A little trim is normal...on mine, it rolls left a little...another guy I seen had a lt40 that always rolled right ... even though in both cases, the airlerons are dead center to the wing when in their resting position...its just imperfections in the wing...if one wing is 1/4 inch longer than the other, or has a smoother LE, it can produce more lift than the other...acting like its own aileron if you think about it...