<!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 6.00.6000.16525" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>I made the attached comment regarding directional
stability tongue in cheek. One of my early Express designs had so little
directional stability it would fall flat thru of a stall turn.
Interestingly this was the only place I was aware of a problem.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I had one airplane with a 15% stab back
in the 80s because I rationalized the more forward CG would reduce pitch
changing effects of turbulence. I can't remember the results
<G>.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>High inertia damps the effects of turbulence - and
works fine if you leave out the snaps and get used to the change in roll timing
<G>.
Nat</FONT></DIV>
<BLOCKQUOTE
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=natpenton@centurytel.net href="mailto:natpenton@centurytel.net">Nat
Penton</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, October 11, 2007 1:24
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [NSRCA-discussion]
Turbulence</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Simple physics tells us moving the center of lift
inboard ( more taper ) will benefit flying in turbulent conditions. As a side
note, since turbulence is fractal, speed will benefit.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Back to subject, and question. Directionally it
appears the less directionally stable the airplane the less change in
direction due to a gust. We prefer the airplane moves over without a change in
direction.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Where and how do we draw the line on
direction stability ?</FONT></DIV>
<P>
<HR>
<P></P>_______________________________________________<BR>NSRCA-discussion
mailing
list<BR>NSRCA-discussion@lists.nsrca.org<BR>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</BLOCKQUOTE></BODY></HTML>