"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.

Unfortunately, it will be with the engine at idle at flat pitch. I will
explain why below.


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?


The prop pitch is maintained by oil pressure. Most single engine piston
installations set up the constant speed prop so that it will go to flat
pitch if oil pressure is lost (the exact opposite of turboprops and piston
twins). This is supposed to maximize your chances of restarting the engine,
but you pay for it with glide range. The propeller will continue to windmill
and create a lot of drag, but with the engine out you have little choice --
your oil pressure will be zero. It makes sense when you consider that most
'engine failures' are caused by fuel mismanagement. All you have to do is
switch tanks and with the windmilling prop your engine will start right up
again. You can make the propeller quit rotating by flying very slowly, but
that will not improve your glide.

Turboprops and piston twins set the prop to feather if oil pressure is lost.
These propellers will stop rotating almost immediately.

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.

You could just stay in the pattern and shut it down. It should start right
up again just by giving it some fuel.