what radio?when i first had my futapa 8sga years ago,one of the mixing switches got bumped at the beginning of a pylon race and I could not turn,nor could i take my eyes off the plane to look at switches,had my caller look for me and luckily got it on the first try.you may have a setup/mixing turned on in the tx and not know it.if you simulate a turn on the ground with the engine off how do the controls respond,also how much dihedral is in the wing?