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Yes, Bob. This was with the 2.17 gearbox and 68x72" prop. The RV
reportedly has a glide ratio of 10:1. So with 9500 MSL (actually about 7500
AGL), I should have been able to glide 10*7500 = 75,000 ft = 14.2 miles.
So at 14.2-12 Miles =2.2 miles at 87 mph = 2.2/87 = .0252 hr = 1.5 minutes
at 750 fpm (of course was not constant but mostly 750) = 1137 ft at the end
of my 12 mile glide at the airport. So fairly close to my estimate of
altitude (also the airport may not have been 2000 above sea level.
In anycase, even with a 10:1 glide ratio (or less) you can still have a fair
chance of finding a spot to set it down and walk away depending on altitude
of course.
Ed Anderson
----- Original Message -----
From: "Bob White" <bob@bob-white.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Monday, December 13, 2004 11:39 AM
Subject: [FlyRotary] Re: Glide distances
Ed,
That's excellent. Your engine quits so you go into test pilot mode and
get all the data you can. Glide is one advantage you RV guys will have
over me I think. From what I've heard, the BD-4 glides a little better
than a rock with power off. I've only got 2 hours flying time in it, so
I'm a little lite on first hand experience. Hopefully soon.
Was this before you upgraded to the "monster" prop?
Bob White
On Mon, 13 Dec 2004 10:47:45 -0500
"Ed Anderson" <eanderson@carolina.rr.com> wrote:
> On my 12 mile engine out glide, I punched up the NRST button on my GPS
> to find the two closest airfields were both 12 miles away (gulp!).
> Since I knew I was going to be gliding around 85 mph that any sort of
> headwind would considerably shorten the glide. Fortunately I had been
> paying attention to the wind direction as I was outrunning a cold
> front, so turned 120 degs for the downwind field.
>
> From 9500 MSL I arrived over the selected airfield with approx
> 1500-2000 ft AGL. I had altitude to do a 360 and a couple of hard
> "S" turns to loose altitude and even then came over the fence at 100
> mph. This with a stubby wing RV-6A.
>
> I did have time in that 8 minute glide to find out that my best glide
> speed (at that weight) was 87 MPH which produced a 750 fpm rate of
> descent. Any slower the rate went up and any faster the rate went up.
> Also were I found what airspeeds the prop would stop at as well as
> what it took to get it going again. So a rather productive 8 minutes
> all things considered {:>).
>
> Ed Anderson
--
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (soon)
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