Patent ID: 6270037
Filing Date: 2001-08-07
Classification: B64C,F02C,F02K

Abstract:
A control system for a gas turbine engine disposed on an aircraft, the aircraft also having a lift fan, the engine being coupled to the lift fan during operation of the aircraft in a vertical mode of flight, the engine having a compressor and a turbine connected together in a rotatable spool, the engine having an exhaust nozzle with an opening that is controllable to thereby control an amount of thrust produced by the engine, the lift fan having airflow passing therethrough in a controlled manner, the lift fan also having a plurality of variable vanes that are controllable to control the airflow passing through the lift fan to thereby control an amount of thrust produced by the lift fan, the control system comprising:means for sensing a parameter indicative of a corresponding operating condition of the engine and for providing a sensed engine signal indicative thereof;means for sensing a parameter indicative of a corresponding operating condition of the lift fan and for providing a sensed lift fan signal indicative thereof;means, responsive to a desired change in attitude of the aircraft operating in a vertical mode of flight, for providing at least one commanded attitude signal indicative of the desired change in the attitude of the aircraft; andsignal processing means, responsive to the sensed engine signal and to the sensed lift fan signal and to the commanded attitude signal, for controlling the opening of the exhaust nozzle and for controlling the amount of airflow passing through the lift fan, wherein the opening of the exhaust nozzle and the amount of airflow passing through the lift fan are both in an amount to keep substantially constant a speed of the rotatable spool, wherein by keeping substantially constant the speed of the rotatable spool the control system provides for relatively rapid response of the aircraft to the desired change in the attitude of the aircraft.