One thing I do know is that if you are using dual elevator servos you MUST make sure they are moving EXACTLY the same amount and there is no offset between the two elevator halves. Also, before Big Dummy broke his prop he did try one other thing I forgot to mention. If you're using a computer radio, mix in flaps with elevator. It tends to smooth out the pitching moment of the airplane. If you don't have flaps, set the ailerons up as flaperons then mix it with the elevator. Just a small amount of flaps with elevator is sufficient. It also helps on landing approach as it slows the plane down some. The engine runs good on the ground, I just haven't had a chance to fly it since breaking the prop. Main problem is I have too many projects going at once. Three engines to run, two airplanes to repair, one airplane to finish, etc., etc.