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Date: Thu, 11 Feb 2010 09:57:03 -0500
Message-ID: <1ab24f411002110657m5c686f12w3bd1d59625a2436b@mail.gmail.com>
Subject: Contr-rotating propellers
From: Lynn Hanover <lehanover@gmail.com>
To: flyrotary@lancaironline.net
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Bill Bradburry wrote:
>
> There have been a lot of these planes.  Howard Hughes built the XF-11
> and damn nearly killed himself with it when it crashed in California.
>
>
>
>  http://www.absoluteastronomy.com/topics/Contra-rotating_propellers
>
>
>
The LARC website from NASA had some studies of contra-rotating props
that showed some significant efficiency increases when the blades were
pitched and spaced correctly.  It also allowed more power to be absorbed
with a short prop, a problem that was starting to become a real headache
for designers at the end of WWII.

I am also a proponent of "suck air from around the spinner so that the
inner portion of the prop becomes useful" school of thought.

http://ernest.isa-geek.org/Delta/Pictures/EngineCowling2.jpg

The Sun&Fun museum (Florida Air Museum) on the south side of the Lakeland
airport has the actual wind tunnel models of that Hughs plane and a gearbox
from it's propeller dive system on display.
They also own the only "Pogo" plane. Recently restored. If you visit Sun&Fun
or the Museum note that the speed limit on Countyline road (4 lane divided,
limited access rural) is 45 MPH and is strictly enforced.

Just up I-4 from Lakeland is the Kermit Weeks Fantisy of Flight Museum. Many
of the display aircraft are flown monthly. A must see attraction.
http://www.fantasyofflight.com/

Lynn E. Hanover

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<div>Bill Bradburry wrote:<br>&gt;<br>&gt; There have been a lot of these p=
lanes.=A0 Howard Hughes built the XF-11 <br>&gt; and damn nearly killed him=
self with it when it crashed in California.<br>&gt;<br>&gt;=A0 <br>&gt;<br>=
&gt;=A0 <a href=3D"http://www.absoluteastronomy.com/topics/Contra-rotating_=
propellers" target=3D"_blank">http://www.absoluteastronomy.com/topics/Contr=
a-rotating_propellers</a><br>
&gt;<br>&gt;=A0 <br>&gt;<br>The LARC website from NASA had some studies of =
contra-rotating props <br>that showed some significant efficiency increases=
 when the blades were <br>pitched and spaced correctly.=A0 It also allowed =
more power to be absorbed <br>
with a short prop, a problem that was starting to become a real headache <b=
r>for designers at the end of WWII.<br><br>I am also a proponent of &quot;s=
uck air from around the spinner so that the <br>inner portion of the prop b=
ecomes useful&quot; school of thought.<br>
<br><a href=3D"http://ernest.isa-geek.org/Delta/Pictures/EngineCowling2.jpg=
" target=3D"_blank">http://ernest.isa-geek.org/Delta/Pictures/EngineCowling=
2.jpg</a></div>
<div>=A0</div>
<div>The Sun&amp;Fun museum (Florida Air Museum) on the south side of the L=
akeland airport has the actual wind tunnel models of that Hughs plane and a=
 gearbox from=A0it&#39;s propeller dive system on display.</div>
<div>They also own the only &quot;Pogo&quot; plane. Recently restored. If y=
ou visit Sun&amp;Fun or the Museum note that the speed limit on Countyline =
road (4 lane divided, limited access rural) is 45 MPH and is strictly enfor=
ced. </div>

<div>=A0</div>
<div>Just up I-4 from Lakeland is the Kermit Weeks Fantisy of Flight Museum=
. Many of the display aircraft are flown monthly. A must see attraction. <a=
 href=3D"http://www.fantasyofflight.com/">http://www.fantasyofflight.com/</=
a></div>

<div>=A0</div>
<div>Lynn E. Hanover<br></div>

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