Actually, Scotty, I do have a fixed-pitch prop.  But my prop has very little drag; I have to use a lot of braking to bring it to a stop (on the ground, of course!). And this with an idle rpm of 680! I'm sure you, with all your knowledge of things aerodynamic, have a copy of "Aerodynamics For Naval Aviators". Look on page 149 where it compares wind-milling vs stopped drag vs pitch. It turns out that a prop with 23 deg. to 60 deg. pitch has less drag wind-milling than stopped. My effective pitch, from VMPH X 1056 / rpm, usually computes to 76". That works out to 27 deg at the 75% radius of a 63" diameter prop. That, along with the minimal area of my prop beyond 12" radius, is the reason it has so little drag. 'True, even though my 235 has a best L/D of 15:1 at 110 mph IAS, it probably won't get that with the engine off. One of these days I'll have to shut off the engine, at altitude, and see if the prop will even wind-mill, and what kind of glide I do get!

Paul,

 

Numerical mumbo jumbo won't get you where you want to go if things get quiet......  Try to get the engine at idle power and see what your sink rate is at best glide - Use this as your best case for the engine out, prop rotating sink rate.  It's fine that you want to rely on the Navy - That means if the engine seized (no oil, a common failure problem) your sink rate is even worse.  Don't quote the false 15:1 rate (where ever you read that in an ad), go find out what it is and scare yourself into reality!  Report back here on the LML for others to learn. 

 

Note: Do any experimentation over an airport.