GP piper 40 wing drops
 

HI everyone,
I have just completed my Great Planes Piper 40 , and though its flying perfectly, i have a small problem.
On low speeds the plane is perfect, but when i go into a dive ( or a turn ) , the left wing drops, so much so that applying even the full right aileron has no affect, and eventually i need to use the rudder to straighen it up.
I am using an OS 70 4 stroke, and i have checked ailerons are working normally on the ground, with no free play, or binding.
One other observation i have had is that on low speeds , ( take off and landing ) , the wings are perfectly level, and its a beauty to fly.
Lastly, i am flying this plane without the cowl, since its easy to adjust the engine and tweak .. can this be a ause ?
I appreacite all of your comments to help me get past this problem.

Thanks !
Gaurav

RE: GP piper 40 wing drops
 

Hmmm The cowl being off shouldnt be an issue.. Well how much throw do you have on your ailerons? Are your ailerons trimmed for level flight at about 1/2 throttle? If you have only a little throw then maybe the engine torque is rolling the airplane to the left.. If you don't have much throw then you wont be able to counteract this, however if you can slow it down and still have aileron control then thats not the issue... I would check your throw and your lateral balance..

RE: GP piper 40 wing drops
 

Please check your wings carefully. You may have a twist in one wing that's being opposed by the ailerons, but as the speed builds up, it overpowers them.

Also check the fuselage/fin for alignment. If the fuselage is off a bit, or the fin is off a bit, the same thing could happen...as the speed builds up, the larger areas of the fuse and fin overpower the ailerons. Adding rudder then adds its control authority to the ailerons to help you level the model.

RE: GP piper 40 wing drops
 

Hi!
Have you checked the latteral balance?
One wing tip could be heavier than the other. Put lead in the light wingtip.

Second, the airplane could be to nose heavy...check this by flying straigh ahead and then turn sharply with only ailerons and elevator..not side rudder (a pylon turn) If the airplane starts to drop its nose in the turn.....then it is nose heavy. Not good.

Third , It might be that you have a twisted wing..check this by using aRobart incidence meter or by just looking from the wingtip towards the wingroot...comparing the angle/twist of the wing.
The wing should have a slight negative twist...this means the wing tip should be flying at a slightly negative angle compared to the wing root. This is called Wash-out! The opposite is Wash-in ..which is not good to have.

Regards!
Jan K
Sweden