Patent ID: 7841185

Claim:
A method of providing propulsive thrust to an aircraft from a gas turbine engine comprising, in axial flow series: a propulsive fan; a compressor; a combustor; a turbine; a final turbine, wherein said propulsive fan produces, during use, a first air flow passing into said compressor and a second air flow which provides propulsive thrust, and wherein said compressor is driven by said turbine via a compressor core shaft and said propulsive fan is driven by said final turbine via a shaft; and an exhaust nozzle through which hot combustion gases are exhausted to provide additional propulsive thrust, the method comprising: operating the gas turbine engine to produce a first propulsive thrust; driving an electrical generator by work taken from the compressor core shaft; bleeding compressed air from the compressor to the exhaust nozzle to provide a reduced propulsive thrust, provided by reducing said second air flow being delivered from said propulsive fan, and maintain the work; and using a controller to determine a proportion of compressed air to bleed to provide the reduced propulsive thrust and maintain the work.