Variable cycle boost propulsor

The present invention relates to a variable cycle boost propulsor system 10 for use on an aircraft. The variable cycle boost propulsor system 10 includes an engine 14, a turbine 30, a fan 34 connected to the turbine 30, and a valve system 46 for delivering the fluid output from the engine 14 to the turbine 30 for driving the turbine 30 and the fan 34 and thereby generating additional thrust for the aircraft. The engine is also used to provide power to one or more systems 27 onboard the aircraft.