I test flew this bird for a guy, 1/4 scale. 72" mainplane, for those not familiar with it is a model of a homebuilt, there are no ailerons, rudder only, no elevators, there is a servo hooked to the trailing edge of the wing which moves it up and down to change the angle of incidence, more angle and the plane goes up, the real ones were banned because they had a nasty habit of tucking the nose in and under and going inverted with no way to gain control, this bird flew svery well Mike