A starter-generator for an aircraft engine comprises a variable
dynamoelectric machine alternatively operable as a motor or as a
generator, having a rotor. A support motor is coupled to the variable
dynamoelectric machine to assist the machine. A torque converter
selectively couples and decouples the rotor to the engine, coupling the
rotor to the engine at some point when the dynamoelectric machine is
operated as a motor. The engine may be started by the dynamoelectric
machine when operated as a motor through a first power train including the
torque converter and may drive the dynamoelectric machine as a generator
through a second power train.
