Method and system for governing an engine at low power

A method for operating a gas turbine engine, the method comprising:

• obtaining a trimmed target compressor speed and trimmed variable geometry mechanism (VGM) settings, the trimmed target compressor speed including a nominal target compressor speed biased using a first engine-specific trim value, the trimmed VGM settings including a nominal VGM setting biased using a second engine-specific trim value, the first engine-specific trim value and the second engine-specific trim value being specific to the gas turbine engine and dependent on at least one parameter of the gas turbine engine operating in a given operating mode;
• governing the gas turbine engine in the given operating mode based on the trimmed target compressor speed and the trimmed VGM settings;
• determining an error between the trimmed target compressor speed and an actual compressor speed of the gas turbine engine;
• and
• adjusting fuel flow to the gas turbine engine based on the error when the gas turbine engine is in the given operating mode.