A dual-use air turbine system for a gas turbine engine of an aircraft is provided. The dual-use air turbine system includes a variable area air turbine mechanically linked to a spool of the gas turbine engine through a multi-speed gear set. The dual-use air turbine system also includes a plurality of valves in pneumatic ducting operable to direct an engine start air flow through an inlet of the variable area air turbine and drive rotation of the spool during an engine start mode of operation. The valves are further operable to direct an engine bleed air flow from a compressor section of the gas turbine engine through the inlet of the variable area air turbine and drive rotation of the spool during an environmental control system active mode of operation.

Disclosed are systems and methods for testing aircraft engine that are not currently associated with a functional aircraft or systems. For testing, systems on the engine being tested are connected with the reciprocating systems (e.g., engine electronic controls, main and motive fuel) on a fully functional aircraft using conduits that have been extended to lengths enabling the connection.

A mobile ground power unit includes a housing in which an engine and an electric generator are disposed. The housing features a canopy having an outer wall facing outside. The outer wall has a single piece covering an upper side of the engine and extending downwards along at least two different vertical sides of the ground power unit. The canopy has an inner wall facing inside. The inner wall features a horizontal area covering the upper side of the engine and is extending from the horizontal area downwards along the at least two different vertical sides. The inner wall and the outer wall define a hollow space between each other. The canopy has an integrated ducting system with an inlet opening within the outer wall of the canopy, whereby the hollow space constitutes an air channel for exchanging fluid between the inside and the outside of the housing.

A mobile ground power unit has a housing in which an engine and an electric generator are disposed. The housing features at least one rotor molded or rotor cast component the housing features at least one rotor molded or rotor cast component that serves as an outer shell or part of the outer shell of the housing, whereby the housing features as the at least one rotor molded or rotor cast component one of a canopy covering at least the upper side of the engine and/or the generator a cable tray arranged sideways in relation to the engine and/or the electric generator.

A power electronics module is provided having one or more power converter semiconductor components. The power electronics module further has a substrate having a first surface to which the one or more components are mounted, and having an opposing second surface from which project a plurality of heat transfer formations for enhancing heat transfer from the substrate. The power electronics module further has a coolant housing which sealingly connects to the substrate to form a void over the heat transfer formations of the second surface. The coolant housing has an inlet for directing a flow of an electrically insulating coolant into the void and an outlet for removing the coolant flow from the void, whereby heat generated during operation of the one or more components is transferred into the coolant flow via the substrate.

A power electronics module is provided having one or more power converter semiconductor components. The power electronics module further has a substrate having a first surface to which the one or more components are mounted, and having an opposing second surface from which project a plurality of heat transfer formations for enhancing heat transfer from the substrate. The power electronics module further has a coolant housing which sealingly connects to the substrate to form a void over the heat transfer formations of the second surface. The coolant housing has an inlet for directing a flow of an electrically insulating coolant into the void and an outlet for removing the coolant flow from the void, whereby heat generated during operation of the one or more components is transferred into the coolant flow via the substrate.

The disclosure relates to a Mobile ground power unit for supplying power to an aircraft parked on the ground, the ground power unit comprising an engine, an electric generator, whereby the electric generator is configured to be driven by the engine, a housing whereby the engine and the electric generator are disposed within the housing, and a fuel tank, wherein the fuel tank comprises a wall that forms at least one channel that allows air to pass from one side of the fuel tank to another side of the fuel tank. The disclosure further relates to a fuel tank for a ground power unit.

A system for starting a gas turbine engine of an aircraft is provided. The system includes a pneumatic starter motor, a discrete starter valve switchable between an on-state and an off-state, and a controller operable to perform a starting sequence for the gas turbine engine. The starting sequence includes alternating on and off commands to an electromechanical device coupled to the discrete starter valve to achieve a partially open position of the discrete starter valve to control a flow from a starter air supply to the pneumatic starter motor to drive rotation of a starting spool of the gas turbine engine below an engine idle speed.

A system for starting a gas turbine engine of an aircraft is provided. The system includes a pneumatic starter motor, a discrete starter valve switchable between an on-state and an off-state, and a controller operable to perform a starting sequence for the gas turbine engine. The starting sequence includes alternating on and off commands to an electromechanical device coupled to the discrete starter valve to achieve a partially open position of the discrete starter valve to control a flow from a starter air supply to the pneumatic starter motor to drive rotation of a starting spool of the gas turbine engine below an engine idle speed.

Disclosed are systems and methods for testing aircraft engine that are not currently associated with a functional aircraft or systems. For testing, systems on the engine being tested are connected with the reciprocating systems (e.g., engine electronic controls, main and motive fuel) on a fully functional aircraft using conduits that have been extended to lengths enabling the connection.