US Patent 9428267 In-flight mechanically assisted turbine engine starting system

An engine starting system for a rotary wing aircraft includes a controller that receives a signal indicative of a start command for an engine, a transmission input module that is mechanically coupled to a transmission system and an accessory gearbox and a starter motor that is mechanically coupled to a compressor drive shaft of the engine. Also, a method for restarting an engine in flight includes receiving by a controller a signal indicative of a start command for the engine, determining by the controller that an overrunning clutch is coupled to the engine, transmitting by a transmission system motive power to the engine in response to the determining that the overrunning clutch is coupled to the engine and driving via a compressor drive shaft a compressor section of the engine according to a design speed.