Abstract: In a gas turbine with stator vanes, actual high speed rotor speed is compared with a value computed from engine pressure to produce an error signal. The error signal is integrated to command stator deflection.

Abstract: A method and system for controlling the position of a variable pitch vane stage (34) in a gas turbine engine (10) uses a feedback loop comparing the current compressor pressure ratio to a reference compressor pressure ratio. The reference pressure ratio is determined from a plurality of current engine operating parameters which identify a unique point on the compressor operating line.

Abstract: A method of starting a gas turbine engine, particularly one having a high inertia rotor, in which the engine is cranked until sufficient air flow is available for lightoff, at which time fuel is injected at a fixed rate until ignition occurs, and fuel flow is then increased at a rate that is a function of rotor speed and ambient temperature. During the acceleration to operating speed, the turbine temperature is compared to a temperature reference that is based on rotor speed and ambient temperature and a lower fuel flow rate is selected, if necessary, to prevent overheating within the engine.

Abstract: A method of detecting rapid loss of electrical load in an industrial free turbine prior to significant turbine overspeed and reducing fuel to a predetermined lower power level thereby to avoid the need for a complete shutdown of the engine is disclosed. The method is unaffected by small power losses and by normal transients.