondering about the Futaba unit. Any
    comments/experiences with this system.  Also is PFM glue the way to
    go for mounting servos in foam wings?
    
                                                   Thanks,
    
                                                   Jim

    See my recent entries in note 737 for the experiences that a friend
    of mine is having with his 7UAPS. He bought it for the same reasons
    you state, and intends to use it in his Legend, but hasn't yet resolved
    the programming difficulties. 
    
    The local hobby shop owner claims expertise at programming these
    things and is willing to help, although the radio was purchased
    from Tower. Stay tuned for the results.
    
    PFM is one of the best adhesives for servo mounting if you're going
    the glued-in route. Gluing in is cetainly the simplest/lightest
    way, but you have to consider the trade offs around ease of removal,
    field maintenance. I've tried foam tape, carpet tape, wood rails
    and screws, wedges, spacers, shims, tube and rod gizmos that took
    me as long to engineer as it did to build the plane, etc. ad nauseum
    and I've finally concluded that gluing in with a removable glue,
    which PFM is, suits me best.
    
    Terry

    The April issue of RCSD is a goldmine of info.
    Bob Champines' article on making pull-pull controls for stabs has
    saved me a lot of work. I will definitely use his T-tail scheme
    on the Legend. I need to find a local source for small pulleys,
    but this is an ideal application for the vinyl coated kevlar cord.
    
    Also I notice that Taylor Collins is advertizing in RCSD now, with
    sharks tooth landing skids and a packet of airfoils. I'm going to
    get him to bring this stuff to the club meeting next week, and will
    check it out and do a product test. 40 airfoils, each in 10 different
    chord lengths, for $20. 
    
    The May issue of Model Builder has a cover picture of two planes,
    both of which I own examples of ! This has never happened. Am I
    sliding towards conformity, or merely gaining the wisdom of advanced
    age ?
    
    Terry

>    Is the Futaba 7 channel computer radio(7uaps I believe) acceptable
>    for use with sailplanes?  This radio is available in fm for $320

I believe so.

I would opt for the JR 347 myself but I'm sure they are all good choices.

Terry - I am intrigued by the other fellows problem with programming the
Futaba Super Seven.  Could you possibly get a hold of his manual and
send me a copy of it?


Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Kay,
    I'll try to copy his manual, probably early next week.
    FWIW the hobby shop owner says the 7UAP isn't capable of being
    programmed for crow.
    The radio owner has discovered more stuff in the manual that may
    bear on his problem.
    
    Terry

    
    	Last night I got my MA. income tax "rebate" check in the mail. 
    I've been waiting for this and Ya, it's already spent.   I called up
    last night and ordered a "Stinger" from Vern Hunt models.  Originally
    designed as a 74" sloper Vern offers the ship with a number of 
    airfoils.  I choose the 214 for thermal duration.  Vern is also
    going to cut the wing a little longer so I can get a true two meters
    out of the wingspan.  He quotes 12 hours to build it ready for paint.
    The wings come sheeted with the stab shaped.  The fuse is fiberglas.
    You add a center keel which secures the radio and there is a nose
    cone over the front of the plane.  He doesn't run a full flying stab
    opting for a stab and elevator combination.  I should have the kit
    by a week from tomorrow.  
    
    
    Tom

    Ok, I'm psyched, stoned, turned on, whatever is necessary to hit
    the slope.
    Yesterday, after a HL session in the park, Lucas and Bill decided
    we should trek up to Jemez Canyon Dam and fly their scratch built
    Ninjas. I didn't have any suitable slope planes finished yet but
    tagged along to soak up ambiance.
    
    Lucas' Ninja has a 2" longer nose. Bills' has a 1" longer nose and
    a wider fuselage. Bill couldn't fly his because he swapped xtals
    at home and wound up with a mismatch.
    We took turns flying Lucas'es. What a blast. Wind was 20-30mph 
    and the first time Lucas stepped up to the edge of the abyss, I
    figured such a little plane would just blow back over the top.
    But no, out it climbs, up to 300 feet above us or 450 ft. above
    the lake. Loops, rolls, spins, skidding turns right in front of
    our faces. High speed down wind passes, u-turn within a fuselage
    length.
    
    The edge of the canyon wall faces WNW, perpendicular to the prevailing
    wind 90% of the time. 300 yards to our right the wall bends parallel
    to the wind and the far wall across the dam. This funnels the wind
    into the desired direction even if it normally would blow at an
    angle to the cliff face where we stand.
    The cliff drops vertically 20ft. then angles down 45-60 degrees
    to the sand strip along the waters edge. Vertical drop is 150-200
    feet. 200 ft. to the left, the lake bank curves away up the valley
    giving a large landing area in case of a down-slope landing.
    The cliff face is exposed volcanic lava, the whole area sits on
    a vast lava upwelling.
    Behind the cliff is a gradual slope down to the parking area then
    across a sand and prarie grass area to a rocky arroyo.
    Landing conditions aren't too bad. No rocks large than a marble,
    and the rotor is manageable. We were landing way back, 50 yards,
    but less conservative methods would be okay when the wind is less.
    
    So now I've got to finish the Lobo flying wing which should work
    well at that site. Then get building the Ninja. I've decided to
    glass the wing using 2-4 oz. cloth and mylar sheet. This should
    be a good test case for my new electric pump.
    
    Terry

    The Ninja really is an incredible plane when the wind is BLOWING.
    Sounds like you'll be happy with the results. It sounds like you've got
    a great site. Forget to bring along the soccer goal?
    
    Anyway, Dan Miner had a couple of fiberglassed foam cores with him last
    week in Acton. He used 3oz cloth with saf-t-poxy and no spars. They
    were incredibly strong and that's probably the way I'll go with the
    initial attempt at the standard class cores I plan to first make. It's
    a flap only wing with the Dodgeson flap mechanism so it should be
    pretty straight forward once I get the time to try it.

    Would the Ninja be a good candidate for 7 cell electrification?
    In other words would it be possible to fit all the electric stuff
    into the fuse?  The kit is reasonably priced, has foam core E374
    wings and an advertised non-electric flying weight of 32 oz.  I wonder
    if ith would be able to thermal decently, it obviously sounds like it
    is capable of decent aerobatics.  I know the E374 was real popular with
    the X-country guys, however it was used on ships with much greater
    wingspans.  Comments?
    
                                                          Regards,
    
                                                          Jim

    You're already starting out with a heavy ship. Putting another 12-16?
    ozs of motor into it won't help matters any. Better choice would be an
    electrostreak. Designed with electric flight in mind and is fully
    aerobatic also. Several are documented in the electric notes.
    
    Thermalling:
    
    On the days when bricks are rising out of construction sites, a Ninja
    will probably thermal!
    
    Seriously, the Ninja is an all plywood (albiet "lite-ply") fuselage and
    that's where it gets most of it's durability. IF you keep the speed up,
    it sinks very little. It covers a lot of ground in the process. I put a
    tow hook on mine and I have some very interesting 30 second flights
    from a 200 foot upstart. A split-S off the line to race the parachute
    to the ground really gets the crowd running for cover ;^)

    re .660-662
    
    The slope site we used doesn't really need a net to land safely.
    there's plenty of room to get back behind the edge and you can approach
    from either direction, parallel to the edge, then turn into the
    wind down below the lip where the rotor isn't effective. There is
    a 200 X 200 ft. rock-free area. Turbulence is the main problem,
    but Lucas had 3 out of 3 landings with no damage. Can't expect much
    better than that.
    
    I'm impressed with the E-374 as a slope airfoil. It works well
    on the big X-C birds because they're cruising at 70 mph most of
    the time and have a lot lighter wing loading than an electric Ninja
    would.
    
    Terry

    Over the weekend I went through my father's library of old magazines,
    including Model Aviation, Model Builder, Flying Models, and RCM, I
    must have looked at over 100 magazines.  I have been reading everything
    I could about electrics.  My problem is, none of these magazines
    columnists seem to fly or be real interested in 7 cell f3e style
    aircraft.  Most if not all the articles deal with electrifying glo
    styled airplanes generally using Astro25-Astro40 motors on 12 - 18
    cells.  Reading about electrified PT-40's and Old Timer's is not
    relavent to what I want.  There are also many reviews about elctrified
    2-meter gliders(CG Electra, Airtronics Eclipse, Kyosho Stratus, etc.)
    all are polyhedral run with cheap direct drive motors.  Outside of
    Hobby Lobby(Expensive) nobody sells, talks about, or flys high
    performance electric f3e style sailplanes.  Hence my interest in
    designing or adapting an existing kit into what I am looking for.
    Maybe I'll just have to bite the bullet and spend $220 for a Graupner
    Cherry, but I'd like to build my own if possible.  Assuming that the
    Ninja or a similar kit can be built without electric power at about
    36oz., then the all up weight with 7-cell pack and motor should be
    no more than 54 oz., which relates to a wing loading of less than 16
    oz./sq. ft. which is not unreasonable for a high performance ship, my
    Elektro_Uhu(considered a trainer by many) has a 14 oz./sq.ft. wing
    loading.  What I am looking for is something between an Electro Streak
    and a Goldberg Electric(yeah Like A Robbe Arcus, Graupner Cherry) but
    that I can build myself.  The electro streak with its short span
    doesn't seem like it would glide to well with the power off and the
    Electa/Eclipse style ships are a little to draggy for high speed 
    flying.  My idea of adapting a slope soarer came after reading about
    Mark Allen(falcon 880 designer) adapting his Isis slope soarer to 
    electric power with great success.  I would have to look at the polar
    for the 374 befor e deciding about the Ninja, the biggest problem
    is shoe horning the equipment into these fuselages.  If anyone knows
    a source of high performance electric gliders besides Hobby Lobby
    please let me know.  I would appreciate any comments or suggestions,
    this is one area of the hobby that seems to have been neglected by
    the magazines reviewers, or possibly their is just no kits fitting
    my criteria available.
    
                                                     Thanks,
    
                                                     Jim

    Jim,
    You've already mentioned most of the F3E style planes available
    in kit or ARF form.
    Most F3E planes including the 7 cell class are scratch built, in
    the sense that you buy a fiberglass fuselage, then cut cores, sheet
    them, stuff everthing in and go fly.
                    
    There are a few guys that make fuselages for F3E, but they don't
    sell them to just anyone, you have to know someone to get one,
    production is limited and the whole thing is too much of a hassle.
    
    Before Wilshire Models went out of business, they had a bunch of
    German F3E type kits in their catalog; smaller cottage industry
    guys that don't export or have any easy acessability outside Europe.
    
    You might send for a catalog from Jerry Slates, Viking Models USA,
    he's got a couple of fuselages that could be adapted to F3E, then
    all you need is wing cores, a few months of agonizing labor, and
    your in business. ;^(.
    
    Terry

    Ciao: 
    
    I have had excellent results in converting larger (2.5-3 mtr) sailplane
    kits to electric, using Astro CO 05 FAI with reduction and from 7 -12 
    SCR 1200mAH cells. In particular I bought a Cheetah sailplane kit from
    Larry Jolly Models and put a 05 in it and with the  E205 foil it flew
    and thermalled very very well; even in winds of 20mph. I also made a
    few wings using the E387 airfoil and the Clark-Y with excellent+ (E387)
    to very good (Clark-Y at only 2 mtrs) results.
    
    So from these results I would be tempted to say that " A good, well
    built and light soarer kit with an efficient airfoil (eg. E387) would
    be a good bet for electric conversion". My experience. Also if you get
    a good, fiberglass fuse (eg Cheetah or Pantera) you have an excellent
    opportinity for fooling around and modifying to your hearts content. I
    believe LJM sells the fuse only for arounr $60 which will get you
    going. I was not too impressed at the built-up wing and prefer to go
    the foam/balsa covering route. Quicker too... 
    
    You can also go the bigger motor route and put in a Astro 25 for
    example and fool around with the # cells vs prop size (ie. reduce
    # cells and increase size a/o pitch and vice versa) to get some
    startling performance going up to thermal and having not too much added
    weight so you keep performance. 
    
    Keep it light, use carbon fiber to keep it strong, build straight and 
    you can't go wrong. Also I tend to not over-build these things and
    always build in a  mechanical 'fuse/circuit breaker' 9eg. the wing
    mounting arrangement) so, incase of a crash/hard landing the 'fuse
    blows' and the rest of the plane is saved. Make them to fly, not
    crash, and you'll save yourself alot of rebuilding.  I have had several
    (more than several..) spectacular incidents with fences, trees, ground
    etc and in 90% of the cases the high-labor wings survived.
    
    Best of luck and boun volante! (good flying!). Ciao, ED

    Jim,
    	I don't know if this helps but... the maker of the STINGER 
    a sailplane I've just bought mentioned some people flying them
    on electric.  He's willing to make the kit with about any
    airfoil you want at a number of spans. He's in the AMA Mag.
    Give him a call if your interested.
    
    
    Tom

RE: Note 399.666 by VARESE::SIEGMANN 

    Ed, I don't know if this was intentional or not but I like your poem:

>>    Keep it light, 
>>    use carbon fiber to keep it strong, 
>>    build straight 
>>    and you can't go wrong. 

    :-)  :-)  :-)
                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Castor Oil!! "    
                      |_____/

    I have an UHU with the speed 600 motor and have flown it about once
    a week for 4 months with no problem. I also have an astro cobalt 05
    that I just put in a trainer plane. It does suck down battery fast
    but I'm still playing with props (and I have no speed control). If
    and when I can spend money on a new motor for the UHU I would not
    put an 05 cobalt. It does not need that much power. I think an
    020 cobalt would put out as much power as a stock cheap CAN motor
    (which 90% of all motors under $30 are even the graupner ones are!!!)
    And you would save weight so the UHU will stay up with no power!!!
    If the motor burned out that fast ask them for a discount on the
    new one. I got hooked on hobby lobby stuff because that's where I
    bought my first plane (UHU). But I'm trying to wean myself from
    thier expensive (but good) stuff. I was also worried about current
    draw on the power switch 20 with the cobalt. But with a 8x5 prop
    and 7 900 mah cells. A 20 amp fuse is holding on the bench. I dropped
    to a 7x3 prop and I'm going to try a 15 amp fuse now (which is what
    I ran the UHU speed 600 at). I always try to put as low a fuse as
    possible so that it blows quick if the prop hits anything (like
    fingers !!!). The fuse even blew once when the prop was way out of
    balance.
    

    Last (or this, depending on your point of view) months Model Airplane
    News has some (3 or 4) articles on F3E Sailplanes (including a Kit).


    Randy

Friday night when I got home I had an Airtronics 741 servo waiting for me.
Sooooooo


I flew the Lovesong Saturday.

Unfortunately my first landing was in the Tar.  Kinda hard
on the sharks teeth and glass on the tail.

It'll take a few more flights to work out the special mix settings
and it is a humbling experience to stretch out the high start I
purchased from Northeast Sailplanes a hundred paces.  Fortunately I
Kevin Ladd help hold the Airplane and release from the High Start.

Now I know why they hold the big ships by the tail booms.

Landing with the crow landing is nothing short of FUN.

As my daughter would say.

Wicked totally awsome and far out.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

	Kay, congratulations on the first flight of the Lovesong! I hope to see
	it up at Acton some time soon. That plane would have been really 
	impressive at the mall show. The rest of the gliders there were pretty
	scuzzy (except for Dan Snow's Spirit, of course!).

	I'm sad to report that my little Predator was involved in a bizarre
	glider incident this weekend. There were only two of us flying gliders
	at the Wayland field Monday morning, and somehow we both tried to 
	occupy the same airspace. I'd call it a mid-air collision, but it
	wasn't very "mid", just about 1 foot off the ground. Bruce Schneider's
	Sagitta T-boned the Predator. The Predator fuse was broken in about 4
	places, and the wing dowel was ripped right out of the wing. The
	Sagitta suffered a nasty scuff on the wing leading edge. This is what
	happens when a 40 oz. sled with a cast iron nose collides with a 14 oz
	lightweight. Oh, well, I'm back into rebuilding mode again. 

	Does anyone else seem to spend 2 hours REbuilding for every 3 hours
	building?

	Dave

    Would anyone have plans to a SPIRIT that they could XEROX a chunk at a
    time. I just bought a SPECTRA (motorized SPIRIT) that I want to try as
    a glider first. I bought the SPECTRA instead of the SPIRIT in case I
    like motorized better than long rubber bands :-). Copy does not need to
    be accurate I just want to see placement of servos etc. so I can get
    the C.G. correct. M/S is MRO4-3/H17. How about it Dan S.?

    Since I want to get the Ninja built pretty soon, I've put the Lobo
    flying wing project on hold although it is 80% done. Got tired of
    designing and fabricating control linkages. However I'm so confident
    that it will fly, that the test flights will take place before I
    cover the wing ! If all goes well then the I'll cover it, and if
    not then no covering will be wasted.
    
    The Ninja will have 3 oz. glass cloth directly on the foam, so
    obviously the way to do this is to build the stab for the Legend,
    which I did last night. Confused ? Well, I decided long ago to build
    a foam stab for the Legend and eliminate some of the road hugging
    weight which has caused many planes to be 8-15 oz. heavier than
    the specs, because of all the nose weight necessary to balance.
    
    The next logical step was to bag the stab with glass cloth rather
    than sheet and cover with film.
    
    Last night I trimmed one of my stab core sets to the Legend planform,
    actually ~3/4" shorter span. The stock Legend stab mount plate fits
    neatly in the center of the core and allows the simple, wobblefree
    bolt-on, stock mounting method. 
    
    The stab is blue foam with a 80% span strip of .014 X 1" carbon
    fiber across the top as the only spar structure. I might add a ~2"
    wide strip of carbon mat across the center section under the cloth.
    
    The stock stab uses spruce spars top and bottom plus shear webs,
    therefore the relatively massive weight.
    
    The separate elevator will be built up, near to stock specs except
    for a balsa t.e. rather than spruce.
    
    I had originally considered a stabilator with pull-pull cords to
    eliminate the oh-so-cute walking beam method of elevator actuation,
    but decided it wasn't work the extra work. Besides, the separate
    elevator is supposed to give "surprisingly smooth and powerful
    elevator action". Exactly the same thing they were saying 15 years
    ago when stabilators were beginning to replace separate elevators.
    This is where I came in.
    
    Anyway, if the stab bagging goes well tonight, I'll be ready to
    tackle the Ninja wings. Now, wasn't that simple ?
    
    Terry
    

    Well, I finally got back to my standard class glider project that I've
    been avoiding all winter. I've been stalled doing the wing sheeting and
    cap strips. I got one wing finished and he second panel only needs the
    cap strips. This is an old full flying V tail design that I always said
    I'd like to build, so this year I did. I finished sheeting the center
    section on the stabs (what is the correct term for a full flying V
    tail?) and got them all aligned. Tonight the control rods go in so I
    can close up the top/bottom of the fuselage. I can figure out the flap
    deflection P^) but I'm wondering what good throws would be for the
    tail? I really don't want to get 300' up and find that it's sensitive
    enough to fly with the trims or that it takes a country mile to make a
    full deflection turn. The fifteen year old plans don't have any
    recommendations. Anyone got any thoughts?

    The glass stab for the Legend came out ok. The epoxy tinting paste
    gives a semi-opaque finish, opaque enough that it isn't possible
    to tell that one side of the stab is blue foam and the other side
    is grey foam. The carbon fiber strip shows up clearly, but the overall
    finish is ,well, glass-like.
    The regular bagging mylar is pretty stiff and has a tendency to
    curl inward, making it difficult to squeegee off the epoxy.
    
    One possible hang up is that with one layer of 3 oz. cloth the finished
    product can be dented by squeezing. I'll let it cure the recommended
    one week before passing judgement.
    I'm considering using 1/32" balsa or Obechi between the foam and
    glass next time. I've got some Obechi on order, and until it arrives
    will continue with the Legend construction, have to get it done
    before some upcoming contests.
    
    Terry
    

    I got a slip from UPS so my 2 meter kit from Vern Hunt Models will
    be delivered today. 
    
    I've got a meeting to attend tonight so I don't expect to get anything
    done.  I will open the box when I get in and have first impressions
    for the notors tomorrow.  Remember, this plane has a fiberglas fuse
    with sheeted foam wings.  We'll see...
    
    Tom

    I assume that that's for launch added dihedral. What's the point if it
    snapped on launch...
    
    My question is, do most gliders leave the rods loose so they can be
    removed and/or replaced?

    It is, indeed, for launch added dihedral. Obviously if you "fold-em-up"
    a spare rod ain't going to help. But, I have seen them bent.
    
    The wing rod in the OLY II is removed/installed each time the wing
    is put together/taken apart.
    
    Steve

    If you're using rods that can be bent on launch, before the structure
    fails, then you've got the wrong rods. Admittedly there are some
    mass market kits out there with rods like that.
    
    Most high performance cottage industry type kits are using at least
    5/16 " dia. machine tool type rod.
    Mark Antry, I think, mentions using *mold release pins*, whatever
    they are, as unbendable wing rod.
    
    The guy in Calif. that advertizes on RCSD, sells a range of sizes.
    I have 3 or 4 of his rods and they do the job, for a price.
    
    I always like to have my main wing rods free to slide out. However,
    If the dihedral is built in by means of bending the rods, a la some
    Graupner kits, then you almost always have to glue them in place
    to prevent rotation when a sudden shock load hits them, giving you
    instant anhedral at the worst possible moment.
    
    The rear rod I often glue in, if only to prevent losing it when
    it falls out unnoticed in transport.
    
    Terry

    The reason why I ask is that I'm about to button up my Cloud Bound 99
    fuselage and I had thought I was going to secure the rods. The rods go
    through the fuselage and rest in holes in the plywood fuselage
    doublers. I think the Oly has two wing halves that get joined and then
    attached. This is a plug them in the side arrangement. What's the norm
    for this type of rod? My concern is that they'll wear the holes over
    time and the wing will become loose and the angle of attack will tend 
    to change. I can leave them loose without problem since the fit is nice
    and tight right now (I probably won't remove them between sessions.
    Just unplug the wings.) I'll bring this along to the next DECRCM
    meeting for show and tell. I hope to fly it at the end of next week in
    Acton (so hurry with your suggestions P^)

    Crossed in the enet. The design called for 3/16" rods (2) front and
    back. It is a 99" plane. I'll be adding wing panels with different
    airfoils as time goes on (and I get the vacumm bagging experience) Both
    rods penetrate the wing panels 6 inches (take a cold shower you guys
    P^) and the first 5 wing ribs in this 6" section are all plywood. Time
    will tell...

    re .686
    
    In this case Jim, you should put brass tube permanently in the fuselage
    and plug the rods into them. This will take the load without problems,
    almost all kits with side-plug wings use this method. 
    
    Letting the rods bear directly on the wood structure, even plywood,
    is asking for the problems you describe.
    The brass tube will also act as a lateral stiffner. 
    
    I don't how long/deep the ply doublers are in the C.B. 99, but if
    it's not too late, having them = ~3/4 of the chord in length and
    at least root thickness in depth is a good idea.
    
    I use ply doublers, and of course brass tubes even on glass fuselages,
    and never have problems, other than ripping the wing roots entirely
    out. :^(.
    
    Terry

    Well, I'm not sure I can put tubes in the fuselage and still get the
    rods in/out. The fuselage doublers are quite large and tie in the
    entire nose of the fuselage. On the outside is a 1/8" ply root rib
    which acts as a fuselage offset so that the flap linkage has space to
    move (Dodgeson design linkage is a good upgrade to the version they
    omitted most of the details for)
    
    The problem is that it is a one piece rod with two dihedral bends at
    the fuselage sides. If I put a tube through the fuselage, I couldn't
    get the bent tube through it. I should probably just glue them in place
    and leve it at that. With my luck with inverted landings (I got blown
    over again today and cracked my fin AGAIN) I think any launch induced
    dihedral will be offset by the inverted stress testing I've been
    experiencing on the ground :^( 
    
    I could put brass tube "eyelets" into the fuselage sides that would
    allow the rod to be removed...
    
    Each rod is one piece as follows:
    
    _________         |      |         __________ rod
             ---------+______+---------
                      |      |
                      fuselage

	
	Yesterday when I got back home from work I found a kit box
just begging to be opened.  But it had to wait for I was late for
a meeting.

	When I got home (11:00 PM) I opened the box to find a ton of
white peanuts.  All staticly charged and jumping at anything that
came near them.  Inclosed I found a fuse half or rather three quarters,
a nose cone, a wood bag , a preshaped stab and two sheeted wings.
This isn't a big shp but then again it's a 2 meter ship.  The sheeting
of the wings was excellent.

	Note *  I'd asked for a 214 airfoil and I'm not sure what I got.
The airfoil I have has undercamber cut into it.  Is this normal for a
214?

			     The shaping of the stab is also excellent
only needing me to cut the elevator from the rear and lightly sand the
ends round.  The glass work is also excellent with the seals rough sanded
and the fuse ready for assemble.  I had intended to install a rudder,
elevator, flap and aileron servo arrangement however shape will not allow this.
If I still want to use the rudder I'll have to use mini servos in this bird for
clearance.  So be it.

The workmanship of this kit is excellent.  The only gripe I have and it's
self induced is that the wing saddle of the fuse doesn't match the airfoil.
Seeing that the fuse was made for a different airfoil than I ordered I can
hardly complain.  A little fussing and filling will solve this problem.




Tom

>	Note *  I'd asked for a 214 airfoil and I'm not sure what I got.
>The airfoil I have has undercamber cut into it.  Is this normal for a
>214?

Yes.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Like I really need another glider project...
    
    If you don't mind me asking, what did the kit cost and did he charge
    extra for the non-standard airfoil? Are you setting this up as a slope
    or thermal ship?  What was the default airfoil?
    
    I printed out an E214 airfoil generated by the template program and
    there is a definite underchamber to the rear of the airfoil. It's also
    a thicker airfoil than I've been playing with recently (S3014, S3021).
    I could mail you the postscript file if you'd like (I generated an 8"
    chord with no leading, trailing, or sheeting lines to get the general
    shape)

    
    	The plane is being set-up as a thermal duration 2 meter ship.
    Hence the change to the 214 airfoil.  I'm not sure what the std.
    airfoil is but I will check the add and get back to you.  The
    prices was 175.00 + shipping.  No extra cost for the change in 
    airfoil.
    		
    
    	last night I did a little work on the plane.  To start the
    horizontal stab has an airfoil sanded into it but the top of the
    vertical stab (made of fiberglas) has been trimmed straight.  So I
    placed the horizontal stab on top of the vertical and keeping the
    gaps in the front and back equal I scribed a line onto the vertical
    stab with a marker.  I then installed a dremel sanding drum in my
    drillpress and set the table up with a block so that the bottom of 
    the drum extended below the surface of the block.  Laying the fuse
    and stab on it's side I was able to sand both sides of the vertical
    stab at the same time getting the two sides to maych the airfoil of the
    horizontal stab.  I then sanded the rear top corner of the vertical
    stab off (per plan) to expose the elevator pushrod and make way for the
    elevator control horn.  Next I turned my attention to the radio layout 
    and ended up deciding to buy four mini servos for the plane.  Then I
    went onto the layout of the flap and aileron servos.  Again I've
    decided to use mini servos but seeing as the wings are sheeted out of
    the box a way to actuate the ailerons was needed.  The plan calls for
    flaparons but I'd prefer ailerons with seperate flaps.  This way I
    could utilize a crows foot landing configuration.  To sold this problem 
    I decided to use bellcranks in the outboard sections of the wing.  I
    will cut out a square in the bottom sheeting and remove the foam so I
    can install the bellcranks. Cutting the channel for the pushrod was the
    next issue.  I solved this by using an aluminum arrow shaft as a cutter
    in a drill.  I was able to drill one wing core last night keeping the
    channel adjacent to the bottom sheeting of the wing panel.  The other
    issue I figured out was how to make an easy filler for the wing saddle
    of the fuse.  I've figured out that I can use a 1/2 x 1/2" stick of
    balsa for the filler.  First I'll place the stick against the bottom of
    the wing from leading edge to trailing edge. Usings a drawing compass
    I will "scribe" a line onto the stick the in a mirror image of the
    bottom airfoil of the wing. Next I'll cut this shape out on the band
    saw.  The next step will be to fit the cut stick against the outside of
    the fuse and transfer the shape of the existing wing saddle to the
    stick.  This is then cut out on the band saw and sanded to a finish
    shape.  I'll glus the cut stick to the fuse wing saddle and....
    
    No maybe I'll glue the cut stick to the wing. This way if I wanted to
    get a second set of wings for sloping the second wing would fit the
    fuse.
    
    
    
    							Tom

    The E214 was specifically designed for variable camber using the flaps.
    Dodgson uses it on his Lovesong.
    

    IMHO the S4061 handily outperforms the E214 on small airplanes.
    The E214 seems to start working well when the span is >100".
    
    We are about to flog this horse again, with variations, when Lucas
    will build one Chuperosa with E214 to compare with my S4061 Chup.
    Then we will both make another set of wings with SD7037. His will
    be polyhedral, mine will be flat (2-3 degrees) with ailerons.
    
    Mike, another Chup owner, has already left town in disgrace (disguised
    as a job transfer) after seeing how his E214 Chup compared to my
    S4061.
    
    Terry

>         <<< Note 399.695 by ELMAGO::TTOMBAUGH "A Fistful of Epoxy" >>>
>                            -< They never give up >-
>
>    IMHO the S4061 handily outperforms the E214 on small airplanes.

Describe outperforms.
My understanding is you probably have a wider speed range and
clearly a higher top end but...

It is also my understanding that at slow speed the E214 (a small one
in a Chuperosa) will out climb you in the same thermal.  I get this
from reading the Northeast Sailplanes Catalogue.

Please elaborate.

Bye          --+--
Kay R. Fisher  | (who owns 2 planes with E214s and loves them).
---------------O---------------
################################################################################

    
    	Last night I got the center keel cut out to support the
    installation of two Mini servos.  One for rudder and the other for
    elevator.  I also installed this keel and it's supporting
    side structures into the front of the fiberglas fuse.  I checked the
    fit of the 500 ma battery and the RX to ameks sure everything OK.
    The keel once installed rubs against the top of the nose cone so
    I'll have to do a bit of sanding on the keel to allow the nose cone
    to fit properly.  This won't effect the fit of the radio.  I also
    realized (after talking to Kay) that to do crows foot you need two
    aileron servos so crows foot in out.  There just isn't enough room.
    
    
    
    Tom

    re 696.
    
    Based on my experiences, the following applies to HL size planes
    only:
    
    The literature always states that the S4061 is supposed to be faster
    etc. than the E214.
    But it seems to me that the slower you fly and the tighter you turn,ie,
    HLG type flying, the better the S4061 does.
    
    Neither Lucas nor I were particularly impressed last summer when
    Mike showed up with an E214 Chup, the first in these heah parts.
    It was ok, but nothing to rush out and build too, we thought.
    Then after all the hoopla over the Nats win, and my experience with
    the S4061 on the Orbiter, I picked up an S4061 Chup when it appeared
    in the hobby shop ~ 3 months ago.
    
    After seeing it fly, Lucas gets real enthusiastic and buys an E214
    version, not yet done.
    
    What it seems to me is that the E214 goes zooming off on the launch
    (hand) real well, probably better than the S4061, but then as it
    slows to cruising speed the L/D isn't as good as the S4061, and
    tight turns are more critical for altitude loss.
    
    This is opposite what the specs say, but it's my observation.
    
    On the few Wind/Lovesongs  flying around here the E214 does quite
    well. Floats well, has a good speed range, etc.
    As the earlier note said, with flaps it's optimized. Without them
    it seems to give away performance to other non-flapped foils.
    
    In a month or so, we'll have some more data points to compare, and
    the SD7037 to compare with.
    
    FWIW, my SD7037 Chup wing will be 3 oz. cloth over Obechi.
    
    My Ninja wing scheme has been modified to 3 oz. cloth over 1/32"
    balsa. I spliced and cut the sheets last night. I used 1/32" balsa
    from Lone Star Models. 10 sheets, ranging in wt. from 4.7 to 5.2
    grams each, and 6 sheets were within 5.0 - 5.2 gms.
    Both Wing panels, before trimming came out to 24.9 grams. I'm impressed
    with their wood quality, if it's always like that.
    
    Terry

    The wood I got for the Cloud Bound 99 and the P-38 from Lone Star was
    very good. Mostly 4x48" sheets but all the quality was there. 

	With this discussion of airfoil performance going on here, I'd like
	to entertain a thought. The thought is: How often do we attribute
	performance differences to the airfoil, when it is actually some 
	other factor causing the difference? 

	The example of the two Chups assumes that they fly differently because
	of the airfoils used. I'm sure the airfoils do have an effect, but
	perhaps one plane was built with a slightly warped wing. Or the
	angle of incidence was a bit off. Or one was significantly heavier
	than the other.

	I've noticed something interesting (and somewhat depressing) with
	my Predator lately. Up until a week or so ago, it was a really sweet 
	flying little plane. It just always seemed to do what I asked it to
	do. As a result of two recent incidents, I've had to do extensive 
	fuselage and tail repairs which have added about 1.5 ounces to the 
	overall weight of the plane (that includes added nose ballast). So
	it's weight is now up to 15.5 ounces from 14 ounces. Doesn't sound
	like much, does it? But it has significantly changed the way it flies!
	
	It's more difficult to thermal from a handtoss now because the wing
	tends to want to drop in a turn. It definitely requires more altitude
	to recover from a stall now, and it doesn't stall "straight", it wants
	to go to one side or the other. In other ways that are hard to put
	in words, it just feels different, not as light and nimble. Yet
	there has been no change to the airfoil, nor have any of the surfaces
	been kicked out of alignment (that I can tell, anyway).

	My only conclusion is that the added weight made a dramatic difference
	in the way it flies. Knowing how much weight variation there can be
	between two different airplanes, I wonder how often this would explain
	performance variations blamed on the airfoil chosen.

	All of which is not to say that the S4061 isn't better than the
	E214 for HLG's, but it's just food for thought.


	Dave

    I'll agree with Dave, especially on small HLG types any little
    thing can affect performance greatly. Drag differences seem to be
    the thing I notice the most. 
    
    On my S4061 Orbiter, with ailerons, at ~16.5 oz. its performance
    is much more *draggy* than the Chup with poly at ~18.5 oz.
    The ailerons just kill it in the turns, it's like popping your
    dive brakes, and the extra drag from the hinge line, even when sealed
    isn't helping.
    
    The weight difference helps the Chup penetrate in gusts but the
    lower drag more than offsets any disadvantage via-a-vis the weight
    penalty. Of course if it were 2 oz. lighter, it could well be even
    more superior.
    The main reason I'm putting ailerons on the SD7037 Chup is to have
    a slope plane for light winds.
    The comparisons with the other Chup versions in HL flying will be
    interesting.
    
    Terry

    I'd like to start a slightly different thread in here. I'm building an
    old standard class glider that has flaps and a flat bottomed airfoil.
    I'll fly it this way initially but I've been gathering info and
    materials to vacuum bag a set of additional wings for it. Well, the
    time is approaching to make some decisions. My initial feeling was to
    go with an S3014 root and transition to an S3021 tip since I've heard
    good things about this combination and found the S3014 pretty good on my
    replacement Gnome wing. My intent is to make a straight (dihedral, not 
    poly) flap wing that will have reasonable penetration but still slow 
    down to a nice tight thermal turn. There seem to be several airfoil
    experimenters out there. What's the latest "hot" thermal airfoil, and
    more importantly, what works well in the real world. I'm not looking
    for an airfoil that only works at 37.3mph, I'm looking for something
    that will give me good general service at a range of speeds and varying
    conditions.

    The 3021/3014 is a good choice and is well proven on the Falcon
    880. I've never heard of it being used with the 3014 inbd.
    transitioning to the 3021 outbd. It's always the other way around.
    The 3014 was designed as a HLG foil with a maximized L/D at a lower
    speed than the 3021, at least this is the theory. The object of
    putting it towards the wing tip is to have the tip section stall
    later, thereby avoiding tip stalls. What would happen the other
    way around, I have no idea.
    
    The SD7037 is the latest "hot" foil. I've never seen it fly on a
    production kit or rational *own-design*, so can't say from personal
    experience. A Dodgson Saber, which uses the SD7037, is nearing
    completion locally so maybe I'll have something to report later.
    
    I like the S4061 too. It works well over a wide speed range, and
    hangs in there on tight low speed turns. The under camber is more
    work on a built up wing, but no problem in foam.
    
    A v-dihedral wing is going to give away some tight turning ability
    to a poly wing, so if this is a major performance goal it's something
    to consider.
    Using flaps mixed as flaperons, with two servos, can help a v-dihedral
    wing in tight turns but it takes some experimentation to get the
    flaperon/rudder travel optimized.
    You'll notice that virtually all non-aileron thermal designs use
    a poly wing. This is no accident.
    
    
    My Ninja wings are ready to be bagged this weekend. I'm using 3/16"
    pine dowels for the leading edge and sheet right over them, then
    trim after bagging. The trailing edge is 1/4" X 1/4" balsa which
    requires very little shaping to conform to the core t.e  dimensions.
    This is a substitute for the stock 1/4"X 1/2" kit material, which
    required you to carve/sand off 1/4" of thickness after installation.
    Must be some kind of character building excercise.
    
    Terry

    I knew it was the 3021/3014 combo but didn't remember which was inboard
    (without my references). I took a 50-50 shot and was wrong P^)

Sounds like the answer is simply keep at it - so I will.

Randy

    re .710
    
    If Ed Ball gets good results using the S-turn technique while actually
                                                                  ^^^^^^^^
    flying R/C gliders, then I say more power to him. But what he describes
    ^^^^^^^^^^^^^^^^^^
    is the classic *Free Flight Thermaling Syndrome*, for lack of a
    better term, and it will do you in every time when push comes to
    shove, and you're out there in a contest scrabbling for every second
    with a pack of hot sticks.
    
    Quite a few free-flighters get into R/C by way of old-timers, and
    this is where I've seen them do this S-turn business, happily sinking
    while the thermal goes off down wind without them.
    JMO.
    
    Terry

    I agree with Terry. Doing S turns sounds like a terrible way to ride a
    thermal. The only time I've found S turns effective in a contest was
    when there was some sort of high altitude ridge lift which would
    sustain your altitude for 3 minutes or so. It was a windy day, and the
    S turns allowed the plane to hold its position. It was a lot like slope
    soaring, only much higher up.
    
    Watch the very good glider pilots, and what you see are circles,
    circles, circles...
    
    Dave
    

    Thios past weekend I got in some building on the Stinger 2 meter
    glider before the demise of my workshop.  To dat eI have the
    aileron cables installed, the wingtips cut at an angle, the
    ailerons cut out and the wing TE faced with 1/8" balsa,  The
    filler balsa strips installed on the fuse and rough sanded to
    the contoure of the fuse, the horizintal stab installed on the
    top of the vertical, the elevator cut out and hinged to the
    stab, the front center keel with it's supports installed and the
    radio once roughly installed to make sure everythnig fits.  THAT'S
    IT NOW UNTIL I GET THE NEW HOBBY ROOM COMPLETED.
    	
    	We worked on that yesterday. We finished boxing up all of the
    hobby gear and finding it new homes in the second bed room of the
    attic.  The benchs have come down with all of the shelving.  I banged
    in all od the nail holes and applied joint compound.  Tonight she's
    going to ge some painters masking paper and mask off all of the
    woodwork.  Tomorrow we'll paint the room and rip up the old carpeting.
    Wednesday night should see the ne flooring going down and the cabinets
    will be delivered on thurday.  So thursday night should see the
    cabinets installed.  Next weekend will be for electrical and then it's
    a wait of the counter tops to come in.  Wouldn't you know that we'd
    pick a color that isn't stocked.  So I shouldn't be building for a week
    or two.
    
    
    Tom

    Gee Tom, how do you push pins into formica?? P^)
    
    I got some work done on my Cloud Bound 99 this weekend. I got the
    fuselage entirely closed and everything sanded to shape. I finished the
    cap strips on the second wing panel and actually hinged one of the
    flaps. Like I don't have enough complexity with the V tail, I've
    decided to throw in another servo and use flaperon mixing for the wing.
    If I don't like it, it's easy enough to take out the fourth servo and
    rebalance.                      
    
    I've decided to paint the fuselage (one of the reasons I got my spray
    setup working again) and I've also decided to put on a layer of .6 oz
    glass cloth. While reading the first 203 replies to "Let us spray" I
    took a liking to the clear epoxy paint method of applying the cloth.
    After asking a couple of people about disadvantages and hearing that
    you just have to avoid air bubbles under the cloth, that's the way I'm
    going to go. Always did like silk and dope over wood. This week will be
    spent (coaching little league) attempting to cover and prep the
    fuselage for spraying of color next weekend. That will give me two weeks
    to work the bugs out before the Maine contest on the 18th.

    Over the weekend I got both Ninja wing halves glassed. Used 3 oz.
    cloth over 1/32" balsa. This works better than 3 oz. cloth directly
    on the foam. 
    I used a 3/16" dowel for the l.e., installed before bagging. Obechi
    would hav been easier to fair into the dowel than the balsa, since
    it's 1/48" thick; I had to run a thin bead of slow UFO along the
    sheeting/dowel joint then wipe it flat.
    The finished wing will look different, fer shure. The milky white
    glass smooth wing contrasting with the bright red ailerons and tips.
    I'll use the Ninja decal from the kit, which is yellow trimmed in
    red. Tonight I start on the fuselage, may glass the bottom only.
    
    The evening paper carried a two page spread with pictures of two
    of our club members slope soaring on the sand hills south, near
    the airport. A pretty good piece, except the reporter became enamoured
    of the concept of the planes being attacked by hawks on virtually
    every flight, resulting in a loss of aircraft virtually everytime
    out. Lucas and Bill got a big kick out of putting that over on him.
    
    Terry

    I hope you don't have some environmentalist fall for it hook, line, and
    sinker and try to stop you from goading the hawks.
    
    What was the final Ninja wing weight?

    Oddly enough, the reporter was the eco-alarmist for the newspaper,
    but he liked the idea of quiet, pollution-free flying.
    The fact that a rowdy band of hawks didn't appear to promptly shred
    the wings during the flying session, was no doubt a disappointment,
    but Bill and Lucas were able to provide enough gory details to *flesh
    out* the story.
    
    Off the top of my head, the Ninja wings came out to ~440 grams,
    minus ailerons. I'll check tonight, but I do remember that there
    was a .4 gram difference between the halves, before joining.
    
    I picked up some blue foam SD7037 Chuperosa cores from our club
    foam guru, so have to get those done. They will have Obechi sheeting,
    and probably conventional balsa 1/4" l.e. because he cut the flat
    on the l.e. that way. To use 1/4" pine dowels as l.e. would be too
    heavy.
    
    Terry

    Ninja wing weight:
    
    Both halves, sheeted and glassed: 242.6 grams.
    
    Complete wing with ailerons and torque rods: 327 grams.
    
    Terry

    Terry,
    	Couldn't you drill some small lightening hope in the solid stock
    ailerons If you could remove 30% of the wood you could get the wing
    to weight app. 300 grams.
    
    
    Tom

    I'm impressed Terry. That's quite a bit lighter than I expected also.
    Maybe there IS hope to all this vacuum bagging stuff P^)
    
    Jim (who's about to give it a try also)

    Re: -1
    
    I would not think that striving to achieve the lowest possible weight
    would be a major consideration on the Ninja.  From what I have read the
    Eppler 374 does not perform well at low speeds.  The Ninja relies on
    strong lift to keep it up, not slow, minimum sink flight
    characteristics(ie like a Gentle Lady).  I remember an article
    published in RCSD a couple years ago where Randy Reynolds(LSF V pilot)
    made a strong case for flying ships like his Sagitta at heavier than
    the then accepted weight.  He felt that the Sagitta's performance
    actually suffered at wingloadings less than 10 oz./sq. ft.  Some
    other flyers took serious issue with Randy's allegation.  
    
                                                      Regards,
    
                                                      Jim

    Having a 2lb 10oz Ninja, I tend to agree with you. It really flies well
    at speed but it tends to mush when slowed down. The reason for wanting
    a light, strong wing on the Ninja is the plywood fuselage. The wing
    isn't the heavy part. My fuselage is scratch built from standard 1/8th"
    ply (while the kit uses "lite" ply) and that added to the weight
    difference. It also requires me to fly it on windier than typical days.

    I'm going to use the Ninja mainly in breezy and above conditions,
    ie > 15 mph, so lightness at all costs isn't a factor. Keeping the
    wings light does help the roll response, and that's what it's all
    about on these small aileron equipped birds. 
    Also I'll be putting in a rudder, 3 servos, so if it's not over
    32 oz. (~908 grams, Ajai) it will be a miracle.
    
    As for the general concept of flying a given design heavier than
    normal, it all depends on the conditions. If you want to cover a
    maximum distance in a minimum time, the heavier plane will win out,
    all else being equal. Add in wind, and this becomes even more true.
    But in calm conditions or when you're looking for minimum sink then
    the lighter plane will have the advantage. I never add ballast to
    any of my planes because I don't fly in wind conditions where it
    would be advantageous, and such wind conditions are rare enough
    around here that my flying time per year is not impacted much.
    
    The guys that fly the Muellers and other full-bore F3B types around
    here are usually at a disadvantage  in one of our typical thermal
    duration contests. They have to zoom all over the sky looking for
    the strongest lift, while the more lightly loaded planes can use
    the weaker thermals. But in the F3B tasks, the high loadings of
    the F3B planes enable them to complete the speed runs two or three
    times faster than the other types.
    
    Terry
    

    After several weekends, and weeks, of wind, yesterday settled down
    and allowed us to have a really good SMTS contest at the sod farm.
    The CD was Phil Renaud and he brought all his F3B equipment so we
    had a first class set up, with intercom communication to the
    down-course sighting ring, 150 meters away, and a multiple buzzer
    system operated from both ends of the course for pilot turn signaling.
    
    The first task was 6 min. thermal with zone landing and a 9 min.
    working time.
    I was flying the Algebra, with non-coupled aileron/rudder, since
    I had to use the Vanguard radio, the Vision being at Airtronics
    for a tune up. Flying rudder on the left stick isn't my idea of
    relaxation , but it graudually got better.
    We flew man-on-man rounds, two groups of 3 and two groups of 2.
    Scoring was normalized to 1000 points for each group winner.
    I launched first in my 2 man group against Tom and his Falcon 880.
    He wisely waited while I fell into a sink hole, and decided that
    I wouldn't get even 3 min. I decided to relaunch, and as the second
    launch started I had 4:57 of working time left. Didn't get to use
    even that, as I fell into another hole and was down in 2:20. Meantime
    Tom had flew far away from my little portion of the sky and maxed
    'er out for 6 min. I did manage 50 landing points.
    
    The second task was a max number of legs on the 150 meter course,
    flown perpendicular to the wind. As many legs as possible in 4 min.
    with a 6 min. working time. The course must be entered from the
    winch end which means you fly two legs, out on the launch, then
    back to enter the course. We flew parallel to the launch lines a
    la F3B rules rather than perpendicular a la SMTS rules.
    I got a good launch so entered the course immediately. THe wind
    was at its highest for the day and the smaller planes were having
    a hard time staying on the upwind side of the the course center
    line. I stayed far upwind, almost too far as it was hard to tell
    how parallel I was staying to the course.
    The Algebra handeled the wind well with no ballast and I lucked
    out and hit the down trim just right allowing me to fly 6 legs almost
    entirely on ailerons only.
    Tom got 10, the highest of all groups.
    Frank demonstrated on the spot improvisation. His little 2 meter
    Gnome-like bird was going to have a hard time in the wind, so he
    stepped back to the bare strip where the sprinkler pipe support
    wheels run and scooped up a handful of damp prarie clay and slapped
    it on the top center section of his wing. It was at least a pound.
    No danger of it falling off, that stuff is STICKy.
    Up she goes, not seeming to mind the extra weight, but when the
    line dropped, it was obvious the aerodynamics were hurtin'.
    He managed 1.5 legs, didn't notice the wind at all and lost nary
    a gram of mud.
    
    The third task was speed, 2 laps, 4 legs, on the 150 meter course.
    Kept the elev. trim right where it was and again flew mainly on
    alierons. Managed to take third fastest time at 42.96 seconds behind
    Tom
    at 39+ and Phil S. at 40+ . Even managed to beat out Phil R. with
    his Eisenmann Camaro which was a full bore F3B plane a few years
    back.
    
    With 3 normalized tasks of 1000 points, Tom cleaned up. I took 6th
    overall, out of 10, so was fairly happy, considering my lousy thermal
    round.
    
    Everyone had so much fun we're going to do another SMTS next month.
    It makes it nice when you have all the right support equipment.
    
    4th of July we have a big SMTS meet, with out of state entrants,
    then that weekend we host a 2 day F3B meet. The national team is
    coming as a final tune-up before heading to Europe and the World
    Championships in Aug. 
    
    Y'all come, heah ?
    
    Terry

    A few more observations of yesterdays contest:
    
    Thornburg was going to fly his standard BOT, the same one he flew
    in the ''77 World Champs, but the batt. was dead so he switched
    to his 2 meter Birdy, a psuedo-mini BOT.
    In the max lap task he got so far down wind that he was way beyond
    the sod farm boundary fence. Got four laps but had to land out,
    totally blind. No damage.
    
    Lucas caught the rudder of his Legend in the damp clay on a too-low
    turn, ripped the rudder off and stopped the plane dead, whiplashing
    the forward fuselage and cracking the fiberglass ahead of the wing.
    Like I said, that clay is sticky.
    
    Taylor stuffed the nose of his Westwind in the thermal landing,
    breaking it off cleanly at the wing l.e.
    "At last, I'm rid of this thing." Were his relieved words.
    
    Phil Shew had his new Multiplex Flamingo out. He competed with his
    Sagitta 900, to 3rd overall, but the Flamingo flies marvalously.
    I flew it at 2000+ feet and it tracks as on rails. The previous
    owner had filled the obechi sheet with something, and Phil just
    hit it with white Krylon spray can to finish. A great glass like
    finish, I've got to find out what that filler is.
    
    The wind died down as the day progressed, so after the contest a
    few of us practiced our speed runs. I learned how to hold the sticks
    properly for that, but never equaled my 42 sec. time.
    Tom gradually worked down to 26 secs with his Falcon 880. Not bad
    for a SMTS type plane, unballasted.
    A good F3B time would be 17-19 secs. Would-be nat'l team menbers
    have to fly 24 secs to be eligible to fly in the selection trials.
    
    Terry
    

    Wow, theres a huge difference between 42 seconds and 17 seconds! What
    is it about the F3B planes that makes such a difference? Is it the
    weight, or clean design, or pilot skill? All of the above?
    
    Dave
    

    All of the above, especially #1 and 3. A typical F3B plane will
    weigh ~90-100 oz. unballasted, although there is a movement toward
    lighter designs recently.
    
    Making high speed pylon type turns with a glider, especially when
    there is no pylon physically present to judge your location by,
    is an art requiring a lot of practice and keeping the nose level
    without bobbing and porposing when exiting the turns is a real good
    trick.
    
    I think my Algebra could do sub 28 sec. speed runs unballasted in
    the hands of an expert pilot.
    The British F3B team used them a few years back at the world champs.
    
    17-18 sec. is around 95 mph average and a hot plane will enter the
    course at 120+ mph, and of course you have to have a caller and
    turn control guy who is familiar with your flying style, etc. ,
    thats why the team has to practice together so much.
    
    Terry

    
    
                   Hello glider pilot,
    
    I am a new NOTES user (From 06 may 1991) but I have quite a long
    experience in RC gliders (about 15 years). I personnally build NO
    kits at all. I build my own gliders from scratch. If you want advises
    about building, balancing or whatever concerning gliders including
    PC software, please ask it to me. It would be a great pleasure to
    help you. My private address is:
    
    
                      Philippe CLEMENT
    
                      Avenue des Acacias 126
    
                      B-5101        ERPENT
    
                      Belgium     EUROPE
    
    My DEC address is BRSRHM::CLEMENT @BRO
    

    Last night I got the electric done and the counter tops installed so I
    had some time to drag the 2 meter (Stinger) down from the attic and
    restart the assembly process.
    
    Using thin UFO and some 1 1/2" wide fiberglas tape I reenforced the
    joint between the fiberglas vertical stab and the balsa horizontal
    stab.  It went mint and I'm sold on using thin CA again.  I also cut
    the channels in the wing for the flap torque rods and reenforced this 
    area with a small sheet of 1/32 ply.  This will also serve to support 
    the rear hold down bolt.  I used 1/16 balsa to cap off the inside of
    the aileron/flap cut outs and installed a 1/32" ply wing tip.  I also
    laminated up three pieces of 1/16" sheet balsa to make a rudder.
    
    I still need to run the cables for the rudder, seperate the flaps from
    the ailerons and add 1/8" balsa to the LE face of the flaps and
    ailerons.  Other than that it's installing the hold down blocks within
    the fuse, sanding the center keel to allow the cone to properly fit,
    drill the wing for wing bolts and hinge the flaps/ailerons.  Then she's
    ready for paint and monocote.
    
    Hopefully she'll fly within two weeks.
    
    
    
    Tom

    The latest issue of Model Airplane News ( I got a freebie) - June 1991?
    has an article on the Ninja. This guy test flew it on Cape Cod, and
    liked the ship. No stark revelations that I could make out, but I
    figured I should let'cha Nijazoids know.
    
    ajai

    Yep, that's the one I mentioned (and Randy? pointed to) in the Vacuum
    bagging note. The article on vacuum baggin and the one after it on
    using carbon fiber is good. (plus all the jets are neat!)

    I don't usually read M.A.N., but will have to look at this issue
    since it is Ninjaistically oriented.
    My Ninja is coming along, I've been dawdling over minor details,
    but now ready for final fuse. sanding and covering.
    I routed kevlar cord through the stab mount plate, then up through
    the stab and back to the rudder. I used small diameter ny-rod to
    lead the cord through the plate, stab, and fuse. bulkheads.
    I mounted a 403 servo right on the fuse center line in the forward
    compartment ahead of the wing for rudder actuation, and mounted
    a 401 servo offset along the fuse side for the elev., using the
    stock ny-rod in the kit. 
    The rcvr will go under the wing. The ailerons use a 102 servo mounted
    in the stock manner in the underside of the wing.
    
    I took the glassed wing to the hobby shop last sat. and blew the
    minds of the proprietor and a couple of power guys who were there.
    So now I'm scheduled to give a demo on glassing with vacuum bagging
    at the next power club meeting. Jeez this isn't exactly rocket science
    folks. Are they still melting celluloid in acetone to make their
    glue?
        
    Terry

    
    	Last night I got some time to add a thin coat of filler to flair
    the edges of the 1/32" ply I added to the center TE of the wing. I also
    cut out servo locations in the wing for the aileron and flap servos.
    I checked my locat hardware store and couldn't find anything that I
    could modify into a toe hook so I guess I'll order a few from Northeast
    sailplanes...  I have to order a hi start also so I'll go with one of
    their units.  Any comments?
	I'll be painting the fuse and monocoting the wings and horizontal
    stabs.   Lime yellow fuse with an orange canopy, white wings and stab
    with a lime yellow stripe and oragne wing tips.  Hopefully it should
    be visible.  If not I'll add a wide strips of chrome monocote to the
    underside of one of the wing panels.
    
    
    Tom

    Tom,
    
      Standard cup hooks can be bent into a great tow hook. Dave Walter
    showed me how last year and it does work great. Get the hooks that are
    simply bent like a question mark and then straighten the circle out and
    you've got a workable cheap hook. I just stick a piece of hardwood
    (motor mount works well) inside the fuselage and screw into that. I
    predrill a few 1/16" holes in the shop and move it around at the field.
    There are also some "L" style hooks but they nick a piece out of them
    to get the 90 degree bend and this weakens them. The question mark
    hooks are simply bent and don't have the weak spot.
    
    I finished the Cloud Bound 99 covering last night and, funny you should
    mention it, put chrome monocoat on the bottom of the flaps. Install the
    radio tonight and give it some test flights tomorrow/over the weekend.
                                                       

	The tow hook Jim mentioned works fine for hi starts, but I don't 
	know how well it would hold up to a winch launch, especially on
	a large plane. Some of the kits these days are coming with an
	adjustable tow hook that consists of an aluminum track and an L
	shaped hook which is threaded on one end. The threaded end goes 
	through a slot in the track into a nut which holds it in tight.
	The problem with this type is that after a few winch launches, the
	hook fatigues where the threads meet the nut. I had one break on
	me in the middle of a contest last year. The zoom at the end of the
	launch seems to be what causes the stress.

	A very simple and strong homemade tow hook was described by Fritz
	Bein in the CRRC newsletter last year. It is not adjustable, so it's
	best to establish the optimum hook placement with some other method,
	then build this in permanently. I have done this on my Prophet and
	I'm quite satisfied with it.

	
                           |    |
                         __|____|__            <---Landing gear strap
                  +--------|----|-------+      <---Tow hook block
		===========|====|============  <---Fuse bottom
                         --|----|--            <---Landing gear strap
                           |    |
                  _________|    |     <---Two 1/16" music wire pieces
                  --------------|         bent into L shape
                      ^
                      |
                Silver solder two
                pieces together


	First bend into an L shape two 1/16" music wire pieces and cut to 
	size. Put the two pieces through the bottom landing gear strap, hold
	them in proper position, and solder to the strap. Keep the solder on
	the BOTTOM so the top of the strap fits flush against the bottom of
	the fuse.

	Now solder together the two pieces where they run parallel to each
	other. File it so it's smooth (don't want the parachute ring to bind
	on it).

	Next drill two holes through the fuse the correct spacing apart,
	and positioning the tow hook in the proper place. With the fuse down
	flush on the bottom strap, place the top strap over the music wire,
	press it down against the tow hook block, and solder it in place.

	
	That's it! This is a super strong hook that won't bend on zoom 
	launches, nor when sliding along the ground. Stay-Brite silver solder
	works very well on the steel wire.

	Dave

    I, too, have made Fritz's double wire tow hook, and I like it.  I
    switched from the classic tow hook design for 2 meters because of the
    tendency for screw-in hooks to work loose and turn.

    However, the idea is a start that can lead to even better designs.  My
    first ECO was to angle the lead wire back rather than have such a
    sudden skid keel as a side-effect.  Abrupt skids might help landing
    points, but they don't do any favors to the structure and contents. 
    Since I don't fly over perfect lawns, rocks and twigs are common.

                           z    z 
                          xxx  xxx             <---Nuts on threaded rod
                  +--------|----|-------+      <---Tow hook block
		===========|====|============  <---Fuse bottom
                         --|----|--            <---Landing gear strap
                           |   / 
                  _________|  /       <---Two 2-56 linkage rods
                  -----------/            bent to shape
                      ^
                      |
                Silver solder two     (I used epoxy, but silver
                pieces together        brazing would be better.)

    This variation is adjustable and re-snug-able.

    But my Chup will still have an old fashioned L.

    Alton

    Back to the topic of flying gliders...
    
    I'm looking at the possibility of adding flaperons to my current ship
    (radio install is tonight, guys) and I was wondering something about
    setting this ship up. It's a V tail so I expect to get some roll
    coupling with the ruddervator and I was wondering how effective a
    slight amount of opposite aileron would be at flattening the turns? I'm
    going to fly this ship with rudder/elevator on the right stick and
    flaps/ailerons on the left. Being a straight winged ship I figured I
    wanted as flat a thermal turn as possible. Can I get this with a V
    tail?

    Jim,
    Is this that Cloud Bound 99 thing? Hard to say what effect opposite
    aileron will have, except that there will be some. 
    V-tails on a straight wing with ailerons probably won't have a whole
    lot of noticeable roll coupling, aileron action should be powerful
    enough to mask it.
    
    Are your flaps/ailerons mixed in the xmtr. or mechanically?
    
    On my straight wing aileron birds, I don't bother with trying to
    get as flat a turn as possible, the drag is less if you let them
    bank and groove through the turn at a higher speed. The net effect
    is that they will go up in the lift as well or better than a flat
    turning poly design.
    
    I've got a Jade Impulse on back order from Hobby Shack. This is
    a 74" foam wing, flat with ailerons, pod and boom V-tail. The pod
    is plastic, boom is T-6061 aluminum. It's supposed to be mainly
    a slope plane but sounds like it might be interesting as a thermal
    machine too.
    
    Terry
    

    >> Is this that Cloud Bound 99 thing?
    
    Thing? You called my masterful creation a thing? 8^) Yes, that's the
    THING I'm currently trying to get a handle on. Unfortunately the mixing
    will be mechanical initially with the possibility of adding an X-347
    somewhere in my future and going over to full electronic mixing. My
    Max6 has one free mix and doesn't allow for V tail mixing in the radio.
    
    As I move up in the glider world and away from the poly-gas-bags I find
    that airspeed is your friend. The Ninja handles so much better with
    some speed behind it. The weekend will tell. They're forcasting tweo
    sunny 80 degree days for New England this weekend. I hope for once that
    they're right!

    
    I worked a little over the weekend on the Stinger.  I got one airoron
    and one flap finished and the center section of the wing fiberglased.
    I used thin UFO for the center section.  It worked great and really
    didn't use all that much CA.  Tonight is golf and then a meeting.
    Having the room rebuilt has hampered the start-up.  I still need to
    get everything back into the room and find the stuff new homes. 
    
    Tom
    
    P.S. Hoping to start covering this week.

>                   <<< Note 399.744 by SA1794::TENEROWICZT >>>
>
>    
>    I worked a little over the weekend on the Stinger.  

Hey Tom, could I convince you to create a Stinger note and direct all
your building/modifying experience into that note.  I like to read
your notes and don't want you to stop writing but I would prefer
pure "Glider" notes in the base glider note.  
    
Please take this in the right light - in the past when I have requested
that someone stay on the subject they have just cold turkey cut off the
note flow.  Certainly not what I wanted.

Soooooooooo

How many smiles to I have to add at the end to still be on your good side?

:-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) 

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    What is a "pure glider note" ?
    
    Maybe we should have a "Glider construction note".
    
    BTW, Tom, When ya gonna finish that Pulsar?
    
    Terry

    
    
    
    The Pulsar should be next after the Stinger comes out of the shop.
    
    
    
    
    Q:  Lets ta=lk about launch routines.  What's your launch routine
    like?  WHat do you do prior to,during and after a launch?
    
    
    Tom

    Before launch : Think about not crashing.
    
    During launch : Crash.
    
    After launch  : Be sorry about crashing.
    
    Sorry, not a good question for a monday.
    
    But seriously folks:
    
    Double check that your receiver is on, ditto xmtr.
    
    Trim so that it climbs straight, ie, little or no rudder corrections
    necessary.
    
    If rudder corrections are necessary, determine if it is due
    to control surface trim, warps, unequal angle of attack between
    wings,  OR...climbing too steeply causing an incipient stall.
    
    After launch, does it fly straight with the same trim settings ?
    If not, why not?
    
    

>	I'll be painting the fuse and monocoting the wings and horizontal
>    stabs.   Lime yellow fuse with an orange canopy, white wings and stab
>    with a lime yellow stripe and oragne wing tips.  Hopefully it should
>    be visible.  If not I'll add a wide strips of chrome monocote to the
>    underside of one of the wing panels.
        
        Try black or a very dark blue instead. Dark colors are usually
        easier to spot against a bright sky.

    One of our club members just returned from a trip to Torrey Pines.
    He took along his Cheetah and got in some flying, in very crowded
    skies filled with hang gliders.
    
    The hang glider pilots carry whistles and give a blast if an RC
    glider comes too close. 
    
    The locals favor large fiberglass scale jobs or tiny pointy nose
    slope racers.
    
    Of course the real disadvantage of flying at Torrey Pines is the
    NUDE BEACH just below the cliff. Bill had several tense moments
    when his attention wandered and he nearly lost it. (the  plane)
    
    They charge 50 cents to fly there. Sounds like a serious lack
    of good 'ol American enterprise to me, and there isn't even a binocular
    concession.
    
    Terry
    

    
    
    
                          Hello Glider Pilots and builders,
    
    I am Philippe CLEMENT from Belgium Europe.
    
    I would like to ask you a question. I mould glider fuselages with
    fiberglass/kevlar/epoxy. I make my moulds with polyester and fiberglass
    (about 10 mm thick or .4"). Then I apply someting like 8 coats of
    wax then I polish the inside of the mould. My problem begins when
    I apply the first coat of pure epoxy: I put it with a smooth paint
    brush to form a thin coat of resine. This will determine the surface
    aspect of the model. The problem is that the epoxy seems to concentrate
    in some location like water on a greassed piece of glass. The resine
    forms thick round drops instead of a thin film as it is supposed
    to do due to the presence of the wax. Is it possible to suppress
    the effect of capillarity between the wax coat and the resine?
    
    
    
                      Does someone have a solution?
    
    I just finish a Speed Astir IIB of 4.2 meter (14 feet). The mould
    I have build for the fuselage weights 15 Kg !!. The fuselage weights
    900 grams which is not too bad. Its length is 1.70 meter, the main
    front surface is more or less a circle of 200 mm diameter. Big enough
    for my cat!
    
    My next project is a glider of about 2.80 meter (8.1 feet) with
    a short fuselage and two bars between the wings and the tail. The
    tail will have a reversed V shape like this picture:
    
    
    
                                  / \
                                /     \
                              /         \
                            /    ______   \
                          /     /XXXXXX\    \
    ---------------------||----|XXXXXXX|-----||-----------------------
                                \XXXXXX/
                                 ------
    
                               Front view
    
    
                                _____
                               /XXXXX\
        ----------------------|XXXXXXX|------------------------
        |                     |XXXXXXX|                       |
        ----------------||-----\XXXXX/-----||------------------
                        ||      -----      ||
                        ||                 ||
                        ||                 ||
                        ||                 ||
                        ||                 ||
                        ||                 ||
                        |---------|---------|
                        |         |         |
                        |_________|_________|
    
    
                                Top view
    
    Maybe I will put a prop with a electric motor between the bars but
    I am affraid for the weight!
    
    What do you think about that ?
    
    
                                              Philippe
                                         
                                           The Highest Flyer
    
    

    Philippe,
    
    Your glider projects are very interesting. What type of airfoils
    do you use ? Do you do mainly thermal soaring, and what type of
    launch system do you use ?
    
    On your epoxy/wax problem, do you use a commercial type of mold
    (mould) release agent ? A spray-on type release agent such as Frekote
    700 is popular here with those who mold their own fiberglass parts.
    I haven't heard that they have the type of problems you describe.
    
    I notice you use polyester resin rather than epoxy to lay-up your
    fuselages. I have a British Algebra which also uses polyester.
    It is thinner, and probably lighter than a equivalent American design
    which uses epoxy resin almost exclusively. The polyester fuselage
    is a little harder to repair but the finished job comes out well.
    
    We'll be interested to hear more about your projects.
    
    Terry

    Last night I finished covering the ailerons on the Ninja and installed
    them on the glassed wings. The wings are natural glass "color" tinted
    slightly white but this is hard to tell on top of the very light
    color balsa.
    
    The ailerons are monokote sky blue, the balsa wing tips are solarfilm
    yellow, ditto the fixed portion of the t.e.
    
    The fuselage is sky blue forward, tan aft, with blue and tan fin
    and stab. As you can tell, I'm trying to use up scrap pieces of
    covering too small for other jobs.
    
    I hinged the elevator and rudder with the Sig Ez-hinge material
    in the kit, but switched to the pink Radio South brand to do the
    ailerons, as it doesn't allow the CA to wick back into the flexible
    area of the hinge as much as the Sig brand does. Flexibility is
    better. I don't know how much I trust this method, have never used
    it before but figured it would be ok on a small plane. 
    
    All that is left to do is glue on the stab and rudder, hook up pull
    cord on rudder, install switch, rcvr. , batt. Then balance it and
    go fly. The spring winds are abateing rapidly of course, but a quick
    tow hook installation and I'm ready for the flat land.
    
    Terry

    Just to finish the Cloud Bound 99 story...
    
    I flew it saturday and it was a REAL handful. The ruddervators were
    ineffective on turns and the plane really wanted to tuck and dive.
    After two flights (and several hand tosses) I packed it in undamaged.
    Post-mortum indicates that I didn't have any washout (and the plans
    don't call for it) so I added some and I was still a little tail heavy.
    
    Now the rest of the story. Friday night I was doing the radio install
    and trying to set up the V tail mechanical mixers. When I went to full
    deflection, the elevator ball link would sometimes pop off. This
    concerned me since it was on the bench without flight loads. I finally
    put a layer of plastic baggie over the ball and that tightened it
    enough to test fly it. In the DECRCM file Jeff F. mentioned the Ace
    electronic mixer available from Tower. I'll check that out tonight and
    probably order one. I was told saturday that the X-347 was out of the
    budget again this month 8^( Anyone else have any experience with the
    Dubro V-tail mixer?
    
    At the end of the first flight, I tucked and hit pretty hard from about
    20 feet and the wings bounced hard enough to touch the tips on the
    ground. Looked like a commercial for carbon fiber. No damage. The wing
    tips came up pretty high on the launches too. The Dodgeson flap linkage
    paid for itself that initial landing when the wings popped apart and
    the linkage dropped free. All in all it should be an eye catching plane
    once I get the bugs worked out but I think I'll ground it until I get
    the servo mixing so I can trash the mechanical mixer. I've got plenty
    of room in the fuselage for a couple of the Ace mixers (yes, flaperons
    too 8^)

    Jim,
    
       Does the Dubro mixer use a sliding tray?  My father had a V-tail
    glider that used the Dubro mixer and it worked fine.  I am sure that
    you can get the mechanical mixer to work, nearly every V-tail sold
    shows a mechanical mixing scheme.  Hobby Lobby sells a fancy sliding
    tray mixer for around $30-expensive but cheaper than a new radio.
    The cheapest radio I have seen that offers V-tail mixing is the World
    Engines EXpert Radio which sells for around $200.
    
                                                            Good luck,
    
                                                            Jim

    Nope. Not a sliding tray. There's a servo "wheel" that you attach to
    your normal wheel that has a molded tube on top. There is an axle that
    fits through the wheel. There are three "wheel collers" that go on the
    middle/both ends of the axle. The elongated set screws for the wheel
    collers are the posts for the ball links. The sockets are on your
    surface controls. You put this on your "aileron" servo and attach the
    two tail cables to the outside "ball links" the elevator servo rod goes
    to the center "ball link". Applying elevator rotates the axle and makes
    both surfaces go up/down. Apllying ailerons makes the two surfaces
    change relative to each other. Using excessive throw, makes the socket
    pop off the ball. this is what I was seeing on the bench friday night.
    
    The sliding tray method is basically the same idea except the servo
    moves instead of the axle rotating. I really don't have room to convert
    to the sliding tray. I need the servos all the way forward to hold my
    lead noseweight in place 8^)
    
    Several electronic possibilities have arisen in the last day or so and
    I'll have to decide what to do after saturday's contest. Last
    saturday's squirrelly flight dash all hope of getting comfortable with
    it for this weekend. I'll go fly the 2 meter class and come back and
    work on the V tail in a more relaxed manner for future contests. I got
    my glass cloth last night at the DECRCM meeting and I think I'll make
    the new wings longer and use it in the open class rather than the
    standard class that it was built for. This will lighten the wing
    loading and improve the characteristics some.

re .751

phillipe,

i just recently began experimenting with fiberglass moulds.  to date i've
successfully molded a pair of fins and rudders for a giant scale me110
project.  success for me however is not a perfect finish, just good
reproducibility and great strenght to weight ratio.  i'm still learning.

anyways, i also made my female molds with glass cloth (chopped) and polyester
resin.  i used a type specifically made for layups.  i believe its waxless, the
deal being that sanding between layers is not essential.

i've had great success getting the inner surface of these molds smooth by
wet sanding, buffing, 8+ coats of wax like you mentioned.  but, to date i've
always left the last coat of wax thin and unbuffed.  i do this because i'm still
paranoid about the part releasing.  in addition to this unbuffed last coat of
wax, i spray on a pva release agent (polyvinyl alcohol).  it has the exact
problem you mention - if i spray it on too thick it beads up just like rain on
a freshly waxed car.  then as it air dries (the alcohol dries fast), it leaves
little hard shriveled junk everywhere the beads were.  unacceptable.  i've
minimized this effect by spraying the pva on very lightly and letting it dry
between many many coats (again it dries fast so its not too bad).  still, the
pva always leaves a somewhat rough (not quite orange peel but not smooth either)
surface.

then when i make parts the surface has 2 kinds of blemishes, the streaks of wax
are clearly visible and pva roughness also is molded in.  for my application
(so far) this is not bothersome.

i'm sure i could get away with buffing the last coat of wax.  as
the part dries (epoxy and fiberglass cloth) in the mold, it turns a darker
color.  the part also shrinks just a bit and i swear sometimes the parts falls
out of the mold all by itself (the parts are not deep but are pancake shaped).

i dont have any molding experience not using pva but others.

i'm surprised the beading of the epoxy resin in the mold is really a problem.
i would think that once cloth was laid down the fully wetted it would force
the resin to stay put.  too bad you can't join the part while wet and use an
air bag to push the resin/cloth against the mold till cured.

kevin

       
    
                      Hy fuselage builders,
    
    I am very sory about my bad English. I think my explanations are
    not very clear to you.(my mother language is french and I learned
    the few english I know by listening Pink Floyd hour after hour)
       To come back to fuselages only the mold itself is made with
    polyester. The model itself, the one made inside the mold IS in
    epoxy. I have finally found a solution for my 'drops forming' problem.
    In the past, I used to apply first a coat of pure resin directly
    against the wax, then let it dry and after a couple of hours, begin
    to laminate the fiberglass. I tried yesterday night another technique.
       As usual, I apply 8 thin coats inside the mold, I polish it to
    get a miror surface and then I put VERY carefully the first layer
    of fiberglass but a special one. It is made by the Klark Shweble
    company (an US factory having a subsidiary in Belgium). Its
    characteristics is that it weights only 40 grams per square meter
    and the fiber density is very high. I try to eliminate all the air
    bubbles between the fiberglass and the mold (it takes hours) and
    I let it "dry" for 4 hours. Notice that my molds are coloured in
    dark blue so that the air bubbles are clearly visible. To accelerate
    the "drying" process and also to have the viscosity of the resin
    as low as possible, I heat the mold with a ramp of infrared lamps.
      When the first coat is just hard enough to keep from moving, I
    begin the lamination with fibreglass of 100 to 200 grams per square
    meter depending of the model. I dismolded this morning and the result
    is P E R F E C T. Note that I use a special epoxy resine especially
    made for lamination. It does not support any addition of micro powder
    but it dries very quickly (more or less 12 hours depending on the
    temperature). I have to log out now because I have to go to fix
    a VAX 100 miles away from here. Thank you for your advise about
    the spray you mentionned. I will write another reply in 399 about
    the kind of gliders I build and the kind of fly I love. See you
    later.
    
    
    
                                                      Philippe
                                                  The Highest Flyer
    
    

    Wow! Do you see a lot of neat kits at a glider contest. I met Sal of
    NorthEast Sailplanes and talked to him afterwards. He flew a Magic
    after the contest and had a GREAT flight. his comment coming back to
    the car was that he should have used it in the contest. He also showed
    me a new Culpepper Models glider that looked interesting. Always on a
    budget, I asked him if they had something in the open class that was
    $150 and competitive. He showed me the plans and instructions for the
    new Alcylone (sp?). This is an all built up plane that can be flown
    with a simple radio that costs $150. Looked like a real nice ship and
    it would be very repairable/modifyable. He'll have them in stock in
    about a week. I have a birthday/Father's day coming that this might be
    within the budget. Has anyone else seen them?

    Congrats to all youse guys. Very good results for the first contest
    of the season. 
    This portends well for more crushing victories as the summer wears
    on; a mob of Deccies rampaging up and down the eastern seaboard,
    sweeping all before them, no ?
    
    Jim, I've never heard of an Alcyclone. What about that new Culpepper
    kit ? Was it that 118" open class, or something else?
    
    Flying model airplanes in Maine ! The mind reels.
    
    Terry

    Actually, Terry, I put one sentence before the others due to being
    interrupted while entering the note. The Alcyclone (sp?) is the new
    Culpepper all built up open class ship for $150. I wasn't sure if it
    was truely new, or just new to NSP.
    

    I think there might be some confusion here.  I watched Sal assembling
    his big white beauty with the T tail and nose cone [note that I don't
    claim to know its name].  (It took him forever to fish out the leads from
    the wing servos.)  I also admired the beauty of a very slim white glider
    that I think Stan flew late in the day; this plane had a hatch cover,
    not a nose cone; it was identified by Sal as the Culpepper Callisto,
    page 40 in the '91 catalog.  There may have been another plane in their 
    stable, but I have no knowledge of any other at the contest.

    Note that Jim Reith in his "Lots of money tied up ...." note refers to
    "plans and instructions for the new Alcylone", not a physical model.
     ^^^^^     ^^^^^^^^^^^^
    Jim, would you care to confirm/revise this?

    FWIW, according to that catalog,

    Culpepper CALLISTO:	99.5 in wing, E193 or S3021, fg fuse,	$159

    Weston Aerodesign MAGIC: 138 wing, FX60-100, nil balsa,	$295 and up

    The Alcylone isn't in the catalogue since they will just be getting the
    initial kits this week. This $150 kit gets you plans, wood, and
    instructions. Everything is built up. It can be flown as a simple
    elevator, flaps, and aileron&rudder coupled 3 ch glider or you can
    stuff a computer radio in and add crow and all the other bells and
    whistles. I consider this to be a cheap open class glider. My expensive
    model comments were more oriented towards the Lovesong/Magic owners
    where it costs you $300 to get the basic kit to start working on it.
    I'm also interested in seeing Kay's Lovesong accounting. Sal's low cost
    solution for standard class was the Pulsar which they list around $130.
    
    If you go through their catalog you will find unlimited ways to spend
    your money. The Magic kit doesn't come with wood because there isn't
    any wood used! It was a great flier and Sal would have done much better
    using it. Their catalog also lists a glider (the name escapes me) which
    you send in your radio to them and they install it at the shop and then
    send you back the completed (and test flown I believe) glider. Only
    $1095.00, you supply the radio! NSP sells the X-347 and Vision radios
    now as well as all the JR servo models. No prices in the servo list but
    they want $419 for the X-347 which is competitive considering the
    catalog came out in March with the preprinted price.

    The latest issue of the PPSS newsletter has a blurb written by a
    guy who built a Weston Magic. I can enter some excerpts if anyone
    is interested.
    I've seen a Weston Merlin, 99", and it uses Spectra cloth in the
    fuselage layup. It certainly makes it light and accounts for some
    of the high prices for his kits. I think the Magic uses Spectra
    too.
    The Merlin nose cone is very flexible but the rest of the fuselage
    seems stiff. Unfortunately the guy who built it did such a poor
    job of finishing/painting the fuselage, that it was impossible to
    get a clear idea of the overall quality of the kit, ditto the wings.
    He is a retired nuklar phissicks type and we often accuse him of
    suffering from C.G.R.I. (Cumulative Gamma Ray Impingement), but
    he does come up with some innovative design ideas, then slathers
    them in orange and blue paint.
    
    Terry

    I got a copy of the Weston Aerodesign catalog a week or so ago.  It
    is a nice catalog and lists all of the Weston kits mentioned
    previously that are sold by NSP.  (Magic, Terminator and 3 others
    that I forgot the name of...)  The catalog is obviously printed on a
    laser printer and is about 20 pages long.  Included is 3-views of
    the glider kits.

    The Weston Aerodesign catalog also has all of the typical composite
    construction materials and for most of them, seems to match and many
    times BEAT the prices from any other source I've seen.  This is a
    "must have" catalog for anyone into composite design.  Of course, I
    can't compare it to the NSP cat. since mine didn't come in the mail
    yet...  :-( 

    I'll try to remember to bring in the catalog so I can enter the
    address here...  (Sending a SASE gets you a catalog.)

    BTW - the $1095. price is for the top-of-the-line version of the
    Terminator.  I think it's 163" wingspan and designed for SERIOUS
    cross country competition.  In the catalog, they mention that it's
    too big to ship via any method but truck.  Or, they suggest, just
    drive to Maryland and fly it home!!!  :-)

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Castor Oil!! "    
                      |_____/

    Well, after some reassuring success with the Cloud Bound 99 yesterday,
    I've started to reexamine the possibility of making additional wings
    for this fuselage. My current plan is to extend the wings out to about
    120" and go with an S3021->S3014 wing design. I'm probably going to cut
    the long panels out as two half cores and then glue them together and
    bag them. I'll use vertical CF ribbon as spanwise spars.
    
    When one uses two airfoils as I will be, where do you transition to the
    tip airfoil? I have studied (ok, drooled over) the NSP catalog trying
    to figure out where each design transitions. My initial thoughts were
    to go with the two piece panels and use the 3021 for the entire inboard
    panel and then use a 3021 root and 3014 tip on the outboard panel.
    These will be single taper, flat wings. If I transition the airfoil in
    this way, do I need to cut any washout into the cores? My feeling is
    no, since the 3014 transition will give me aerodynamic washout. This
    will be a full camber changing wing.
    
    How far out should I start to transition the airfoil? What does the
    Falcon 880 do? It sort of reads in the catalog like the 12 inch tip
    panels are the transition. 

    Jim,
    I'd say your transitioning plan should work ok. I don't know
    exactly how the Falcon 880 transitions but it is usual to do it
    from root to tip of the outboard panel, whatever its length.
    
    With those airfoils and full span camber changing, washout is
    superfluous.
    Glad to hear that the 'ol Clod Bound is coming along. (excuse my
    spelling, I've been learning to touch type recently.;^)
    
    
    My Ninja has been completed for over a week, just waiting for spare
    time and reasonable weather to coincide. Got around to weighing
    it last night. 32.08 oz. with 500ma batt., 3 servos, and a 2" X
    1/8" tow hook. Wing area is 493 sq. in. , 7 sq. in. smaller than
    stock due to sanding and trimming. 9.38 oz/sq. ft. wing loading.
    This is real close to nominal advertized values for this kit, so
    I saved a little weight somewhere, probably on sheeting/covering
    and rudder actuation.
    
    Then I cleaned off the work bench and started on the ..............
    yes, the L....E....G....E....N....D.....
    Got the elevator actuator done, the part that is inside the fin.
    There are "only" 9 parts associated with this device, and 5 different
    materials, carbon fiber, steel, spruce, nylon, and brass. Of course
    this doesn't include the actuator mounting assembly which is four
    more parts, spruce, ply, and balsa.
    I have to have this done by July, for an upcoming round of contests.
    
    Terry