<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META content="MSHTML 5.50.4134.600" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=031220321-21072003> Hey Dean, Jim Martin was a great pilot! Good to
hear he's still around. Mike</SPAN></FONT></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> Dean Pappas
[mailto:d.pappas@kodeos.com]<BR><B>Sent:</B> Monday, July 21, 2003 12:32
PM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> RE: fixed vs.
rectracts ... Drag and turbulence<BR><BR></FONT></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></BODY></HTML>