TPE331 TCDS
"TYPE: Single-shaft engine with two-stage centrifugal compressor, three-stage axial turbine, and singular annular combustion chamber"
thanks brian- of course the 331 IS a singleshaft like ( nearly) everybody knows...
@V1....ooops: you,re are pretty right and i can confirm this also for the large versions of the pt6a. we had some time ago a TQ sensor fault and it clearly is located on the reduction gearbox. ( PT6A-41)
the feather of the prop with a complete oil loss seems very logical since the PT6a does not have mechanical pitch locks on the prop . the -41 definitly will feather e.g on a normal shutdown with the prop lever full forward.
the clue then is : shut down in any case... with a feathered prop you will have no use even when the engine still delivers power, and you highly risk to toast the turbine in the next minute...
one interesting point is what happens in singleshaft turbines which have mechanical pitch locks on the prop. ( but NTS may in this situation also initiate an autofeather as a result )