THRUST CONTROL APPARATUS FOR A JET PROPULSION ENGINE AND ACTUATING MECHANISM THEREFOR

摘要

An aircraft, employing upper surface blowing to augment and supplement aerodynamic lift for short takeoff and landing (STOL) operation, has a turbofan jet propulsion engine cantilevered in a forward position on each wing. In the STOL mode the engine exhaust is discharged rearwardly over the upper airfoil surface of the wing and is turned downwardly over extended trailing edge flaps by the Coanda effect to augment lift. On approach for a short landing a portion of the fan air from the engine is diverted through vectoring channels and is directed downwardly and forwardly. The diverted fan air by its rearward thrust component provides a subtractive effect on the forward drive thrust of the engine to reduce forward air speed while its upward thrust component compensates for the reduction in aerodynamic lift attending reduced forward air speed. By selectively diverting a portion of the fan air the aircraft can achieve a steep angle of descent while maintaining a relatively low rate of descent. The resulting glide path can be varied by altering the magnitude and angle of the diverted fan air stream as well as by engine power and flap setting variations. An exhaust reversing door, incorporated in the engine exhaust nozzle, includes a lip door mounted at the rearward, upper portion thereof which throttles the rearward exhaust flow to maintain engine load matching when the vectoring channels are opened. Actuating linkage for operating the lip door is connected between fixed engine structure and the lip door in such a manner so as not to interfere with the operation of the reversing door.