Windmill starting
In my Herc (C-130) days, we used to be able to windmill start an engine. In the event of the Gas Turbine Compressor (GTC) not working or there being a problem with bleed air for starting, we could back another herc up close to the one with the problem. Then power up the good aircraft and the resultant prop wash would spin the engine on the bad aircraft, once at a suitable speed the receiving crew would initiate the start and all being well get one engine going, this would then provide bleed air to start the other engines.