Multi-engine aircraft power and propulsion systems and methods of restarting an engine of a multi-engine aircraft during fight are provided. One such method comprises: determining a condition to the effect that a flame in the combustion equipment of the second gas turbine engine has been extinguished; responsive to the determination, supplying electrical power from the electrical energy storage system to one or more of the electric machines of the second gas turbine engine and operating said one or more electric machines as motors to limit a reduction in a speed of the one or more spools of the second gas turbine engine following extinguishment of the flame in its combustion equipment; and restarting the second gas turbine engine by relighting the combustion equipment of the second gas turbine engine.

A method for igniting a continuous combustion engine including an electronic engine control member, a high energy box, a spark plug ignition circuit and a fuel solenoid valve, cooperating with a starter motor, the method being implemented by the electronic engine control member and including precharging the high energy box before an engine starting procedure, activated on an engine starting command, the precharging being controlled by switching on the electronic engine control member, or by putting the engine in idle mode.

Aircraft hydrogen fuel systems and methods and systems of starting such systems are described. The aircraft hydrogen fuel systems include a hydrogen burning main engine, a main tank configured to contain liquid hydrogen to be supplied to the main engine during a normal operation, and a starter tank configured to contain gaseous hydrogen to be used during a startup operation of the main engine. Methods and processes for starting and/or restarting such systems are described.

Aircraft hydrogen fuel systems and methods and systems of starting such systems are described. The aircraft hydrogen fuel systems include a hydrogen burning main engine, a main tank configured to contain liquid hydrogen to be supplied to the main engine during a normal operation, and a starter tank configured to contain gaseous hydrogen to be used during a startup operation of the main engine. Methods and processes for starting and/or restarting such systems are described.

Embodiments are directed to systems and methods for controlling an aircraft engine inlet comprises determining a required engine RPM for an engine in-flight restart based upon current aircraft parameters, detecting a command to initiate the engine in-flight restart, and managing a position of an engine inlet barrier to control a volume of air entering an engine intake, wherein the ram air causes an engine turbine to achieve the required engine RPM. The required engine RPM may be an N1 gas generator RPM. The engine inlet barrier may be a hinged door positioned within the engine inlet or a series of inlet variable guide vanes that are configured to rotate between a closed position and an opened position. The position of the engine inlet barrier may be controlled by a flight control computer or an engine control computer.

Embodiments are directed to systems and methods for controlling an aircraft engine inlet comprises determining a required engine RPM for an engine in-flight restart based upon current aircraft parameters, detecting a command to initiate the engine in-flight restart, and managing a position of an engine inlet barrier to control a volume of air entering an engine intake, wherein the ram air causes an engine turbine to achieve the required engine RPM. The required engine RPM may be an N1 gas generator RPM. The engine inlet barrier may be a hinged door positioned within the engine inlet or a series of inlet variable guide vanes that are configured to rotate between a closed position and an opened position. The position of the engine inlet barrier may be controlled by a flight control computer or an engine control computer.

A gas turbine engine includes a fan. Also included is an oil pump operatively connected to the fan by a main input drive gear, the drive gear rotating when the fan rotor rotates in either a first or second direction of the fan. Further included is a gear train intermediate the main input drive gear and the oil pump, the gear train including a first and second pinion gear, the first and second pinion gear each driven by the main input drive gear, the first pinion gear driving a first gear through a first clutch, the second pinion gear driving a second gear through a second clutch. Only one of the clutches transmits rotation from the respective pinion gear to the respective gear when the fan is rotating in the first direction, with the only the other clutch transmitting rotation when the fan is rotating in the second direction.

The invention relates to a drive system for an aircraft which is constructed for operation with a liquid fuel and a gaseous fuel, including at least one engine having a combustion chamber for operation with the liquid fuel and/or the gaseous fuel and per fuel at least one separate tank chamber which is or can be brought into connection in flow terms with the combustion chamber via a fuel line for supplying it with the corresponding fuel.

A drive system which is optimized in terms of emissions and efficiency can be provided in that the drive system is constructed in such a manner that, in the event of firing at a great height, exclusively gaseous fuel is or can be used in the at least one engine during a firing operation at a great height.

An aircraft provided with a power plant provided with at least one combustion engine mechanically connected to a drive system, the drive system comprising two electric machines each connected to the combustion engine by a kinematic chain, the two electric machines being electrically connected to at least one electrical power source. The aircraft comprises a management system controlling at least a mechanical power or an engine torque delivered by each of the two electric machines as a function of a current operating mode, the management system being configured, during a superior operating mode, to control the two electric machines in order for the two electric machines to deliver different and non-zero mechanical powers or engine torques.

An electrical power system architecture and method for allocating power includes a power distribution bus configured to receive power generated by a first engine having a first generator and a second generator, a first set of electrical buses connected with the power distribution bus and associated with the first engine, and a second set of electrical buses configured to selectively connect with the power distribution bus.