I have a 50cc sized Extra 260 that has required quite a lot of up trim to fly straight and level. Balance is right on the suggested CG. Incidence on the wings and elevators is 0 degrees. When the engine is slowed to idle the plane tends to flare upwards.
I read on another site, that wing incidence should be +1 degree for an aerobatic plane to prevent too much up trim. My question is, since trying to adjust wing incidence on my plane would be difficult, could the ailerons be set slightly up or down to create the same effect? Not sure which way they would have to go.

You should be able to decrease the down thrust on your engine and solve the problem. You want your thrust angle such that the plane stays level no matter what you do with the throttle.

I had thought of that but the engine already has quite a lot of up thrust in it now. Any more and it wont line up with the cowl.

Ohh the world of ARFs.

If you want it setup correctly it may not match the cowl. If you built it from scratch you normally can fix problems like that before its put together.


If you are trying to fly competition, I'd worry less about the look of the spinner in relation to the cowl and more on how the plane flies.

Post #2 describes a condition that I don't think you or anyone else can achieve without a mix because the laws of physics say the wing makes more lift as speed (i.e. throttle) increase which causes the airplane to climb or descend depending on throttle setting. That said, one can try to get as close to the "ideal" as he can. I agree that you need more up thrust.