flat spin problems, what is causing this death spin.
 

Ill check in to every thing, take pics, make drawing ect and get back to ya. Flypaper, a old hacker, I never consider anyplane that can fly an old hacker:D,lol, I do have one, but I think it would never cras no matter what.lol. very ugly, ground wouldnt let it hit.

flat spin problems, what is causing this death spin.
 

Dago:

Your old hacker that the ground would not allow to touch wouldn't be an "UGLY" stick, would it? Haw.

Reminds me of helicopters, don't really fly, the ground rejects them. Double haw.

Folks, I really don't think stall/spin. He had left aileron in, and full throttle. Would combine to a left spin, not right.

After a really bad crash, hold plane in hands, and mash.

Bill.

flat spin problems, what is causing this death spin.
 

well, I guess you can call a Lt-40 a ugly stick,lol.
its is ugly and a half and weights a ton. the flying brick is its name, and every one askes, what ever happen to the brick.
So do you have a Idea about what is causing these little over and arounds this plane is having?lol

flat spin problems, what is causing this death spin.
 

Since I've got several thousand hours in AgWagons and Agtrucks, let me clue you in on a couple of things. #1, the FS Cessnas will fly just fine without a tailcone (also less tailwheel and 1/2 of vertical stabalizer) I ripped both off on a damn fence I didn't see. #2, those original wing tips were put on to help the convert wingtip vortices to lift, instead of washing off the end of the wing. The original AgWagons did not have these and still flew fine.

The one thing you can't do with a model is load it up with 300 gal of water or fertilizer and really see what dogs these crop dusters are with a full load.

By the way, I drove two of these and an AgCat into the ground and walked away without a scratch.

flat spin problems, what is causing this death spin.
 

Well, I got all my advice from a ex crop duster as well, but some of use know that he dosnt always know,lol.

The one thing you can't do with a model is load it up with 300 gal of water or fertilizer and really see what dogs these crop dusters are with a full load. --what do you mean by this?

flat spin problems, what is causing this death spin.
 

Ag planes are designed to carry heavy loads, as a matter of fact, it's almost impossible to do any weight and balance on them.
When you take off with a load, depending on outside temp and alt., etc., you flying just above stall 'till you get some load off. The FS agplanes also have a very high angle of incedence, so that when your flying 5 feet over a crop, your fusilage is actually pointing down for visibility, while the wing is more or less horizontal. Remember, I'm not an aeronautical engineer, I just "Kick the tire and light the fire"

flat spin problems, what is causing this death spin.
 

Dago:

Not being an aero engineer, merely a driver, I bow to the superior knowledge of Bruce M. and PoisonPaper.

But I'm still inclined toward a radio problem.

Find nothing else, blame the radio gear.
. Still hurts, but not like a kick in the rear.

Bill.

flat spin problems, what is causing this death spin.
 

thanks for the info, but one thing, you say its almost impossible to balance a ag plane. with the loads and all, but as a moddle, it dosnt dunp a load , only the fuel from the tank I use, so wouldnt this make it a differ matter, of would the fuel tank kinda be lick the hopper in a ag plane, only not dumped as fast. ive seen the agplanes fly around my school, it seems they only are in the air at least 15 mins max, so that seems that my R/C agwagon would also kinda be scale in that matter.

Crash
 

Man, make a post, walk away for a couple hours and the thread explodes.

No radio problems here, might be now due to crash damage but not before. Low to moderate speed, right after takeoff, dials in the ailerons, and poof, aircraft snaps to opposite direction, classic accelerated stall. Coulda, mighta saved it with rudder but you have to be really quick and know to go for it. The tip situation probably didn't help and while I mentioned adverse yaw, its probably no biggie (but didn't help either), and is just one more on the heap. Actually, on a flat bottom airfoil on a power plane, it can be quite bad, particularly on planes like the Carl Goldberg Eagles. The Cg situation was the major factor here, unfortunately, its one we can't really explore anymore.

Comparing real AgWagon to model AgWagon characteristics isn't necessarialy valid but is fun for shooting the breeze.

flat spin problems, what is causing this death spin.
 

Im not sure about this, but i do have rudder mixing in with it, wouldnt that be a helping factor, or a accident waiting to happen.
I notice, you say dual rates, which I do fly this plane at 100% because its never affected me till now, so lets say we add dual rates to the picture, now lets explore more, and I really wonder how close the model agwagon is to the real agwagon.

Ive noticed my agwagons tail goes back and forth in flight, mainly due to the amount of dihedral, its tryign to find the right spot, so it wiggles, Ive heard the real agwagon has the same deal going on. its kinda neat I think

flat spin problems, what is causing this death spin.
 

I don't know about PP's background but I'm making this up and learning as I go. The aerodynamics of what makes our toys fly has always fascinated me so I've tried to learn as much as I could. This forum has provided a light year jump ahead thanks to the sticky problems and sharing thoughts with some of the minds around here. If I'm ahead of some of you then it's only because I cheated and jumped the start.... :D

But I totally agree that the radio is suspect until proven innocent. If I had seen the model fly I may have a different opinion but since we are doing this over the net nothing is obvious or can be dismissed regardless of what we think. And then there's the chance that we are fighting two problems here. The model may indeed have a stall/snap problem that's just brought on by the radio glitching thanks to an intermittent problem.

Thud Driver. If the model was prone to this problem and he bank and added a little elevator and it glitched to full up in response that would certainly trigger a very nasty snap thanks to the trim I suspect. Or it may have been just plain ol' nasty like that damn Piper Cub from Hell was to me.

But then I don't like the sound of that tail end sorta wandering around. Sounds like it was responding to something other than dihedral. DR, dihedral doesn't make a model do that sort of stuff. But a hunting tail speaks to me of Dutch Roll and very nasty snap possibilities related to that. Dutch Roll is a sign of too little vertical tail area coupled with short moments and too much dihedral. Dutch Roll can also be aggravated into the sort of nonsense that your model is being accused of. AND..... <drum roll-cymbal crash> Dutch Roll is also aggravated by a nose heavy condition in the free flight models where I'm used to seeing it.

I think I'm starting to see a pattern here..... and it's not plaid.... :D

As Thud Driver said it's probably not any of the individual item by itself but add 'em all together and you have a busted model.

Stall
 

Pretty much everybody I've seen who has experienced this type of incident complains of radio failure. Doh, in a stall/snap/spin like this, you're out of control and the radio naturally appears to be the culprit. Normal tendency is to add more opposite aileron and more back stick which only makes it worse (followed by a call of "I don't have it!"). Given sufficient altitude and anti-spin inputs, you'd be able to recover and we'd be back to the same situation that started this thread. That's an awfully coincidental glitch for an airplane that has had a history of snap/spin with normal elevator inputs.

flat spin problems, what is causing this death spin.
 

Bruce:

Tha pattern isn't plaid? I was hoping for a clan tartan, giving an excuse to increase the Scotch in my blood. One drink at a time.

Dutch roll goes right back to my suggestion, lo these many posts ago, about increasing the empennage area.

I too have tried to learn more about these nasty machines, I used to catch a ration from my CO about bugging the line crew, he said an O-2 had no business trying to be an E-5. But I had a D**n good ground crew, we got along very well.

What leads me even further toward a radio problem is Dago saying it flew well at first, and progressively got worse. (Pardon the unintended rhyme) I really don't think he would have soaked up enough fuel to alter the wt/balance that badly. And the radio never cures itself.

Comment?

The plane tends to Dutch roll, almost as bad as hitting a pole.

Bill.

flat spin problems, what is causing this death spin.
 

I think its time to do a small radio test in my test bed airplane, my kadet senior, has so many test flights on it ,its not even funny, ill tell the story later. Im still not sure what to think about whats going on with my agwagon, if each one of you would, tell me exactly what you think is happening, weather radio, snap, dutch roll, stall, Im only 17 and been into planes for 3 years, so my knowledge is not to high at the moment, but i do have a fiarly good knowledge, but not that good.:D:D:D:D:D

flat spin problems, what is causing this death spin.
 

I find much comfort in the fact that you can recognise when you're doing this. I thought that perhaps it was a subconcious compulsion at this pint, er, point...... :D

Thud, I'm tending to believe you and certainly more than one has gone down with the pilot blaming the radio rather than the real cause. But it IS a possibility that can't be overlooked given the backgound of the set. And even a quick up glitch would cause DR to respond exactly as you described and suddenly we have the same situation regardless of whether it was a pilot induced control or a radom glitch that started it. There, happy Bill?

Either way the model is still the cause of it's own downfall. In that you're 100% right. If it didn't have the stall/spin problem then a glitch wouldn't fire it off line like this. And there ARE all the other times that DR was able to recover after it got into a bad situation.

If indeed it was a bit dutch roll'y then moving the CG back to where it should have been may have made it just that little bit more stable. The straw on the camel's back and all that.

DR, what was the snap/ spin reactions of the other model like? It was stable in normal flight you said but I'm thinking about what it was like when you purposely snap rolled it. Did it recover immediatley or did it like to keep turning for a 1/4 or 1/2 roll before it came back to normal? Or did it tend to keep spinning by itself after you started one and it needed to be flown out of the spin or took a turn or two to come out by itself?

flat spin problems, what is causing this death spin.
 

I cant answer you question about the first plane, it didnt last but 4-5-6 flights, so I never got a chance to test that one out. But however in rebuilding this plane I will how ever make sure the plane is balanced properly. But incase I will install electronics into my test bed kadet to make sure that the radio is working correctly. I do have a 2nd agwagon, needs covering, I will balacne that one and wring it out to see it I can get any of the same problems from the 1st agwagon.
I will say at the moment, pilot error, I dont think so, yet, I could be wrong.

flat spin problems, what is causing this death spin.
 

I wouldn't call it pilot error either... other than not knowing just exactly what to do with a crazy unstable snap rolling moster that is....

As Thud Driver said adding more left as a reaction to a right snap is actually the wrong thing to do but it's what most of us would have done in the same situation. What happens is that the added lift of the dowwardly deflected aileron on the right wing made that wing go into an even worse and much more draggy stall than it was in during the snap that yanked the model over in the first place. So in this case aileron was the wrong control to use. Instead a fast application of neutral aileron along with a big shot of left rudder and perhaps a little down elevator may have brought it back under control by unloading the wing and letting it start flying again. But as I said, most of us would have just pulled the left aileron harder and then started to consider other courses of action. But from what you said it was too late by that time.

Just for the hell'uv'it you might want to try this. Find out what the airfoil is supposed to be and make up a little 1/32 plywood template of the first 1/4 of the wing section shape at the tip or a few ribs inward. Use this to check the shape of the leading edges near the tips of both wings. They should be within a thin pencil line of matching that template if you expect the airfoil to perform as promised. If it isn't then it's time to shape it correctly. Remove the high spots and fill in the low spots using the lightweight model or wall filler and reshape until you're eyes are crossed and you can only see a very narrow and even line of light around that template. I may be going overboard here but this is a VERY important spot of your model if you want it to fly well.

flat spin problems, what is causing this death spin.
 

lol, i guess ill have to be a expert builder and flyer with this plane. I have figured out a take off pattern for this plane. a take off should be ,able to hgain speen and gain alt before yanking it to the side. guy, I think we have this problem solved, maybe.

flat spin problems, what is causing this death spin.
 

Thats comical Bill. My Hacker "is" an ugly stick type plane I use for testing airfoils and such things. Everybody needs one. For some reason they seem to last the longest.
Dago, If your test plane works all right with that radio it eliminates that problem. As said above it could be a combination of things. If I was me, I would take out half the dihedral, If your going to rebuild the wing anyway. At our field I don't Know how many times I've heard ' it kept turning left when I gave it right', usually at takeoff. Iwould put in differential too. Thats where it would help. If you want to know how,just holler. Also makes for more axial rolls on flatbottom or semi symetrical wings. Thats where they're not quite flat bottomed.

my test bed plane
 

Thanks flypaper , im not sure what im going to fo with that plane right now, its done it 3 times to many , to fast, so im going to take a break from it.
That test bed kadet I told you about, heres some of its flights, first flight was done with 16 wheels, then 21 wheels, then mods to the air frame,then put on a differ tri gear the didnt work, then mad it a tail dragger, o yes while being made a bigger tri gear , it sprung a fuel tank leak, the whole front end had to be rebuilt. Its a heck of a plane, took 2 years to build, on and off.

flat spin problems, what is causing this death spin.
 

o yes, it never made the flight with those 13 wheels, the engine wouldnt run, took it of and had a friend look at it, then I had to use the some wheels for anothe plane, so it uses 4 inch wheels.

flat spin problems, what is causing this death spin.
 

Dago:

What on Earth was the reason for the multi-wheel trucks? Just to be different? Was there some logic to it? Wow.

Gord:

I have two "Sticks." An Ultra Stick 120 w/Saito, newest plane, got the bugs out now, fun. Other is an Ace "Littlest Stick." Cox 020, rudder only, keeps you on your toes.

But I don't have a "Hacker." What usually happens when I am attacked by the "Wild Hair" is another plane built. That's why Sam and I are cramped in our four rooms and bath. Too many planes. And Sam doesn't take up much room: He's a ten year old tom cat.

And a flat bottomed wing was a minor factor in my one major crash in years, stupidity was the major factor. High speed inverted pass, ran out of down elevator.

Hacker or fancy plane. Lessons in flying? We all gain.

Bill.

flat spin problems, what is causing this death spin.
 

the reason for a 21 wheeled beast was to be different, plus i was wanting to see what would happen, its just me. just like making my agwagon into a sort of racing plane.

flat spin problems, what is causing this death spin.
 

Dago Red; That multi wheeler might work good at our mushy field in the spring. Don't stop experimenting with your stuff. not enough guys like you around anymore. Read all you can on aerodynamics and experiment some more. I've been playing with models for 50 yrs and still learning. Always new things to try out. Go at it!