Fred, I'm not an expert or nothing, but I 'm gonna take a shot... 1st check your TX and make all ATV setting are centered__ALL TRIMS are centered, lateral balance is acceptable( on a trainer nowadays,I fly it 1st then add weight to the wing if necessary on either panel)__CG is acceptable, not too much right thrust in engine mount__ sometimes on ARF's they overdo it, ailerons are moving freely,__also be sure they are flat w/ bottom of wing panel,also tork rods aren't binding,__make sure wing is centered on fuse__also not canted front or back on fuse, also vertical and horizontal stabs are mtg properly___Basically I taking you back thru the set-up and assy process...Also chx for any control rod flexing__ chx visually and manually by lightly grabbing the surface and moving the TX stick simultaneously__NOW if all this fails 1. You have a torquey engine which can be managed OR 2. you have a warped wing which depending on how bad can be fixed w/ your covering iron or heatgun. As a note when I built a cheapy ARF trainer once it had a wooden rail motor mount and like a ding-dong I put TOO much right thrust in it and the dang thing never flew right___ so I renditioned it..... HTH.....Rob