Abstract: A high wing, twin jet gyrodyne having air jet reaction, contrarotating rotors powered with bypass air from twin turbofan engines. Tail pipes from the turbofan engines are disposed parallel to and at opposite sides of a longitudinal duct for discharging bypass air rearwardly. Control valve means can control supply of bypass air selectively to the hollow rotor mast for driving the rotors and to the longitudinal air discharge duct. The aft portions of the tail pipes and of the air discharge duct are connected by a horizontal stabilizer and rudders are located in the slipstream discharged from the tail pipes and the air discharge duct. The wings have drop tip sections providing flotation outriggers in their downwardly projecting positions.