<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML xmlns="http://www.w3.org/TR/REC-html40" xmlns:v =
"urn:schemas-microsoft-com:vml" xmlns:o =
"urn:schemas-microsoft-com:office:office" xmlns:w =
"urn:schemas-microsoft-com:office:word" xmlns:st1 =
"urn:schemas-microsoft-com:office:smarttags"><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.6000.16525" name=GENERATOR><!--[if !mso]>
<STYLE>v\:* {
BEHAVIOR: url(#default#VML)
}
o\:* {
BEHAVIOR: url(#default#VML)
}
w\:* {
BEHAVIOR: url(#default#VML)
}
.shape {
BEHAVIOR: url(#default#VML)
}
</STYLE>
<![endif]--><o:SmartTagType name="PersonName"
namespaceuri="urn:schemas-microsoft-com:office:smarttags"></o:SmartTagType><!--[if !mso]>
<STYLE>
st1\:*{behavior:url(#default#ieooui) }
</STYLE>
<![endif]-->
<STYLE>
<!--
/* Font Definitions */
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:Forte;
panose-1:3 6 9 2 4 5 2 7 2 3;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
p.MsoEnvelopeReturn, li.MsoEnvelopeReturn, div.MsoEnvelopeReturn
{margin:0in;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:Forte;}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:Arial;
color:navy;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;}
div.Section1
{page:Section1;}
-->
</STYLE>
</HEAD>
<BODY lang=EN-US vLink=purple link=blue bgColor=#ffffff>
<DIV><FONT face=Arial size=2>Stuart,</FONT></DIV>
<DIV><FONT face=Arial size=2>Stick to your guns. You may be in the minority, but
you're right !!! In the past I've told guys to do exactly as you
indicate. I.E., go to a vertical upline in a strong crosswind and when you
observe the lean into the wind, give opposite rudder to change the fuse angle to
the opposite direction by several degrees and then just let go of all controls
(eliminates any unconcious inputs ) and watch the aircraft fuse angle rotate
back to the windward direction. </FONT></DIV>
<DIV><FONT face=Arial size=2>Unfortunately, full scale pilots have been
erroneously indoctrinated by their training and there is no way that
you will be able to convince them otherwise, no matter the proof.
</FONT></DIV>
<DIV><FONT face=Arial size=2>They'll tell you about a bubble of air that the
airplane is flying in, but what happens when they establish a "crab
angle"? Does the airplane leave the bubble? Does it take the bubble with
it? If it stays in the bubble, then it, the bubble, moves away from the
flight line at the speed of the wind and that's a long distance when flying from
one end of the box to the other. This all becomes an aerodynamic/physics snafu
that will always be with us. Call it what you will, ........it's real, it's
visible, it's reproduceable, and it's not Rocket Science.</FONT></DIV>
<DIV><FONT face=Arial size=2>What it comes down to is a matter of personal
perception and it's not worth not still liking each other despite such minor
disagreements.</FONT></DIV>
<DIV><FONT face=Arial size=2>I hope to be here next year when this comes up
again. ;>)</FONT></DIV>
<DIV><FONT face=Arial size=2>G.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></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=schale@optonline.net href="mailto:schale@optonline.net">Stuart
Chale</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> Wednesday, October 10, 2007 1:02
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Weather
Vane</DIV>
<DIV><BR></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">You’re right Ron,
that was more like 5 cents worth </SPAN></FONT><FONT face=Wingdings color=navy
size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Wingdings">J</SPAN></FONT><FONT
face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">I do not think the
crab or weather-vaning that I am seeing in a cross wind is my inputs.
Heck most of the time my rudder inputs are wrong anyway </SPAN></FONT><FONT
face=Wingdings color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Wingdings">J</SPAN></FONT><FONT
face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"> Obviously we
don’t know how faithful wind effects are in simulators but I just played with
a strong crosswind in Aerofly and the after establishing a straight vertical
the plane would crab into the wind. Left going one way and right going
the other. I think this is duplicating what I see when flying the real
toys. I guess we will all have to experiment with the next windy
day.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Stu<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<DIV>
<DIV class=MsoNormal style="TEXT-ALIGN: center" align=center><FONT
face="Times New Roman" size=3><SPAN style="FONT-SIZE: 12pt">
<HR tabIndex=-1 align=center width="100%" SIZE=2>
</SPAN></FONT></DIV>
<P class=MsoNormal><B><FONT face=Tahoma size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">From:</SPAN></FONT></B><FONT
face=Tahoma size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">
nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org] <B><SPAN
style="FONT-WEIGHT: bold">On Behalf Of
</SPAN></B>ronlock@comcast.net<BR><B><SPAN
style="FONT-WEIGHT: bold">Sent:</SPAN></B> Wednesday, October 10, 2007 12:08
PM<BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> <st1:PersonName
w:st="on">NSRCA Mailing List</st1:PersonName>; <st1:PersonName w:st="on">NSRCA
Mailing List</st1:PersonName><BR><B><SPAN
style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [NSRCA-discussion] Weather
Vane</SPAN></FONT><o:p></o:p></P></DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">I thought I'd throw in my 2 cents worth, but maybe it
turned into too much. Ya been warned
<G>.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">There is a strong, almost overwhelming, visual
perception that airplanes weathervane into the wind as seen by an observer on
the ground. <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">If the airplane is partly connected to the ground (as
in takeoff or landing roll) it will likely weathervane into the
wind. (Like a real weathervane on the barn). Putting
more side area behind the CG probably increases the weathervane
effect.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">But once airborne, an airplane no longer feels wind on
side of the airplane and does not weathervane in the sense that the
weathervane on the barn does. Nor does the hot air balloon mentioned in
an earlier post.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">Just after take off, we likely see the nose is pointed
some amount into the wind. This visual perception is true. But is it
proof of weathervaning? It probably weathervaned into the wind during
take off roll. Once airborne the weathervane is now what we call a crab angle
into the wind.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">We all know stall turns are easier to do "into the
wind". Is it because they weathervane? On the upline
to a stall turn in a cross wind, does the pilot wind correct the airplanes
track? Most of us do, consciously or not. If we
are having any success at all with the wind correction, the fuselage is
"leaning" into the wind a bit It's certainly easier to get a stall
turn by continuing into the established lean, than it is to go against the
lean to the downwind direction. <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">Pilots try to make heading adjustments to hold track,
or hold distance in lines and maneuvers. Those adjustments (crab angles)
can appear to be a result of weathervaning, but are often pilot inputs,
consciously or not.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">Related things to consider-
<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">Airplanes do get "hit" in the side, top and bottom
when in turbulent wind, and wind shear situations. We fly low, and are
often in turbulence. There may be short, nearly random, turbulent air
effects that result in a weather vane type
effect.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">A free flight glider does not weather vane into the
wind. The glider may fly in circles, but it will drift downwind at the
overall average of the wind speed. No matter how much side area is
put behind the CG, it will not find and maintain a heading into the
wind.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">Given flight in no wind situation, a string tied on
nose of an airplane blows exactly backwards and parallel to the
fuselage. (unless the airplane is out of rig, or has control surface
inputs). If flown in a cross wind direction, the airplanes track
across the ground changes, but the string stays straight. (not
counting any effect of propeller induced spiral
airflow)<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">The old full scale stories about loosing airspeed and
stalling while doing a "downwind turn" fit into this discussion to a
degree. Does wind hit the tail of an airplane as it turns downwind
thereby reducing airspeed? In the "old" days, pilots often flew
low and partly judged airplane speed by visual observation of ground
speed. (similiar to our situation of observing from the
ground) This could lead to the perception of plenty of ground
speed being plenty<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">Sorting out the visual perception of the "obvious"
weather vane effect is tough. Lots of things complicate the observation
- pilot inputs, turbulence, paralax, and more.
<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">IMHO, bottom line, it's not wind hitting side of
airplane, no matter how much side area is behind the
CG.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">Later, Ron<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">In summary, I agree that as observers on the ground,
we "see" effects that appear to be weathervaning. But the "real"
cause<o:p></o:p></SPAN></FONT></P></DIV></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>