A gas turbine engine shut-down system includes a pump configured to draw a flow of fuel from a source, a fuel nozzle configured to receive the flow of fuel from the pump, a fuel shut-off valve in fluid communication with the pump, a recirculation circuit for circulating excess fuel to a location upstream of the pump; a solenoid valve in communication with the pump and the recirculation circuit; and a fuel-bypass valve. The fuel-bypass valve includes a first opening connected to the fuel pump, a second opening connected to the fuel shut-off valve, a third opening connected to the recirculation circuit, a fourth opening connected to the solenoid valve, and a piston disposed within the fuel-bypass valve and movable between a plurality of positions.

A method and decoupler for disengaging an output shaft from an engine in a back drive event with a backdrive decoupler. The backdrive decoupler includes a threaded shaft and a retention mechanism selectively coupling the output shaft to the threaded shaft. In a backdrive event, the decoupler decouples the output shaft from a drive shaft.

A dual trip manifold assembly (TMA) includes an isolation valve assembly having a first valve configured to receive a flow of fluid from a hydraulic system fluid supply. The first valve is configured to channel the flow of fluid to at least one hydraulic circuit. The isolation valve assembly also includes a second valve configured to receive the flow of fluid from the at least one hydraulic circuit. The second valve is further configured to channel the fluid flow to a trip header. The first valve and the second valve are synchronized to each other such that rotation of one valve causes a substantially similar rotation in the other valve.

A speed control system and a power load balance detector for a turbine is provided. The speed control system includes a speed wheel with a plurality of teeth. A timer stores a time stamp when each of the teeth passes by a speed probe. A first speed estimate is determined for overspeed protection, and a second speed estimate is determined for operational speed control. The power load balance detector trips or shuts down the turbine when an unbalance is above a first threshold and the speed of the turbine is above a second threshold.

A gas turbine engine comprises a relatively high pressure compressor coupled to a relatively high pressure turbine by a relatively high pressure shaft; a relatively low pressure compressor coupled to a relatively low pressure turbine by a relatively low pressure shaft rotatable independently of the high pressure shaft; a first combustor located downstream of the high pressure compressor and upstream of the high pressure turbine; and a second combustor located downstream of the high pressure turbine, and upstream of the low pressure turbine. The engine further comprises a coupling arrangement configured to selectively transfer torque between the high pressure shaft and the low pressure shaft.

Aircraft turbine engine (10), comprising at least one first compressor, an annular combustion chamber (70) and at least one first turbine (46), which define a first flow duct (22) for a primary flow, characterised in that it comprises, between said combustion chamber (70) and said first turbine (46), a device (55, 55′) for discharging at least part of said primary flow.

A bowed rotor start mitigation system for a gas turbine engine of an aircraft is provided. The bowed rotor start mitigation system includes a motoring system and a controller coupled to the motoring system and an aircraft communication bus. The controller is configured to determine at least one inferred engine operating thermal parameter from at least one aircraft-based parameter received on the aircraft communication bus. The motoring system is controlled to drive rotation of a starting spool of the gas turbine engine below an engine idle speed based on determining that the at least one inferred engine operating thermal parameter is within a preselected threshold.

A method is provided of controlling a gas turbine having a shaft connecting a compressor to a turbine, as well as having a reheat system, and a gas turbine. The method includes the steps of: operating the engine using the reheat system to provide a mass flow rate of reheat fuel into a gas flow of the gas turbine engine downstream of an exit of the turbine; detecting a shaft break event in the shaft; and in response to this detection, maintaining the mass flow rate of the reheat fuel being provided into the gas flow downstream of the turbine exit, whereby the maintained mass flow rate of reheat fuel raises a back pressure downstream of the turbine and thereby reduces a rotational speed of the turbine.

A turbine vane of a turbine engine is described. The turbine vane includes a blade and a root. The root includes a stilt having lateral flanks with a curvilinear profile. The stilt includes a frangible zone suitable for undergoing a breakage of the stilt if radial forces higher than a threshold are exerted on the vane, in particular centrifugal forces during an overspeed state of the turbine. The frangible zone includes at least one oblong frangibility recess formed on at least one of the lateral flanks of the stilt, the oblong recess extending in an axial direction of the stilt along a longitudinal axis parallel to or included in a minimum cross-sectional plane which contains a minimum cross-section of the stilt.

A method for stopping an engine of a rotorcraft in overspeed, the rotorcraft comprising at least one engine, the engine comprising a gas generator and a power assembly, the power assembly comprising at least one power turbine rotated by gases originating from the gas generator, the power assembly comprising at least one power shaft rotationally secured to the power turbine, the power assembly rotating about a longitudinal axis at a speed referred to as the “speed of rotation”. The method comprises steps consisting in measuring a current value of the speed of rotation, determining a time derivative of the current value of the speed of rotation, referred to as the “current derivative

[00001]$\left(\frac{dN2i}{dt}\right)”,$

and automatically stopping the engine when the current derivative

[00002]$\left(\frac{dN2i}{dt}\right)$

changes sign.