Hello barry, been talking with Mike McConville about the problem. He asked me to check for wing warp on the side it snaps to. Wing looked good (both) but noticed some play in the aileron on the left wing. The screw was loose enough to be pushed out of the hole and had enough play to let it deflect over an 1/8 inch both ways. Re-glued with some microballons and I am going to test the thing later this week.