Originally Posted by
wrench1
PT6s are definitely not all created equally. Just look at the differences between a PT6A and PT6C. While the FCUs/GOVs are very different between aircraft types most of the basic core parts are the same. For example, I believe the start flow dividers are similar but rigged differently. But another thing to keep in mind on the start side is an airplane has a very light prop to spool up vs the xsmn/MR of say a 212. It's still the most bulletproof engine type out there in my humble opinion.
well I can tell you from experience that the difference in spinning a prop or a rotor in regards the start has nothing to do with it. Once while troubleshooting a vibration in a 212, maintenance disconnected the drive shaft and had me start the engines. I was very concerned that with no drag on the engine it would be some sort of crazy start and possibly over speed. Well to my surprise the start was exactly the same as with the transmission connected. Uneventful.