Thrust-deflecting vane devices of v/stol aircraft

Two tail control surfaces operable doubly as thrust-deflectng vanes are rotatably supported on respective lateral sides of a jet engine of a V/STOL aircraft. Each tail surface (8) can be actuated to rotate about an axis parallel to the engine axis (9) and also to rotate about an axis perpendicular to the engine axis. The tail surfaces can be placed in outer positions on respective lateral sides of the engine for high-speed flight to function as stabilizer surfaces and to be placed within the engine exhaust gas stream and, moreover, to be placed in an inclined state relative thereto thereby to deflect the stream downward for slow-speed or hovering flight.