Abstract: An aspect includes a method for motoring control for multiple engines of an aircraft is provided. A controller can determine a motoring time of a first engine starting system to cool a first engine. The controller can compare the motoring time of the first engine starting system with a motoring time of one or more other engine starting systems of one or more other engines of the aircraft. The motoring time of the first engine starting system can be controlled relative to a tolerance of the motoring time of the one or more other engine starting systems by adjusting the motoring time of the first engine starting system relative to the one or more other engine starting systems in a motoring sequence based on comparing the motoring time of the first engine starting system with the motoring time of the one or more other engine starting systems.

Abstract: An aircraft engine, has: a low-pressure compressor and a high-pressure compressor located downstream of the low-pressure compressor; a gaspath valve upstream of the high-pressure compressor, the gaspath valve movable between an open configuration and a closed configuration; and a bypass flow path having in flow series a bypass inlet, a bypass valve, and a bypass outlet, the bypass inlet fluidly communicating with the gaspath upstream of at least one stage of the low-pressure compressor, the bypass valve having an open configuration in which the bypass valve allows a bypass flow and a closed configuration in which the bypass valve blocks the bypass flow, the bypass outlet fluidly communicating with the bypass inlet via the bypass valve and with the gaspath at a location in the gaspath fluidly downstream of the gaspath valve, downstream of the low-pressure compressor, and upstream of the high-pressure compressor.

Abstract: A switching device including at least one main breaker, an actuator configured to cause a change of state of the main breaker, from a first to a second state, counter to a spring generated force, the actuator being powered by a control signal equal to a first level to cause the change of state of the main breaker then to a second, lower level, to hold the main breaker in the second state. The switching device comprises a current sensor configured to control the control signal to increase it to a third level higher than the second level if the current flowing in the main breaker is higher than or equal to a given operating threshold, to avoid a spurious change of state of the main breaker. The switching device comprises a re-armable protection system for controlling the time for which the control signal is held at the third level.

Abstract: Turbine engine systems and aircraft having such systems are described. The turbine engine systems include a combustor arranged along a core flow path of the turbine engine, a drive shaft having at least a compressor section and a turbine section coupled thereto, a cryogenic fuel tank configured to supply a fuel to the combustor, and an expansion turbine mechanically coupled to the drive shaft, the expansion turbine configured to receive fuel from the cryogenic fuel tank and expand said fuel, wherein expansion of said fuel by the expansion turbine drives rotation of the expansion turbine to provide power input to the drive shaft.

Abstract: A gas turbine engine includes a low-pressure spool, a high-pressure spool, and an electric motor. The low-pressure spool includes a low-pressure compressor in rotational communication with a low-pressure turbine and a fan via a first shaft. The high-pressure spool includes a high-pressure compressor in rotational communication with a high-pressure turbine via a second shaft. The electric motor is operably connected to the second shaft. The electric motor is configured to apply a rotational force to the second shaft.

Abstract: A system is provided for multi-engine coordination of gas turbine engine motoring in an aircraft. The system includes a controller operable to determine a motoring mode as a selection between a single engine dry motoring mode and a multi-engine dry motoring mode based on at least one temperature of a plurality of gas turbine engines and initiate dry motoring based on the motoring mode.

Abstract: A method for operating a hybrid electric propulsion system of an aircraft, the hybrid electric propulsion system comprising a turbomachine, an electric machine coupled to the turbomachine, and a propulsor coupled to the turbomachine, the method comprising: operating the turbomachine to drive the propulsor; receiving data indicative of a failure condition of the hybrid electric propulsion system; and extracting power from the turbomachine using the electric machine to slow down one or more rotating components of the turbomachine in response to receiving the data indicative of the failure condition.

Abstract: The present disclosure relates to an architecture of a propulsion system of a multi-engine helicopter comprising turboshaft engines connected to a power transmission gearbox, characterized in that it comprises: at least one hybrid turboshaft engine capable of operating in at least one standby mode during a stable cruise flight of the helicopter; at least two systems for controlling each hybrid turboshaft engine, each system comprising an electric machine connected to the hybrid turboshaft engine and suitable for rotating the gas generator thereof, and at least one source of electrical power for the electric machine, each reactivation system being configured such that it can drive the turboshaft engine in at least one operating mode among a plurality of predetermined modes.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: An engine includes a single cylinder, at least one sensor, a fuel injector, and a controller. The at least one sensor is configured to generate sensor data for an engine condition. The controller is configured to perform a comparison of the engine condition to a threshold and in response to the comparison, generate a first command to deactivate the fuel injector after a first predetermined time period and a second command to reactivate the fuel injector after a second predetermined time period.

Abstract: There is provided a dynamic motoring system and method for an aircraft engine. Motoring of the engine is initiated for an initial motoring duration and at an initial motoring interval. At least one engine parameter is measured in real-time during the motoring, the at least one engine parameter comprising a temperature of the engine. The initial motoring duration and the initial motoring interval are modified in real-time, based on a value of the at least one engine parameter during the motoring, to obtain a modified motoring duration and a modified motoring interval. The motoring continues for the modified motoring duration and at the modified motoring interval, with a speed of rotation of the engine being controlled using the modified motoring interval.

Abstract: A hybrid-electric propulsion system for an aircraft is provided herein that can include a propulsor and a turbomachine comprising a high pressure turbine drivingly coupled to a high pressure compressor through a high pressure spool. An auxiliary power unit can be operably coupled with a starter motor. An electrical system can comprise a first electric machine coupled to the turbomachine. The first electric machine can be separate from the starter motor. A controller can be configured to provide electrical power from an electric power source to the first electric machine to drive the first electric machine to start, or assist with starting, the turbomachine.

Abstract: A system may comprise a sensor configured to measure a characteristic of an engine component. A valve assembly may have an airflow outlet in fluid communication with the engine component. The valve assembly may include a first valve. A first valve control device may be coupled to the first valve and configured to control the first valve based on a measurement by the sensor. A second valve may be in fluidic series with the first valve. A second valve control device may be coupled to the second valve and configured to control the second valve based on the measurement by the sensor.

Abstract: Methods and systems are provided for presenting an energy state associated with an aircraft with respect to an operating envelope region for a procedure to restart an engine of the aircraft. One method involves providing a graphical user interface display having a first reference axis corresponding to a first energy state parameter and a second reference axis corresponding to a second energy state parameter different from the first energy state parameter, providing a graphical representation of an operating envelope region associated with a procedure for starting an engine of the aircraft with respect to the first and second reference axes, obtaining current values for the first and second energy state parameters for the aircraft, and providing a graphical representation of the aircraft positioned with respect to the first and second reference axes based on the current values for the first and second energy state parameters.

Abstract: The invention relates to a method for starting a turbine engine in cold weather, including a starting system intended for rotating a drive shaft of the turbine engine, the method comprising the following steps: —a pre-starting step in which a first starting signal is generated to control the drive shaft in a first direction of rotation about a longitudinal axis (X) and in a second opposite direction of rotation in an alternating manner; and —a starting step in which a second starting signal is transmitted to the starting system in order for the latter to drive the drive shaft of the turbine engine in a normal direction of rotation and in which the drive shaft is rotated until a rotation speed that causes the turbine engine to start.

Abstract: A signal processing apparatus includes a CPU which executes an input step of receiving an input of a measurement value of a target parameter at a first time, in which noise is superimposed on a true value of the target parameter, a calculation step of calculating a variation amount of the measurement value of the target parameter at the first time, based on a maximum likelihood estimate of the target parameter at a second time and calculating a maximum likelihood estimate of the variation amount, and an output step of outputting a value obtained by adding the maximum likelihood estimate of the variation amount to the maximum likelihood estimate of the target parameter at the second time, as a maximum likelihood estimate of the target parameter at the first time.

Abstract: A fuel and oil system includes a fuel pump, an oil pump, and a fixed electrical drive. A first electric motor controller of the fuel and oil system supplies a variable electrical drive, and a second electric motor controller supplies a variable electrical drive. The fuel pump is selectively connected to and driven by the first electric motor controller or the second electric motor controller. The oil pump is selectively connected to and driven by the second electric motor controller or the fixed electrical drive.

Abstract: The present disclosure is directed to a method of operating a combustion system to attenuate combustion dynamics. The method includes flowing, via a compressor section, an overall supply of air to the combustion system; flowing, via a fuel supply system, an overall flow of fuel to the combustion system; flowing, to a first fuel nozzle of the combustion system, a first supply of fuel defining a richer burning fuel-air mixture at the first fuel nozzle; flowing, to a second fuel nozzle of the combustion system, a second supply of fuel defining a leaner burning fuel-air mixture at the second fuel nozzle; and igniting the richer burning fuel-air mixture and the leaner burning fuel-air mixture to produce an overall fuel-air ratio at a combustion chamber of the combustion system.

Abstract: A method of controlling at least part of a start-up or re-light process of a gas turbine engine, the method comprising: increasing an angular velocity of a low pressure compressor; determining if an exit pressure of the low pressure compressor is equal to or greater than a first threshold pressure; in response to determining that the exit pressure of the low pressure compressor is equal to or greater than the first threshold pressure, controlling rotation of the low pressure compressor using a first electrical machine and controlling rotation of a high pressure compressor using a second electrical machine, to increase angular velocity of the high pressure compressor; determining if an exit pressure of the high pressure compressor is equal to or greater than a second threshold pressure.

Abstract: An aspect includes a system for pre-start motoring control for multiple engines of an aircraft. The system includes a first engine starting system of a first engine and a controller. The controller is operable to control a motoring time of the first engine starting system relative to one or more other engine starting systems of one or more other engines of the aircraft by adjusting the motoring time of the first engine starting system within a tolerance of the motoring time of the one or more other engine starting systems in a pre-start motoring sequence.

Abstract: Herein provided are methods and systems for detecting an abnormal engine start of a gas turbine engine. An inter-turbine temperature of the engine is measured during engine start. The inter-turbine temperature is compared to an inter-turbine temperature threshold which depends on at least one additional parameter. An abnormal engine start is detected when the inter-turbine temperature exceeds the threshold. The at least one additional parameter may comprise engine rotational speed. The at least one additional parameter may comprise time.

Abstract: The invention relates generally to gas turbine engines used for electrical power generation. More specifically, embodiments of the present invention provide systems and ways for improving gas turbine engine reliability through an electric motor backup system for cooling features of the turbine section.

Abstract: 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.

Abstract: Methods and systems for supply of fuel for a turbine-driven fracturing pump system used in hydraulic fracturing may be configured to identify when the supply pressure of primary fuel to a plurality of gas turbine engines of a plurality of hydraulic fracturing units falls below a set point, identify a gas turbine engine of the fleet of hydraulic fracturing units operating on primary fuel with highest amount of secondary fuel available, and to selectively transfer the gas turbine engine operating on primary fuel with the highest amount of secondary fuel from primary fuel operation to secondary fuel operation. Some methods and systems may be configured to transfer all gas turbine engines to secondary fuel operation and individually and/or sequentially restore operation to primary fuel operation and/or to manage primary fuel operation and/or secondary fuel operation for portions of the plurality of gas turbine engines.

Abstract: A method of maintaining rotor tip clearance and compressor operational line during a transient operation of a gas turbine engine is disclosed. In various embodiments, the method includes applying high spool auxiliary power to a high speed spool for a first time period, applying low spool auxiliary power to a low speed spool for a second time period, sensing one or more operational parameters of the gas turbine engine during the transient operation, and ceasing application of power to the high speed spool, based on the one or more operational parameters.

Abstract: A combustor has a structure enabling selective control of the amount of air supplied to the liner and the transition piece and includes a liner having one end connected to a fuel injector, the liner comprising an inner liner surrounded by an outer liner having a first opening that is elongated in a circumferential direction of the outer liner and is configured to introduce cooling air into an annular space between the inner liner and the outer liner; a liner sliding cover configured to adjust an opening degree of the first opening; and a transition piece connected at one end to the other end of the liner and connected to a turbine at the other end, the transition piece having an effusion hole configured to supply cooling air to a combustion chamber, the effusion hole having an opening area that is less than the opening degree of the first opening.

Abstract: A method for operation of a hybrid propulsion system is provided that includes providing a hybrid propulsion system including a gas turbine engine, an electrical system, and a controller configured to cause the gas turbine engine to produce a first mechanical power output and to cause the electrical system to produce a second mechanical power output. The method further includes causing the gas turbine engine to produce the first mechanical power output and causing the electrical system to produce the second mechanical power output, which causes a drive shaft of the gas turbine engine to rotate. The method further includes decreasing production of the first mechanical power output when a combination of the first mechanical power output and the second mechanical power output for take-off or climb is a predetermined percentage of a predetermined parameter of the gas turbine engine.

Abstract: A control device includes a fuel equivalent value calculation unit for determining the flow rate of fuel supplied to a gas turbine in accordance with a target value deviation between an actual rotation speed and a target rotation speed, an upper limit deviation calculation unit for obtaining an upper limit deviation which is a deviation between a set upper limit output and an actual output, a lower limit deviation calculation unit for obtaining a lower limit deviation which is a deviation between a set lower limit output and the actual output, and a parameter-changing unit for changing any one parameter among the target rotation speed, the actual rotation speed, and the target value deviation so that the target value deviation decreases when the actual rotation speed decreases and the upper limit deviation is small, and so that the target value deviation increases when the actual rotation speed increases and the lower limit deviation is small.

Abstract: A hybrid electric propulsion system includes a gas turbine engine and an electric machine coupled to the gas turbine engine. A method for operating the propulsion system includes determining, by one or more computing devices, a baseline power output for the gas turbine engine; operating, by the one or more computing devices, the gas turbine engine to provide the baseline power output; determining, by the one or more computing devices, a desired power output greater than or less than the baseline power output; and providing, by the one or more computing devices, power to, or extracting, by the one or more computing devices, power from, the gas turbine engine using the electric machine such that an effective power output of the gas turbine engine matches the determined desired power output.

Abstract: A system for starting a gas turbine engine of an aircraft is provided. The system includes a pneumatic starter motor, a discrete starter valve switchable between an on-state and an off-state, and a controller operable to perform a starting sequence for the gas turbine engine. The starting sequence includes alternating on and off commands to an electromechanical device coupled to the discrete starter valve to achieve a partially open position of the discrete starter valve to control a flow from a starter air supply to the pneumatic starter motor to drive rotation of a starting spool of the gas turbine engine below an engine idle speed, where the controller modulates a duty cycle of the discrete starter valve via pulse width modulation.

Abstract: The invention provides a method and system for managing the usage of a plurality of battery units (102a-102n) to power an electric vehicle using a computer-controlled electric circuit (110). To start with, a computer (104) selects two or more battery units from a plurality of battery units to form a series connection as the initial set of battery units to power the electric vehicle. The computer (104) then identifies one or more battery units from the initial set of battery units to be replaced based on a pre-determined discharge level, a malfunction or a disconnection of the one or more battery units. The computer (104) then identifies one or more replacement battery units and hands over energy flow from the one or more battery units to be replaced to the one or more replacement battery units by controlling a plurality of relay switches (112a-112n) in an iterative/recursive manner.

Abstract: A gas turbine engine has a LP spool including an LP shaft and a HP spool including an HP shaft, an accessory gear box (AGB) drivingly engaged to a plurality of accessories, an engine starter drivingly engaged to the AGB, and a drive shaft drivingly engaged to the AGB. In a first engine mode, the drive shaft is drivingly engaged to the HP shaft and is disengaged from the LP shaft, the engine starter is in driving engagement with the HP shaft via the drive shaft, and the LP shaft is disengaged from the AGB. In a second engine mode, the drive shaft is drivingly engaged to the LP shaft and is disengaged from the HP shaft, the LP shaft is in driving engagement with the AGB via the drive shaft, and the HP shaft is disengaged from the AGB.

Abstract: A method of operating a hybrid-electric propulsion system for an aircraft includes determining a flight phase parameter for the aircraft is equal to a first value, and operating the hybrid-electric propulsion system in an electric charge mode in response to determining the flight phase parameter for the aircraft is equal to the first value. The method also includes determining the flight phase parameter for the aircraft is equal to a second value different from the first value, and operating the hybrid-electric propulsion system in an electric discharge mode in response to determining the flight phase parameter for the aircraft is equal to the second value.

Abstract: An aspect includes a system for pre-start motoring synchronization for multiple engines of an aircraft. The system includes a first engine starting system of a first engine and a controller. The controller is operable to synchronize a motoring time of the first engine starting system with one or more other engine starting systems of one or more other engines of the aircraft by extending the motoring time of the first engine starting system to match, within a synchronization tolerance, the motoring time of the one or more other engine starting systems in a pre-start motoring sequence.

Abstract: A gas turbine engine comprises a compressor driven by a shaft, and a reference starting schedule, the compressor having a reference stability boundary, with the reference starting schedule defining a reference working line. A method of starting the gas turbine engine is described in which the method comprises the steps of: (i) accelerating the rotational speed of the shaft towards an engine idle speed; (ii) defining for the compressor, as the rotational speed increases, an operational working line; and (iii) modifying at least one operating parameter of the gas turbine engine as the rotational speed increases such that for a rotational speed, an operational working line is closer to the reference stability boundary than the reference working line is to the reference stability boundary.

Abstract: The invention relates to a method of monitoring a start-up sequence of a turbomachine that comprises a compressor equipped with a rotor, a starter capable of driving the rotor in rotation and a combustion chamber. The start-up sequence comprises a first phase during which the starter increases the rotation speed of the rotor up to an instant at which fuel is injected into the turbomachine combustion chamber, and a second phase after the first phase that terminates when the starter stops driving the rotor. The method includes: acquisition (ACQ) of a signal representative of the rotation speed of the rotor during the start sequence; detection (DRP1, DRP2, INT) of an instant at which there is a sudden change in the variation of said signal with time, the sudden change instant thus detected being deemed to be the instant at which an air-fuel mix is ignited in the combustion chamber.

Abstract: A method of starting a gas turbine engine having a rotor comprising at least a shaft-mounted compressor and turbine, with a casing surrounding the rotor includes an acceleration phase, a bowed-rotor cooling phase, during the acceleration, and a combustion phase. The bowed-rotor cooling phase comprises a time where the rotational speed of the rotor is maintained below a bowed-rotor threshold speed until a non-bowed condition is satisfied, wherein the air forced through the gas turbine engine cools the rotor. The combustion phase occurs after the bowed-rotor cooling phase and upon reaching the combustion speed, wherein fuel is supplied to the gas turbine engine.

Abstract: A starter air valve comprising: a housing comprising an inlet at a first end, an outlet at a second end opposite the first end, and a center portion between the first and second end, the outlet being fluidly connected to the inlet through a fluid passage; a first piston located within the housing between first end and center portion, the first piston configured to block airflow through the fluid passage when in a closed position and allow airflow through the fluid passage when in an open position; a second piston located within the housing between second end and center portion, the second piston configured to block airflow through the fluid passage when in a closed position and allow airflow through the fluid passage when in an open position; and a manual override system configured to move from closed to open position at least one of the first and second pistons.

Abstract: A power generation system includes one or more processors and memory storing instructions that cause the one or more processor to execute a series of steps. That is, the one or more processors receive data indicative of a plurality of inputs associated with the power generation system, such that the plurality of inputs include a flow rate of a valve coupled between an inlet of a compressor in the power generation system and an exhaust of the compressor, where the valve fluidly couples a first fluid exiting the exhaust of the compressor to the inlet of the compressor.

Abstract: A turbine engine equipped with an electrical apparatus with rotor and an epicyclic reduction gear train, includes a sun gear driven by a drive shaft about an axis of rotation, a ring gear surrounding the sun gear and configured to drive a fan shaft about the axis, and an annular row of planet gears interposed between the sun gear and the ring gear and held by a planet carrier fixed to a stator housing of the turbine engine. The stator of the electrical apparatus is fixed to the stator housing with an annular member for apparatus support. The annular member includes elongate legs that axially traverse the reduction gear. The annular member includes a first annular element for fixing to an annular flange integral with the stator housing. The stator of the apparatus has a first annular fixing flange connected integrally to opposed longitudinal extremities of the legs of the annular member.

Abstract: A system for planning operation of a power plant capable of a first mode driving a power generator using a turbine and a second mode not driving the power generator using the turbine over a predetermined period. A determination unit determines whether a predicted power-selling price is higher than a power generation cost; and a planning unit calculates a loss index of the first and second modes in a case where the predicted selling price is equal to the generation cost or less within the predetermined period and formulates a plan to operate the power plant in a mode having a smaller loss index. The loss index of the first mode includes a power-selling loss that is a difference between the predicted selling price and the generation cost, and the loss index of the second mode includes a loss that is caused by not driving the power generator.

Abstract: In one embodiment, a power generation planning support apparatus includes an acquiring module configured to acquire a physical quantity that represents a startup condition of a turbine. The apparatus further includes a first storage module configured to store first information that represents a relationship between a startup schedule of the turbine and the physical quantity. The apparatus further includes a predicting module configured to predict the startup schedule of the turbine, based on the physical quantity acquired by the acquiring module and the first information stored in the first storage module. The apparatus further includes an outputting module configured to output the startup schedule predicted by the predicting module.

Abstract: Herein provided are methods and systems for setting an acceleration schedule for engine start of a gas turbine engine. A rotational acceleration measurement of the engine after the engine is energized in response to a start request is obtained. The rotational acceleration measurement of the engine is compared to an acceleration band having a maximum threshold and a minimum threshold. An acceleration schedule is determined based on a position of the rotational acceleration measurement of the engine in the acceleration band.

Abstract: The invention relates to an architecture of a propulsion system of a multiple-engine helicopter comprising turboshaft engines (5, 6), characterised in that it comprises: at least one hybrid turboshaft engine (5) that is capable of operating in at least one standby mode during a stable flight of the helicopter, the other turboshaft engines (6) operating alone during this stable flight; an air turbine (30) that is mechanically connected to the gas generator (17) of the hybrid turboshaft engine (5) and is suitable for rotating said gas generator (17); means for withdrawing pressurised air from the gas generator (27) of a running turboshaft engine (6); and a duct (31) for routing this withdrawn air to said air turbine (30).

Abstract: Systems and methods for detecting an issue with a starter are provided. One example aspect of the present disclosure is directed to a method for detecting an anomaly with an air turbine starter. The method includes receiving, by one or more controllers, data indicative of a frequency associated with an integrated air turbine starter from one or more sensors located on a stationary portion of the air turbine starter to monitor a rotating portion of the air turbine starter. The method includes determining, by the one or more controllers, an anomaly associated with the integrated air turbine starter based at least in part on the data indicative of the frequency. The method includes providing, by the one or more controllers, a notification indicative of the anomaly associated with the integrated air turbine starter.

Abstract: A system and a method for adjusting an angle of at least one stator vane of a low pressure compressor (LPC) of a two spool gas turbine engine is disclosed. Variable stator vanes are rotatably coupled to a stationary case in one of the stages of the LPC. An actuator is coupled to at least one of the variable stator vanes for imparting rotation of the stator vane about a radius of the case. Various coupling or linkage arrangements may be made so that rotation of one vane results in rotation of the other vanes disposed along the case. The controller includes the stored constraints, the ability to estimate operating condition, and the ability to estimate optimum targets.

Abstract: A method and system for operating an inlet door of an auxiliary power unit are provided. A control signal comprising at least one inlet door command is output. In response to the at least one inlet door command, at least one feedback signal is received and compared to the at least one inlet door command. If the at least one received feedback signal matches the at least one expected feedback signal, operation of the auxiliary power unit is allowed. Otherwise, operation of the auxiliary power unit is inhibited.

Abstract: An apparatus for discriminating ignition in a gas-turbine aeroengine is configured to discriminate that ignition occurred in a combustion chamber upon discriminating that a calculated high-pressure turbine rotational speed change rate at a detected high-pressure turbine rotational speed equal to or greater than a predetermined rotational speed threshold is equal to or greater than a predetermined rotational speed change rate threshold and that the change rate has been equal to or greater than the predetermined rotational speed change rate threshold continuously for a predetermined time period or longer, whereby whether or not ignition of an air-fuel mixture occurred in a combustion chamber can be accurately discriminated or determined without using a dedicated sensor or detector even when an EGT sensor or detector fails.

Abstract: The start-up system comprises a control loop, which regulates in real time the opening of a valve of an air feed of a start-up turbine based on the current measured speed of rotation of a rotor of the turbomachine and a predetermined speed value, said start-up turbine being capable of turning the rotor of the turbomachine for the purpose of the start-up.

Abstract: A method of protecting fuel hardware for a gas turbine engine in an aircraft is disclosed. The method may include determining a current altitude of the aircraft, and controlling a temperature of fuel for the gas turbine engine based at least in part on the current altitude. A thermal management system for a gas turbine engine in an aircraft is also disclosed. The thermal management system may include a sensor configured to detect a current altitude of the aircraft, and a controller in operative communication with the sensor. The controller may be configured to manage a fuel temperature for the gas turbine engine based at least in part on the current altitude detected by the sensor.