After 2 great flight and like 20 touch and go's with some crosswinds (No Gusts ) on the third fligt I decided to try something different: Nose towards the wind of about 7 mph 3/4 of throttle I tried a half a loop and at the top continue inverted and try some inverted flight. When I got to the top then tried to pull of the loop it came inverted and tried to keep it that way but the plane went crazy! It suddenlty flipped arround and nosed straight down to mother earth spinning rapidly. I tried to controll the spin with ailerons and up elevator to pull out of the dive but nothing! It would not respond at all until it made a big bang.

It broke in a million pieces and had to pull the engine out of the dirt. I had a hangar 9 Arrow with semi-sym wing, a TT .46 and a 10X6 prop.

1- Was it a Tx-Rx failure? Should I send the receiver back for checking?
2- Did it stall? What did I do Wrong and how to prevent it?
3- Although I checked with other pilots, could it be someone turning on a radio on the same frequency?

Please advise!

Oh! BTW does anyone have a spare trainer? LOL Thanks!s

Could you have over-controlled it? Or was it just not responding? Battery may have come loose.

With a crash, that hard, definitely return the receiver to service. You will also want to check out all your servos to make sure they weren't damaged as well. Check the voltage on your battery, if it is still in tact. I would recommen you throw the switch out and buy a new one. They are inexpensive, but often do cause problems.

I had a crash similar to yours, the problem turned out to be a loose crytal. It was a UCD .60. After that, I started taping my crystals in with magic tape. I also use heavy duty after market switches with the external charge jack. These have heavier wiring. Also I heat shrink the battery and servo extensions, connections, so they can't come loose either.

Now for some questions.

1. Did you pull the throttle back and if so, did it respond?
2. Did you feel the airplane was responding to any of your commands?
3. Was there enough left to see if the battery, receiver, switch and any servos would work at all?

Many times it is impossible to tell what caused the problem.

Hope you had enough left to get a new ARF or Kit going soon. Got to get back in the saddle as soon as possible. Also, Flat bottom trainers with dihedral usually don't fly very well inverted, so you may want to go to a little more aerobatic trainer for your second airplane.

(PS. Mike East has some great questions and logical statistics after this, you may want to consider also.)

Good luck. Let us know how you make out with the salvage operation.

Mike Boyd
AMA 7197

sounds like it went into an inverted flat spin to me. and full ailerons and elevator would make it spin harder but there are just too many variables to say for sure, to get out of a spin you chop the throttle and let go and I can usually stop it buy touching opposite rudder. I could be anything from the battery went dead to receiver to bad servo to bad switch.

To get out of a spin, do all the things your mind is screaming at you to NOT do:

1. Neutralize all controls.
2. Apply full throttle to gain flying speed.
3. Gently apply elevator to pull out.
4. Lower throttle to cruising speed.

Sounds like it might have snap-stalled and spun. For the radio to fail at just that precise moment in time is a little far-fetched, IMO. You could have gotten crossed up on the controls while inverted, too.

Dr.1

My guess that the loose crystal sound most likely. I have seen this at least twice lately. I put a rubber band around the crystal once it is set in the receiver.

Hud

A loose crystal? I've never heard of this epidemic, but I'll have to keep this in mind in the future.

The chances of stalling an Arrow to that extent are almost non existant. As soon as the nose drops and it gains any airpseed whatsoever its going to be flying again. Flying inverted isnt any more stressful than flying upright on the electronics.

Just guessing here but respectfully, my money would be on...
1. Panic set in, you got confused and you and overcontrolled it into the ground. 75%
2. Your receiver battery voltage was low. 10%
3. You had some sort of mechanical failure 10%
3. You had some frequency interference. 5%

Some questions.
Exactly what was the last control input you gave just before it went nuts?
Was it twitchy. Jerky little pulses??
Where was the throttle on the way in? What was the throttle doing, where was it set?
HOW did it go in? Were you trying to save it? Could you see that your inputs were effecting the plane in any way, good or bad??

.1- last control imput was to try to level wings at inverted with the ailerons because it came out of the halve loop with one wing digging, can't remember which.

2- The trottle was at 75% and to be honest I did not touch it in the way down. I at that time was panicking. Lack of experience I guess.

3- No twichwes or pulses that I could notice.

4- Right after the wing doug in the nose was pointing straight to mother earth and then it started to spin, I tried to control the spin with aileron imput contrary to the spin and gave it up elevator, did not touch the throttle. Non of these imputs seamed to affect the attitude of the plane at all

What kind of airspeed did you have at the top of this half loop? Slower or faster than your normal successfull landing speed? Remember the flat botom wing with dihedral is designed to fly slow but when you go inverted you now have a flat top wing and reverse dihedral requiring more air speed to maintain stability. How many rotations (about) did the plane make before striking terra firma and did the rotations accelerate or slow as you lost altitude? From what altitude (about) did this, what I think we all suspect, stall occure? As DR1 driver mentioned neutral stick inputs untill the plane regains airspeed is the trick here but requires some altitude and personal calm.

When I tried to pull out of the halve loop it did not look to be going to fast. Better said kind of slow but remember that this model is not flat bottom wing, it is semi and the dihedral is minimum.

After I am done with landing practice would you recomend to go with a bigger prop? Remember I was flying with a TT .46 and a 10X6 prop to better slow it down . Maby a 11X6 would be better for attempting some tricks? Is it correct to assume that a bigger diameter and lower pitch prop gives the model better climbing capabilities?

Try not to overanalyze a crash. Everyone, I mean everyone, crashes sooner or later. You either over controlled the airplane or you battery failed for one reason or another. Get your receiver checked out, buy a new battery; do not use the old one, get a new plane and jump back into the sky as soon as possible.
You are losing sleep over something that is eventually going to happen again.
Regards,
doubledee

The first thing that I do when I get myself into a situation like this is to CHOP THE POWER. Just an idea that has save many of my airplanes from mother earth.

the dropping olf the wing at the top of the loop is a sign of a stall,semi symetrical wings produce less lift inverted.then it sound like you got into a flat spin which is difficult to recover from insome designs especially if the cg is bit too far aft.flat spin usually has the nose just a tad low not pointing straight down.to recover you need full throtle full down elevater netral airlerons and rudder till the nose drops speed picks up and it goes into a normal spin then recover from that.remember the flat spin from top gun.no control at all till airspeed is regained..definetly send the radio back for repair and what the find.

You have described just what happened! The only thing is that although the nose was not pointing straight down it was more down that flat!.

Oh and let me please ask what does cg is bit too far aft . mean?

Now, How shoud that manuver be performed correctly? I will be getting another arrow (I dont like flat bottom trainers precisely because I think I can do more with the semy).

In the instructions for your airplane there should be a CG range, forward CG will fly ok, CG in the center will fly the best, Aft CG is a for the more experienced pilot as the airplane is not as easy to control. Remember that too far aft CG usually means that the airplane only fly's once

Ok so AFT means............... nose or tail heavy? The plane was just about neutral.

an aft balance point is a slight tail heavy plane.unable to recover from a spin is a sign as well as a touchy elevater control.

two way to fly inverted one is like you tried ,a half loop,just do it at full throtle and then throtle back once you are at the top,other way is just to do a half roll.even a flat bottom airfoil will fly inverted.i used to fly my s ray inverted it would even climp a bit but took full power on the veco 19 and nearly full down[up ]

You need to remember that a stall does not depend on any one set of conditions but rather on a set of conditions and can occur at nearly any speed or flight attitude. I have been in a full scale Pitts aircraft at 4000 ft aimed straight down at over 100 mph with the stall warning blaring at me. This can be un-nerving the first time.

UN-NERVING? that is the best way to describe the filling! combined with impotency. It was sad to loose my flight mate and throwing it in a trash bin. I need to learn to avoid these situations and to recover in the event of another emergency.

sounds like radio or something broke, rubberbands on the wing
I had an arrow there semi-symmetrical and don't that much dihedral
they fly great inverted not likely you'll get a arrow to spin without really trying

That was my first thought, it seamed to me to be completely unresponsive to any input. At first I suspected some sort of radio interference but could not find any suspects in the same freq. The other day I had some interference when someone was flying a big jet. The day of the accident there was jet activity as well. I don't know if those radios could have overwhelmed my signal.

How high where you when you did the loop ?
If you had the recommended flight control throws there no way you overcontroled it
I had throws as high I could get them and never had a lick of trouble
the arrow is as easy as they get to fly and do some nice stunt flying too
pretty hard to crash because of a stall unless your on the deck
let me ask the dumb questions batteries charged ?
not too many flights for the 600mah rx pack etc /?
I don't think I'd fly more the 4 times on the 600 pack?

When I came out of the halve loop I was like 3 mistakes high.
The battery pack was charged for 14 hours the night before and it is a 1100 and it was the third flight of the day and I checked the pack and it is still 5.3 V. I am going to send the receiver and the switch back to JR to have it checked.

I still do not know if I will be buying another Arrow or just move on to a [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGTS5&P=7]Sea Bee[/link] that I had reserved for more advanced flying. I will try it next time out with the instructor by my side and see how it feels. If I am not ready though I will be getting another arrow.