ranchpig

Hey all,

Haven't written in a while ... been busy re-building (hehe)

Ok to bring it up to date: Lost a GP's 60 Trainer to tip stall and ended up with kindling.
Bought a new Hobistar 60 and some weird unexplained "hand of God" thing tossed it into the ground and pretty much destroyed the wing, engine, tail feathers, and part of fuselage. Right after take off it rolled left and augered into the ground.

Wellllllll, after many a night and lots of epoxy, lol, i had it ready. Went to the field and i'm not kidding less than 5 mins after unpacking wind started howling. Too windy to even taxi... and this is a big plane. Waited a few days and finally was rewarded with a NO-Breeze day... rare in the rockies. After several test taxis... finally let her rip.

Tracked straight for about 100' and slowly gave her up elevator and within about 3 feet high it started to drop the left wing and 2 feet more it was sideways and then it was over. No repairs this time. Figure i'll strip it and start a fire.

Don't ask me what happened. I've replayed those 5 seconds over and over and I think i have a radio or receiver problem. It was almost an instant replay of the last crash. I thought it was wind last time. There was a heavy cross breeze. It was fairly well balanced and control surfaces were as close as you can get without air trimming. Ground checks were fine and of course it taxied ok? There's no way it could have tipped that fast even giving it full right aileron. Something was amiss and i have no idea. Totally clueless. My best guess is the first crashed jinxed up the receiver or servo or something. But again... i have no way of knowing.

Well... i dare anyone to match that crash record. Three crashes in Three flights (if you can call them that!)

Oh well! My zagi is on its way. HA HA HA
Hopefully i won't be posting that one here!

WCB

Did you balance it laterally? Left wing could have been way heavy. Kinda sounds like it could have been tail heavy from what you describe, but you said you balanced it...so I'm not sure. Sorry about your loss.

jettstarblue

THRee crashes in three flights?! Don't get me started! O.K. since you did; I once had a student that proclaimed himself fit to fly, waaay before he was ready. (Larry if you are out there you know who you are).
He went through at LEAST 5 planes in five flights, THEN HE DECIDED IT WAS THE PLANES, AND BOUGHT AND CRASHED TWO HELI'S!!!!!!!!!
Last I heard he was in bankruptcy court, and undergoing therapy for something or another.

Jetts

antslake

My Feedback: (1)

I have seen two planes crash in this manor, and it was the elevator not being even.
The first plane had a single elevator that was ever so slightly warped, which caused it to roll like that, and the other had a split elevator, one servo on each half, and he didn't have the servos set up right, causing it to roll.

Once your in a roll and starting to climb (and stall) your done.

EagleOne

Sounds like a familiar story to me..........

It happened with me twice (2 "flights" two crashes)....exaclty the same as you described, rolling to the left after takeoff.

After many hours of intense investigation, by hundreds or brain cells
I finally found out what the problem was. I had Z-Bends on the throttle pushrods plus a copper tube joining the wing (the airplane was of my own design....). I found that the most likely cause was interference caused by these components.

I switched the radio equipament (receiver, battery and servos) to another plane to check if my Rx had went bad....And it flew without any problem.....Now I am using the same Rx and servos on my SPA3D and so far I had no problems.........

So, if you have metalic Z-bend at the throttle pushrod, EXCHANGE it!!!!I can't stress that enough!!! Put some nylon clevis and forget about interference or glitches.....Also, remove any kind of metal-metal contact that can vibrate between itself (like nail package for ballast (i used that too and.....), replace them by lead weights), also keep the antenna as far from metal components (pushrods, etc) as possible.

If the problem continues, then i'd say check you Rx or Tx.....

Hope it helps,

clm2206

Hi Ranchpig. Have you checked the rx crystal? it has probably been damaged in the first crash, and since you don´t tell it has been replaced, I suppose you should check it.

ranchpig

Jettstar Blue Wrote: "He went through at LEAST 5 planes in five flights, THEN HE DECIDED IT WAS THE PLANES, AND BOUGHT AND CRASHED TWO HELI'S!!!!!!!!!"

Hey!!!! Larry was my instructor! Now i know why .... lol He said i wasn't doing TOO bad yet.

Good stuff guys... for sure.

I do have Z-bends at servos.... hmmmm. Vibrating crystal. Thought of that. Maybe before i sell that radio/reciever i should spend 10 bucks on a new one. But what IF it's not that. Larry would be Proud.

Elevator isn't warped... at least not enough to have caused that quick a roll. If it is it's imperceptable. In fact all control surfaces were "pretty" straight. As far as heavy wing....I don't think so. It tipped like it had a 1/2 lb on left wing. It was that rapid. It actually rolled faster than the plane could in flight.

We'll see... got a few more planes to try... but Zagi is next one til confidence re-appears.

rc-sport

My Feedback: (12)

Its a plain old simple tip stall, not enough speed on take off.

Droopy

I'm surprised I haven't heard this mentioned. I did this twice in 2 weeks on 2 different planes. A lot of guys think they have radio problems when they really have the ailerons reversed. With mine, I preflighted, and double checked since it was the first flight and STILL got it backwards!! TWICE!! (And I'm a professional pilot... Don't ask...) I managed to save the second one, but it really feels like the plane stopped responding and just rolled into the ground.

Just a thought,

John

Mike Buckley

I was reading the replies waiting to see if anyone said it, but Droopy beat me to it. Sounds like the ailerons were reversed. In all the crashes that have occured at our field only 2 that I can think of were due to radio problems. All the rest... yep you guess it PILOT ERROR! Sorry to be harsh but....

Mike

realdeal

My Feedback: (45)

Third vote for aileron reversal. I've seen it happen to the best. They check that the ailerons wiggle (without checking direction) or get confused about the proper direction then your scenario unfolds pretty much every time. The roll evens looks faster because you are right on the ground.

I saw a guy maiden a giant scale P-51 with ailerons reversed. He's one of the better pilots in the club. Luckily he caught the error with his first movement and was able to climb VERY high while his spotter tried to fix things. It was a new computer radio so they were breaking out the manual all the while the pilot is going all over the place trying to maintain orientation and control. He was doing unintentional rolls, loops, and other indescribable maneuvers. They finally got the servo reversed and he landed to fly again.

FWIW - I always have my spotter confirm my control surface direction before a maiden flight or after major modifications to a plane. I check it myself silently then I move the surface and have him tell me which way it moved. So far so good.


The only other time I've seen that type of crash is with a high performance plane that didn't have enough airspeed to takeoff. I can't imagine a trainer plane would have a wicked tip stall. I especially can't imagine two different ones behaving the same way. All the trainers I've seen and flown will maintain a wings level attitude during a stall unless you have the CG way off.

jettstarblue

Caught in the rotor wake of an earlier heavy iron take-off?
Jetts

Combat Addict

If you have your alierons reversed, I don't think you had a very good preflight check.
Before I take off I
1 Check the battery
2 Put in fuel
3 Move to starting line
4 Check all the control surfaces everytime. Especially the first time.
5 Start the engine
6 Run the engine up and down once with the glow deal, and once with out. I do this to get any bubbles out of the tubing.
7 Rock and Roll

Check these things before you take off.

EagleOne

Actually Ii haven't thought about the aileron reversal problem..........that's quite suggesting since, on my case, I was using flaperons and from analysing the crash video, I noticed the right aileron was drooped right after the takeoff. when I gave command to recover from the roll, it only worsened. It was on the first time.
On the second time, after I recovered from the roll, it rolled to the side opposite of what I wanted..........

Now I am not so sure if it was radio interference or dumb pilot error

Next time I fly it (after the rebuilding) I will check that. BTW thanks...

Windwalker

My Feedback: (2)

Nobody's mentioned it but the wing could have been warped-even right from the factory with one side washed in and one washed out. Seen several guys crash planes that the wing was spared only to find that it was so twisted it never should have gotten off the ground in the first place! Sorry about your plane KK, but I have to ask....What are you tryin' to do--beat my record?[sm=lol.gif]

DeepStall

TBH i think that wing warping wouldnt cause such a fast roll as discribed. I have taken off twice with my ailarons reversed.. and got away with it.. Call it lightning reactions. But i i know i wont be as lucky next time so i always double check it. Thank god for puter radios just work your way through s few menues and reverse it :P

Spaceclam

on a trainer, the only balance that really makes a difference is the cg. on my pt-40, my right wing was about 2 oz heavy and it didn't require trimming. i fixed it and it still didn't require trimming. did you stand behind the plane and move the surfaces to make sure they were opperating corectly? i made a mistake similar to that one where i accidentally (god knows how) put elevon mixing on my trainer and barely managed to get it back using only rudder. the flight lasted about 5 seconds. it would have gone in if i hadn't tried my rudder.

rayzer 13

servo reverseed bummer, forget to tighten the wing bolts down bummer, warped wing bummer, forget to test raidio 50 feet with antania down engine at full reves bummer, how about this think well I've got a cool computer radio lets just dial it in during flight. dumb