A gas turbine engine includes a compressor section, the compressor section including a variable inlet guide vane which is movable between distinct angles to control the airflow approaching the compressor section. A control is programmed to position the vane at startup of the engine to direct airflow across the compressor section. The engine includes a fan for delivering bypass air into a bypass duct positioned outwardly of a core engine including the compressor section. The position of the vane is configured to direct airflow across the compressor section while an aircraft associated with the gas turbine engine is in the air, and to increase a windmilling speed of the compressor section and the turbine rotors. A method and variable inlet vane are also disclosed.

A gas turbine engine includes a compressor section, the compressor section including a variable inlet guide vane which is movable between distinct angles to control the airflow approaching the compressor section. A control is programmed to position the vane at startup of the engine to direct airflow across the compressor section. The engine includes a fan for delivering bypass air into a bypass duct positioned outwardly of a core engine including the compressor section. The position of the vane is configured to direct airflow across the compressor section while an aircraft associated with the gas turbine engine is in the air, and to increase a windmilling speed of the compressor section and the turbine rotors. A method and variable inlet vane are also disclosed.

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.

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.

Embodiments are directed to systems and methods for controlling an aircraft engine inlet comprises determining a required engine RPM for an engine in-flight restart based upon current aircraft parameters, detecting a command to initiate the engine in-flight restart, and managing a position of an engine inlet barrier to control a volume of air entering an engine intake, wherein the ram air causes an engine turbine to achieve the required engine RPM. The required engine RPM may be an N1 gas generator RPM. The engine inlet barrier may be a hinged door positioned within the engine inlet or a series of inlet variable guide vanes that are configured to rotate between a closed position and an opened position. The position of the engine inlet barrier may be controlled by a flight control computer or an engine control computer.

A method of controlling at least part of a start-up or re-light process of a gas turbine engine, the method comprising: determining when a flame in a combustion chamber of a gas turbine engine is extinguished, during a start-up process or re-light process or during operation; purging the combustion chamber by controlling rotation of a low pressure compressor using a first electrical machine, and controlling rotation of a high pressure compressor using a second electrical machine, the combustion chamber downstream of the low pressure compressor and high pressure compressor; and controlling rotation of the low pressure compressor using the first electrical machine, and controlling rotation of the high pressure compressor using the second electrical machine to restart the start-up process or perform the re-light process.

A method of controlling at least part of a start-up or re-light process of a gas turbine engine, the method comprising: determining when a flame in a combustion chamber of a gas turbine engine is extinguished, during a start-up process or re-light process or during operation; purging the combustion chamber by controlling rotation of a low pressure compressor using a first electrical machine, and controlling rotation of a high pressure compressor using a second electrical machine, the combustion chamber downstream of the low pressure compressor and high pressure compressor; and controlling rotation of the low pressure compressor using the first electrical machine, and controlling rotation of the high pressure compressor using the second electrical machine to restart the start-up process or perform the re-light process.

Examples described herein provide a computer-implemented method that includes determining a thrust requirement to satisfy a desired glide slope. The method further includes determining, based on the thrust requirement, whether thrust matching can be maintained while operating a first gas turbine engine in a fuel-burning mode and operating a second gas turbine engine in an electrically powered mode. The method further includes, responsive to determining that thrust matching cannot be maintained, commanding fuel flow to a combustor of the second engine to cause the second gas turbine engine to operate in the fuel-burning mode.

Examples described herein provide a computer-implemented method that includes determining a thrust requirement to satisfy a desired glide slope. The method further includes determining, based on the thrust requirement, whether thrust matching can be maintained while operating a first gas turbine engine in a fuel-burning mode and operating a second gas turbine engine in an electrically powered mode. The method further includes, responsive to determining that thrust matching cannot be maintained, commanding fuel flow to a combustor of the second engine to cause the second gas turbine engine to operate in the fuel-burning mode.

A hybrid electric propulsion system including: a gas turbine engine comprising a low speed spool and a high speed spool, the low speed spool comprising a low pressure compressor and a low pressure turbine, and the high speed spool comprising a high pressure compressor and a high pressure turbine; an electric motor configured to augment rotational power of the high speed spool or the low speed spool; and a controller to: detect an in-flight windmill re-start condition of the gas turbine engine; and cause power to be supplied from a power source to the electric motor in order to augment rotational power of the high speed or the low speed spool during the detected in-flight windmill re-start condition.