Winter / Focus / Prop Drag

[Del Rykert]

If you are looking for irrefutable proof go up in a full scale or for R/C
take a clean design with low idling engine up and do some downlines. Bump
you idle trim up on some and leave it as low as you can on others. Will be
more pronounced with 4 cycles turning big side blade props.

For more proof..  Ever see what happens to a model that kicks back up in the
air but the prop stays on windmilling...  You can't fly it any more except
like a ton of bricks.. If that doesn't convince you nothing will. I flew a
friends model that it happened to. It only broke the prop on landing in
weeds as it landed on its nose.

     Del K. Rykert
     AMA - 8928
     NSRCA - 473
     Kb2joi - General


----- Original Message ----- 
From: "Chuck Czarnik" <CCzarnik at arclp.com>
To: <discussion at nsrca.org>
Sent: Thursday, December 04, 2003 6:20 AM
Subject: RE: Winter / Focus / Prop Drag



Autogyros depend upon a windmilling prop..  They don't fly too well with
a stopped rotor.  I'm not an engineer, but this satisfied me years ago
when this debate came up in some of the GA circles I was in.

Hope this helps, Chuck

-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]
On Behalf Of Adam Glatt
Sent: Wednesday, December 03, 2003 10:16 PM
To: discussion at nsrca.org
Subject: Re: Winter / Focus / Fuel/Electric.

John, experimentation or theory, though I have yet to hear anyone
qualify the statement that a slow turning prop causes more drag than a
stopped one with an explanation.

John Ferrell wrote:

>As I am sure you are aware, full scale pilots have been taught for many
>years that a windmilling prop creates more drag that a stopped prop.
>
>How do you determine what rpm generates the most drag?
>
>John Ferrell
>6241 Phillippi Rd
>Julian NC 27283
>Phone: (336)685-9606
>johnferrell at earthlink.net
>http://home.sprintmail.com/~johnferrell/dixiecompetitionproducts/
>NSRCA 479 AMA 4190  W8CCW
>"My Competition is Not My Enemy"
>
>
>----- Original Message ----- 
>From: "Doug Cronkhite" <seefo at san.rr.com>
>To: <discussion at nsrca.org>
>Sent: Wednesday, December 03, 2003 4:28 PM
>Subject: RE: Winter / Focus / Fuel/Electric.
>
>
>
>
>>Well.. you fix that by setting a good idle speed before you take off.
You
>>never let the motor stop in flight for a few reasons.. 1) as you
>>described, it looks weird.. 2) a stopped prop is not the best solution
for
>>downline breaking.. 3) the start/stop is hard on the gears..
>>
>>-Doug
>>
>>
>
>
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