Abstract: There is disclosed a gas turbine engine comprising: an electrically-powered motor configured to rotate a driven spool of the gas turbine engine; a primary controller configured to conduct a primary function using the motor; and a bow controller configured to selectively control the motor to perform a rotor bow mitigation operation in which the motor drives the driven spool to rotate to mitigate a non-uniform thermal distribution in a rotor of a spool of the gas turbine engine.

Abstract: There is provided a method of starting a gas turbine engine, comprising: selecting a baseline starting procedure of the gas turbine engine based on environmental data; receiving condition information for the gas turbine engine and/or for a starting system of the gas turbine engine, the condition information comprising at least one of: health information for the gas turbine engine and/or the starting system; maintenance information for the gas turbine engine and/or the starting system; and operation information relating to an expected future usage of the gas turbine engine. The method further comprises determining a predicted degradation profile for the gas turbine engine and/or the starting system based on the condition information; determining a starting procedure of the gas turbine engine by adapting the baseline starting procedure based on the predicted degradation profile; and controlling the gas turbine engine and/or the starting system according to the determined starting procedure.

Abstract: There is provided a method of starting a gas turbine engine, comprising: selecting a baseline starting procedure of the gas turbine engine based on environmental data; receiving condition information for the gas turbine engine and/or for a starting system of the gas turbine engine, the condition information comprising at least one of: health information for the gas turbine engine and/or the starting system; maintenance information for the gas turbine engine and/or the starting system; and operation information relating to an expected future usage of the gas turbine engine. The method further comprises determining a predicted degradation profile for the gas turbine engine and/or the starting system based on the condition information; determining a starting procedure of the gas turbine engine by adapting the baseline starting procedure based on the predicted degradation profile; and controlling the gas turbine engine and/or the starting system according to the determined starting procedure.

Abstract: A method of operating a gas turbine engine having a spool includes executing, by a controller, a pre-shutdown procedure. The pre-shutdown procedure includes: determining a parameter associated with a thermal condition of the gas turbine engine; and calculating an idle period for an idle rotation operation to be performed in a shutdown procedure. Calculation of the idle period is based on the determined parameter.

Abstract: A method of operating a gas turbine engine having a spool includes executing, by a controller, a shutdown procedure. The shutdown procedure includes: performing an idle rotation operation; determining a parameter associated with a thermal condition of the gas turbine engine while the idle rotation operation is performed; determining, based on the determined parameter, whether the gas turbine engine has met a pre-determined criterion corresponding to a thermally stabilised condition; and terminating the idle rotation operation in response to a determination that the gas turbine engine has met the pre-determined criterion.

Abstract: There is provided a method of starting a gas turbine engine, comprising: selecting a baseline starting procedure of the gas turbine engine based on environmental data; receiving condition information for the gas turbine engine and/or for a starting system of the gas turbine engine, the condition information comprising at least one of: health information for the gas turbine engine and/or the starting system; maintenance information for the gas turbine engine and/or the starting system; and operation information relating to an expected future usage of the gas turbine engine. The method further comprises determining a predicted degradation profile for the gas turbine engine and/or the starting system based on the condition information; determining a starting procedure of the gas turbine engine by adapting the baseline starting procedure based on the predicted degradation profile; and controlling the gas turbine engine and/or the starting system according to the determined starting procedure.

Abstract: There is disclosed a gas turbine engine comprising: an electrically-powered motor configured to rotate a driven spool of the gas turbine engine; a primary controller configured to conduct a primary function using the motor; and a bow controller configured to selectively control the motor to perform a rotor bow mitigation operation in which the motor drives the driven spool to rotate to mitigate a non-uniform thermal distribution in a rotor of a spool of the gas turbine engine.