An aircraft propulsion system is disclosed that includes at least one hybrid-electric powerplant for delivering power to an air mover for propelling the aircraft, wherein the at least one hybrid-electric powerplant includes a heat engine and an electric motor arranged in a parallel drive configuration or an in-line drive configuration.

A hybrid electric engine control module (ECU) can be configured to be operatively connected to a hybrid electric aircraft powerplant having a heat engine system and an electric motor system to control a torque output from each of the heat engine system and the electric motor system. The ECU can be configured to determine whether at least one of the electric motor system or the heat engine system are in a normal mode such that one of the electric motor system and/or the heat engine can provide a predetermined amount of torque. The ECU can be configured to switch to a degraded mode if either of the electric motor system or the heat engine system cannot provide the predetermined amount of torque. In the degraded mode the ECU can be configured to control the electric motor system and the heat engine system differently than in the normal mode or to not control one or both of the electric motor system or the heat engine system.

A power plant a for an aircraft having a hybrid-electric propulsion system including a nacelle body including therein an electric motor directly connected to a gearbox for driving a propeller, wherein the gearbox is connected directly to a heat motor for driving the propeller, and at least one heat exchanger for cooling the electric motor or the heat motor.

A method includes providing thrust to an aircraft through a power train from a heat engine connected to the power train. The method includes controlling an electric motor connected to the power train to counter torque ripple in the power train from the heat engine. A system includes a power train for providing thrust to an aircraft. A heat engine is connected to the power train. An electric motor is operatively connected to the power train. A controller is operatively connected to control the electric motor. The controller includes machine readable instructions configured to cause the controller to control the electric motor to counter torque ripple in the power train from the heat engine.

A hybrid electric engine control module (ECU) configured to be operatively connected to a hybrid electric aircraft powerplant having a heat engine system and an electric motor system to control a torque output from each of the heat engine system and the electric motor system. The ECU can be configured to receive a torque command and split output power between the electric motor system and the heat engine system. Additionally and/or alternatively, the ECU can be configured to balance a total torque against a second total torque of a second aircraft powerplant.

A hybrid propulsion system includes a heat engine configured to drive a heat engine shaft. An electric motor configured to drive a motor shaft. A transmission system is connected to receive rotational input power from each of the heat engine shaft and the motor shaft and to convert the rotation input power to output power. A first lubrication/coolant system is connected for circulating a first lubricant/coolant fluid through the heat engine. A second lubricant/coolant system in fluid isolation from the first lubrication/coolant system is connected for circulating a second lubricant/coolant fluid through the electric motor.

An electrical power system is disclosed for an aircraft having a hybrid-electric propulsion system, which includes a battery assembly for storing energy, an electric motor controller operatively connected to the battery assembly for conditioning and controlling power to an electric motor, and an electric motor receiving power through the motor controller for delivering torque to a shaft of the hybrid-electric propulsion system.

A hybrid power drive system for an aircraft that comprises a rotor and a first power drive sub-system. The first power drive sub-system includes at least one engine in connection with the rotor and provides a first power to the rotor. The hybrid power drive system also includes a second power drive sub-system connected in parallel to the first power drive sub-system, which supplements with a second power the first power delivered to the rotor during operation of the aircraft. In addition, an electric power source provides a third power to the second power drive sub-system.

A rotary propulsion system for a tiltrotor aircraft operable to transition between rotary and non rotary flight modes. The rotary propulsion system includes an engine coupled to a freewheeling unit. A gear system positioned between the freewheeling unit and a proprotor assembly has a torque path coupling assembly disposed between an engine side gear assembly and a rotor side gear assembly. In a disengaged position, the torque path coupling assembly interrupts the torque path between the engine and the proprotor assembly. In an engaged position, the torque path coupling assembly completes the torque path between the engine and the proprotor assembly. A hybrid power unit is configured to accelerate the engine side gear assembly to match the output rotating speed to the input rotating speed enabling the torque path coupling assembly to shift from the disengaged position to the engaged position.

A computer-implemented method of assessing a health of a gas turbine engine of a hybrid-electric propulsion system for an aircraft includes receiving, by one or more computing devices, data indicative of an amount of electrical power provided to, or extracted from, an electric machine. The method also includes receiving, by the one or more computing devices, data indicative of an operating parameter of the hybrid-electric propulsion system. The method also includes assessing, by the one or more computing devices, a health of the gas turbine engine based at least in part on the received data indicative of the amount of electrical power provided to, or extracted from, the electric machine and the received data indicative of the operating parameter of the hybrid electric propulsion system. The method also includes providing, by the one or more computing devices, information to a user indicative of the health of the gas turbine engine.