Abstract: An apparatus for the detection of either or both of water and ice within a system, more specifically, but not exclusively, the detection of either or both of water or ice crystal ingestion, or ice accretion on an aerofoil, within a gas turbine engine. The apparatus and method compares the measured temperature of the first region with a second temperature value, measured at a distinct second region of the aerofoil, wherein the second radial position of the second sensor is radially offset from the first radial position of the first sensor.

Abstract: 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.

Abstract: A gas turbine engine comprising: an engine core comprising a compressor; a compressor bleed valve in communication with the compressor and configured to release bleed air from the compressor; at least one component provided at the inlet of the engine core having a de-icing conduit, configured to receive the bleed air; and a flow controller, configured to provide bleed air to the de-icing conduit of the at least one component in response to either or both of a requirement to de-ice the component and a requirement to release bleed air from the compressor to optimise operation of the core.

Abstract: A shaft apparatus for a gas turbine engine comprising: a first shaft portion; a second shaft portion; and a ratchet mechanism configured to permit the first shaft portion to rotate with respect to the second shaft portion in a first direction, and to prevent the first shaft portion from rotating with respect to the second shaft portion in a second direction opposite to the first direction. A gas turbine engines comprising the shaft apparatus and methods of operating a gas turbine engine are also disclosed.

Abstract: 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.

Abstract: A gas turbine engine comprising an engine core comprising a compressor; a compressor bleed valve in fluid communication with the compressor and configured to release bleed air from the compressor; and a combustor comprising a fuel manifold configured to provide fuel to the combustor; wherein the fuel manifold is in thermal contact with a cooling conduit; and the gas turbine engine further comprises a fluid conduit to supply bleed air from the compressor bleed valve to the cooling conduit.

Abstract: A shaft apparatus for a gas turbine engine comprising: a first shaft portion; a second shaft portion; and a ratchet mechanism configured to permit the first shaft portion to rotate with respect to the second shaft portion in a first direction, and to prevent the first shaft portion from rotating with respect to the second shaft portion in a second direction opposite to the first direction. A gas turbine engines comprising the shaft apparatus and methods of operating a gas turbine engine are also disclosed.

Abstract: An apparatus for the detection of either or both of water and ice within a system, more specifically, but not exclusively, the detection of either or both of water or ice crystal ingestion, or ice accretion on an aerofoil, within a gas turbine engine. The apparatus and method compares the measured temperature of the first region with a second temperature value, measured at a distinct second region of the aerofoil, wherein the second radial position of the second sensor is radially offset from the first radial position of the first sensor.

Abstract: A gas turbine engine comprising: an engine core comprising a compressor; a compressor bleed valve in communication with the compressor and configured to release bleed air from the compressor; at least one component provided at the inlet of the engine core having a de-icing conduit, configured to receive the bleed air; and a flow controller, configured to provide bleed air to the de-icing conduit of the at least one component in response to either or both of a requirement to de-ice the component and a requirement to release bleed air from the compressor to optimise operation of the core.