Propulsion system (2) for a helicopter (1) comprising a main engine (9), a main rotor (3), a main gearbox (4) including an output mechanically connected to the main rotor (3), a reduction gearbox (13) mechanically coupled between the main engine (9) and a first input of the main gearbox (4), and an assistance device (10).

The assistance device (10) comprises a first electric machine mechanically coupled to the reduction gearbox (13) and configured to operate as an electric generator to take off energy produced by the main engine (9), and a second electric machine mechanically coupled to a second input of the main gearbox (4), the second electric machine being supplied with electrical power by the first electric machine and configured to operate as an electric motor to deliver additional mechanical power to the main gearbox (4).

An example aircraft includes a parallel propulsion unit, the parallel propulsion unit comprising: a propulsor configured to provide forward propulsion of the aircraft; a gas turbine engine configured to drive the propulsor; an electrical machine configured to generate, for output via one or more electrical busses, electrical energy using mechanical energy derived from the gas turbine engine; and a power sharing module configured to control a ratio of the mechanical energy used to drive the propulsor and used to generate electrical energy; and a plurality of series propulsion units, each series propulsion unit comprising a respective propulsor of a plurality of propulsors that are configured to provide vertical propulsion of the aircraft and a respective electrical machine of 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 one or more electrical busses.

A hybrid propulsion chain for an aircraft, the hybrid propulsion chain comprising a plurality of propulsion rotors connected to an electrical distribution module by a plurality of electrical connections, the electrical distribution module being connected, on the one hand, to a non-propulsion turbine engine via an electrical generation system and, on the other hand, to an electric battery, each propulsion rotor comprising a stator member and at least one rotor shaft which is configured to be rotated with respect to the stator member when the stator member is electrically powered, the hybrid propulsion chain comprising an auxiliary mechanical drive system mechanically connected to the non-propulsion turbine engine, the auxiliary mechanical drive system comprising a plurality of mechanical connections for mechanically rotating at least one rotor shaft of each propulsion rotor.

A hybrid propulsion chain for an aircraft, the hybrid propulsion chain comprising a plurality of propulsion rotors connected to an electrical distribution module by a plurality of electrical connections, the electrical distribution module being connected, on the one hand, to a non-propulsion turbine engine via an electrical generation system and, on the other hand, to an electric battery, each propulsion rotor comprising a stator member and at least one rotor shaft which is configured to be rotated with respect to the stator member when the stator member is electrically powered, the hybrid propulsion chain comprising an auxiliary mechanical drive system mechanically connected to the non-propulsion turbine engine, the auxiliary mechanical drive system comprising a plurality of mechanical connections for mechanically rotating at least one rotor shaft of each propulsion rotor.

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.

An aircraft turbine engine includes a gas generator and a fan arranged upstream from the gas generator and configured to generate a main gas flow, one portion of which flows in a flow path of the gas generator to form a primary flow, and another portion of which flows in a flow path around the gas generator to form a secondary flow. The gas generator has a low-pressure body with a rotor driving the fan and a low-pressure compressor situated upstream from an intermediate housing. The turbine engine also includes an electric machine, mounted coaxially downstream from the fan and upstream from the intermediate housing. An intermediate shaft is driven by the rotor of the low-pressure body and drives rotors of the electric machine and of the low-pressure compressor.

An aircraft turbine engine includes a gas generator and a fan arranged upstream from the gas generator and configured to generate a main gas flow, one portion of which flows in a flow path of the gas generator to form a primary flow, and another portion of which flows in a flow path around the gas generator to form a secondary flow. The gas generator has a low-pressure body with a rotor driving the fan and a low-pressure compressor situated upstream from an intermediate housing. The turbine engine also includes an electric machine, mounted coaxially downstream from the fan and upstream from the intermediate housing. An intermediate shaft is driven by the rotor of the low-pressure body and drives rotors of the electric machine and of the low-pressure compressor.

A computer-implemented method for optimally operating a hybrid-electric propulsion system by control of equipment dynamics. Prior to start of a mission, an original energy management plan is generated which is calculated to minimize estimated life-cycle operating costs for the vehicle during the mission. During an initial portion of the mission, operations of first and second power sources, a power distribution system, and a propulsion system are controlled such that a power mixture is supplied to the propulsion system from the first and second power sources in accordance with the original energy management plan. During the initial portion of the mission, a modified energy management plan is generated which is calculated to minimize estimated life-cycle operating costs for the vehicle. During a subsequent portion of the mission, operations of the first and second power sources, power distribution system, and propulsion system are controlled such that a power mixture is supplied to the propulsion system from the first and second power sources in accordance with the modified energy management plan.

A vertical take-off and landing aircraft using a hybrid electric propulsion system includes an engine, a generator that produces electric power using power supplied by the engine, and a battery that stores the produced electric power. A motor receives the electric power stored in the battery and electric power produced by the generator but not stored in the battery and provides the power to a thrust generating apparatus. A controller selects either silence mode or normal mode, and determines the amount of electric power stored in the battery and the amount of electric power not stored in the battery from the electric power supplied to the motor. In the silence mode, the controller supplies only the electric power stored in the battery and controls a duration by adjusting output power of motor. In the normal mode, the controller supplies electric power not stored in the battery.

A vertical take-off and landing aircraft using a hybrid electric propulsion system includes an engine, a generator that produces electric power using power supplied by the engine, and a battery that stores the produced electric power. A motor receives the electric power stored in the battery and electric power produced by the generator but not stored in the battery and provides the power to a thrust generating apparatus. A controller selects either silence mode or normal mode, and determines the amount of electric power stored in the battery and the amount of electric power not stored in the battery from the electric power supplied to the motor. In the silence mode, the controller supplies only the electric power stored in the battery and controls a duration by adjusting output power of motor. In the normal mode, the controller supplies electric power not stored in the battery.