I can't say that I have tried every prop and engine combination, but I have
never been able to stop a prop without pulling the nose up to an alarming
attitude...you can pretty much count on it windmilling.

You are experiencing "flat plate drag." In cruise and reduced power descent,
the prop is pulling the airplane through the air (duh). As manifold pressure
is reduced toward idle, the prop governor flattens the pitch in an attempt
to maintain RPM, but when it hits the low pitch stops, that's all there is.
If you go all the way to idle, the windmilling prop drives the engine...the
crankshaft is turning, the pistons are doing their thing, etc, but no motive
force is produced.What you do get is disturbed air over the horizontal
stabilizer, reducing its effectiveness. You goal is to set the MAP to where
the prop is essentially idling, neither pulling nor creating drag. That will
be at about 11 inches in most cases. If you set up a long glide to final,
just as a test, play with the manifold pressure and if you have a sensitive
butt you will almost feel it when you have pulled the throttle back too far.

Bob Gardner

"Ed" wrote in message
...
I'm fairly new to GA after a 19 year break flying jets. I routinely
fly a single engine experimental with a constant speed prop mounted on
a Lycoming IO-360.

2 QUESTIONS:

1. What's the proper setup to simulate the way the plane would glide
in case of an engine failure? I'm looking for pitch and possibly a
manifold pressure number here.

2. It that motor quits, will it still rotate through the flying
airspeed envelope or can I expect it to stop rotation (assuming it's
not frozen due to a mechanical failure)?

In idle, with the prop at flat pitch, it feels too draggy and comes
down like a rock. With it at high pitch, it seems to have too
optimistic a glide ratio. What's the happy medium?

I don't live near a dry lake bed or I'd just shut it down and find
out. I have the proper airspeeds for max range and min sink out of
the POH but it does not quote any type of glide ratio.

Ed