Abstract: A propulsion system includes a propulsor, an engine, an electrical assembly, and a protection circuit. The engine is coupled with the propulsor. The electrical assembly includes a battery, a motor control unit, an electric motor, and an electrical distribution system. The electrical distribution system is configured to electrically interconnect the battery and the motor control unit. The electrical distribution system includes a contactor between the battery and the motor control unit. The motor control unit is electrically connected with the electric motor. The electric motor is coupled with the propulsor. The protection circuit includes a current sensor configured to measure an electrical current between the battery and the motor control unit. The protection circuit is operable to identify a reverse current flow using the measured electrical current and transmit a protection open control signal to the contactor to control the contactor to switch to an open state.

Abstract: A system is provided for an aircraft. This aircraft system includes an aircraft structure, an electrical power storage and an air system. The aircraft structure includes an internal compartment. The electrical power storage is housed within the internal compartment. The air system is configured to direct pressurized air into the internal compartment. The air system includes a plurality of air sources and a flow regulator. The flow regulator is configured to fluidly couple each of the air sources to the internal compartment.

Abstract: A system is provided for an aircraft. This aircraft system includes an aircraft structure, an electrical power storage and an air system. The aircraft structure includes an internal compartment. The electrical power storage is housed within the internal compartment. The air system is configured to direct pressurized air into the internal compartment. The air system includes a plurality of air sources and a flow regulator. The flow regulator is configured to fluidly couple each of the air sources to the internal compartment.

Abstract: A hybrid electric system for a rotorcraft can include a first thermal engine, a second thermal engine, and an electrical machine. The first thermal engine can be sized to produce a maximum first thermal engine power that is below a one-or-more-engine-inoperative (OEI) requirement power and the second thermal engine can be sized to produce a maximum second thermal engine power that is below the OEI requirement power. The electrical machine can be sized to provide at least a remaining power needed to reach the OEI requirement power in an OEI state.

Abstract: Methods and systems for method for managing a hybrid-electric powerplant (HEP) comprising a thermal engine and an electric motor are described. The method comprises transmitting a thermal power command to the thermal engine to generate a thermal power output; transmitting an electric power command to the electric motor to generate an electric power output; comparing the thermal power output to the thermal power command and the electric power output to the electric power command; detecting a fault when the thermal power output deviates from the thermal power command or when the electric power output deviates from the electric power command; and accommodating the fault by modulating the thermal power command in response to a deviation in the electric power output and modulating the electric power command in response to a deviation in the thermal power output.

Abstract: A hybrid electric system for a rotorcraft can include a first thermal engine, a second thermal engine, and an electrical machine. The first thermal engine can be sized to produce a maximum first thermal engine power that is below a one-or-more-engine-inoperative (OEI) requirement power and the second thermal engine can be sized to produce a maximum second thermal engine power that is below the OEI requirement power. The electrical machine can be sized to provide at least a remaining power needed to reach the OEI requirement power in an OEI state.

Abstract: Methods and systems for method for managing a hybrid-electric powerplant (HEP) comprising a thermal engine and an electric motor are described. The method comprises transmitting a thermal power command to the thermal engine to generate a thermal power output; transmitting an electric power command to the electric motor to generate an electric power output; comparing the thermal power output to the thermal power command and the electric power output to the electric power command; detecting a fault when the thermal power output deviates from the thermal power command or when the electric power output deviates from the electric power command; and accommodating the fault by modulating the thermal power command in response to a deviation in the electric power output and modulating the electric power command in response to a deviation in the thermal power output.