Rapid response attitude control logic for shaft-driven lift fan STOVL engine

摘要

A short take-off and vertical landing (“STOVL”) aircraft has a conventional gas turbine engine that is selectively mechanically connected to a vertically-oriented lift fan by a drive shaft when the aircraft operates in a vertical flight mode. An engine control provides for rapid response attitude control of the aircraft when the pilot initiates desired changes in the attitude (i.e., pitch, roll and/or yaw) of the aircraft. The control achieves the rapid response by varying both the inlet guide vanes of the lift fan and the area of the engine nozzle. These variations result in a substantially constant low rotor speed, which facilitates the desired rapid attitude response and corresponding aircraft control.