A propulsion system of an aircraft includes a hybrid electric gas turbine engine, and a nacelle at least partially enclosing the hybrid electric gas turbine engine. The nacelle includes a first nacelle half and a second nacelle half. Each of the first nacelle half and the second nacelle half include an outer nacelle sleeve, an inner nacelle sleeve radially offset from the outer nacelle sleeve such that a flowpath is defined between the outer nacelle sleeve and the inner nacelle sleeve, and an upper bifurcation connecting the outer nacelle sleeve to the inner nacelle sleeve at an upper end of the nacelle. The flowpath is circumferentially continuous between the upper bifurcation of the first nacelle half and the upper bifurcation of the second nacelle half.

The invention relates to a hybrid propulsion architecture (100) for an aircraft, comprising: a first source (102) of a first energy type, second sources (104) of a second energy type different from the first energy type, electrical propulsion systems (106), an electric power supply network (118) connecting the first and second sources (102, 104) to the electrical propulsion systems, such that each electrical propulsion system is powered by the first source and by one of the second sources, the architecture being characterised in that it further comprises: means for segregating (120) the electrical propulsion systems, which means are arranged in the electric power supply network and configured to impose a direction of flow of the electric power from the first source to the electrical propulsion systems.

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.

A system includes a first electric motor that when in operation imparts rotation to a fan stage of an engine. The system also includes a combustion section of the engine comprising a combustor that when in operation generates combustion gas through ignition of fuel and compressed air. The system further includes a turbine of the engine coupled to a shaft of the engine, wherein the turbine when in operation receives the combustion gas from the combustion section and imparts rotation to the shaft using the combustion gas.

A hybrid-electric propulsion system for an aircraft includes a turbomachine, the turbomachine including a first spool and a second spool. A method for operating the hybrid electric propulsion system includes operating, by one or more computing devices, the turbomachine such that the first spool mechanically drives a prime propulsor of the hybrid-electric propulsion system; and modifying, by the one or more computing devices, a speed relationship parameter defined between the first spool and second spool by providing electrical power to, or drawing electrical power from, an electric machine mechanically coupled to the first spool, the second spool, or both.

A hybrid electric propulsion system includes a gas turbine engine and an electric machine coupled to the gas turbine engine. A method for operating the propulsion system includes determining, by one or more computing devices, a baseline power output for the gas turbine engine; operating, by the one or more computing devices, the gas turbine engine to provide the baseline power output; determining, by the one or more computing devices, a desired power output greater than or less than the baseline power output; and providing, by the one or more computing devices, power to, or extracting, by the one or more computing devices, power from, the gas turbine engine using the electric machine such that an effective power output of the gas turbine engine matches the determined desired power output.

A hybrid-electric propulsion system for an aircraft includes a propulsor and a turbomachine. The turbomachine includes a high pressure turbine drivingly coupled to a high pressure compressor through a high pressure spool. The hybrid electric propulsion system further includes an electrical system including a first electric machine, a second electric machine, and an electric energy storage unit electrically connectable to the first and second electric machines. The first electric machine is coupled to the high pressure spool of the turbomachine and the second electric machine is coupled to the propulsor for driving the propulsor to provide a propulsive benefit for the aircraft. The hybrid electric propulsion system also includes a controller configured to provide electrical power from an electric power source to the first electric machine to drive the first electric machine to start, or assist with starting, the turbomachine.

An aircraft having a vertical takeoff and landing fight mode and a forward flight mode. The aircraft includes a fuselage and an X-tiltwing that is rotatable relative to the fuselage between a vertical lift orientation and a forward thrust orientation. The X-tiltwing has oppositely disposed V-wing members each having first and second wing sections. In the vertical lift orientation, the first and second wing sections of each V-wing member are generally in the same horizontal plane. In the forward thrust orientation, the first and second wing sections of each V-wing member are generally in the same vertical plane. A distributed propulsion system is attached to the X-tiltwing such that a plurality of propulsion assemblies is attached to each wing section. A flight control system is operably associated with the distributed propulsion system to independently control each of the propulsion assemblies.

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.

A rotor system for a rotorcraft includes a first rotor assembly defining a rotation axis, a second rotor assembly offset from the first rotor assembly along the rotation axis, and a drive system connected to the first and second rotor assemblies. The drive system includes a first electric motor disposed along the rotation axis and operably connected to the first rotor assembly, and a second electric motor disposed along the rotation axis and operably connected to the second rotor assembly to rotate the second rotor assembly about the rotation axis independent of rotation of the first rotor assembly about the rotation axis.