To Test For... Do this... Look for this...
And Adjust This... Elevator Alignment
This sounds weird, but I had to correct for misalignment of the split-elevator halves in my Skyvolt a couple of times. For precision aerobatics buffs, a better way to do this is to pull into the loop - and once inverted, push forward into an outside loop to return to level flight. Repeat ad nauseum. If the model rolls in the same direction in both the inside and outside loops, then the problem is still a warped elevator half. If it rolls opposite ways, then one elevator half has more throw than the other.