The present disclosure provides methods and systems for operating a rotorcraft comprising a plurality of engines configured to provide motive power to the rotorcraft. The rotorcraft is operated in a first flight regime. A target output power range for at least one of the plurality of engines is determined, the target output power range associated with operating the rotorcraft in a second flight regime different from the first flight regime in which at least one first engine of the plurality of engines is operated in an active mode to provide motive power to the rotorcraft and at least one second engine of the plurality of engines is operated in a standby mode to provide substantially no motive power to the rotorcraft. A graphical representation of the target output power range for the second flight regime is produced via a flight display in a cockpit of the rotorcraft.

A propulsion system for providing propulsion of an aircraft includes a plurality of electric motors coupled with a rotor of the aircraft to drive the rotor and a propulsion motor control. The propulsion motor control includes at least one processor electrically connected with at least one electric motor to actuate the at least one electric motor and at least one battery electrically connected with the at least one processor and at least one electric motor to provide power to the at least one processor and the at least one electric motor. The propulsion motor control actuates the plurality of electric motors based on a desired torque level to drive the rotor to provide propulsion of the aircraft.

An aircraft propulsion system comprises a propulsor, a motor and a reduction gearbox coupled to a prime mover at an input side, and the propulsor at an output side. The reduction gearbox is configured to provide a reduction ratio between the input and output. The reduction gearbox is configured such that the input side rotates in an opposite direction to the output side, and the prime mover, motor, propulsor and reduction gearbox are configured such that gyroscopic forces of the propulsor, motor, prime mover and reduction gearbox generated during aircraft manoeuvres and/or propulsion system failures are substantially cancelled.

There are described methods and systems for operating an aircraft having two or more engines. One method comprises operating the two or more engines of the aircraft in an asymmetric operating regime, wherein a first of the engines is in an active mode to provide motive power to the aircraft and a second of the engines is in a standby mode to provide substantially no motive power to the aircraft; governing the first engine in the active mode using a first governing logic; and governing the second engine in the standby mode using a second governing logic, the second governing logic based on a target compressor speed and variable geometry mechanism (VGM) settings that are adjusted using trim values dependent on at least one parameter of the second engine in the standby mode.

There are described methods and systems for operating an aircraft having two or more engines. One method comprises operating the two or more engines of the aircraft in an asymmetric operating regime, wherein a first of the engines is in an active mode to provide motive power to the aircraft and a second of the engines is in a standby mode to provide substantially no motive power to the aircraft; governing the first engine in the active mode using a first governing logic; and governing the second engine in the standby mode using a second governing logic, the second governing logic based on a target compressor speed and variable geometry mechanism (VGM) settings that are adjusted using trim values dependent on at least one parameter of the second engine in the standby mode.

For aircraft taxiing, an aircraft is equipped with an electric machine installed in a propulsor gearbox (PGB), in parallel to the gas turbine, working in motor mode during taxi, and in generator mode during flight phases (such as take-off, climb, cruise, descent, approach and landing). Typical current systems which use an electric machine in the PGB do not use the electric machine in motor mode for taxi operations (i.e., it is only an additional generator). An optimized power supply providing a combination of a thermal engine such as an Auxiliary Power Unit (APU) and an electric energy storage system such as a battery provides power to the PGB electric machine even when the gas turbine is off.

For aircraft taxiing, an aircraft is equipped with an electric machine installed in a propulsor gearbox (PGB), in parallel to the gas turbine, working in motor mode during taxi, and in generator mode during flight phases (such as take-off, climb, cruise, descent, approach and landing). Typical current systems which use an electric machine in the PGB do not use the electric machine in motor mode for taxi operations (i.e., it is only an additional generator). An optimized power supply providing a combination of a thermal engine such as an Auxiliary Power Unit (APU) and an electric energy storage system such as a battery provides power to the PGB electric machine even when the gas turbine is off.

A turboshaft engine for a rotorcraft includes a first spool and an independently rotatable second spool. The first spool includes a low pressure compressor, a first set of variable guide vanes disposed at an entry of the low pressure compressor, and a low pressure turbine drivingly engaged to the low pressure compressor. The second spool includes a high pressure compressor, a second set of variable guide vanes disposed at an entry of the high pressure compressor, the second set of variable guide vanes independently operable relative to the first set of variable guide vanes, and a high pressure turbine drivingly engaged to the high pressure compressor. One or both of the low pressure compressor and the high pressure compressor includes a mixed flow rotor.

A compact electric motor assembly unit includes an electric motor and an integrated thermal management system. A heat exchanger may be mounted directly to the electric motor and/or form part of the motor housing. A coolant pump may be mounted directly to the electric motor, The coolant pump may be connected either to a drive shaft of the electric motor or to a gear train disposed inside of the electric motor. In certain cases, the coolant pathways for the thermal management system are all located internal of the electric motor assembly unit.

A compact electric motor assembly unit includes an electric motor and an integrated thermal management system. A heat exchanger may be mounted directly to the electric motor and/or form part of the motor housing. A coolant pump may be mounted directly to the electric motor, The coolant pump may be connected either to a drive shaft of the electric motor or to a gear train disposed inside of the electric motor. In certain cases, the coolant pathways for the thermal management system are all located internal of the electric motor assembly unit.