Gas turbine engine stall margin management

An aeronautical gas turbine engine comprising:

• a compressor section;
• a combustion section located downstream of the compressor section;
• a turbine section located downstream of the combustion section, the turbine section mechanically coupled to the compressor section by one or more shafts;
• an electrical machine in mechanical communication with the one or more shafts, the electrical machine including a starter-electric generator for generating electrical power;
• and
• a controller operably connected to the starter-electric generator,
• wherein the gas turbine engine defines a compressor pressure ratio that is a ratio of a stagnation pressure at an upstream end of the compressor section to a pressure at a downstream end of the compressor section,
• wherein the gas turbine engine defines a compressor mass flow rate that is rate at which a mass of air flows through the compressor section,
• wherein the gas turbine engine defines an operation line that is a plot of the compressor pressure ratio against the compressor mass flow rate during steady state operation of the turbofan engine,
• wherein the gas turbine engine defines a stall line that is a plot of the compressor pressure ratio against the compressor mass flow rate that indicates a highest compressor pressure ratio that still consistently allows for stable airflow through the turbofan engine,
• wherein the stall margin is a margin between the stall line and the operation line,
• wherein the controller is configured to reduce an amount of electrical power drawn from the starter-electric generator to an amount below a desired amount to be drawn in order to generate an increased stall margin, and
• wherein the controller is configured to operate the gas turbine engine at a transient engine condition in which the gas turbine is operated within the increased stall margin closer to the stall line than the operation line.