T.R | Title | User | Personal Name | Date | Lines |
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82.5 | How do I get down? | FROST::SOUTIERE | | Tue Mar 17 1987 13:33 | 18 |
| Let's get into this subject a little more!
What are some of the techniques used in landings, such as how should
you approach the strip, where should you be standing in reference to
the plane, etc...?
I've been practicing my landings, but I really don't have any concrete
way of approach. Also, should the plane touch-down before or after it
passes you? Is one easier than the other? Should I be looking at some
kind of reference? And should I just let the planes lack of air-speed
bring it down or should I use some down elevator?
These are just a few of the questions I have on this subject, and all
suggestions are welcomed. Thanks!
Ken
|
82.6 | Here's a start | SPKALI::THOMAS | | Tue Mar 17 1987 14:16 | 40 |
|
In response to your general questions I'll give you an outline
on how to land a powered RC plane. This was learned from a magazine
article so it's not my revelation.
The method is simple. The reasons are complex. I'd have to go
back and find the article I got this from to detail the flight control
interactions.
To start set your plane trimmed out for level flight. Now fly
the plane past your self from one side to the other ( at a decent
altitude). Reduce the throttle setting to "0" until the plane slows.
You will notice that without any elevator input the plane will begin
it's decent. Now increase the throttle setting a click at a time until the
decent is at an acceptable angle of decent. This throttle setting is
your landing throttle setting.
Now the process for landing. Start again by bringing the plane
across yourself and reducing throttle until the plane slows. At this
point increase the throttle the two or three etc.etc. clicks you
predetermined was your landing setting. Turn the plane 90 degrees on
your base leg on the landing procedure. Stay or this heading until you
can turn a second 90 degree turn and be lined up with the landing strip.
Your angle of decent will be constant. If you find that you are
undershooting the strip the correct input is increased throttle. Don't
peg it just add in enough to stop the decent until you feel that your
back on the correct angle of decent. If your coming in high then added
elevator input is used to slow the plane to increase the angle of
decent. Be careful that the added elevator isn't sufficient to stall
the plane. That is the basics of a landing.
As far as where you land, for beginners it is sometimes helpful
to finish a landing as the plans passes then as this helps in
orientation. However once your comfortable with landing break yourself of
this habit. LAND ON A LINE PERPENDICULAR TO YOUR FEET. IF YOU CAN DO
THIS YOU CAN LAND AT ANY FIELD YOU MAY FLY AT. NO MATTER HOW LONG OR
SHORT THE APPROACH OR THE LANDING STRIP.
Tom
|
82.7 | heres one | ROCKET::ONEILL | | Fri Mar 27 1987 06:55 | 8 |
| I'm no pro at landing but thought it might help if I mention this.
When learning to land it's very nerve racking to see 200+ dollars
comming closer and closer to the ground and sometimes I'ts hard
to concentrate but one thing I've found that helps is to keep in
mind , and I'm sure you've heard it before, push the stick twords
the down wing, this will keep things reasonably leveland has helped
me on many occasions to eliminate some of the confusion (I've even
been found to say this out loud as I'm landing)
|
82.9 | put it down in front of you | SA1794::TENEROWICZT | | Wed Mar 29 1989 09:41 | 11 |
| Dan, Threr is an easy way to get over the field uneasyness
problem. Learn to land the ship so that it touches down perpendicular
to your feet. In other words, in front of you. Not to either side.
Once learned you will find that of you can take off from a field
you can land in that same field. Also it's good to take a few landing
approaches early into the first flight at a new field. In this way
you get a quick feel for the landing while the fuel and other odds
are on your side.
Tom
|
82.8 | take your time,don,t rush | RUNWAY::MORIN | | Fri Nov 10 1989 18:47 | 20 |
| moving your control stick to the dipping wing is a good trick
to rember when your plane is comming toward you,BUT if you
are still at this stage ,your not ready to land yet!!
only atempt to land when you can fly final approch with
the wings level,instead make high passes over the runway
with a instucter by your side to give you confidence.
after a while you will get a little lower,and before
you know it your instucter will be able to talk you
threw a landing,,and dont feel bad about asking someone to
help you.i dont know of anyone who has learned this hobby
on his own...
by the way the way i teach people to correct the wings
when a plane is comming towards then is to make them turn
there back to the plane,and look over your shoulder
happy landing,s
paul morin (who cant spell,but can sure fly
|
82.10 | How to land your model plane | 17852::SOUTIERE | | Fri Mar 23 1990 09:42 | 15 |
|
Since I've been flying the MUNK I've noticed I'm having promlems
on my landing approaches. I am usually above 50ft when I start
my approach. I cut the engine to an idle and let the plane
descend on its own. I sometimes find myself diving a bit to
bleed off altitude but this results in increased speed which is
not what I want.
My question is;
How do the majority of you approach you landings...ie what
altitude, speed....do you apply down elevator...etc....?
Ken
|
82.11 | STAY OFF THAT DOWN.......! | PNO::CASEYA | THE DESERT RAT (I-RC-AV8) | Fri Mar 23 1990 10:25 | 64 |
| Ken,
Never, I repeat, NEVER try forcing the ship down with down elevator on
landing approach. The airplane will hesitate 'taking' the down, then
suddenly, pitch down dramatically and, unless you're high enough, you
can't catch it with up elevator fast enough and end up dorking the
model in, sometimes VERY hard!
The _perfect_ landing approach is the result of practice, practice and
more practice. Just as with a 1:1 power plane, the throttle is pulled
on the downwind leg when the plane is directly opposite to the point of
intended touch down. A nose-down glide is then established and
maintained throughout base and final legs and, when perfectly executed,
the plane will touch down right on target with no further application
of power or adjustment to rate-of-descent. Of course, it's an
imperfect world we dwell in and, while practice will yield frequent
perfect landings, adjustments are frequently required.
So, returning to the scenario just described, we've chopped power and
established our nose-down attitude. This establishes the rate of
descent which will result in either touching down exactly where we want
to be or be too long or too short. Now, believe it or not,
rate-of-descent is controlled mainly with throttle, e.g. if you
percieve you are going to be too short, add power to stretch the glide
but maintain the same glide angle, that is, leave the elevator alone.
This way, the transition when the power is pulled is less drastic...the
nose won't drop so drastically and you're right back in the desired
power-off glide. Power may be added and held clear to the ground but,
in this event, wait to chop the power 'til the plane's on the ground.
Pulling power at 2-or-3' invariably causes the nose to drop and PRANG,
you just bought a prop, bent a nosewheel (or nosed over with a
taildragger) or worse.
Now, in the too long scenario what do you do when you can't reduce
power any further? Easy...you go around and set it up again, trying
this time to set up closer, lower or both. Ideally, you should always
try to be just a tad short of perfect as a little power always puts you
where you need to be where, if you set up too long, you have to go
around or run out into the puckerbrush after yer' plane.
I always set up by pulling throttle to several 'clicks' above idle just
before turning onto the base leg. This allows me to pull the throttle
a little more should I find I'm too long/high. More often, however, I
hold this power setting 'til I have the threshold made, then chop and
glide/flare to landing. In cases where I hold power all the way in
(like into a headwind or where my approach was way short), I hold those
'clicks' of power 'til the wheels are rolling then gently 'milk' the
power down to idle. Again, chopping the power suddenly _can_ upset the
applecart.
The whole secret to a good landing is in the approach; a well flown
approach invariably leads to a good landing and the converse of this is
equally true. This returns us to my original point that practice,
_practice_, PRACTICE and still more _PRACTICE_ is the only way to
polish up those approach skills. Every flight should include several
touch and goes prior to landing. Start this regimen and it may
surprise you how quickly the approaches and, therefore, good landings,
start coming almost automatically.
|
| | 00 Adios, Al
|_|_| ( >o
| Z__(O_\_ (The Desert Rat)
|
82.12 | Monk's need flat desserts | RVAX::SMITH | I'm an RC DV8 | Fri Mar 23 1990 11:25 | 12 |
| Al, good stuff but can you elaborate more on bleeding airspeed.
The problem we face out here in the N.E. is trees and small fields.
It's not uncommon to have to have to maintain a base leg of 75 feet
or more due to trees. Then when you turn final, you have to drop
down to around 20 feet so that you don't go long. The Monk is a
fairly fast landing ship if you can't make long low final approaches.
In a case like the above, where you can't make a nice constant descent
(there by controlling airspeed), what would you suggest.
Steve
|
82.13 | Still confused.... | 17852::SOUTIERE | | Fri Mar 23 1990 11:59 | 10 |
| I guess I'm a bit confused on the "add power" to raise the nose.
Don't you have to add a bit of up elevator to raise the nose? I
figure by adding just power, you are only increasing the speed of
the plane but not adding much elevation. I know that if you add
more power than you trimmed out for, the nose will rise, but on
a landing approach you aren't going to add alot of power (??) so
how does the nose rise? Do you trim the plane just prior to the
off power sequence? MORE INFO!
Ken
|
82.14 | Aero 101 and how to slip (down, not up) | PNO::CASEYA | THE DESERT RAT (I-RC-AV8) | Fri Mar 23 1990 13:47 | 103 |
| Re: .2 & .3,
Steve, Yer' sure right about different technique(s) being required to
drop in over obstacles to hit a small field. I don't have to tell you
that dropping the nose for a rapid descent increases airspeed which
aggravates the "float-past" problem. And, obviously, at some point
you'll reach a situation where the obstacles are too high, too close or
the field too small to get into, period...full scale aircraft have the
same problem(s). Obviously, elevator alone cannot control the
increased airspeed resulting from a rapid letdown over the trees as the
increased speed will cause the plane to balloon and there's nothing you
can do about it: increased speed will result in ballooning when the
angle of attack is increased, that's all there is to it, period!
Full scale deals with the problem in many ways; the most common method
to get into a small field over tall obstacles once was to "slip" the
aircraft, i.e. set it up in a cross controlled, side-slip (e.g. left
aileron, right rudder) where the plane approaches with one wing low,
presenting its side to the slipstream for maximum drag. This is a
tricky procedure and controls must be released just before flaring but
it can be learned through practice. The slip (or side-slip) was common
before the advent of flaps which are really the best way to approach the
problem. I'd hazard a guess that Eric, Dan or the other Panic pilots
have no difficulty letting down into the smallest fields when they use
that full span flap on the top wing for landing.
The slip and the use of flaps both create the same effect, that of
allowing the aircraft to descend more steeply with no increase in
airspeed. As to what I'd suggest for your particular fields, I have to
hedge my bets and admit that I can't really advise anything without
actually seeing/flying from them. However, in the case of a clean,
non-flap equipped ship, I have to believe that the slip may be the only
method which will allow a rapid descent without building up
unacceptable airspeed. About the only other option is, don't fly
except on windy days where airspeed can be maintained at a safe level
while ground speed is reduced by the winds velocity to an acceptable
level.
If you want to practice slips, here's how: first, get plenty of
altitude cause it'll feel plenty slippery the first coupla' times you
try it. OK, now, shoot a traffic pattern at this safe altitude and, as
you turn onto final (upwind), simultaneously dial in left aileron and
right rudder (kinda' like a knife-edge) such that the ship is skidding
with its left side towards you. Use elevator to keep the nose from
dropping too much and throttle to adjust rate of descent. What you
look for is a rather vertical descent with minimal (if any) increase in
airspeed. Once you feel fairly comfortable with setting up this
attitude, you're ready to try landing with it; let the plane descend
all the way down 'til you're ~6' high and [you should be] near the
threshold of the field, then SMOOTHLY return all controls to normal,
that is UN-cross control them and flare to the touchdown. BTW, simply
reverse everything to do a slip to the right.
Nope, it isn't real easy but it's a valuable skill to have and well
worth learning...not to mention the fact that the maneuver is
impressive looking as hell and you'll dazzle spectators and fellow
pilots alike with it! :B^) Seriously, if you can't get into a field
by slipping, you probably just CAN'T get into it with that particularly
model.
Ken, Yer' not the first, nor will you be the last to be confused by
the old "add power to raise the nose" rule. In ideal terms, a full
scale instructor (or a model instructor, if he's worth his salt) will
tell you that you control altitude with throttle and airspeed with the
elevator. Now, that's fine in theory and we can accept that more or
less power will cause the plane to fly higher or lower and that
increasing the angle of attack with elevator increases drag/decreases
airspeed (and vice-versa) but, as you said, a combination of controls
is really required.
However, from a given trim and power setting, I stand by the statement,
"add power to raise the nose." At that given trim/power setting, the
elevator is getting its mechanical advantage/power from two distinct
sources: from its passage through the air AND from the propwash over
it. Let's think of it as, for explanation purposes, a 10-lb sandbag
representing power derived from passage of the elevator through the air
and another 10-lb sandbag representing the propwash...both these
sandbags are placed atop the hz. stab and the aircraft is in desired
trim with this 20-lb combined weight on the elevator.
Now, if we want to raise the nose, we _could_ increase up elevator,
adding [say] 5-lb's more pressure by so doing but, increasing the angle
of attack thusly may well provoke a stall as the airspeed drops
proportionately. So, instead, let's add a touch of power; this adds
the desired extra 5-lbs pressure wich raises the nose, increases the
angle of attack AND adds the necessary airspeed to keep airspeed above
stall speed.
Once the aircraft is trimmed for some particular attitude, even small
power changes should be noticeable as changes in pitch attitude. In
actual practice, you're right, we'll coordinate useage of throttle and
elevator but it's _very_ important to recognize which is the primary or
most vital control...in the landing exercise, it's the throttle! Once
I've got my landing attitude established, subsequent changes in pitch
and/or rate-of-descent are accomplished primarily with throttle.
Any clearer? Or, have I managed to further confuse the issue??
|
| | 00 Adios, Al
|_|_| ( >o
| Z__(O_\_ (The Desert Rat)
|
82.15 | | HEFTY::TENEROWICZT | | Fri Mar 23 1990 14:14 | 53 |
| I've wote this before someplace but I'll be dammed if I can find
it.
"By using the controls at hand we can make the landing sequence
almost mechanical, like clock work"
Here's how.... First to follow on with some of what has been written
is the previous notes...
Elevator controls-------------Airspeed
Throttle controls-------------Altitude
Most poeple this it's the other way around. It's not.
To start fly the plane past yourself in a straight line. Reduce
throttle completely and allow the airplane to slow down. You will
notice that in order to keep the plane at a constant altitude as
it slows that you will apply elevator. However the elevator will
have the end result of slowing down the aircraft and you will observe
the plane starting to decend on an angle. You will notice that
with the throttle completely reduced the angle will become excessive.
As the plane slows down and the angle of decent becomes excessive
add throttle one click at a time until the angle of decent is
acceptable. Remember how many clicks you have input into the
throttle. This is your landing throttle setting.
Now it's time to practice. Let the plane fly parallel to yourself
and reduce the throttle. As the plane slows add the predetermined
throttle setting and fly past yourself. Turn onto final and fly
the plane at this throttle setting. If the angle of decent isn't
sufficient to land the plane two alternatives can be chosen.
First, reduce throttle a little more. This will increase the
angle of decent. If the angle as previous set is sufficient then
the second alternative of to fly further downwind after the preset
throttle setting has been input. This will give more distance
between the final turn and the landing area.
If however the landing is short you add throttle. DON'T ADD ELEVATOR.
elevator will stall the plane. Next time to try landing input the
predetermined throttle setting however cut the base leg a little
shorter.
You will find that there are a couple of throttle settings that
work dependent on the weather conditions your flying in. Calm weather
will have a reduced throttle setting. Windy conditions will require
a little more throttle so you'll be flying the plane in.
Tom
|
82.16 | Be careful you don't "slip" | RVAX::SMITH | I'm an RC DV8 | Fri Mar 23 1990 14:37 | 26 |
| Ah yes, the ole "slip it right in" technique. I used to do that
with full scale and it was a blast. You come down like an elevator
without increasing airspeed. That's one of the things I want to
try with the Fiesta. Just havn't got up the nerve yet. We have a
field out here (Crow Island) where that would come in handy.
It IS a very effective maneuver.
Just to answer the original question (how do people do it), I start
my landing approach on the down wind leg directly opposite me. I
chop the throttle all the way back to idle, and then maintain level
flight (slight up elevator will be needed) to bleed off speed. When
the speed is right (practice, practice, practice) I let off the
elevator I've been holding and begin the descent adding in about
3 to 4 notches of power (again, this depends on wind conditions).
The proper descent for your plane is derrived through instructor
knowledge and practice. If it's done correctly, I hold that descent
rate all the way through the base leg and final approach. Most
adjustments will be made on the final approach. As Al has stated,
add or reduce power to make the threshold. For my particular plane,
I'll throttle back to idle about 6 feet up and 10 to 15 feet out
from the end of the runway. About 2 to 3 feet up I'll begin the flare.
Keep on flaring as needed to touch down.
This is the way Charlie Watt tought me to land, and I think my landings
come out pretty good. MOST OF THEM ANYWAY.
|
82.17 | What about dead stick approach | GIDDAY::CHADD | SPR VAX9000 CS Planning | Fri Mar 23 1990 17:32 | 29 |
| All the above refer to power on landings, what about dead stick. As somebody
who has most of his landings dead stick as a Pylon racer has two engine speeds,
go very fasts, and stop. Try this approach; pun intended.
Start the approach at 50-100' in front of you heading down wind at an altitude
determined by the glide angle of the model; eg my RCM Expert is about 50', My
F3D is about 15'.
Next commence a slow half circle that will bring you on to the end of the
runway heading up wind.
If you find during the turn you are too high turn your half circle into a 1/4
and do an "S" approach after the 1/4 circle, too low and tighten up the circle
in to more of an ellipse.
H H N N
H N N
N N
H N N
N L L L L N
H N L N
H= To high H N L N
L= To low H N L N
N= Normal HN L N
|-------------|
| |
|
82.18 | Prop change may help! | CSC32::CSENCSITS | | Fri Mar 23 1990 22:04 | 11 |
|
I solved the problem of trying to slow down buy installing a 14
6-10 pitch prop on my Munk. Since I'm running a OS .91 four stroke on
it and flying at 7200' things go alittle quicker. The thin air doesn't
help to slow things down much. This prop (a "four stroke prop") when
the power is applied really moves the Munk. But when the power is
taken away it's like someone just put a rope on the tail of the plane.
I mean it really slows quickly. You might want to try this. It works
well for me.
John
|
82.19 | More landing - uggg | FSHQA2::BJORGENSEN | | Sun Mar 25 1990 14:29 | 41 |
| Al, I thought you landing explanations were outstanding. A few other notes
that have helped me both in modeling and 1:1.
Set up - practice, practice, practice flying a consistent rectangular pattern.
Invariably, a sloppy pattern leads to a poor, or hit or miss landing.
Practicing these at pattern altitude is very helpful, particularly in the
even of a cross wind.
The approach - Consistently, I used fight the natural crab or weathervaining
that results in anything other than a direct head wind approach, or heaven
forbid a direct tailwind approach. Don't fight it - it the only way to
prevent drifting off the center line. Just correct with a little rudder just
before flair - or sometimes note real importing with trikes - but with a
tail wheel, could result in the infamous tail loop and PRANG.
Judging distance - it'll never be the same unless you have the luxury of flying
indoors, or you just never get any winds - is it that way at PNO?? Only kidding
Al. Whoever said pitch controls speed, and throttle controls distance was
right on - don't ever forget it. Assuming I've got throttle - I like to shoot
just a little short - dead sticks another issue. If you have you attitude set
up, just add a little throttle and your airspeed shouldn't change significantly.
If you have a slippery aircraft, the attitude of the craft will have to be very
flat. That's why you rarely see flaps on 1:1 biplanes - they have *lots* of
resistance. permitting a steep, slow decent in the pattern. The 1:1 J-3 that
I fly has a nice fat wing, when I pull back on the throttle, you can set up
a nice approach a 65 indicated with a steep angle of decent. No flaps are
needed - if your to high, just add a little slip - creating *lots* of drag.
It almost feels like your on an elevator, and looking down the runway on final
through the side windows a strange sensation. If you over shoot with a flap
equipped plane on a short field with full flaps, you'd better be prepared
for a go around - period. Be it full scale or models.
Slip - keep you windward wing down - into the wind. Feed in the aileron and
rudder at the same time - `feeling' it throughout the procedure. Hold it
as long as necessary - right up to flair if needed, then straighten out
and flair.
Enough babbling - but certainly a topic that always, at least in my book,
can use rehearsal. Some great ideas here - keep um rolling.
Brian
|
82.20 | I need PRACTICE... | 17852::SOUTIERE | | Mon Mar 26 1990 08:04 | 12 |
| Okay, things are starting to make sense, but I want to make sure
I understand flairing. Flairing is done by adding POWER and not
AILERON.....correct? I guess its time to train the left hand!
For some reason, this makes me nervous. I don't like to add power
just before the plane touches down. But until I try it, I'll take
the words of the experts. (its kinda like trusting a compass over
your own instincts....)
Thanks for the info.
Ken
|
82.21 | "Drag it" in | RUTLND::JNATALONI | | Mon Mar 26 1990 08:13 | 25 |
| This will only serve to support what has been said so far about
how to control speed and distance in landing. This pertains to
full scale aircraft, but the flight characteristics are the same.
I had occasion to watch a lot of "short field" landings at a dirt
strip in Korea. The aircraft type using this strip were T-6's,
C-47's, C-54's, P-2V's and others.
"Throttle controls distance". - the accepted practice at this
strip was as follows, and if they didn't do it this way they were
in deep rice paddy muck:
Come in short....then hold the aircraft up with throttle....so called
"Draggin' it in". The when at the fence - chop it ! that's it !
Every once in a while someone would come down the chute in what would
otherwise be a normal approach, go a little "long", and then - - - !
Fun to watch, but I wouldn't care to share the emotions of panic that
some of those jockeys must have had.
The point I'm trying to make here, without getting into war stories,
is that it's true; your "Throttle" will get you up and down, rather
than your elevator. (At least in this "low speed" flight realm).
john
|
82.22 | Try this on for size | RVAX::SMITH | I'm an RC DV8 | Mon Mar 26 1990 10:18 | 72 |
| Ken,
There's alot of thing we do in the realm of flying that we take
for granted. You don't realize how complicated it is until you try
and put it into words. In a previous reply, I said "flare as needed".
Three little words. Now let's see what it takes to explain that.
Please do not equate flaring with adding power or giving any
alieron input. That's not to say you wouldn't do either, but if
it's anything, it's PART of flaring and not a description of flaring.
My definition of flaring would be "that part of the landing
sequence, usually the very last thing, during which you end your
approach descent and begin to slow the plane so that it settles
softly onto the runway."
Let's begin with the down wind leg. We'll assume that your initial
approach altitude is correct and that you have mastered your approach
descent. So, you chop your throttle and begin your descent to the
runway. You already understand that once you chop the throttle,
the plane will drop it's nose and begin to come down. In order to
keep this descent at an acceptable rate, you will add in some up
elevator, or add power as the situation demands. The object is to
establish a rate of descent that, once you have gone through the
entire approach, will put you 3 or 4 feet up over the threshold
of the runway.
Now your coming over the end of the runway. If you do nothing,
and just maintain the rate of descent you have established, you
will land hard. The best you can say is that you "flew" the plane
onto the ground. What you actually want to do at this point is
"transition" into your landing. You do this by flaring. As you cross
the end of the runway, you need to "break" your rate of descent.
Do this by adding just enough up elevator to level the plane and
stop the descent. When you do this, the plane does not have the
power to maintain level flight, so it slows some more and once again,
begins to sink. At this point, you add a little more up elevator
to once again attempt to maintain level flight. The same thing will
happen (the plane cannot maintain level flight), so it will slow
some more, and sink some more. Add more up elavator etc. until the
plane settles gently onto the runway.
This, basically is flaring. What I described would apply mostly
to a "No wind" situation. If your fighting a head wind, you would
most likely carry power through your final approach, probably breaking
your descent quite a ways out and maintaining altitude up to the
threshold, and then cutting power and settling in using the method
described above.
The use of power or any control input would be used for corrections
during the approach. For example, if you flare too high, and your
airplane is going to "drop" onto the ground, adding a touch of power
will generally pull it through and allow you to land normally.
Different condition require different methods, but once you
understand the basics, a little common sense should get you through
most landings.
One more thing. Remember I said that way back when you start
your initial approach, you would cut power and add a little up
elevator? Well, you would be holding this up elevator to one degree
or another all the way through your approach. Consider what makes
the elevator and other control surfaces work. Air flowing over them.
If your coming in short and add power, 2 things happen. You increase
speed, which increases air flow over the elevator, which makes it
more effective, which raises the nose. You also increase prop wash
which helps do the same thing. That's why adding power during your
descent raises the nose and extends your approach.
Regards,
Steve
|
82.23 | HOW'S THAT AGAIN.......?? | PNO::CASEYA | THE DESERT RAT (I-RC-AV8) | Mon Mar 26 1990 10:44 | 44 |
| Re: .10, Ken,
I'm gonna' assume you meant elevator, not aileron. The answer's still
no, not necessarily.
The flare maneuver is used to do the final slowing of the aircrat just
prior to touch down. With a model, flare should start a foot or less
over the runway; the elevator is used to attempt to HOLD that last
foot or so of altitude. Of course, this isn't possible but in
attempting to hold the ship off, what happens is that the angle of
attack gradually increases as you increase the amount of up elevator,
trying to hold the plane off. The plane gently slows and descends the
last few inches to a smooth touch down...when properly executed, you'll
hit full up elevator just as the wheels touch. If you were holding any
throttle adjustment during the approach, NOW is the time to gently milk
it off. If the plane balloons when you start to flare, you're too fast,
applied too much up elevator or both.
What I've described here is called a full stall (or 3-point) landing
wherein the aircraft's wing is completely stalled (generating no lift)
just at the point of touch down. For a taildragger, all 3-wheels will/
should make contact at the same time. For a trike-geared ship, the
mains will touch first with the nosewheel up out of harm's way.
Wheel-landings (taildraggers only) are preferred by fighter type models
as they are much more realistic. This is where the ship is essentially
flown onto the ground, mains first, and it rolls out in a horizontal
attitude carrying the tail high 'til speed bleeds off sufficiently for
the tail to drop when the wing finally quits flying/producing lift.
Once learned, the wheel-landing is easy enough and is much prettier
IMHO than a stall-landing but the full-stall should be mastered _first_
so the mechanics of landing can be ingrained into you. Wheel-landings
require a full understanding of the landing maneuver as touch down
speed is higher and the wing is still flying which can get you into
_real_ trouble if you don't understand what's happening.
Perfect the full-stall technique first, then we can speak to the
technique for wheel-langings.
|
| | 00 Adios, Al
|_|_| ( >o
| Z__(O_\_ (The Desert Rat)
|
82.24 | Ooops..... | MISFET::SOUTIERE | | Mon Mar 26 1990 10:45 | 15 |
| BOO BOO made in my last reply. I met to say ELEVATOR not aileron.
So correct me if I still misunderstand....when landing you must
use your elevator somewhat ALONG with power? If so then I have
not been too far off. I just need to try the power trick to
maintain a proper glide pattern.
I usually try to cut power on the downwind leg and bleed off my
altitude during the rest of downwind along with base and by the
time I turn on final I should be pretty well set, but from that
point on I use the elevator to maintain a level nose and add just
a tad more just before she touches down, in essence, I flair.
Its just different with the MUNK....probably due to its weight.
Ken
|
82.25 | More on Landing.... | FSHQA1::BJORGENSEN | | Mon Mar 26 1990 12:30 | 15 |
| Under normal circumstances, and plane should land when it's fully,
aerodynamically stalled - optimally, just above the ground. Be it a
747 or ultralight, the 1:1's are the same. Some circumstances
do however require you to "fly" the plane on the ground. For example,
if I flying the 1:1 J-3 on a windy day, I would opt for a "wheel" landing,
landing the plane on the main gear, and slowing it down on the ground, letting
the tail wheel settle - same for trikes.
So in most cases, you want to hold the plane off the ground until it STOPS
flying. The inadvertent "bounce" occurs when the plane is landed without
a full stall. The elevator should usually be all the way back just when you
touch down.
/Brian
|
82.26 | Did I say that?????? | RVAX::SMITH | I'm an RC DV8 | Mon Mar 26 1990 13:51 | 6 |
| Ken, after reading Al's response and re-reading mine, I was in error
when I suggested starting the flare 3 to 4 feet up. Don't ask me
why I said that, but I did. Al is in fact correct when he states
that you should continue the approach down to about a foot, then
start the flare and keep feeding in up elevator trying to maintain
that foot.
|
82.27 | Here's another one | CURIE::ANKER | Anker Berg-Sonne | Mon Mar 26 1990 16:43 | 38 |
| Nobody has mentioned a totally different landing
technique. This one is absolutely mandatory with my Byron's F16,
and is used by all passenger jests that I fly on.
Try to notice the nose attitude next time you are on a
landing airliner. Its pointed UP! And the jet comes in with a
fair amount of power. This is the ONLY way to keep speed down
and completely consistent with the "use elevator for speed
control" principle. In order to prevent the plane from coming in
at too steep a descent the throttle is applied, once again
consistent with the stated principles. When landing my F16 I
apply up elevator as soon as I get on to the final leg and then
use the throttle all the time to maintain the right rate of
descent. As the plane closes in on the ground even more throttle
is fed in until it makes a "perfect" touchdown. I quoted perfect
because on a grass field the F16 slams the nose wheel into the
ground as soon as the main wheels touch the grass.
If I try to execute the landing approaches described
earlier the F16 floats right through the field at high speed. No
way will you get it on the ground.
The fascinating thing is that this type of landing also
works on a regular prop plane. You better have some experience,
because you don't want to raise the nose so high that the wing
stalls. But this is a great manouver if you want to land the
plane at basically zero speed.
_
/ |
_----____/==|
/__====-------
|-
/
/
Hang in there!
Anker
|
82.28 | How about landing gliders? | MALLET::NEALE | Ici on parle Europ�en | Tue Mar 27 1990 05:49 | 8 |
| Would any of our experts like to make some comments on landing a
glider? Without a "noise and go" device up front, you do not have the
"throttle controls rate of descent" facility. On the bigger machines
with brakes/flaps/spoilers you obviously have some control over rate of
descent, but on my simple 78" span rudder/elevator job, which floats on
and on if you try to flare out, it seems that the only choices are to
fly in a big field, or drive it in nose first like a javelin!
|
82.29 | How I do it | CURIE::ANKER | Anker Berg-Sonne | Tue Mar 27 1990 10:07 | 58 |
| Re: <<< Note 1197.18 by MALLET::NEALE "Ici on parle Europ�en" >>>
I'll depart from my usually reserved, unopinionated,
normal self and give you an opinion. Having owned three flap-
and spoiler-less gliders and flown them in competition I have a
bit of experience.
Interesting enough, most glider pilots end up short on
spot landings, so the first point is to maintain speed at a
fairly low altitude. Since there is no engine, elevator controls
both speed and altitude converting potential energy into kinetic
and vice verca.
The problem of coming in too low and slow is impossible
to recover from unless you can pick up thermals at 6 feet - I
can't and only know one person who can.
The other one, too high and/or fast is the one you would
rather be in. The answer to controlling speed/altitude is drag,
even if you don't have extra-drag devices. I use four systems
that I'll describe separately.
The first is using ground drag! Hit the ground at high
speed. It's amazing how fast grass slows down a plane once its
gliding along the ground. Solid dirt slows it down even faster,
but demands a fair bit of structural integrity! My SIG Riser was
great at being dorked into the ground, so my technique was simply
to come in at a safe altitude and dork the ship into the ground
when inside the landing zone.
The second method is to extend the glide path. If
there's wind it works well to crab sideways back and forth until
the right altitude and speed is reached and then drop the nose
and come into the landing spot.
The third is a great variation of the second. By
flapping the rudder back and forth, about a cycle per second, the
ship will increase drag very effectively as it yaws back and
forth.
The fourth only works with some ships. If the leading
edge is very blunt you can give up elevator and slow the ship
down to the point where it loses altitude very effectively.
Don't do this if it has a tendency to tip stall! It's not very
fun to see a glider suddenly head straight for the ground from 20
feet altitude!
_
/ |
_----____/==|
/__====-------
|-
/
/
Hang in there!
Anker
|
82.30 | What's a glider????? | RVAX::SMITH | I'm an RC DV8 | Tue Mar 27 1990 10:15 | 14 |
| I'm not all that familiar with gliders, but I'd say basically it's
all judgment. You get one shot, and your either right or wrong.
I think experience is the only teacher here and you learn how to
judge your approach through repetition.
As far as getting it on the field, you basically "fly" a glider
right to the ground with no flare. Although....... with a "little"
down elevator, gliders tend to sink vertically rather than dropping
the nose. So, if you flare a couple of inches off the ground to
get the plane horizontal, and then feed in a little down, it should
settle vertically onto the runway rather than dropping the nose
and going in like a spear.
Come on glider guiders......how's it done
|
82.31 | landing gliders | CSC32::M_ANTRY | | Tue Mar 27 1990 10:31 | 51 |
| We'll it is true about gliders that you only get one shot. I was home
at Christmas and me and my brother were flying his power plane off of a
two lane road out in the sticks. There was a little crosswind and he
was nervous about landing on the road. I told him that I would land it
for him. So the first thing that I did was pull throttle and trim and
killed the engine. I told him "OK, its a glider now!!!!" and proceeded
to grease it in on the road right in front of us!
People do have trouble landing gliders. I preach that a good landing
is made in the pattern and not on final (same goes for power). I tell
people to fly a nice square pattern and learn to judge when and where
you should be. While flying on your downwind leg if you are short turn
early, if you are long turn later and just adjust every leg of your
pattern as needed. Some things you can do is to extend your base leg
past the point of where you would turn final and let it continue on
base and then make a 180 degree turn and fly back along base and turn
final if things look OK. The whole thing is to just adjust and be
creative in the pattern until things look about right.
I would not advocate a beginner trying to force a plane onto the ground
because the down elevator translates to speed which translate back into
altitude and next thing you know they are in trouble. On my Gentle
Lady on small fields I would just put it into a comfortable circle
inside the field and let it loose altitude. Get used to flying it
close to the ground and make your pattern low and slow (normal
airspeed). The most important thing just like in power is not to try
to get altitude by using elevator. Like they said before the last
thing you want is a stall 10' of the ground(but with a 2m poly plane it
should survive to fly again due to the low mass).
Some tricks I would use to get a plane down from altitude are if you
are high enough fly inverted (Let a power guy try that with a plane
that has 12 degrees of dihedreal in it!!!!) then as you get lower pull
it out like a split-S or put it into a very tight circle (almost stand
it up on its wing verticaly), but this takes lots of up elevator to
counter act for the loss in lift and will generate quite a bit of
airspeed so leave yourself some room to bleed off the airspeed as you
roll out of this death spiral.
On 2 min percision duration tasks I would stay at altitude until 1:20
and then go into the death spiral. Hey it worked and won me a couple
contests. I could land that gentle lady (no spoilers, no nothing)
better than I could most anything else.
Bottom line for landing gliders, hit the ground with the wings level
where ever that is and you will be fine. Accuracy can always be
improved with a plane that still flys!!!!!!
Happy Landings.....
|
82.32 | WE'RE NOT IN KANSAS ANYMORE, TOTO...... | PNO::CASEYA | THE DESERT RAT (I-RC-AV8) | Tue Mar 27 1990 11:09 | 48 |
| Re: .-1, Mark,
Wow! Some of those techniques sound pretty bee-zarre!! But, having
almost zero glider experience, I have to yield to yer' experience and
assume these are good techniques.
As I said, I have almost no glider time but landing can't be _too_ much
different than landing an oldtimer which has no flaps, spoilers, etc.,
just rudder and elevator. The technique I use that works great for me
is to start orbiting the intended landing area while still up quite
high. As the ship slowly loses altitude with each orbit, I steadily
thighten the diameter of the circular orbit. The path through the air
would look like a coil spring with a much smaller diameter at the
ground than at the top, sorta' like the classic image most of us have
of a tornado.
I keep the ship out in front of me at all times and, as the ship
finally gets low enough (a pure judgement call), I break out of the
circling pattern and fly a loose rectangular pattern, adjusting the
length of each leg to suit. Once on final, yer' pretty much committed;
if yer' too low/short, that's the way it's gonna' be...without engine,
you just can't stretch it beyond a small amount. If too high/long, I
"S" turn it gently to spill off excess altitude/airspeed to the desired
level. Now, simply guide the ship to the desired spot and flare just
before touch down.
This and, really, ANY technique requires that you make a number of
judgement calls based on knowledge of how the ship should appear at
various stages of the approach. Again, and I can't stress this enough,
the only way to acquire this knowledge is PRACTICE, PRACTICE, PRACTICE.
If you don't know instinctively how the plane should appear at the
critical points in the pattern, no technique in the world will make a
landing automatic for you. You simply must practice until things
kind'a go on automatic for you and, if you practice enough, I assure
you that day _will_ come.
One last parting shot: If you want to go up, give the plane some up-
elevator. If you want it to go down, give it _more_ up-elevator! The
message not too cleverly hidden in there is to always be alert to stall
when using up-elevator near the ground. A snap, spin and crash from
even low altitudes (20-30' and below) is almost always a nasty thing
and it's frequently fatal!!
|
| | 00 Adios, Al
|_|_| ( >o
| Z__(O_\_ (The Desert Rat)
|
82.33 | Aggressive glider guiding....... | CSC32::M_ANTRY | | Tue Mar 27 1990 13:21 | 8 |
| Bizar???? Maybe the point you are missing is, in some of my techniques
you noticed I was trying to get the glider down in a hurry. That is
usually because it a percision duration event. In other words put the
glider on the ground at 6 mins, not 6 mins and 15 secs. So that is why
they may seem a little aggressive.
Take care
|
82.34 | NO OFFENSE, AMIGO...... | PNO::CASEYA | THE DESERT RAT (I-RC-AV8) | Tue Mar 27 1990 13:56 | 18 |
| Re: .-1, Mark,
Nope! I perceived what'cha meant but was puzzled as to how flying
inverted would help slow the ship, especially when it's followed by a
split-S. Again, I bow readily to yer' expertise in a field I have
virtually no exposure to. I'd certainly never contest anything to do
with sailplanes.
I think my reaction emanated from the perspective of a relative novice,
which I AM when it comes to sailplanes. These techniques sounded a bit
bizarre/radical if my primary objective was simply to get down in a
restricted area all in one piece without benefit of flaps/spoilers/speed
brakes, etc.
|
| | 00 Adios, Al
|_|_| ( >o
| Z__(O_\_ (The Desert Rat)
|
82.35 | | CURIE::ANKER | Anker Berg-Sonne | Tue Mar 27 1990 13:57 | 25 |
| Re: <<< Note 1197.22 by PNO::CASEYA "THE DESERT RAT (I-RC-AV8)" >>>
Al,
In most glider events the point is to make a point
landing. Pretty landings don't get you anything. The number of
points you make by being within a few inches of the center of the
circle will make the difference between an average performance
and being in the leaders. Making a pretty landing is easy, just
peep it flying until the ground catches up with you. Trying to
get it to land at a specific point without the ability to make
another circuit is a different story and VERY different from
power plane flying.
_
/ |
_----____/==|
/__====-------
|-
/
/
Hang in there!
Anker
|
82.36 | Short field landings - lift the nose | LEDS::LEWIS | | Tue Mar 27 1990 14:19 | 12 |
|
I have to echo Anker's earlier reply about how to lose altitude
quickly if you don't know how to crab and don't have flaps.
Every time I see someone consistently coming in too hot I suggest
they raise the nose just a tad during the entire approach. They are
almost always amazed at how much difference this makes. Don't
overdo it (obviously), since the resulting stall/snap won't be very
pretty. But give it a try, I for one have excellent results with it.
BTW, still use the throttle (as mentioned severl times) to control the
flight path.
Bill
|
82.37 | It's a friend impresser!!! | CSC32::M_ANTRY | | Tue Mar 27 1990 14:20 | 6 |
| re: .-2 Flying inverted is not the most efficent use of an airfoil, so
hence it looses altitude pretty good, plus the WOW factor is thrown in
also for the spectators. This is when you are spec'd out and want to
come down without pulling the wings off from excessive speed and you
have no spoilers/flaps etc. The split-s is done with plenty of
altitude left.
|
82.38 | Do as I say, not as I do | ELMAGO::TTOMBAUGH | High Plains Drifter | Tue Mar 27 1990 14:21 | 12 |
| I think what Mark had in mind by flying inverted, was to increase
the sink rate while not increasing forward speed, and I assume,
would be done at a higher altitude, not during the last few seconds
of flight. This technique works well with lightly loaded Gentle
Lady type aircraft that should be kept at lower speeds and not horsed
around too much lest you snap a main spar.
I usually have my best luck in spot landings by keeping it a little
faster and lower than I think I should, then dorking it in and letting
it slide up to the spot. I virtually never do this sucessfully.
Terry
|
82.39 | | HEFTY::TENEROWICZT | | Tue Mar 27 1990 14:46 | 19 |
| Gee I guess Pattern fliers are the best landers then...
They have power on,land on or near a spot and have to make it look
pretty
:-):-)
Tom
|
82.40 | Anyone can fly with a engine!!!! | CSC32::M_ANTRY | | Tue Mar 27 1990 15:04 | 8 |
| No Tom Glider guiders are the best landers......
They have to land at the exact center of a 50' diam circle percisly at
the specified time and with no busted pieces or missing parts, right
side up.
All This with NO ENGINE!!!!!!!
|
82.41 | I hope this isn't too long winded but here goes anyway... | SHTGUN::SCHRADER | | Tue Mar 27 1990 15:30 | 87 |
| I pretty much agree with what's been said so far but an important point
has been left out. That is the difference between how the elevator
affects the rate of decent vs how it affects the angle of decent.
Everything that I'm going to say here can be found in the book "Stick
and Rudder" by Wolfgang Longschlige (the spelling of the author's name
is wrong but it goes something like that). This is a full scale pilot's
book and I've seen it in a number of book stores. The book explains
this better than I can but I'll try to get the basic idea across. BTW,
this book was copyrighted sometime during the 1940's, the information
in there is timeless and I highly recommend it.
Most of what I'm going to say here applies to the longer term effects
which happen when the controls are kept in a more or less constant
position and when the engine is either off or at idle. The same
arguments work if the engine is producing thrust but I won't go into
that right now to keep this shorter. At the moment controls are moved
to a new position, there are transient effects which damp out into the
longer term steady state conditions (more about this later).
First the rate of sink... As up elevator is increased (in a long term
sense), the rate of decent decreases until the angle of attack has
increased enough for the wing to stall. This part is pretty simple,
pulling in up elevator tends to make the rate of sink lower (assuming
that you don't stall).
Now the decent angle... This is more complicated. The angle of decent
is determined by the lift to drag ratio (L/D) that the aircraft is
operating at. If the L/D is, say, 10 then for every 10' that the
aircraft moves forwards, it drops 1'. If the L/D were 5 then it would
drop 1' for every 5' of forward travel (twice as much). Now we get to
what the elevator does. As the angle of attack (AOA) of the wing (and
airplane) changes, the L/D changes. The elevator is the control that
determines the angle of attack. At some elevator setting (i.e. angle of
attack) which varies from airplane to airplane, the L/D is at it's
maximum. For a given altitude the max L/D AOA gives you the greatest
distance before you hit the ground. The max L/D occurs at a fairly low
AOA which translates into a fairly high flight speed. As up elevator
(and therefore AOA) is increased), the drag increases due to the higher
AOA (basically the same effect that you get when you hold your hand out
of a moving car and change the angle of your palm), the L/D decreases,
and the angle of decent gets steeper. The practical effect of this is
that as up elevator is increased (again assuming that the stall AOA is
never reached), the airplane drops at a steeper angle (note that the
sink RATE is lower but the sink ANGLE is steeper). At first this seems
counter-intuitive it makes complete sense once you work through the
physics of what is happening.
Now a practical example... Let's say that you're out a ways, a little
low, and your engine dies. The best thing to do is the head back in a
fairly fast glide (a glide, NOT a dive). This gives you a fairly good
L/D and gets you over the field with the most altitude (or closer to
the field if you were really low). Another reaction could have been to
give it up elevator to attempt to "keep it in the air longer". Yes, the
up elevator will keep it the air longer but the the increased AOA will
kill you L/D and make you come down shorter than a faster glide would
have. The point is that the thing that you want to do with the altitude
that you've got is not to "stay in the air longer" but to "travel the
greatest horizontal distance".
At times I've read in the magazines about guys going dead stick then
trying to "stretch their glide" and snap stalling the plane into the
ground. This should NEVER happen since you get the best distance at a
fairly low AOA. If you're near the stall then you sink rate will be low
but you'll be coming down steeply. This ISN'T what you want if you're
trying to get back to the field and aren't sure that you'll make it.
One of the things that's tempting to say after seeing this stuff for
the first time is "but, if I'm going along and I put in up elevator
then then plane goes up..". If you're flying one of those crazy Panics
with a 120 up front at full throttle then yep, put in up and it'll go
UP. If you're gliding, then feeding in the up makes the plane zoom up
and gain a little altitude before it stabilizes at the greater sink
angle. For a few seconds the plane will stay above the original glide
slope. Eventually the higher sink angle catches up with you and you
fall below the original glide slope. The same thing happens in reverse
when you reduce the amount of up elevator. If the engine is producing
thrust then all of this gets modified since engine thrust will cancels
an equivalent amount of aircraft drag, which in turn changes the
effective L/D and therefore the glide angle (or climb angle if there is
enough thrust).
All of this ties back into the stuff about using the engine to control
sink rate and the elevator to control airspeed but this is getting a
little longer than I had intended so I'm going to cut it off here since
it's all in the book anyways.
Glenn Schrader
|
82.42 | | 39463::REITH | Jim Reith DTN 291-0072 - PDM1-1/J9 | Tue Mar 27 1990 15:30 | 3 |
| Dorking it in isn't the "best" landing though...
What was Kay's comment about Competitive Javelin guiding?? ;^)
|
82.43 | Gimme them 'ol time landings | ELMAGO::TTOMBAUGH | High Plains Drifter | Tue Mar 27 1990 16:14 | 7 |
| "Best", in this case means maximum landing points awarded; without
parts falling off or the airplane coming to rest inverted. As for
being javelins, heck yes, why else build the fuselages from
kevlar and carbon fiber?
Terry
|
82.44 | Silly me... | 39463::REITH | Jim Reith DTN 291-0072 - PDM1-1/J9 | Tue Mar 27 1990 17:00 | 3 |
| And there I was just stretching another 5-10 seconds out of the ground effect.
;^)
|
82.45 | How I get My RC Planes to Slip | WR2FOR::BEATTY_WI | | Sat Mar 31 1990 23:49 | 42 |
| I get a major kick out of slipping my RC planes out of the sky real
steep and under control. I have a small bud nosen champ that flys
so realistically its definitely not RC trainer material but because
of its realistic characteristics it slips great.
Final leg is no place to learn to slip you pride and joy however!
I learn the process on each of my planes up high where I can blow
it and try again. Lower the power to where you would if you were
going to land. Begin by putting in some rudder, as the plane begins
to turn with rudder application slowly counter the turn with opposite
aileron. Keep progressing with this until you are able to counter
a full rudder deflection with opposite aileron and only have the
wing you are lowering with aileron slightly lower than the opposite
side. You'll know you have it right when its flying along sideways
and holding a straight track, neddless to say but unless you have
the power too high it will be coming down too!
Since you are presenting so much area to the wind you can let the
nose down and not zoom the plane. If you do raise the nose it will
slow down quickly. Some planes have increased stall speeds or
aggravated stall characteristics in a slip, do give it a try up
high first.
If you are landing in a crosswind, be sure to have the lowered wing
on the upwind side of the crosswind. You can get tipped over easy
if you do it the other way. Also the aggravated stall characteristics
occassionally show themselves quicker when you slip away from the
wind. I understand that the aggravated stall that can occur when
slipping usually comes from "blanketing" of the tail surfaces that
leads to buffeting and temporary loss of pitch control.
Not all of my planes can be made to slip. I have a couple with
what are essentially no dihedral wings where right rudder causes
the left wing to dip, you pattern flyers are familiar with this.
If you are having trouble getting it to slip try to find the point
at which your plane will fly level with the least power then begin
crossing the controls.
Will
|
82.46 | I'll second what is already said | KBOMFG::KLINGENBERG | | Wed Apr 04 1990 09:32 | 56 |
|
Just to second what is already said: My experience (with mostly
gliders and electrics with empty battery = only one try) says
that the pattern before the actual landing is very important
and gives a lot of room for correction. What should ideally be
straight legs with two 90� corners can be modified with different
angles to stretch or shorten the flight path. If you're way to high,
you can fly up and down a bit downwind of the field until you have a
nice height to come in.
The second thing (already said, too): You should not fly at the
lowest sink rate velocity, but a little faster at the best glide
angle velocity. Your path is _a_lot_ longer that way, chances are
better to make it back to the field (if you are too far out) and
you are not that prone to stall.
I remember a club internal glider contest I attended a few years
ago with my old FIESTA. Goal was an exact time (200 sec, I seem
to remember) and a _nice_ landing in a defined area. Sticking the
plane in would not have done the job, since the landing was judged.
I wouldn't have done it to my pride and joy, anyhow. When I found
out during the approach that the headwind was stronger than I had
assumed and the plane seemed to not make it to the field, I remem-
bered this 'best angle of glide' thing of the theory. I gave it some
down - and boy, it came down fast - but it picked up some airspeed.
I arrived at the field in the height of the wheat beneath, began to
flare and managed to glide about 100 meters in the ground effect
(where the headwind is a lot lower). As you probably guessed, I only
fell about 0.5 m short of the marked area...
If you come in too high, a slip is of course possible for gliders
as well as for powered planes. Ailerons are necessary, though, and
I am still not capable of doing it. I prefer to have spoilers.
Regarding necessary power on landings with jets:
Shortly before touch-down, you want to have the lowest possible
airspeed, this means the highest possible CL. This means a high
angle of attack and high drag. This is especially true for delta
shaped wings (as your F16, Anker). To cope with this drag on jets,
you have to put in some power. The full size European SST, Concorde,
has a throttle setting of 2/3 during landing approach (probably not
too far from cruise setting)!
Try to practice landings and landing approaches consciously. See the
landing as the most important pattern you want to learn, not the 'bad
thing at the end of every flight'. Study the behaviour of your plane
in safe heights (glide angle at lowest speed, higher speeds, height
loss during curves etc.). This makes you confident that you are still
in full control when the earth is closer and you can determine in
which height you can still curve or better land straight and walk a
bit longer. Good luck!
Regards,
Hartmut
|
82.47 | landing technique | UPWARD::CASEYA | THE DESERT RAT (I-RC-AV8) | Wed Apr 25 1990 19:26 | 39 |
| Ajai,
Tom's idea to use a liece of fuel-tubing to extend the vent to the top
of the tank also sounds good if yer' having trouble getting the
bent-brass tube to cooperate. Just remember to notch the sides of the
fuel tubing with a razor blade/knife or equivalent the same as
described for the brass and it should provide the identical function
and safeguards.
Several times now you've mentioned "holding the nose up" during yer'
landing approaches and I have to comment that, if that's _really_
what'cher doin', yer' forming a BAD habit. You should never try to
hold the nose up with elevator in low/no power situations 'til the
plane is at "flatten and flare altitude!" Doing so is simply BEGGING
for a stall/snap/spin/crash episode and, while yer' trainer might be
letting you get away with it, less docile/forgiving/friendly sport
types may NOT!! Try to get into the habit of letting the aircraft
glide to touchdown with the nose slightly down, only raising the nose
with elevator the last coupla' feet as you flatten the glide and,
finally, flare to touchdown. This is how the higher performance types
will DEMAND to be handled so you might as well be learning that way
right now as opposed to developing a habit that's almost guaranteed to
get you into deep-sneakers very shortly down the road.
Thanx fer' the well wishes this weekend. I really want to do well and
bring some "braggin' rights" back to the notesfile and will do my best
to make that happen. I don't believe a win is possible, taking into
account the _considerable_ competition, especially in the hardware
department. Heck-a-mighty, some of these guys have 3-times the $$$ in
their landing gear as I have in my entire airplane. However, the ol'
MiG continues to fare respectably in competition and a good strong
finish in the top-10 (or even 5) is certainly within the realm of
possibility. I'll give 'er muh' best shot, amigo.
__
| | / |\
\|/ |______|__(o/--/ | \
| | 00 <| ~~~ ____ 04 ---- | --------------------
|_|_| (O>o |\)____/___|\_____|_/ Adios amigos, Al
| \__(O_\_ | |___/ o (The Desert Rat)
|
82.48 | familiarity and practice | DPDMAI::GOLDSTEIN | | Fri Sep 07 1990 19:00 | 18 |
| ref. previous notes on high angle of attack landings.
As most of you probably know, a symetrical airfoil will allow
a nose high approach, using power to control the rate of descent.
This is your typical carrier approach. However, with an R/C aircraft,
a constant angle of attack approach is problematical . Keeping track
of how much elevator that you are applying will give a good indicator
of the amount of lift that is left in your wing. From there its all
power controlled descent to touchdown. Knowing the low speed handling
characteristics of your ship (established with experimentation at
higher altitudes) is essential. Stalling and crashing on landing is
more often the result of insufficient familiarity and a lack of
practice. Landing is one of the prettiest manuevers that an aircraft
executes. Practice makes them better.
David
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82.49 | First question - ABCs of side-slipping are...?? | HPSRAD::AJAI | | Wed Oct 17 1990 14:20 | 13 |
| OK, jeopardy contestants, here is the first question.
How do you do a sideslip? Can all planes do it to differing degrees? I
know the basic technique is to apply opposite ailerons and rudder, and
you modulate one or the other control to maintain aircraft attitude. I
would like to hear how you do it wrt wind, and where you should be in
your pattern so you can then do a landing.
I want to do those 45 to 90 degrees to the field side-slips, hedge-hop,
then land.
ajai
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82.50 | | SNAX::SMITH | I FEEL THE NEED | Wed Oct 17 1990 15:05 | 20 |
| Ajai,
When you master those 90 degree to the field side slips, please
let me know so I can video the feat. 8^)
Basically, you've got it down. Opposite rudder and aileron. You
just want to make sure you do it so that your "up wind" wing is the one
you drop. Picture yourself sitting in the cockpit. You have a right
to left cross wind. You'll want to feed in left rudder and right
aileron to keep the right wing down into the wind. You don't want
to raise the right wing and let the wind get under it.
The side slip is done on final approach. When depends on how high you
are. In your case, I'd start about 2 miles out. 8^) Actually, in a
typical CMRCM approach you could start it just past the dirt road on a
left to right approach. The idea being that you should be just short
of the runway apron when you abort the slip and straighten everything
out.
Steve
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82.51 | | WRASSE::FRIEDRICHS | Kamikaze Eindecker pilot | Wed Oct 17 1990 15:34 | 13 |
| Slipping is one of the few basic maneuvers that I have found to be
MUCH easier in a full scale plane than a model... In a 1:1 plane,
you can get a much better feel for the slip, and the amount of
each control to hold... In addition, you are using your feet on
the rudders rather than telling both hands to do opposite things.
My opinion is that slips with R/C models is one of the most
difficult maneuvers to learn. Being close to the ground, there is
little room for mistakes...
cheers,
jeff
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82.52 | How do you decide what to modulate? Rudder or Aileron? | HPSRAD::AJAI | | Wed Oct 17 1990 15:50 | 25 |
| >> When you master those 90 degree to the field side slips, please
>> let me know so I can video the feat. 8^)
You!!
That referred to fuselage position/attitude, not flight path (which could be
more like 45 degrees).
>> The side slip is done on final approach. When depends on how high you
>> are. In your case, I'd start about 2 miles out. 8^)
Aw C'mon. You haven't seen my 20 feet high t&g patterns on those evenings
I decide to do 50 or a 100 t&g's! Shake off those knees-knocking-beginner
flapping attempts you have pictured in your head, will ya? :-)
Re -.1, I have to agree somewhat, since my own experience being a full
scale glider pilot bear out your comments, Jeff. However, I have seen Tom
Kosowski [sp?] slip in and out with his Piper Cub (1/3 scale though?),
that makes me feel real envious. Maybe it is big enough.
My FS seems to "dive" on its side. Not too impressive. And the feeble side
slips don't make me drool
ajai
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82.53 | slip, slip, slipping, slipped... oops ! | GALVIA::ECULLEN | It will never fly, Wright ! | Fri Oct 26 1990 11:43 | 17 |
| >each control to hold... In addition, you are using your feet on
>the rudders rather than telling both hands to do opposite things.
Yes that is a difficult thing - coordinating the hands - reminds me
of those early days coordinating the ailerons when the plane was coming
towards you and then away - but it then just sinks in and you forget
about it. Can't really say taht of slipping yet though. I think as Ajai
say there in .-1 that its easier with a larger model. But I keep
trying !
>My opinion is that slips with R/C models is one of the most
>difficult maneuvers to learn. Being close to the ground, there is
>little room for mistakes...
Simply Yes !
Eric.
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82.54 | Which Way to Slip | LEDS::WATT | | Fri Oct 26 1990 13:26 | 7 |
| Steve,
Wouldn't you want to apply Right Rudder in a left to right cross
wind? You want to yaw the nose into the wind when side slipping in for
a landing unless I'm missing something here.
Confused
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82.55 | Which way to slip......UP | SNAX::SMITH | I FEEL THE NEED | Fri Oct 26 1990 13:44 | 24 |
| Hummmmm.....Now your going to go and make me think!!!!!!! Did I
slip about the slip???? Unless someone else wants to correct me,
I'll stand with what I said before, at least for now. First of all,
unless we both have opposite pictures in our minds, if the wind is
blowing left to right--------------->>>>>>>> and you apply right
rudder --------------->>>>>>> you'd be pointing the nose down wind,
not into the wind. Other than that, the idea behind a side slip is to
maintain a straight in approach while presenting the side of your
aircraft to the forward direction of flight creating all kinds of drag,
thus dropping you out of the sky (in a controlled manner). You counter
the yaw effect with opposite aileron to keep the plane going straight
ahead. The other rule in cross wind landings is to keep the upwind wing
down. So, in the example above (arrows) you are correct that you would
apply right rudder and left aileron, but I think your correct for
different reasons than you might have thought.
Steve
|
82.56 | Slippin Around | LEDS::WATT | | Wed Oct 31 1990 13:33 | 7 |
| Now I agree with you, Steve. You want to point the nose into the wind
and keep the up wind wing low when sideslipping in for a cross wind
landing. You only need the opposite aileron if the plane has lots of
roll coupling with the rudder.
Charlie
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82.57 | Side slip practice at Crow island! | HPSRAD::AJAI | | Fri Nov 02 1990 17:53 | 40 |
| Well, this afternoon at Crow Island was fun. I notched up 4 flights for
a total of 86 minutes of flying time. It was the first time that I was
flying at a new site on my own, and boy, did it feel different! I can
just imagine how hard it must be for those competing around the
country, to learn *that* aspect of flying - i.e. being able to deliver
the piloting skills honed at the home field at a different place!
Dan Snow, Dan Weier, Evil Eric (the organiser), Charlie WAtt, Dave
Walter, Jim Cavanagh, Jim Reith, Jeff Friedrichs, Kay Fisher (did I
miss someone?) were at the field. I'll leave out the details, but
everyone had a good time.
Jim's engine quit, and he had a long haul back. The trees let him go,
and he disappeared into a hollow at the end of the field, which was
filled with water - a fairly decent sized pond. he was lucky to land
_just_ at the shore, about 6" from water!!
Why am I putting all this here - Ah! Yes, I was practising side
slipping most of the time, though having 4+ planes in the air on many
occassions made for some disconcerting moments! The plane seemed to
sideslip better the wrong way - i.e. with the windward side of the wing
up!!
As I got better, I got lower. Upon Kay's query, I checked out the
rate/angle
of decent hands off, vs side slipping - and found them to be the same.
The only difference, as he pointed, is that I didn't build up speed
SSing.
Tomorrow is supposed to hit record breaking temperatures - 75+ - and by
law, Injuns have a right to enjoy Indian Summers by flying their
planes...
:-)
gotta run
ajai
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82.58 | How far are the trees from runway? | CSC32::CSENCSITS | | Sun Nov 04 1990 14:00 | 5 |
| I'm having a hard time picturing how far away from the runway the trees
are. Here in Colorado Springs, it's not the trees as much as the hills
and cattle that make landing difficult.
John
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82.59 | pretend you're a glider | DPDMAI::GUYER | | Fri Mar 15 1991 14:09 | 18 |
| I think .41, Schrader, gave the best technical explaination of the
effect of angle of attack on landing. Real planes have published
speeds for things like best angle of climb, best rate of climb and best
glide speed. All of these things address the angle of attack vs drag
ratio. As he said, increased angle of attack means increased drag.
The elevator and the throttle interact in that they are trying to do
the same thing, that is control lift. The elevator does it through
changes in angle of attack and the throttle does it through speed
(airflow over the wing). A change in one always affects the other.
However, only one of them is 100% reliable, the elevator. I always
make my landings power off (engine at idle, not stopped). It protects
me from an unexpected engine failure and as long as it is running I can
still use it in an emergency if I judged wrong. To get a full scale
license you have to demonstrate simulated dead stick landings and I
always taught my students to maintain as little throttle over the fence
as possible. I do not believe in the "drag it in over the fence approach"
|