Hi folks, I've been working on a little high-wing foam board plane using the remains of my Pilatus Porter - roughly 800mm wingspan. I've a flight problem that has me baffled. The plane is reasonably stable with either rudder turns or banked turns, but as soon as I apply more than a little up elevator (think bank and yank) the plane immediately and aggressively self-rights. At first I didn't understand it was caused by the elevator, but I can replicate the problem at will now. All I can manage is slow turns, anything more aggressive, and the plane levels and straightens up. Any clues? Thanks.