GAS TURBINE ENGINE

Gas turbine engines 101, 601, 701 and methods of starting gas turbine engines are provided. One such gas turbine engine 101, 601, 701 comprises: an electronic engine controller 204; one or more spools, one of which is designated a starting spool for starting the engine, and which has a required starting torque τs; a permanent magnet alternator 202 mechanically coupled with the starting spool, the alternator 202 being configured to, in a motor mode, provide a peak torque of τa, and, in a generator mode, generate electrical power for the electronic engine controller 204; and an electrical starter-generator 203 mechanically coupled with the starting spool. The starter-generator 203 is configured to, in a motor mode, provide a peak torque of τsg, and, in a generator mode, generate electrical power for an external load. τsg + τa ≥ τs and τsg, τa < τs, and the electronic engine controller 204 is configured to, during a start procedure, operate both the permanent magnet alternator 202 and the starter-generator 203 in a motor mode to drive the starting spool.