The invention deals with the restriction on the mode change of an engine due to latching in the case of restarting the engine that has stopped in flight. A FADEC that controls an engine of an aircraft in accordance with a mode, includes a latch operating section that latches the mode, and an in-parking/in-flight determining section that determines whether the aircraft is on the ground or flying off the ground. The latch operating section operates when the in-parking/in-flight determining section determines the aircraft is on the ground, and does not operate when the in-parking/in-flight determining section determines that the aircraft is in fight.

The method allows to detect flameout in a combustor of a turbine system; it comprises the steps of: A) measuring angular acceleration of a shaft of the or each turbine of the turbine system, B) calculating a flameout indicator as a function of the angular acceleration, and C) carrying out a comparison between the flameout indicator and at least one threshold.

A control system for an in-flight engine restart system of a rotorcraft includes an engine control unit that controls and detects status of an engine. The control system also includes a flight control computer that communicates with the engine control unit, an engine operation control system, and a pilot interface including pilot controls. The engine operation control system includes a processor that initiates a health check of the in-flight engine restart system to determine an in-flight engine restart system status. The engine operation control system processes engine mode of operation commands to establish an engine mode of operation, and delivers commands to aspects of the in-flight engine restart system including the engine control unit based on processing of the engine mode of operation commands. The engine operation control system reports the in-flight engine restart system status and results of the engine mode of operation commands to the flight control computer.

A control system for an in-flight engine restart system of a rotorcraft includes an engine control unit that controls and detects status of an engine. The control system also includes a flight control computer that communicates with the engine control unit, an engine operation control system, and a pilot interface including pilot controls. The engine operation control system includes a processor that initiates a health check of the in-flight engine restart system to determine an in-flight engine restart system status. The engine operation control system processes engine mode of operation commands to establish an engine mode of operation, and delivers commands to aspects of the in-flight engine restart system including the engine control unit based on processing of the engine mode of operation commands. The engine operation control system reports the in-flight engine restart system status and results of the engine mode of operation commands to the flight control computer.

An assistance device for a free-turbine engine of an aircraft having at least two free-turbine engines, the device including an electrical starter machine for providing prolonged assistance to the gas generator of a first engine using energy produced by an electric generator machine driven by the second engine, the device further including at least one electricity storage member electrically connected to the electrical starter machine for providing a burst of assistance to the gas generator, wherein the electrical starter machine is powered by a first power converter enabling it to exchange energy with the storage member for providing the burst of assistance, and that transmits thereto the energy supplied by a second power converter for the prolonged assistance.

An assistance device for a free-turbine engine of an aircraft having at least two free-turbine engines, the device including an electrical starter machine for providing prolonged assistance to the gas generator of a first engine using energy produced by an electric generator machine driven by the second engine, the device further including at least one electricity storage member electrically connected to the electrical starter machine for providing a burst of assistance to the gas generator, wherein the electrical starter machine is powered by a first power converter enabling it to exchange energy with the storage member for providing the burst of assistance, and that transmits thereto the energy supplied by a second power converter for the prolonged assistance.

In one aspect, a fuel supply system may include a fuel injector having a primary and a secondary pilot fuel nozzle in fluid communication with a primary and a secondary fuel circuit, respectively, and a main fuel nozzle in fluid communication with a main fuel circuit. The fuel injector may also define a by-pass fuel circuit connected between the primary circuit and the secondary circuit and/or the main circuit. The system may also include a primary fuel manifold configured to be fluidly connected to the primary pilot fuel nozzle via the primary fuel circuit. Moreover, the system may include a by-pass valve provided in operative association with the by-pass fuel circuit. The by-pass valve may be configured to be opened such that a portion of the fuel flowing through the primary circuit from the primary fuel manifold is directed to the secondary circuit and/or the main circuit.

In one aspect, a fuel supply system may include a fuel injector having a primary and a secondary pilot fuel nozzle in fluid communication with a primary and a secondary fuel circuit, respectively, and a main fuel nozzle in fluid communication with a main fuel circuit. The fuel injector may also define a by-pass fuel circuit connected between the primary circuit and the secondary circuit and/or the main circuit. The system may also include a primary fuel manifold configured to be fluidly connected to the primary pilot fuel nozzle via the primary fuel circuit. Moreover, the system may include a by-pass valve provided in operative association with the by-pass fuel circuit. The by-pass valve may be configured to be opened such that a portion of the fuel flowing through the primary circuit from the primary fuel manifold is directed to the secondary circuit and/or the main circuit.

Several embodiments include a system and method for providing thrust recovery in an aircraft engine. The system and method enables a wider range of safe operation for aircraft where the aircraft engine is rapidly reactivated from a substantially deactivated state. The method thereby reduces noise output and fuel usage during descent and shortens runway lengths and occupancy time required for landing. Thrust recovery is provided via the use of stored bleed air being re-injected back into the aircraft engine. An onboard air storage tank and a system of valves facilitating this method are disclosed.

A method for use in a turbine control system includes controlling fuel supply to a gas turbine engine at least in part using a fuel supply limit determined as a first function of a rotational speed of a shaft of the gas turbine engine. The method also includes obtaining a first value representative of a rotational speed of the shaft, and differentiating the first value within a processing unit. The processing unit determines an adjusted fuel supply limit as an adjusted function of the first value. The adjusted function is based on the first function and the differentiated first value. The method further includes controlling the fuel supply to the gas turbine engine at least in part using the adjusted fuel supply limit.