On Tue, 13 Apr 2004 16:15:11 -0700, "Peter Duniho"
wrote:

snip

Next time, pull the prop to *minimum* RPM and see your glide angle decrease.

It'll likely be years, I don't do GA anymore.

Have pulled mis-rigged PT6A props to "flat" on short final a couple of
times, have the stained shorts to prove it.

Not sure how that statement fits in to the discussion, but the PT6 governors
work differently from those found on most piston-engine singles.

Doesn't have anything to do with it, this is Usenet. You really owe to
yourself to try it once, though. It's similiar to tromping on a
non-ABS brake pedal at 40 mph. Gets your attention at 75 feet AGL with
the nose down coming-over-the-fence.

Before I posted, I called my gov shop buddy to make sure his views
coincided with what I remembered from hanging around in his shop. He
related same, that the gov bench doesn't indicate useable gov pressure
until around 1500-1600 rpm.

You mentioned "gov pressure" in an earlier post, and I still don't
understand what you mean. The force to change the prop blade angle comes
from springs and oil pressure, not the governor itself. All the governor
does is adjust oil valves to control how the oil moves through the pitch
change mechanism.

The base of a governor is another oil pump, stepping up engine oil
pressure to over 175 psi. Maximum pressure is limited by a
spring-loaded pop-off valve, just like the engine oil pump.

http://www.mccauley.textron.com/prop...g03govern.html

was the best picture I could find of it in a 30 second Google.

In any case, as with the others, I've had no trouble at all reducing the
blade pitch even in low-RPM, idle-power situations. I have no reason to
expect I'd have any trouble in an actual engine failure, assuming the engine
continued to windmill and run the oil pump.

Agreed, like I indicated in another post, the oil pump/governor
doesn't care what's turning it.

TC