Technology required to develop a pneumatic thrust deflector was investigated. Pneumatic thrust deflection is achieved by blowing a thin sheet of air tangentially across a curved surface adjacent to the slipstream produced by a turbojet engine. Controlling the angle of thrust deflection requires no moving surfaces because the angle of deflection varies with the momentum of the jet sheet. Increasing the momentum of the jet sheet results in an increase in the thrust deflection angle. A wide range of thrust deflection, through 60 deg, was achieved in a series of investigations using a small turbojet simulator and the J402-CA-400 turbojet engine. This mechanically simple pneumatic system can provide high performance aircraft with a thrust deflecting capability for increased maneuverability, heavy lift capability, or short takeoff and landing (STOL) capability.