Perhaps the stopped prop is less drag because it's stalled.
Below is data taken from my flight test. My idle setting was about 800 to
900 rpm, a little high, at the time. Speeds are indicated knots. My plane
stalls at about 50 knots indicated so I didn't check the glide below 60 kts.
Surely the ratio will start back the other way before it stalls. I have a
KR-2 with Diehl wings, 3 blade Warp drive taper blade 58" prop set at 19.5
degrees at the tip, A65, empty weight is 623 lbs., full fuel is 14 gal and I
weigh about 180.
Glide
Speed Descent Distance Glide
kts ft/min NM/1000 ft. Ratio
60 400 2.50 15.18
65 442.5 2.45 12.93
70 525 2.22 11.73
75 625 2.00 10.56
80 750 1.78 9.39
85 800 1.77 9.35
90 900 1.67 8.80
95 1100 1.44 7.60
100 1500 1.11 5.87
BTW, Bill's 2.5 miles per 1000 ft altitude is a glide ratio of 13.2 : 1 (if
I calculated correctly).
Ken Jones, [email protected]
Sharonville, OH
N5834, aka The Porkopolis Flying Pig
----- Original Message -----
From: "Barry Kruyssen" <[email protected]>
To: "KRnet" <[email protected]>
Sent: Thursday, June 16, 2005 6:31 PM
Subject: Re: KR> what a day./ glide rato..
>
> ----- Original Message ----- From: larry flesner I doubt if a stopped
> propeller is going to triple that number
>
> A stopped prop actually produces less drag, don't know the reason but have
> tried it in self launch gliders (without feathering the prop) both idling
> engine and stoped, there is noticeably less drag when the prop was
> stopped. Also it is better for the prop to stop vertically so any
> vortices from the prop don't upset the air flow over the wing, so I'm told
> but I couldn't tell the difference :-)
>
> regards
> Barry Kruyssen
