Abstract: A control system for an in-flight engine restart system of a rotorcraft includes an engine control unit that controls and detects status of an engine. The control system also includes a flight control computer that communicates with the engine control unit, an engine operation control system, and a pilot interface including pilot controls. The engine operation control system includes a processor that initiates a health check of the in-flight engine restart system to determine an in-flight engine restart system status. The engine operation control system processes engine mode of operation commands to establish an engine mode of operation, and delivers commands to aspects of the in-flight engine restart system including the engine control unit based on processing of the engine mode of operation commands. The engine operation control system reports the in-flight engine restart system status and results of the engine mode of operation commands to the flight control computer.

Abstract: One aspect is an electrical augmentation system for a gas turbine engine. The electrical augmentation system includes an electric motor operably coupled to a shaft of the gas turbine engine, and an energy storage device operable to provide a temporary increased current source to the electric motor. The electrical augmentation system includes a control system having a torque demand anticipation circuit operable to determine an anticipated torque increase condition for the gas turbine engine. Based on the anticipated torque increase condition, the torque demand anticipation circuit commands a temporary torque increase by the electric motor using the energy storage device.

Abstract: An electrified propulsion system for a rotary wing aircraft includes a flight control computer that receives a signal indicative of a power demand on an engine; an engine control system that is in communication with the engine and is configured to control operation of the engine at a selected operating point; a generator that is in mechanical communication with the engine and is configured to receive mechanical power from the engine and convert the mechanical power to electrical power; an electric motor that is in electrical communication with the generator and is configured to receive the electric power; and a rotor that is in mechanical communication with the electric motor; wherein the electric motor is configured to control rotation and provide the mechanical power demand of the rotor at the selected operating point in response to the received signal.

Abstract: A control system for an in-flight engine restart system of a rotorcraft includes an engine control unit that controls and detects status of an engine. The control system also includes a flight control computer that communicates with the engine control unit, an engine operation control system, and a pilot interface including pilot controls. The engine operation control system includes a processor that initiates a health check of the in-flight engine restart system to determine an in-flight engine restart system status. The engine operation control system processes engine mode of operation commands to establish an engine mode of operation, and delivers commands to aspects of the in-flight engine restart system including the engine control unit based on processing of the engine mode of operation commands. The engine operation control system reports the in-flight engine restart system status and results of the engine mode of operation commands to the flight control computer.

Abstract: A torque converter for converting torque between an input shaft and an output shaft includes an impeller operably connected to the input shaft and rotatable therewith. The torque converter further includes a turbine operably connected to the output shaft and rotatable therewith. A fluid flow system directs a flow of motive fluid through the impeller and through the turbine to drive rotation of the output shaft relative to the input shaft. A lockup mechanism is engageable to urge rotation of the output shaft at an output shaft rotational speed identical to an input shaft rotational speed. A switching module controls an actuation system to urge engagement of the lockup mechanism.

Abstract: One aspect is an electrical augmentation system for a gas turbine engine. The electrical augmentation system includes an electric motor operably coupled to a shaft of the gas turbine engine, and an energy storage device operable to provide a temporary increased current source to the electric motor. The electrical augmentation system includes a control system having a torque demand anticipation circuit operable to determine an anticipated torque increase condition for the gas turbine engine. Based on the anticipated torque increase condition, the torque demand anticipation circuit commands a temporary torque increase by the electric motor using the energy storage device.

Abstract: An engine starting system for a rotary wing aircraft includes a controller that receives a signal indicative of a start command for an engine, a transmission input module that is mechanically coupled to a transmission system and an accessory gearbox and a starter motor that is mechanically coupled to a compressor drive shaft of the engine. Also, a method for restarting an engine in flight includes receiving by a controller a signal indicative of a start command for the engine, determining by the controller that an overrunning clutch is coupled to the engine, transmitting by a transmission system motive power to the engine in response to the determining that the overrunning clutch is coupled to the engine and driving via a compressor drive shaft a compressor section of the engine according to a design speed.

Abstract: An electrified propulsion system for a rotary wing aircraft includes a flight control computer that receives a signal indicative of a power demand on an engine; an engine control system that is in communication with the engine and is configured to control operation of the engine at a selected operating point; a generator that is in mechanical communication with the engine and is configured to receive mechanical power from the engine and convert the mechanical power to electrical power; an electric motor that is in electrical communication with the generator and is configured to receive the electric power; and a rotor that is in mechanical communication with the electric motor; wherein the electric motor is configured to control rotation and provide the mechanical power demand of the rotor at the selected operating point in response to the received signal.

Abstract: An electrified propulsion system for a rotary wing aircraft includes a flight control computer that receives a signal indicative of a power demand on an engine; an engine control system that is in communication with the engine and is configured to control operation of the engine at a selected operating point; a generator that is in mechanical communication with the engine and is configured to receive mechanical power from the engine and convert the mechanical power to electrical power; an electric motor that is in electrical communication with the generator and is configured to receive the electric power; and a rotor that is in mechanical communication with the electric motor; wherein the electric motor is configured to control rotation and provide the mechanical power demand of the rotor at the selected operating point in response to the received signal.

Abstract: An engine starting system for a rotary wing aircraft includes a controller that receives a signal indicative of a start command for an engine, a transmission input module that is mechanically coupled to a transmission system and an accessory gearbox and a starter motor that is mechanically coupled to a compressor drive shaft of the engine. Also, a method for restarting an engine in flight includes receiving by a controller a signal indicative of a start command for the engine, determining by the controller that an overrunning clutch is coupled to the engine, transmitting by a transmission system motive power to the engine in response to the determining that the overrunning clutch is coupled to the engine and driving via a compressor drive shaft a compressor section of the engine according to a design speed.

Abstract: An electrified propulsion system for a rotary wing aircraft includes a flight control computer that receives a signal indicative of a power demand on an engine; an engine control system that is in communication with the engine and is configured to control operation of the engine at a selected operating point; a generator that is in mechanical communication with the engine and is configured to receive mechanical power from the engine and convert the mechanical power to electrical power; an electric motor that is in electrical communication with the generator and is configured to receive the electric power; and a rotor that is in mechanical communication with the electric motor; wherein the electric motor is configured to control rotation and provide the mechanical power demand of the rotor at the selected operating point in response to the received signal.

Abstract: A rotary wing aircraft propulsion system includes an engine, a heat exchanger cooling a fluid from the engine and a thermoelectric generator in thermal communication with the fluid to generate electrical power. The thermoelectric generator provides electrical power to at least one aircraft component.

Abstract: A torque converter for converting torque between an input shaft and an output shaft includes an impeller operably connected to the input shaft and rotatable therewith. The torque converter further includes a turbine operably connected to the output shaft and rotatable therewith. A fluid flow system directs a flow of motive fluid through the impeller and through the turbine to drive rotation of the output shaft relative to the input shaft. A lockup mechanism is engageable to urge rotation of the output shaft at an output shaft rotational speed identical to an input shaft rotational speed. A switching module controls an actuation system to urge engagement of the lockup mechanism.

Abstract: A rotary wing aircraft propulsion system includes an engine, a heat exchanger cooling a fluid from the engine and a thermoelectric generator in thermal communication with the fluid to generate electrical power. The thermoelectric generator provides electrical power to at least one aircraft component.