A hybrid electric propulsion (HEP) system included in an aircraft includes a generator configured to output a first power, an energy storage system configured to output a second power, a propulsion system configured to generate thrust based on at least one of the first power and the second power, and an HEP controller in signal communication with the generator, the battery, and the HEP system. The HEP controller is configured to detect loss of the first power output from the generator, to determine an altitude of the aircraft and to actively control delivery of the second power to the propulsion system based on the altitude during the loss of the first power.

An aircraft hybrid electrical propulsion (HEP) system includes an electrical system configured to deliver power to a plurality of electrical loads, a propulsion system configured to generate thrust in response to an input power, and an HEP controller in signal communication with the electrical system and the propulsion system. The HEP controller is configured to monitor a load demand of at least one electrical load among the plurality of electrical loads and to actively control the input power to actively control the thrust in response to changes in the load demand.

A mobile engine-generator vehicle that uses the same motor system for mobility as it does for electrical power generation. The mobile engine-generator vehicle is configured to provide electrical power to an external load via an electrical outlet mounted to the vehicle.

An example hybrid aircraft propulsion system includes one or more power units configured to output electrical energy onto one or more electrical busses; a plurality of propulsors; and a plurality of electrical machines, each respective electrical machine configured to drive a respective propulsor of the plurality of propulsors using electrical energy received from at least one of the one or more electrical busses.

An aircraft is provided including a fuselage extending between a forward end and an aft end. An aft engine is mounted to the fuselage at the aft end of the fuselage. The aft engine includes a nacelle having a forward section. An airflow duct is also provided extending at least partially through the nacelle and including an opening on the forward section of the nacelle. The opening is configured for providing an airflow to, or receiving an airflow from, the forward section of the nacelle to increase an amount of, e.g., boundary layer airflow received within the aft engine during operation of the aircraft, to guide the flow of boundary layer airflow into the engine more smoothly, or to reduce a distortion on the engine.

A hybrid emergency power unit for an aircraft comprises a controller, a generator-motor coupled to the controller, a hydraulic pump coupled to the generator-motor, a battery pack coupled to the controller, and a turbine coupled to the generator-motor. During a bleed air mode, the turbine and the generator-motor supply electricity to the controller, which is configured to rectify an output of the generator-motor for consumption by one or more electrical systems on the aircraft. During an augment mode, when bleed air provides insufficient power, the controller is configured to draw at least some power from the battery pack and convert the output of the generator-motor for consumption by the one or more electrical systems. During an emergency mode, the controller is configured to draw electricity from the battery pack and provide power to drive the generator-motor, which in turn drives the hydraulic pump and provides electrical power to aircraft systems.

A method for testing a hybrid power plant equipping a rotary-wing aircraft comprising at least one lift rotor, the hybrid power plant being configured to rotate the at least one lift rotor, the hybrid power plant comprising at least one heat engine configured to rotate the at least one lift rotor; and at least one electric motor supplied with electrical energy by at least one electrical power source, the at least one electric motor being configured to rotate the at least one lift rotor at least when at least one of the at least one heat engine fails.

A method for testing a hybrid power plant equipping a rotary-wing aircraft comprising at least one lift rotor, the hybrid power plant being configured to rotate the at least one lift rotor, the hybrid power plant comprising at least one heat engine configured to rotate the at least one lift rotor; and at least one electric motor supplied with electrical energy by at least one electrical power source, the at least one electric motor being configured to rotate the at least one lift rotor at least when at least one of the at least one heat engine fails.

A power generation system for an aircraft includes: a storage tank for storing hydrogen; a fuel cell configured to generate power from the hydrogen; a fuel supply line configured to supply the hydrogen from storage tank to the fuel cell; a fresh air supply line configured to supply air to a cabin air supply system; and a fuel-air heat exchange system, wherein the fuel supply line and the air supply line pass through the fuel-air heat exchange system such that the hydrogen cools the air in use.

A power generation system for an aircraft includes: a storage tank for storing hydrogen; a fuel cell configured to generate power from the hydrogen; a fuel supply line configured to supply the hydrogen from storage tank to the fuel cell; a fresh air supply line configured to supply air to a cabin air supply system; and a fuel-air heat exchange system, wherein the fuel supply line and the air supply line pass through the fuel-air heat exchange system such that the hydrogen cools the air in use.