Abstract: The disclosed invention consists of several improvements to well known Quad Tilt-Rotor (QTR) aircraft. The first is that during a wing-borne flight, one pair of tilt-rotors, which can be substantially larger than the other pair, is feathered and stopped. This can promote vehicle aerodynamic efficiency and can be utilized to increase vehicle speed. Second is that the wings are not attached to the fuselage at a fixed angle of incidence like on conventional QTR aircraft, but can also be tilted in respect to the fuselage independently of the tilt-rotors. Furthermore, each rotor and each wing can be tilted with respect to fuselage to any tilt-angle without limit, which gives the vehicle unprecedented ability to position the fuselage in any attitude in respect to the vehicle direction of flight.