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Technology developed for the Circulation Control Wing high-lift system has been extended to augment lift by entraining and redirecting engine thrust. Ejecting a thin jet sheet tangentially over a small curved deflecting surface adjacent to the slipstream of a turbofan engine causes the slipstream to flow around that deflecting surface. The angle of deflection is controlled pneumatically by varying the momentum of the thin jet sheet. The downward momentum of the slipstream enhances wing lift. This concept of pneumatically deflecting the slipstream has been applied to an upper surface blowing high-lift system and to a thrust deflecting system. The capability of the pneumatic upper surface blowing system was demonstrated in a series of investigations using a wind tunnel model and the NASA Quiet Short-haul Research Aircraft (QSRA). Full-scale thrust deflections greater than 90 deg were achieved.

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.