A method of operating a turbine engine that includes actuating a starter motor of the turbine engine such that a motoring speed of the turbine engine increases, and actuating a plurality of variable stator vanes of the turbine engine such that the plurality of variable stator vanes are at least partially open to control the motoring speed of the turbine engine.

A system and method for improved system efficiency of an integrated power and control unit (IPCU) of an aircraft is disclosed. The system uses an open-loop cooling system and turbo machine power matching to provide wide operation range without over-sizing. In order to reduce the temperature of the air flow through the cooling heat exchanger, the cooling turbine need to expand further in the same time generating power but the power could be higher than the compressor could absorb so a generator that would convert the power and used in supplying the aircraft would result in more efficient system.

Systems and techniques for engine starter control may include determining a current speed band associated with an engine start for a current time increment, determining a previous speed band associated with the engine start for a previous time increment within the engine start, receiving a measured current value, determining a target current value based on the current speed band, the previous speed band, whether an acceleration or deceleration occurred between the current speed band and the previous speed band, and a mode of a system for engine starter control, and adjusting a current for the engine start based on the target current value.

A method of operating a twin engine helicopter power plant, the power plant comprising: two turboshaft engines each having an engine shaft with a turbine at a distal end and a one-way clutch at a proximal end; a gear box having an input driven by the one way clutch of each engine and an output driving a helicopter rotor; a bypass clutch disposed between the proximal end of each engine shaft and the input of the gear box; and power plant management system controls for activating the bypass clutch; the method comprising: detecting when a rotary speed of an associated engine shaft is less than a rotary speed of the gear box input; activating the bypass clutch to drive the associated engine shaft using the rotation of the gear box input; and starting an associated engine by injecting fuel when the bypass clutch is activated.

A gas turbine engine starting system including an electric start generator (ESG) free of temperature sensors and configured to provide torque to a gas turbine engine. A fuel metering module is configured to provide a quantity of fuel to the gas turbine engine, and an electronic control system (ECS). The ESG includes a plurality of subcomponents. The ECS is configured to predict a future temperature of the ESG, predict that at an ongoing start or an uninitiated start will be unsuccessful, and provide the prediction that at an ongoing start or an uninitiated start will be unsuccessful to an operator. The prediction of the future temperature of the ESG is based on a plurality of historical ESG thermal trending information and an input ambient temperature. The prediction that at an ongoing start or an uninitiated start will be unsuccessful is based on the future temperature of the ESG.

A gas turbine engine starting system including an electric start generator (ESG) free of temperature sensors and configured to provide torque to a gas turbine engine. A fuel metering module is configured to provide a quantity of fuel to the gas turbine engine, and an electronic control system (ECS). The ESG includes a plurality of subcomponents. The ECS is configured to predict a future temperature of the ESG, predict that at an ongoing start or an uninitiated start will be unsuccessful, and provide the prediction that at an ongoing start or an uninitiated start will be unsuccessful to an operator. The prediction of the future temperature of the ESG is based on a plurality of historical ESG thermal trending information and an input ambient temperature. The prediction that at an ongoing start or an uninitiated start will be unsuccessful is based on the future temperature of the ESG.

A method of cooling a shaft of a gas turbine engine includes moving a control valve towards a position that inhibits fluid flow from a high pressure air source to an air turbine starter and enables fluid flow from a blower motor to the air turbine starter, in response to a gas turbine engine shutdown. The method further includes operating the blower motor to provide air to the air turbine starter.

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.

Aircraft hydrogen fuel systems and methods and systems of starting such systems are described. The aircraft hydrogen fuel systems include a hydrogen burning main engine, a main tank configured to contain liquid hydrogen to be supplied to the main engine during a normal operation, and a starter tank configured to contain gaseous hydrogen to be used during a startup operation of the main engine. Methods and processes for starting and/or restarting such systems are described.