Abstract: Apparatus for producing a component of thrust at right angles to the main thrust direction of a jet engine. The apparatus comprises a deflecting device which provides a surface, bounded by side walls normal to the surface, that curves outwardly from tangency to the main thrust direction at the tail pipe edge. A series of control ports extending transversely of the curved surface at the point of tangency are connected to ambient air pressure through a normally open remotely controlled air valve. Closure of the air valve causes that portion of the jet stream adjacent to the curved surface to follow the surface because of the Coanda effect, thus producing a thrust component normal to the main jet stream. The device is particularly useful for yaw control of air cushion equipped jet powered aircraft when taxiing and during the low speed portions of takeoff and landing runs.