Abstract: An unmanned air vehicle capable of vertical take-off and landing, hovering and high-speed horizontal cruise flight. A forward centerbody houses an engine and carries a single rotor assembly having a plurality of propellers lying in a plane substantially perpendicular to the centerline of the forward centerbody. A coaxial aft centerbody is secured to the aft end of the forward centerbody and typically houses the vehicle avionics. A plurality of stators extend outwardly of the aft centerbody, in a plane substantially parallel to the propellers. A single toroidal duct surrounds the rotor assembly and the stators and is secured to the stators. A plurality of movable control vanes are secured between the duct and aft centerbody aft of the stators. A flight control system, typically housed in the aft centerbody, controls the engine and the vanes to cause the vehicle to selectively move upwardly, downwardly, hover or translate to forward, horizontal, motion with the rotor in a plane within 80.degree. of vertical.