A gas turbine includes a compressor configured to compress air; a combustor configured to mix and combust fuel and compressed air compressed by the compressor; a turbine configured to obtain rotational power using combustion gas generated by the combustor; an inlet guide vane disposed at an intake of the compressor to adjust a flow rate of air flowing into the compressor; a bleed line configured to return a part of the compressed air pressurized in the compressor to the intake of the compressor; and an on-off valve disposed in the bleed line. When the output of the gas turbine increases, a preset maximum value limit of the inlet guide vane is corrected based on a valve opening degree command value of the on-off valve and a compressor intake temperature such that the gas turbine achieves a predetermined performance.

A control system is provided for a turbine valve. The turbine valve has a first coil and a second coil to control or sense movement of a mechanical valve positioner. Two valve positioners are provided with each valve positioner having two drive circuits to drive the first and second coils. Switches are provided such that only one drive circuit is connected to each coil at a time. The control system may also include a hydraulic pilot valve section and a main hydraulic valve section. Feedbacks are used to determine a pilot valve error and a main valve error which are combined to determine a turbine valve error. The turbine valve error is repeatedly determined to minimize the error.

A multi-engine aircraft includes a first engine drivingly engaged to a common rotatable load and a second engine drivingly engaged to the common rotatable load, the second engine having a bleed air system and a control system in communication with a compressed air switching system. The control system controls operation of the second engine and/or the compressed air switching system. The compressed air switching system includes a switching valve that is displaceable between at least a first position and a second position, the first position interconnecting a lower pressure inlet and a switch outlet, and the second position interconnecting a high pressure inlet and the switch outlet. The switch outlet is in communication with the bleed air system of the second engine. The control system actuates the switching valve to switch between the first and second positions.

A breaker between two electrical circuits is provided that is closed when electrical properties in both of the electrical circuits are matching. Two check circuits are provided for comparing electrical properties of the two electrical circuits. Each of the check circuits sets a corresponding authorization to close the breaker. The breaker is only closed if both check circuits set an authorization to close the circuit.

An assembly is provided for a turbine engine with an axial centerline. This assembly includes a turbine engine structure and a valve assembly. The turbine engine structure includes an outer duct wall, an inner duct wall, a first flow path and a second flow path. The inner duct wall is radially inward of the outer duct wall. The first flow path is radially inward of the inner duct wall. The second flow path is radially outward of the inner duct wall and is radially inward of the outer duct wall. The valve assembly includes a valve element and a valve actuator. The valve element is configured to regulate flow of fluid between the first flow path and the second flow path. The valve actuator is configured to move the valve element. The valve actuator is positioned entirely radially outward of the outer duct wall.

An assembly is provided for a turbine engine with an axial centerline. This assembly includes a turbine engine structure and a valve assembly. The turbine engine structure includes an outer duct wall, an inner duct wall, a first flow path and a second flow path. The inner duct wall is radially inward of the outer duct wall. The first flow path is radially inward of the inner duct wall. The second flow path is radially outward of the inner duct wall and is radially inward of the outer duct wall. The valve assembly includes a valve element and a valve actuator. The valve element is configured to regulate flow of fluid between the first flow path and the second flow path. The valve actuator is configured to move the valve element. The valve actuator is positioned entirely radially outward of the outer duct wall.

A hybrid-electric aircraft system is provided and includes first and second hybrid-electric engines, first and second ducting systems fluidly communicative with each other and with the first and second hybrid-electric engines, respectively, and a control system. The control system is operably coupled to each of the first and second hybrid-electric engines and to each of the first and second ducting systems. The control system is configured to run the first hybrid-electric engine normally, to run the second hybrid-electric engine in a lower power mode and to control each of the first and second ducting systems to direct bleed air from the first hybrid-electric engine to the second hybrid-electric engine.

A turbine speed probe diagnostic system is provided. The turbine includes a speed probe and a speed reading circuit. A speed lead connects the speed probe and speed reading circuit together to transmit speed signals from the speed probe to the speed reading circuit. A speed probe diagnostic circuit is also provided for connection to the speed lead. An isolation switch is provided to isolate the speed probe diagnostic circuit during normal operation when the speed reading circuit is receiving speed signals from the speed probe. When no speed signals are being received, the isolation switch closes and the speed probe diagnostic circuit performs a test on the speed probe or speed lead.

A control system of a gas turbine engine is provided. The engine has a fuel flow metering valve which regulates a fuel flow to the engine, and one or more variable geometry components which are movable between different set points to vary an operating configuration of the engine. The control system has an engine fuel control sub-system which provides a fuel flow demand signal for controlling the fuel flow metering valve. The control system further has a variable geometry control sub-system which determines current set points to be adopted by the variable geometry components given the current engine operating condition in order to comply with one or more engine constraints. The control system further has an optimiser that receives the current set points and determines adjusted values of the set points which optimise, while complying with the engine constraints, an objective function modelling a performance characteristic of the engine, the objective function adapting to change in engine performance with time. The control system further has a feedback loop in which the adjusted values of the set points thus-determined are sent to the variable geometry control sub-system to vary the current set points.

A control system of a gas turbine engine is provided. The engine has a fuel flow metering valve which regulates a fuel flow to the engine, and one or more variable geometry components which are movable between different set points to vary an operating configuration of the engine. The control system has an engine fuel control sub-system which provides a fuel flow demand signal for controlling the fuel flow metering valve. The control system further has a variable geometry control sub-system which determines current set points to be adopted by the variable geometry components given the current engine operating condition in order to comply with one or more engine constraints. The control system further has an optimiser that receives the current set points and determines adjusted values of the set points which optimise, while complying with the engine constraints, an objective function modelling a performance characteristic of the engine, the objective function adapting to change in engine performance with time. The control system further has a feedback loop in which the adjusted values of the set points thus-determined are sent to the variable geometry control sub-system to vary the current set points.