A liquid fuel system for an aircraft engine includes a first fuel supply conduit hydraulically connected to a fuel source, a second fuel supply conduit hydraulically connected to the engine, a fuel return conduit hydraulically connected to the second fuel supply conduit, and a fuel pump. The fuel pump has a main inlet hydraulically connected to the first fuel supply conduit, an outlet hydraulically connected to the second fuel supply conduit, and an intermediate inlet hydraulically connected to the fuel return conduit. The intermediate inlet is located between the main inlet and the outlet and in use has a pressure between the main inlet pressure and the outlet pressure. A method of supplying a liquid fuel to an aircraft engine is also described.

A liquid fuel system for an aircraft engine includes a first fuel supply conduit hydraulically connected to a fuel source, a second fuel supply conduit hydraulically connected to the engine, a fuel return conduit hydraulically connected to the second fuel supply conduit, and a fuel pump. The fuel pump has a main inlet hydraulically connected to the first fuel supply conduit, an outlet hydraulically connected to the second fuel supply conduit, and an intermediate inlet hydraulically connected to the fuel return conduit. The intermediate inlet is located between the main inlet and the outlet and in use has a pressure between the main inlet pressure and the outlet pressure. A method of supplying a liquid fuel to an aircraft engine is also described.

A method for reducing an engine core speed is disclosed, which includes determining a condition of an engine during operation of the engine, and controlling an engine turbine clearance based on the condition of the engine so as to influence the engine core speed. An engine system comprising an engine core speed reducing system is also disclosed.

A method for reducing an engine core speed is disclosed, which includes determining a condition of an engine during operation of the engine, and controlling an engine turbine clearance based on the condition of the engine so as to influence the engine core speed. An engine system comprising an engine core speed reducing system is also disclosed.

A method for reducing an engine core speed is disclosed, which includes determining a condition of an engine during operation of the engine, and controlling an engine turbine clearance based on the condition of the engine so as to influence the engine core speed. An engine system comprising an engine core speed reducing system is also disclosed.

A method for reducing an engine core speed is disclosed, which includes determining a condition of an engine during operation of the engine, and controlling an engine turbine clearance based on the condition of the engine so as to influence the engine core speed. An engine system comprising an engine core speed reducing system is also disclosed.

A fuel supply circuit for an aeronautical cryogenic turbomachine including: at least one cryogenic reservoir containing a liquid fuel topped with a boil-off gas and including a high-pressure liquid pump to supply at least one main propulsion device of the turbomachine with liquid fuel, an auxiliary turbomachine including an electric generator, a gas compressor to supply the auxiliary turbomachine with gaseous fuel, and a buffer gas reservoir connecting the gas compressor to the cryogenic reservoir to reinject gas into the cryogenic reservoir in order to maintain the pressure in the cryogenic reservoir above a predefined value, the electric generator supplying the high-pressure liquid pump and the gas compressor.

A fuel supply system for fuel injectors of a multi-stage combustor of a gas turbine engine is provided. The system has a metering and splitting arrangement which receives a pressurised fuel flow and controllably meters and splits the received flow into metered pilot and mains flows for injecting respectively at pilot and mains fuel discharge orifices of the injectors to perform staging control of the combustor. The system further has pilot and mains fuel distribution pipeworks respectively distributing fuel from the metering and splitting arrangement to the pilot and mains discharge orifices. The system further has a controller which is configured to command the metering and splitting arrangement to provide the metered flows, to select the pilot distribution pipework and deselect the mains distribution pipework for pilot-only operation.

Methods and systems for fault detection of a fuel control unit of an engine are provided. Exceedance of at least one engine parameter beyond a safety threshold, associated with excessive fuel flow to the engine, is detected at an engine controller associated with the engine. The fuel control unit is commanded, via the engine controller, to implement a reduction in the fuel flow to the engine. Following the commanding of the fuel control unit, subsequent exceedance of the at least one engine parameter beyond the safety threshold is detected at the engine controller. A fault of the fuel control unit is determined at the engine controller, based on the subsequent exceedance. In response to determining the fault of the fuel control unit, at least one countermeasure to the fault of the fuel control unit is triggered by the engine controller.

Methods and systems for fault detection of a fuel control unit of an engine are provided. Exceedance of at least one engine parameter beyond a safety threshold, associated with excessive fuel flow to the engine, is detected at an engine controller associated with the engine. The fuel control unit is commanded, via the engine controller, to implement a reduction in the fuel flow to the engine. Following the commanding of the fuel control unit, subsequent exceedance of the at least one engine parameter beyond the safety threshold is detected at the engine controller. A fault of the fuel control unit is determined at the engine controller, based on the subsequent exceedance. In response to determining the fault of the fuel control unit, at least one countermeasure to the fault of the fuel control unit is triggered by the engine controller.