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<DIV><SPAN class=962055518-21072003><FONT face=Arial color=#0000ff size=2>That's
right.</FONT></SPAN></DIV>
<DIV><SPAN class=962055518-21072003> <FONT face=Arial
color=#0000ff size=2>Dean</FONT></SPAN></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Wayne Galligan
[mailto:wgalligan@goodsonacura.com]<BR><B>Sent:</B> Monday, July 21, 2003 2:40
PM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> Re: fixed vs.
rectracts ... Drag and turbulence<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>THANKS DEAN....
So a properly set fixed gear setup(with wheel pants) should have a
better or cleaner air flow(less turbulence then the retract
cutout).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>WG<BR></FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=d.pappas@kodeos.com href="mailto:d.pappas@kodeos.com">Dean
Pappas</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, July 21, 2003 1:32
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: fixed vs. rectracts ...
Drag and turbulence</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>Hi
Wayne,</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>Here's what
little I know from both a theoretical and practical
basis.</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>In general, our
open wheel wells stink! </FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>They are draggy
and may cause all kinds of turbulence.</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>Some ar worse
than others, and there is no easy way, short of a flight test or wind
tunnel,</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>of telling which
</FONT></SPAN><SPAN class=240125815-18072003><FONT face=Arial size=2>setups
will be cleaner. </FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>Tricycle-geared
retracts are generally better than tail-draggers because the wheel
wells are aft</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>of
the wing's high-point.</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>According to one
"real" aerodynamicist I spoke to, the best setups for drag reduction are in
order:</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>1) retracts with
good tight fitting doors. </FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>2) cleanly
faired fixed gear.</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>3) retracts the
way we presently do them.</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>4) crude fixed
gear.</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>5) and retracts
with poorly fitting doors can possibly end up being
horrible!</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>As far as
turbulence goes:</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>Our open
wheel wells in the leading edge made this guy cringe!</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>He warned that
poorly located fixed gear can cause turbulence with the flow under the wing
root.</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>Now from a
practical point, I can recount my own experiments and one done by Jim
Martin</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>about a million
years ago. (okay in the early seventies!)</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>I have taped the
wheel wells over and put small streamlined tires on both my JEKYLL ( about 4
years ago) </FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>and an old
tail-dragger TIPORARE (after the Tangerine contest in '83). Both planes
showed no discernable speed</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>difference, but
</FONT></SPAN><SPAN class=240125815-18072003><FONT face=Arial size=2>there
was no fancy instrumentation. The JEKYLL flew the same, but I thought
that</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>the TIPO
</FONT></SPAN><SPAN class=240125815-18072003><FONT face=Arial size=2>(named
TURNARARE) rolled more nicely. I thought that the transition, as
I started to apply</FONT></SPAN><SPAN class=240125815-18072003><FONT
face=Arial size=2> </FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>the down
pressure in a slow roll, went more smoothly. I eventually discovered that
a slack piece of tape </FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>across the wheel
well in the area of the wire strut gave me the same benefit. Other
builders make very </FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>shallow and
narrow troughs for the wire, probably for the same reason. Since I fly from
fairly rough grass,</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>the tape allowed
more strut bend without binding. </FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>Experiments with
big P-51 style gear doors on the Jekyll showed that it was affected horribly
by turbulence</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial size=2>with the gear
down, with or without the wells taped over. Result? Pants and legs should be
as small as practical.</FONT></SPAN></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=240125815-18072003>Jim Martin
(team member in '73) put heavy duct-tape over </SPAN><SPAN
class=240125815-18072003>the </SPAN><SPAN
class=240125815-18072003> wheel wells of his BANSHEE when he
forgot</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN
class=240125815-18072003>the air pump for his Rhom-Airs. Just last
year, he told me that he </SPAN></FONT></FONT><FONT face=Arial><FONT
size=2><SPAN class=240125815-18072003>thought the plane flew maybe a tiny
bit </SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=240125815-18072003>better,
despite the heavy tape. </SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN
class=240125815-18072003></SPAN></FONT></FONT> </DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN
class=240125815-18072003></SPAN></FONT></FONT> </DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN class=240125815-18072003>I hope
this muddies the waters adequately,</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN
class=240125815-18072003>
Reagards</SPAN></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT size=2><SPAN
class=240125815-18072003> Dean
P.</SPAN></FONT></FONT></DIV>
<DIV><SPAN class=240125815-18072003><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Wayne Galligan
[mailto:wgalligan@goodsonacura.com]<BR><B>Sent:</B> Thursday, July 17,
2003 4:23 PM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> fixed
vs. rectract l.g.<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>Ok now. lets get down to the aerodynamic
aspect of the rectract vs. fixed gear. Anyone have some valid
plus/minus on the two. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial
size=2>WG<BR></FONT></DIV></FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>