In accordance with at least one aspect of this disclosure, there is provided a method of accelerating a gas turbine engine. The method includes adding torque to a core of the gas turbine engine to accelerate rotation of the core by controlling fuel flow to a plurality of fuel injectors of the gas turbine engine. The method also includes adding torque to the core by powering an electric machine that is operatively connected to the core. In embodiments, controlling fuel flow to the plurality of fuel injectors is based on feedback from the electric machine.

There is provided a monitoring method and system for an aircraft engine. At an engine controller, a current value of an ageing parameter of at least one component of the aircraft engine is obtained, the at least one component having a life limit associated therewith. Based on the current value of the ageing parameter, it is determined, at the engine controller, whether the life limit of the at least one component has been reached. A start of the aircraft engine is inhibited, at the engine controller, when the life limit of the at least one component has been reached.

Technology for operating an engine smoothly is provided. In an aircraft propulsion system, a controller causes at least a first engine among the plurality of engines to be stopped and causes a second engine, which has not been stopped, to be operated when an aircraft is flying in a prescribed flight mode and causes the first engine to be operated and causes the second engine to be stopped when a detector detects that the temperature related to the first engine is less than or equal to a first prescribed temperature.

Technology for operating an engine smoothly is provided. In an aircraft propulsion system, a controller causes at least a first engine among the plurality of engines to be stopped and causes a second engine, which has not been stopped, to be operated when an aircraft is flying in a prescribed flight mode and causes the first engine to be operated and causes the second engine to be stopped when a detector detects that the temperature related to the first engine is less than or equal to a first prescribed temperature.

Methods and systems for calibrating an engine having a rotating shaft are provided. Readings from a plurality of speed sensors provided in one of a plurality of configurations about the shaft are obtained over a plurality of rotations of the shaft, the readings indicative of the passage of position markers and associated with a first precision level. A parameter indicative of relative spacing between the plurality of speed sensors is determined by applying a statistical algorithm to the readings, the parameter being associated with a second precision level higher than the first precision level. The parameter is compared to reference parameters associated with the plurality of configurations to identify an actual speed sensor configuration from amongst the plurality of configurations. The engine is calibrated based on the actual speed sensor configuration.

Methods and systems for calibrating an engine having a rotating shaft are provided. Readings from a plurality of speed sensors provided in one of a plurality of configurations about the shaft are obtained over a plurality of rotations of the shaft, the readings indicative of the passage of position markers and associated with a first precision level. A parameter indicative of relative spacing between the plurality of speed sensors is determined by applying a statistical algorithm to the readings, the parameter being associated with a second precision level higher than the first precision level. The parameter is compared to reference parameters associated with the plurality of configurations to identify an actual speed sensor configuration from amongst the plurality of configurations. The engine is calibrated based on the actual speed sensor configuration.

A system and method is disclosed for the start-up and control of pulsejet engines and this system includes an Electronic Fuel Injection (“EFI”) system that further includes one or more electrically controlled fuel injectors that can be selectively operated for start-up and control of such pulsejet engines. According to the system and method, the rate and/or pattern of fuel delivery to pulsejet engines can be varied not only by controlling the amount of time the fuel injectors are open versus closed to define a “duty cycle,” but also with the capability to selectively disable one or more fuel injectors in the programmed manner for start-up and control of such pulsejet engines.

A system and method is disclosed for the start-up and control of pulsejet engines and this system includes an Electronic Fuel Injection (“EFI”) system that further includes one or more electrically controlled fuel injectors that can be selectively operated for start-up and control of such pulsejet engines. According to the system and method, the rate and/or pattern of fuel delivery to pulsejet engines can be varied not only by controlling the amount of time the fuel injectors are open versus closed to define a “duty cycle,” but also with the capability to selectively disable one or more fuel injectors in the programmed manner for start-up and control of such pulsejet engines.

A fuel conditioning and control system provides dynamic control and steady state operations of a gas turbine provided fueled by supercritical liquefied petroleum gas (LPG). The fuel conditioning and control system comprises a storage for LPG fuel; a fuel delivery sub-system connecting the storage to turbomachinery; and a control system. The gas turbine includes a gas turbine core control that provides at least one operational data of the gas turbine to the control system. The fuel delivery sub-system includes at least one sensor for sensing at least one property of the LPG fuel in the fuel delivery sub-system, where the at least one sensor providing data on the at least one property of the LPG fuel to the control system. The control system analyzes the data on the at least one property of the LPG fuel and at least one operational data of the gas turbine for dynamic control of LPG fuel to the gas turbine under dynamic and steady state conditions.

An aircraft that includes a hybrid-electric propulsion system is provided. In one aspect, the hybrid-electric propulsion system includes at least one propulsor that includes a gas turbine engine and an electric machine mechanically coupled with a spool of the gas turbine engine. When idle operation is commanded, electrical power is provided to the electric machine to cause the electric machine to apply torque to the spool and fuel provided to the engine can be reduced. Thus, the electric machine is controlled to provide a power assist to maintain the engine at the commanded idle speed whilst reducing fuel consumption.