If doing a manual start (CFM`s again) and you decide to abort start (due to whatever reason you decided to) - and if you wanted to then Crank - (for whatever reason you decided to Crank) - then is there a lower speed (N2) that you would wait for like on the L1011 - you had to wait for the turbine speed to get below a certain . . .speed or the starter would crash start the engine at a higher turbine speed = not good. I do not see this written anywhere.
I had this happen to an engine (not CFM) in the test cell a few decades back. The engine had preservative oil in the fuel system, and the test crew did not flush it properly. In fact there was some residual oil pooled in the LPT section. First start attempt he had a puff of flame in the tailpipe; this panicked him and he chopped fuel and hit the starter at the same time.
Not too smart.
As the starter was winding up, N2 was unwinding, and when the starter clutch caught, it overstressed the "shear point" on the tower shaft. We had to cannibalize another engine to resume the test.
