Abstract: A thrust reverser is provided for use with an asymmetric aircraft gas turbine engine exhaust nozzle. The thrust reverser includes a movable aerodynamic flap downstream of the asymmetric nozzle casing which is rotatable about one pivot in order to effect in-flight thrust vectoring through deflection of the exhaust stream, and which is also independently rotatable about another pivot to effect thrust reversing. In the reverse thrust mode, the leading edge of the flap is immersed into the exhaust stream, thereby splitting the stream into two portions, one of which is deflected upward and forward by a turning vane incorporated into the leading edge of the flap, and the other portion of which is deflected downward and forward by a hinged lip connected to the flap trailing edge. The thrust reverser thus permits the exhaust stream to be ejected in the vertical plane to produce reverse thrust without an accompanying pitch moment even though the exhaust nozzle is not symmetrical in the vertical plane.