The PT6 and some other turboprop engines are "free turbines"
with a gas generator section that sends gas to a separate
turbine/gear box assembly. Until the engine develops oil
pressure, the prop is feathered. Other turbine engines, the
Garrett TPE331 being the most common example, has a solid
shaft that drives the prop from the gas section. These
engines are shutdown after locking the prop blades at near
zero pitch, otherwise the loads required to start the engine
would strain the starter motor. In-flight feather and
restarting requires that the prop be manually unfeathered
to restart the engine.

The complications of the TPE331 over the PT6 are a prime
reason the PT6 is the preferred engine by most pilots. The
low cost and slightly high fuel specs make the TPE331 make
it popular with bookkeepers.

http://home.swipnet.se/~w-65189/turb...ne_engines.htm

http://www.pwc.ca/en/3_0/3_0_2/3_0_2_1_1.asp

http://www.aircraftenginedesign.com/TPE331pics.html



"Robert M. Gary" wrote in message
oups.com...
|
| Jim Macklin wrote:
| You can feather the prop on a PT6 free-turbine engine
and
| this is a normal training and testing procedure. You do
| this at idle or very low power settings. On a piston
| engine, feathering the prop stops rotation, so the
engine
| quits.
|
| On a PC game, the electrons stop flowing?
|
| I wondered about that. In a turboprop the engine starts
with the blades
| feathered. However, I don't have the experience to comment
on them.
|
| -Robert
|