I have about a dozen flights on my new H9 Extra 260 with DA50.

Whenever I use more than about 5-7 degrees of elevator, the plane corkscrews to the right. I've checked the movement of both halves of the elevator and they appear very equal. I've got no mixing set to other control surfaces (my radio doesn't support it, I don't think--Hitec Flash 5)

any ideas or suggestions? Is this common with the H9 260?