Methods and systems for fault detection of a fuel control unit of an engine are provided. Exceedance of at least one engine parameter beyond a safety threshold, associated with excessive fuel flow to the engine, is detected at an engine controller associated with the engine. The fuel control unit is commanded, via the engine controller, to implement a reduction in the fuel flow to the engine. Following the commanding of the fuel control unit, subsequent exceedance of the at least one engine parameter beyond the safety threshold is detected at the engine controller. A fault of the fuel control unit is determined at the engine controller, based on the subsequent exceedance. In response to determining the fault of the fuel control unit, at least one countermeasure to the fault of the fuel control unit is triggered by the engine controller.

An aircraft propulsion system includes a gas turbine engine; a generator; a storage battery; a motor which drives a rotor, using at least one of the electric power which is output from the generator and the electric power which is output from the storage battery; a detection unit which detects the number of revolutions of the engine shaft; an engine control unit which controls at least a fuel flow rate of the gas turbine engine; and a generator control unit which controls the operation of the generator. When the number of revolutions satisfies a predetermined condition, at least the generator control unit executes a control for reducing a sudden change in the number of revolutions.

In a fuel control system (10) for a gas turbine engine (1) having a gas generator (4) and a turbine (6) driven by the gas generator (4): a main fuel regulator (12) determines a demand (W.sub.fdem) of fuel flow (W.sub.f) to be introduced in the gas turbine engine (1), based on an input request (PLA); and a first limiter stage (14), operatively coupled to the main fuel regulator (12), causes an adjustment of the fuel flow (W.sub.f) based on engine safety operating limits. The first limiter stage (14) is provided with a Ngdot limiter (20) to cause an adjustment of the fuel flow (W.sub.f) when the gas generator speed rate of change (N.sub.gdot) is determined to overcome acceleration/deceleration scheduled safety limits; the Ngdot limiter (20) implements a predictor (23), to perform a prediction (W.sub.fdot) of the fuel flow rate of change (W.sub.fdot), or fuel flow (W.sub.f), allowing the gas generator speed rate of change (N.sub.gdot) to track a scheduled reference value (Ngdot.sub.ref).

The invention concerns a method for monitoring the operating state of a system for positioning variable-geometry members (18) of a turbomachine (10), the members (18) being configured to travel over an operating area comprising a first position P1 and a second position P2, the method comprising the steps of: -(E23) determining a first pivoting speed V1 from the first position P1 to the second position P2; -(E25) determining a second pivoting speed from the second position P2 to the first position P1; and -(E26) determining an anomaly in the operation of the system for positioning the members (18) if the first speed V1 is lower than a first determined speed threshold and/or if the second speed V2 is lower than a second determined speed threshold.

A system and method for adaptively controlling a cooldown cycle of an auxiliary power unit (APU) that is operating and rotating at a rotational speed includes reducing the rotational speed of the APU to a predetermined cooldown speed magnitude that ensures combustor inlet temperature has reached a predetermined temperature value, determining, based on one or more of operational parameters of the APU, when a lean blowout of the APU is either imminent or has occurred, and when a lean blowout is imminent or has occurred, varying one or more parameters associated with the shutdown/cooldown cycle.

In a fuel control system (10) for a gas turbine engine (1) having a gas generator (4) and a turbine (6) driven by the gas generator (4): a main fuel regulator (12) determines a demand (W.sub.fdem) of fuel flow (W.sub.f) to be introduced in the gas turbine engine (1), based on an input request (PLA); and a first limiter stage (14), operatively coupled to the main fuel regulator (12), causes an adjustment of the fuel flow (W.sub.f) based on engine safety operating limits. The first limiter stage (14) is provided with a Ngdot limiter (20) to cause an adjustment of the fuel flow (W.sub.f) when the gas generator speed rate of change (N.sub.gdot) is determined to overcome acceleration/deceleration scheduled safety limits; the Ngdot limiter (20) implements a predictor (23), to perform a prediction (W.sub.fdot) of the fuel flow rate of change (W.sub.fdot), or fuel flow (W.sub.f), allowing the gas generator speed rate of change (N.sub.gdot) to track a scheduled reference value (Ngdot.sub.ref).

A method of controlling electrical power supplied to a component of a vehicle, the method comprising: receiving a signal comprising information associated with an operating condition of a gas turbine engine; determining whether a parameter exceeds a predetermined threshold value using the information in the received signal; and controlling a reduction in electrical power supplied to a component of a vehicle from a generator of the gas turbine engine if the parameter exceeds the predetermined threshold value.

A fuel assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a fuel valve that meters flow of fluid between a combustor and a fuel supply, and a controller in communication with the fuel assembly. The controller is programmed to receive data corresponding to a present rotational speed of a gas turbine engine component and data corresponding to at least one present flight condition, and is programmed to cause a flow rate from the fuel valve to change in response to determining that a rate of change in an acceleration rate relating to the present rotational speed meets at least one predetermined threshold. At least one predetermined threshold relates to an engine light-off event of the combustor and is based upon the at least one present flight condition.

Methods and systems for measuring an axial position of a rotating component of an engine are described herein. The method comprises obtaining a signal from a sensor coupled to the rotating component, the rotating component having a plurality of position markers distributed about a surface thereof, the position markers having an axially varying characteristic configured to cause a change in a varying parameter of the signal as a function of the axial position of the rotating component. Based on the signal, the method comprises determining a rotational speed of the rotating component from the signal, determining the varying parameter of the signal, and finding the axial position of the rotating component based on a known relationship between the axial position, the rotational speed, and the varying parameter of the signal.

An example method includes obtaining a representation of a change in rotational speed of an electric machine; obtaining a representation of an expected change in rotational speed of the electric machine; and determining, based on the obtained representation of the change in rotational speed of the electric machine and the representation of an expected change in rotational speed of the electric machine, whether a disconnect device has failed, wherein, when operating in an engaged state, the disconnect device is configured to couple rotational mechanical energy between the electric machine and a rotating device, and wherein, when operating in a disengaged state, the disconnect device is not configured to couple rotational mechanical energy between the electric machine and the rotating device.