Why do we pull the props back to feather prior to shutting down? I cannot
see
any reason for this. This seems a useless procedure on the shutdown
checklist.

This is going back a few years, like 30
+, to my Beech 99 ground school. The P&W engines have always been 'free
turbine" compared to the Garrett TPE series that are direct connect or bigger
stuff like the Allison T-56/501D22. It has something to do with engine oil
scavange I think. Another part is that the engines can idle at lower rpm with
feathered props. Also the newer P&W 100 series have prop brakes so the engines
on the ATR and DASH eight can be running as APU's.

Any more I just sell them not fly them.
I am sure someone will prove me wrong.

Walt