The Boeing Company
Hybrid aircraft turbine engine starting system and method

Abstract:

A system and method for starting an aircraft turbine engine includes a primary starting subsystem and a secondary starting subsystem. The primary starting subsystem is coupled to a shaft of the aircraft turbine engine and has a dedicated power source. The secondary starting subsystem is also coupled to the shaft of the aircraft turbine engine and has a shared power source. A controller controls the operation of the primary starting subsystem and the secondary starting subsystem while starting the aircraft turbine engine. The primary starting subsystem may be an Auxiliary Power Unit coupled to an Air Turbine Starter. The secondary starting subsystem may be a Starter Generator coupled to a battery also used to power the Emergency Hydraulic System. The primary starting subsystem is always operated at full power during starting while the secondary starting subsystem is preferably operated in a sequence of different power levels.