Abstract: A controller for operating a gas turbine engine, wherein the gas turbine engine is installable in an installation platform, wherein the gas turbine engine includes a compressor, a turbine, and a shaft connecting the turbine to the compressor. The controller includes a program which instructs the controller to run a computer dynamic model of the gas turbine engine, wherein the computer dynamic model has inputs including engine operating conditions and installation platform operating conditions. The controller also is programmed to calculate a dynamic limit on mechanical power extraction from the shaft based at least on the running of the computer dynamic model of the gas turbine engine. A method for operating a gas turbine engine installed in an aircraft includes running a computer dynamic model of the engine and calculating a dynamic limit on mechanical power extraction from a shaft of the engine based at least on the running of the model.

Abstract: A system for providing air to a compressor of an auxiliary gas turbine engine of an aircraft. A system turbine has an inlet adapted to receive compressed air from the aircraft. A system compressor is mechanically coupled to the system turbine and has an inlet adapted to receive atmospheric air. The outlets of the system turbine and the system compressor are fluidly connectable to the inlet of the compressor of the auxiliary gas turbine engine. A method includes providing compressed air from an aircraft to an inlet of a system turbine mechanically coupled to a system compressor. The method includes providing atmospheric air to an inlet of the system compressor. The method includes providing the inlet of the compressor of an auxiliary gas turbine engine with air from an outlet of the system turbine and with air from an outlet of the system compressor.

Abstract: A non-aircraft-propelling auxiliary gas turbine engine assembly includes an auxiliary gas turbine engine and a mixing damper. The auxiliary engine and the mixing damper are installable in an aircraft having at least one aircraft-propelling main gas turbine engine. The auxiliary engine includes a compressor having a compressor inlet. The mixing damper has first and second inlets and has an outlet. The outlet is fluidly connectable to the compressor inlet. The first and second inlets are adapted to receive first and second gas streams which have been compressed by at least one main engine. An aircraft component includes a mixing damper. A controller includes a program which instructs the controller to increase/decrease a first gas stream in response to increasing/decreasing electrical demands on an electric generator operatively connected to an auxiliary gas turbine engine of an aircraft.

Abstract: A non-aircraft-propelling auxiliary gas turbine engine installable in an aircraft having a cabin adapted to be pressurized. The auxiliary gas turbine engine includes an auxiliary-gas-turbine-engine compressor having an inlet, wherein the inlet is adapted to receive pressurized air from the cabin. A method for operating a non-aircraft-propelling auxiliary gas turbine engine of an aircraft includes providing pressurized air from the cabin of the aircraft to an inlet of a compressor of the auxiliary gas turbine engine. The method includes providing compressed air from the compressor to a combustor of the auxiliary gas turbine engine and includes providing combustion gases from the combustor to a turbine of the auxiliary gas turbine engine, wherein the turbine is mechanically coupled to the compressor.