An aircraft propulsion system having a variable airflow capture area is provided. The propulsion system includes a main propulsion source and an auxiliary propulsion source. In a first mode, the auxiliary propulsion source is stowed within an aerodynamic profile of the aircraft, and the main propulsion source provides all of the propulsion force for powering flight of the aircraft. In a second mode, the auxiliary propulsion source is deployed to augment the airflow capture area of the main propulsion source and increase an overall airflow capture area of the propulsion system. In the second mode, the auxiliary power source is operated by power extracted from the main propulsion source. The main propulsion source may include one or more low bypass ratio engines. The auxiliary power source may include one or more auxiliary thrust fans coupled at a plurality of locations on the aircraft.

A method is provided for operating a hybrid-electric propulsion system having a first engine, a second engine, a first electric machine coupled to the first engine, and a second electric machine coupled to one of the first engine or the second engine. The method includes: receiving data indicative of a first engine operating parameter, a second engine operating parameter, or both; determining a first engine operating parameter margin, a second parameter operating margin, or both; determining a load share for the first engine, the second engine, or both, or between the first engine and the second engine based on the first engine operating parameter margin, the second engine operating parameter margin, or both; and transferring a first amount of power to or from the first electric machine and a second amount of power to or from the second electric machine in response to the determined load share.

A hybrid-electric propulsion system includes a turbomachine and an electrical system, the electrical system including an electric machine coupled to the turbomachine. A method for operating the propulsion system includes receiving, by one or more computing devices, a command to accelerate the turbomachine to provide a desired thrust output; receiving, by the one or more computing devices, data indicative of a temperature parameter approaching or exceeding an upper threshold; and providing, by the one or more computing devices, electrical power to the electric machine to add power to the turbomachine to provide, or assist with providing, the desired thrust output in response to receiving the command to accelerate the turbomachine and receiving the data indicative of the temperature parameter approaching or exceeding the upper threshold.

The present invention includes a distributed propulsion system for a craft that comprises a frame, a plurality of hydraulic or electric motors disposed within or attached to the frame in a distributed configuration; a propeller operably connected to each of the hydraulic or electric motors, a source of hydraulic or electric power disposed within or attached to the frame and coupled to each of the disposed within or attached to the frame, wherein the source of hydraulic or electric power provides sufficient energy density for the craft to attain and maintain operations of the craft, a controller coupled to each of the hydraulic or electric motors, and one or more processors communicably coupled to each controller that control an operation and speed of the plurality of hydraulic or electric motors.

A hybrid electric propulsion system for an aircraft is provided that includes a thermal engine, an electric motor, a gearbox, an electric power storage unit, a propulsion unit, and a controller. The thermal engine has a main oil pump configured to be driven by the thermal engine. The gearbox is in communication with the thermal and electric motors. The propulsion unit includes a propeller having propeller blades, and a pitch change mechanism. The controller is in communication with the thermal and electric motors, the propulsion unit, and a memory storing instructions. The instructions when executed cause the controller to control the electric motor to operate using electrical power from the electric power storage unit to cause the main oil pump to actuate and produce a flow of engine oil to the pitch change mechanism for a period of time sufficient to feather the propeller blades.

A method of operating a hybrid engine for an aircraft, the hybrid engine having a thermal engine and an electric motor. The method includes verifying, using an engine control unit of the hybrid engine, that a selected power level is under a predetermined threshold for operation of the hybrid engine in a sub-idle hybrid mode. The method further includes operating the hybrid engine in the sub-idle hybrid mode, using the engine control unit, by controlling the thermal engine to operate in a standby mode, and by controlling the electric motor to operate in an active mode wherein the electric motor provides a majority of a propulsive power to the aircraft, wherein in the standby mode the thermal engine operates in a sub-idle condition to provide at most minimal propulsive power to the aircraft.

A method of operating a hybrid engine for an aircraft, the hybrid engine having a thermal engine and an electric motor. The method includes verifying, using an engine control unit of the hybrid engine, that a selected power level is under a predetermined threshold for operation of the hybrid engine in a sub-idle hybrid mode. The method further includes operating the hybrid engine in the sub-idle hybrid mode, using the engine control unit, by controlling the thermal engine to operate in a standby mode, and by controlling the electric motor to operate in an active mode wherein the electric motor provides a majority of a propulsive power to the aircraft, wherein in the standby mode the thermal engine operates in a sub-idle condition to provide at most minimal propulsive power to the aircraft.

A lever for adjusting output of a hybrid-electric powerplant of an aircraft includes a lever configured to move over an overall range of positions. Movement of the lever adjusts the output of the hybrid-electric powerplant between at least two modes of operation. In a first subset of positions within the overall range of positions, the hybrid electric powerplant is configured to operate an engine having a mechanical output, output first electrical energy from a motor/generator driven by the mechanical output of the engine, and drive a propulsion mechanism by the mechanical output of the engine. In a second subset of positions within the overall range of positions, the hybrid electric powerplant is configured to operate the engine having the mechanical output, receive second electrical energy at the motor/generator, drive the mechanical output with the motor/generator using the second electrical energy, and drive the propulsion mechanism by the mechanical output.

A lever for adjusting output of a hybrid-electric powerplant of an aircraft includes a lever configured to move over an overall range of positions. Movement of the lever adjusts the output of the hybrid-electric powerplant between at least two modes of operation. In a first subset of positions within the overall range of positions, the hybrid electric powerplant is configured to operate an engine having a mechanical output, output first electrical energy from a motor/generator driven by the mechanical output of the engine, and drive a propulsion mechanism by the mechanical output of the engine. In a second subset of positions within the overall range of positions, the hybrid electric powerplant is configured to operate the engine having the mechanical output, receive second electrical energy at the motor/generator, drive the mechanical output with the motor/generator using the second electrical energy, and drive the propulsion mechanism by the mechanical output.

A method of and system for operating a hybrid electric propulsion system for an aircraft in a start sequence is provided. The hybrid electric propulsion system includes a thermal engine, an electric motor, a gearbox, an electric power storage unit, and a propulsion unit having a propeller having propeller blades. The method includes: driving the propeller from a static state to a target rotational speed within a predetermined range of speeds using the electric motor; transitioning the propeller blades from a feathered mode to an unfeathered mode while the propeller is being driven at the target rotational speed solely by the electric motor; starting the thermal engine; and transitioning the driving of the propeller using the electric motor to driving the propeller using the thermal engine.