REDUCING LOW FLIGHT MACH NUMBER FUEL CONSUMPTION IN A GAS TURBINE WITH ELECTRIC MACHINES

A gas turbine engine (101) for an aircraft, comprises a high-pressure (HP) spool comprising an HP compressor (105) and a first electric machine (117) driven by an HP turbine (107), the first electric machine (117) having a first maximum output power; a low-pressure (LP) spool comprising an LP compressor (104) and a second electric machine (119) driven by an LP turbine (108), the second electric machine (119) having a second maximum output power; and an engine controller (123) configured to identify a condition to the effect that the LP turbine (108) is operating in an unchoked regime, and, in response to an electrical power demand being between zero and the first maximum output power, only extracting electrical power from the first electric machine (117) to meet the electrical power demand.