Grey beard, It's way too late to figure out what was wrong with my GP Cap, It hit hard, and there was not enough left to rebuild. I thought it was odd, as it was a beautiful build, and the wing and tail surfaces were exact as far as incidence, engine thrust set up as per instructions, etc. I fooled around a bit with CG and thrust angle for engine, but, alas, it was destroyed before I could fine tune it. I know a few other modelers have had to modify the engine thrust angle on this plane as well. It is unfortunate I never had the opportunity to figure out what was wrong with it. On the other hand, when I had the GP Extra 300s, it flew perfect right from the get-go.