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Conference vmszoo::rc

Title:Welcome To The Radio Control Conference
Notice:dir's in 11, who's who in 4, sales in 6, auctions 19
Moderator:VMSSG::FRIEDRICHS
Created:Tue Jan 13 1987
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1706
Total number of notes:27193

1639.0. "Lunchtime Excitement" by WMOIS::WEIER (Keep those wings spinning!) Thu Nov 17 1994 10:32

             
    Didn't know whether to write this in the "Interference" note, or a
    "Lunchtime" note. I elected to start a "Lunchtime" note.
    
      On Tuesday, I decided to take advantage of the nice weather to get a 
   couple lunchtime flights in on the X-cell. 
      I headed up to Merrimack and spent the first few minutes doing
    minor adjustments to the pitch curve and high end needle. The end
    result was I was really getting close to having the engine running
    great.
      I did some hovering and then took it upstairs. The forward flight
    and climb were faster and better than ever. I spent the next minute or
    two doing several stall turns, immelmans, and split ez's ( The
    immelmans and split ez's were a first for me with this chopper, as I
    previously wasn't getting enough power from the engine.
      At this point I was about to switch to idle-up, check out the pitch
    curve, and then try a couple loops, when with no warning I lost
    complete control of the chopper.
      I was directly across from the pits, out over the first row of trees
    when it happened. It happened so fast, that without videotape, its
    tough to re-construct the events, but here is my recollection.
      I "seemed" to get some intermittent control back for a second or two,
    but the control was not enough to avoid the trees and/or make a
    landing. The chopper went down through the trees, ripping off the tail
    boom and the blades. The tail boom and blades ended up landing on the
    ground. The main part of the chopper was worse, it ended up crashing
    into the creek about a foot from shore. By the time I recovered it, the
    electronics, engine, etc were full of water. The ONLY thing I was
    grateful for is that it didn't get stuck in a tree!
    
       Needless to say, this one got me PISSED! Its one thing loosing
    something due to pilot error, but unexplained failures are even more
    irritating AND scary!.
    
       I luckily was able to go home for an hour, where I removed the
    engine, reciever, gyro, and servos, and dried them out ( and oiled up 
    the engine and all the bearings on the heli real good.)
    
       It is hard to tell what caused the failure, but if I had to guess
    the probabilities, they go like this:
    
            90 percent - radio interference
             9 percent - mechanical failure
             1 percent - catastrophic bearing failure somewhere on the
                         chopper which caused "metal - metal" interferance.
    
       I am expecially concerned there may be a radio problem due to the
    two planes getting "shot down" on Saturday. I was on channel 41, they
    were on 51 and 54. This was a JR 10S PCM reciever driven by a 388, so
    I should have been almost "Hit proof".    
    
       This crash was also disturbing because it mimicked the SHuttle crash
    I had last October at the same field. Similarities include:
    
             Both flights on a weekday
             Both at Merrimack
             Both problems appeared out of nowhere and caused total loss
             of control (Shuttle, CHannel 45, and the X-cell channel 41)
             (I changes frequencies after the Shuttle crash)
             Both choppers crashed into the same creek
             Both had extensive damage. 
       
    
       I have taken inventory of the broken "bits", and have started the
    long painful process of rebuilding this chopper again for the second
    time in 3 months. I have already spent $100 on parts, and have another
    $150 - $200 on order. My plan is to take it slow, make sure EVERTHING
    is right, and just get it ready for next spring. Unfortunatly, this
    will slow down me getting the Gremlin, Unic, and LA-1 completed.
    
         Damage:
    
             Main rotor blades
             blade yoke
             blade axle
             main shaft
             CF tail boom
             CF drive shaft
             CF Tailrotor pushrod
             Skids
             Head Button
             Windshield ( suprisingly, the fiberglass canopy survived )
             fly bar
             fly bar doublers
             fuel tank
             Lower left CF main frame
             assorted linkages and bits
    
    
    
         The good news is the engine, reciever, servos, gyro, battery,
    switch, 90% of the mainframe, canopy, and the complete tail unit survived. 
    The gyro kept running,despite being submerged in water again. The reciever
    and servos allworked after drying them out, but I will probably send the 
    reciever to JR and have it checked out.
      
         To add insult to injury, when I tried posting a note on Tuesday 
    afternoon, the system crapped out, so I lost that too!
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1639.1Tough situation and tougher lossSNAX::SMITHI FEEL THE NEEDThu Nov 17 1994 10:4513
    Well, I hope there are no more Gremlin Combat contest at the
    Merrimack field. If so, I won't be there. I'm on ch. 54.
    
    This "interference" seems to be pretty wide spread. I would DEFINATELY
    get a scanner down there and find out what it is. Unfortunately, these
    pager companies can be WAY off frequency and STILL be within FCC 
    guidlines. Even if they were way over power limits, if there that
    close, it doesn't matter. They're normal power will wipe everyone out.
    
    I'd still want to find out the source of the interference though. If
    it is a pager company, it's possible they're doing something SO illegal
    like operating on unassigned channels, that you might be able to get
    some satisfaction.
1639.2OUCH!! I can feel the pain.MKOTS3::MARRONEThu Nov 17 1994 12:4221
    Dan, I'm REAL sorry to hear about the chopper crash.  Darn (this is
    more politically correct than the word I'm thinking of), just when
    you had it all fixed up and ready to wring out, this has to happen.
    
    In your analysis of the two Merrimack hits, what time of day was it?  I
    think we need to keep very precise records from now on to help find out
    any trends to these hits.  Funny, when there was all that construction
    going on near the field a few years ago, I don't remember any
    significant increase in interference due to all the machinery and
    probable pagers/cellular phones in use at the time.
    
    If the theory about a pager company blasting across our channels is
    correct, then we have to get on this quick to avoid any further
    disasters.
    
    I just called Al Ryder about getting the district scanner again for a
    look see.
    
    News at 11.
    
    -Joe
1639.3Days/TimesWMOIS::WEIERKeep those wings spinning!Thu Nov 17 1994 12:5815
    
      Joe,
    
        The hit last year was on a Monday at about 4:00 pm. This hit was
    on a Tuesday about 12:30.
                                                                     
        What I am speculating is that something is happening ( ie; pager
    activity) during normal business hours that may be the culprit, because
    up to the 2 hits on Saturday, I haven't had a problem in the evenings,
    or on weekends, and Al Ryder's tests came up clean ( he did them in the
    evening).
        The troubls is, the Saturday interference puts a hole in that theory
    (unless the activity is spreading across the weekends too). It may be
    its been there for awhile, but is random enough that we just happened
    to avoid it ( for the most part).
1639.4Status reportMKOTS3::MARRONEFri Nov 18 1994 12:2320
    Al Ryder is speculating that we are getting hit by RC equipment being
    operated by renegades flying close to Merrimack, ie, just across the
    river in Derry.  He also believes that a spectrum scan done on the
    ground level may never see interference up above the tree line where we
    fly.  Another grim possibility is that some kid is operating an RC car
    with some outdated, very wide band equipment in the aircraft band.  
    
    Al said he once tried to get information out of the FCC about all the 
    frequencies being used for broadcasting in NH, and was told the only
    way to get this info was to go to 
    Washington DC and make copies of their microfiche files if he was 
    interested.  A real attitude!!  There might also be a way to go down to
    Boston to do the same thing.  
    
    Al said he would order the scanner today.
    
    Finding the culprit(s) whether accidental or otherwise, will be a
    daunting task.
    
    -Joe
1639.5maybe but...GAAS::FISHERBXB2-2/G08 DTN 293-5695Fri Nov 18 1994 13:1829
>                     <<< Note 1639.4 by MKOTS3::MARRONE >>>
>                               -< Status report >-
>
>    Al Ryder is speculating that we are getting hit by RC equipment being
>    operated by renegades flying close to Merrimack, ie, just across the
>    river in Derry.  He also believes that a spectrum scan done on the

I suspect Al is wrong in this case.

I say this because our RC transmitters output very little power.
750 milliwatts is the legal max.

I know the AMA wants fields 3 miles apart or something like that
but the reality is you can't shoot someone down if the plane
is closer to him than you.  Even with antenna orientation bad
and everything else - you still can't capture another set unless
you are significantly close.  If a fellow had some really old set
that was very very very wide band - he would be wasting power
in the sidebands and without the nice high peak he would have
to be even closer to re-capture your receivers attention.

But I could be wrong and am anxious to hear the final answer
when you finally find it.

Bye          --+--
Kay R. Fisher  |
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1639.6Dave W, yout duck has been outdone! :)WMOIS::WEIERKeep those wings spinning!Fri Dec 09 1994 14:4719
    
    
       Went down to RC Buyers at lunch to pick up a few things. While I was
    there, Bob B. asked me if I heard about (John Doe) in the club who
    is building a Chipmonk.
    
       Seems he was driving home the other night, and spotted a dead
    Chipmonk on the side of the road and.......... you guessed it!
    
       He put the critter in a bag, brought it home, put it in the
    freezer (boy was his wife suprised when she came home! :), the next day
    he took it to his buddy the Taxidermist, had it stuffed, and then
    installed it in the cockpit of the Chipmonk. He even has a servo rigged
    so the head turns from side to side!
    
       You meet the most creative ( and sick :) people in this hobby!
    
                                       
                                 
1639.7Did he dress up the chipmonk like Rocky?NETCAD::WALTERMon Dec 12 1994 11:216
    Well, I guess it's a good thing he isn't building an A-10 Warthog!
    
    Not to be outdone, I will be gunning for ducks during my commute from
    now on. The problem is that the darned things spend most of THEIR 
    commuting time at 10,000 feet!
                                                                     
1639.8Get your cartoons straight! :)WMOIS::WEIERKeep those wings spinning!Mon Dec 12 1994 12:029
    
     Rocky was a flying SQUIRREL, not a Chipmonk! Alvin, Simon, and
    Theodore are the Chipmonks! get your cartoons straight will you! Anyone
    who drives a station wagon MUST have kids, so therefore you MUST
    watch cartoons on a regular basis! :) :) (Couldn't resist :)
    
     I quess its also good he wasn't building an F-14 "Tomcat", or an
    F-15 "Eagle" ( He could really get in trouble there!:). An F-18 "Hornet 
    would have been an easy one though ( If it was already dead :)
1639.9Quack, quackNETCAD::WALTERTue Dec 13 1994 17:229
    Aw, f'God's sake, what difference does it make? Squirrel or chipmonk,
    it's still just a miserable rodent! So put the leather helmut and
    goggles on the stuffed vermin and we'll just SAY that it's Rocky!
    Y'know, to please you and the kids who wander through the pits.
    
    Me, I'd rather have a duck in the cockpit ANY day.
    
    Quack
    
1639.10Merry X-masWMOIS::WEIERKeep those wings spinning!Thu Dec 22 1994 09:275
    
    
         May all of you and your families have a happy and safe holiday
    
                                                                Dan
1639.11RANGER::REITHThu Dec 22 1994 09:528
Shouldn't this be under weekend excitement? 8^)

A Merry and safe holiday season to all!

Jim

As the sleigh slowly disappeared towards the horizon, a voice was heard to
say... "I ain't got it!"
1639.12A great yearSNAX::SMITHI FEEL THE NEEDThu Dec 22 1994 09:577
    New milestones were reached. New planes purchased and flown. Good times
    with good friends.
    
    A very merry Christmas and happy New Year to all.
    
    
    Steve
1639.13Took a deep breath and......WMOIS::WEIERKeep those wings spinning!Thu Feb 02 1995 15:3913
    
    
        Well today at lunch, I decided to take another risk, and sent off
    another reciever to JRSA to have the frequency changed from 41 to 31.
    ( I guess I just like to live on the edge! :)
    
        I am only sending a single item this time instead of 4, hopefully
    they can keep track of it?
    
        With any luck, I should recieve a brand new 10S transmitter in
    about 3 months! :)                                        
        
                                                           Dan