An engine pylon for an aircraft and comprising an inverted U-shaped upper spar with two lateral walls, a U-shaped lower spar with two lateral walls, where the free ends of the lateral walls of the spars are adjacent, an arrangement to the free end of a lateral wall of one spar to the free end of the lateral wall of the other spar, and ribs between the spars where each has a top end fixed to the lateral walls of the upper spar and a bottom end fixed to the lower spar. Such an engine pylon thus offers a reduced number of component parts and a single row of fixings per side, enabling a saving in weight and in assembly time.

The subject matter of this specification can be embodied in, among other things, a system that includes a flexible structure, a power inverter, a first electromechanical device configured to urge movement of a first portion of the flexible structure based on power received from the power inverter, a second electromechanical device configured to urge movement of a second portion of the flexible structure based on power received from the power inverter, a feedback sensor configured to provide a feedback signal indicative of alignment between the first portion and the second portion, and a controller configured to control operation of at least one of the first electromechanical device and the second electromechanical device based on the feedback signal.

The subject matter of this specification can be embodied in, among other things, a system that includes a flexible structure, a power inverter, a first electromechanical device configured to urge movement of a first portion of the flexible structure based on power received from the power inverter, a second electromechanical device configured to urge movement of a second portion of the flexible structure based on power received from the power inverter, a feedback sensor configured to provide a feedback signal indicative of alignment between the first portion and the second portion, and a controller configured to control operation of at least one of the first electromechanical device and the second electromechanical device based on the feedback signal.

An aircraft propulsion system includes a hydrocarbon fuel store, a hydrogen fuel store, an engine system capable of producing thrust by combusting hydrocarbon fuel and/or combusting or oxidising hydrogen fuel, a conveying system to convey hydrocarbon and hydrogen fuel from the fuel stores to the engine system and a control system to control the respective flow rates of the fuel within the conveying system. The control system adapts the fractions of the total fuel energy flow rate to the engine system represented by the hydrocarbon and hydrogen fuel energy flow rates in order to reduce climate warming impact caused by at least one of carbon dioxide, water vapour and condensation trails and/or increase climate cooling impact caused by condensation trails produced by the aircraft propulsion system compared to a dual-fuel propulsion system in which a reserve of hydrocarbon fuel is entirely combusted before any of a reserve of hydrogen fuel.

An aircraft propulsion system includes a hydrocarbon fuel store, a hydrogen fuel store, an engine system capable of producing thrust by combusting hydrocarbon fuel and/or combusting or oxidising hydrogen fuel, a conveying system to convey hydrocarbon and hydrogen fuel from the fuel stores to the engine system and a control system to control the respective flow rates of the fuel within the conveying system. The control system adapts the fractions of the total fuel energy flow rate to the engine system represented by the hydrocarbon and hydrogen fuel energy flow rates in order to reduce climate warming impact caused by at least one of carbon dioxide, water vapour and condensation trails and/or increase climate cooling impact caused by condensation trails produced by the aircraft propulsion system compared to a dual-fuel propulsion system in which a reserve of hydrocarbon fuel is entirely combusted before any of a reserve of hydrogen fuel.

An air start unit for starting and servicing jet engines in aircraft and other flying machines, wherein at least one compressor is provided for generating air and a power supply for supplying electrical power consumers. The air start unit drives the compressor with at least one electric motor, with the electric motor drawing the electrical energy for operation from a high-voltage battery. The electric motors then in turn drive the compressor, which generates compressed air from ambient air for the purpose of starting and servicing the jet engines in aircraft and other flying machines. With an appropriate battery capacity, the air start unit can also supply power consumer of these aircraft and other flying machines via the power supply.

Multiple propulsion units mounted inside an enclosure near openings can be used to control the fluid flow in and out of the openings and also to determine the total fluid flow at any additional uncontrolled openings. By controlling the fluid flow, where such control is available, and by considering the resulting flow at any uncontrolled enclosure openings, it may be possible to achieve a desired thrust vector but have a more favorable weight/shape/efficiency than would be possible without the enclosure and use of coordinated control of fluid flow into or out of some openings. The designed geometry of the enclosure is an important consideration and will have an effect on the overall thrust magnitude and direction. A grouping of propulsion systems can be coordinated to achieve a more general thrust vector and associated moment on a vehicle.

A gas turbine engine is disclosed having a tip clearance control system. The tip clearance control system has a cabin blower system, a casing arranged in use about a rotor of a gas turbine engine and a fluid delivery passage. The cabin blower system having a cabin blower compressor arranged in use to compress fluid used in a cabin of an aircraft and to compress fluid conducted via the fluid delivery passage into heat exchange with the casing.

A gas turbine engine is disclosed having a tip clearance control system. The tip clearance control system has a cabin blower system, a casing arranged in use about a rotor of a gas turbine engine and a fluid delivery passage. The cabin blower system having a cabin blower compressor arranged in use to compress fluid used in a cabin of an aircraft and to compress fluid conducted via the fluid delivery passage into heat exchange with the casing.

An air-breathing turbojet engine for a hypersonic vehicle is shown. The engine comprises a pump for pumping a cryogenic fuel, an inlet configured to compress inlet air by one or more shocks, a cooler to cool the compressed inlet air using the cryogenic fuel, and a turbo-compressor to compress the air further. A precooler cools the compressed inlet air using compressed cooled air from the turbo-compressor. A combustor receives compressed cooled air from the turbo-compressor and a first portion of the cryogenic fuel for combustion. A first turbine expands and is driven by combustion products, and a second turbine expands and is driven by a second portion of the cryogenic fuel. The first turbine and the second turbine drive the turbo-compressor via a shaft. An afterburner receives combustion products from the first turbine and the second portion of the cryogenic fuel from the second turbine for combustion therein.