Disclosed is an air cycle machine (ACM) having: a turbine; a compressor; a compressor shaft connected to the compressor and configured to receive rotational energy from a gearbox; and a turbine shaft connected to the turbine and configured to provide rotational energy to the gearbox; wherein the turbine shaft and the compressor shaft operate at different rotational speeds.

An engine system includes an engine duct and a tail cone arranged radially inwardly of the engine duct. The tail cone has an outer surface and an inner surface. A generator housing is arranged in the tail cone. The generator housing includes an outer surface portion spaced from the inner surface of the tail cone. A generator is mounted in the generator housing. An air duct extends from the generator, through the generator housing, through the tail cone, and through the engine duct. The air duct includes an opening exposed to an air stream passing over the engine duct.

A vehicle includes a vehicle body, a vehicle power source, and an actuator. The vehicle power source includes a housing and a power generator. The housing is rotationally mounted on the vehicle body and is configured to rotate, relative to the vehicle body, about a first rotational axis. The power generator is rotationally mounted within the housing and is configured to rotate about a second rotational axis and generate power. The first rotational axis and the second rotational axis are orthogonally disposed. The actuator is coupled to the housing and is operable to selectively rotate the housing about the first rotational axis. By gimballing the rotating mass of the power source a gyroscopic torque can be applied to the vehicle improving its maneuverability.

Aircraft power and propulsion systems and methods of operating the systems, one method includes: operating electric machines of gas turbine engines as generators to extract mechanical power from spools and generating electrical power therefrom; meeting an electrical power demand of a plurality of electrical loads connected with an electrical system by supplying the plurality of electrical loads with electrical power generated by the electric machines; determining when there is an electrical system and/or the gas turbine engine fault and an amount of electrical power generated by the power and propulsion system is reduced to a lower level; and responsive to the determination: during a time period ΔT, controlling the plurality of electrical loads reducing the electrical power demand; and during the time period ΔT, meeting at least part of the electrical power demand of the plurality of electrical loads by discharging the electrical energy storage system.

Multi-engine aircraft power and propulsion systems and methods of starting the engines of multi-engine aircraft disclosed, including supplying electrical power from an electrical power source to electric machines of the a first gas turbine engine and operating electric machines as motors to drive rotation of spools of the first gas turbine engine; starting the first gas turbine engine by lighting combustion equipment of the first gas turbine engine; operating the electric machines of the first gas turbine engine as generators to extract mechanical power and generate electrical power from spools of the first gas turbine engine; transferring the electrical power to electric machines of a second gas turbine engine and operating the electric machines as motors to drive rotation of spools of the second gas turbine engine; and starting the second gas turbine engine by lighting combustion equipment of the second gas turbine engine.

A twin-engine aircraft power and propulsion system including first and second propulsive gas turbine engines, each having combustion equipment and a first and second spool; first, second, third, and fourth electrical power generation sub-systems including electric machines respectively mechanically coupled with the first spool of the first propulsive gas turbine engine, the second spool of the first propulsive gas turbine engine, the first spool of the second propulsive gas turbine engine, and the second spool of the second propulsive gas turbine engine; and first, second, third, and fourth power channels respectively connected with distribution sides of the first electric machine, second electric machine, third electric machine, and fourth electric machine.

A fuselage rear end of an aircraft, comprising a structural part comprising a skin and longitudinal and transversal reinforcing members and a fairing. The structural part longitudinally spans over the whole rear end and comprises a first portion in which the transversal reinforcing members occupy the whole perimeter of the corresponding fuselage section and at least a second portion in which the transversal reinforcing members occupy only a portion of the perimeter of the corresponding fuselage section. The fairing is located below the second portion of the structural part.

A system is provided for multi-engine coordination of gas turbine engine motoring in an aircraft. The system includes a controller operable to determine a motoring mode as a selection between a single engine dry motoring mode and a multi-engine dry motoring mode based on at least one temperature of a plurality of gas turbine engines and initiate dry motoring based on the motoring mode.

An electrical energy generator system for an aircraft, the system including a streamlined fairing containing at least one turbine housed in the front portion of the fairing, and an electrical energy generator connected to said turbine. The front portion of the fairing is fitted with air admission means that are movable between an open position in which the turbine is exposed to the stream of air outside the fairing and a closed position in which the turbine is masked inside the fairing. The system may serve to reduce the aerodynamic drag caused by turbulence present at a wing tip for a conventional wing having sharp edges during stages of takeoff, climbing, and cruising; and during stages of descent it makes it possible to recover the kinetic and potential energy that has been accumulated by the aircraft during its stages of climbing and cruising.

This invention concerns an aircraft propulsion system in which an engine has an engine core comprising a compressor, a combustor and a turbine driven by a flow of combustion products of the combustor. At least one propulsive fan generates a mass flow of air to propel the aircraft. An electrical energy store is provided on board the aircraft. At least one electric motor is arranged to drive the propulsive fan and the engine core compressor. A controller controls the at least one electric motor to mitigate the creation of a contrail caused by the engine combustion products by altering the ratio of the mass flow of air by the propulsive fan to the flow of combustion products of the combustor. The at least one electric motor is controlled so as to selectively drive both the propulsive fan and engine core compressor.