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<DIV><FONT size=2 face=Arial>Jim:</FONT></DIV>
<DIV><FONT size=2 face=Arial>Interesting definition. Back when I started
flying "Radio Control Aerobatics" (the name then, as I recall) one
definition of a snap roll was a "horizontal spin." Inasmuch as the (then)
inputs were the same, it wasn't totally incorrect to define it that
way.</FONT></DIV>
<DIV><FONT size=2 face=Arial>Bill Glaze</FONT></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=joddino@socal.rr.com href="mailto:joddino@socal.rr.com">James
Oddino</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern discussion</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, October 17, 2009 12:14
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] How I
became an expert Snap Judge (TIC)</DIV>
<DIV><BR></DIV>
<DIV>Hi Ron,</DIV>
<DIV><BR></DIV>
<DIV>I found a definition that I think we can live with.</DIV>
<DIV><BR></DIV><SPAN
style="LINE-HEIGHT: 19px; FONT-FAMILY: sans-serif; FONT-SIZE: 13px"
class=Apple-style-span>
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style="Z-INDEX: auto; POSITION: static; BACKGROUND-COLOR: white; COLOR: black; FONT-SIZE: 13px">
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<TR>
<TD><A
style="BACKGROUND-IMAGE: none; COLOR: rgb(204,34,0); TEXT-DECORATION: none; -webkit-background-clip: initial; -webkit-background-origin: initial"
class=new title="Snap Roll (page does not exist)"
href="http://en.wikipedia.org/w/index.php?title=Snap_Roll&action=edit&redlink=1">Snap
Roll</A>; Flick roll; Flick</TD>
<TD>A family of rapid autorotational or "horizontal spins," not unlike
spins. Rotation is induced by a rapid pitch input followed by
rapid <A
style="BACKGROUND-IMAGE: none; COLOR: rgb(0,43,184); TEXT-DECORATION: none; -webkit-background-clip: initial; -webkit-background-origin: initial"
class=mw-redirect title="Yaw angle"
href="http://en.wikipedia.org/wiki/Yaw_angle">yaw</A> input, thus
stalling one wing further than the other. This imbalance in lift causes
the high speed roll.</TD>
<TD>
<DIV style="TEXT-ALIGN: center; WIDTH: 191px" class=center>
<DIV style="MARGIN-LEFT: auto; MARGIN-RIGHT: auto" class=floatnone><A
style="BACKGROUND-IMAGE: none; COLOR: rgb(0,43,184); MARGIN-LEFT: auto; MARGIN-RIGHT: auto; TEXT-DECORATION: none; -webkit-background-clip: initial; -webkit-background-origin: initial"
class=image
href="http://en.wikipedia.org/wiki/File:Aeros_fig_flickroll.svg"><IMG
style="BORDER-BOTTOM-STYLE: none; BORDER-RIGHT-STYLE: none; BORDER-TOP-STYLE: none; MARGIN-LEFT: auto; VERTICAL-ALIGN: middle; BORDER-LEFT-STYLE: none; MARGIN-RIGHT: auto"
id=b182592f-895a-4f92-b51d-b1ec0d5d4856 alt="Aeros fig flickroll.svg"
src="cid:1F8710DE9127413EA2AA579966EF8A82@glazecstp32xp" width=108
height=33 apple-height="yes"
apple-width="yes"></A></DIV></DIV></TD></TR></TBODY></TABLE></SPAN>
<DIV><BR></DIV>
<DIV>Notice that it says rotation is induced by one wing stalling further than
the other. It doesn't say the roll can't be maintained (prolonged) by
using ailerons. I also believe "stalled further than the other" simply
means producing less lift than the other not stalled beyond the critical angle
of attack. </DIV>
<DIV><BR></DIV>
<DIV>So I guess it is up to the judge to determine if he sees a break in pitch
and a break in yaw that starts the rotation before ailerons are applied.
Just kidding.</DIV>
<DIV><BR></DIV>
<DIV>Jim</DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV>
<DIV>On Oct 16, 2009, at 8:11 AM, Ron Van Putte wrote:</DIV><BR
class=Apple-interchange-newline>
<BLOCKQUOTE type="cite">
<DIV>Yes, I agree with the elimination of the autorotation/stall requirement
and describe the desired flight path, not how to achieve it.<BR><BR>Ron
VP<BR><BR>On Oct 16, 2009, at 9:41 AM, James Oddino wrote:<BR><BR>
<BLOCKQUOTE type="cite">Ron, I agree completely with you and Jerry.
My point is we can get a similar airframe response at similar
asymmetrical lift on the left side by using ailerons along with rudder and
elevator. Autorotation refers to rolling induced by an unstable
CL/alpha that occurs only on the right side. There, as alpha
increases lift decreases so the wing descends resulting in alpha
increasing and so on. On the rising wing, alpha is decreasing so
lift is increasing so the wing keeps rising. The result is a
spontaneous, continuous roll.<BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite">This is untrue on the left side but we can and do
induce rotation with ailerons. If we want to fix the rules we should
probably get rid of the autorotation/stall requirement and describe the
desired flight path, not how to achieve it. Agree?<BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite">Make sense?<BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite">Jim<BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite">On Oct 16, 2009, at 6:58 AM, Ron Van Putte
wrote:<BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">Jerry's point is that the airplane can't get to
the portion of the CL/alpha curve to the right, above the critical
alpha. Too many Gs on the airplane at normal flying
speed.<BR></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">Ron VP<BR></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">On Oct 16, 2009, at 12:36 AM, James Oddino
wrote:<BR></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">The way I see it, most of the folks think that
the wing is stalled or it isn't. This is not the case.
Stalled typically refers to the portion of the CL/alpha curve to
the right, above the critical alpha. The CL does not go to zero
when alpha exceeds the critical 15 or so degrees but drops with a
relatively low slope. That means it is still providing lift.
It can also be at different values on each panel. This is
what Jerry was talking about when he referred to stalling the wing
asymmetrically. (See excerpt
below).<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">I submit we can create a similar asymmetrical
Lift on the left side of the curve, below the critical angle and
produce a SNAP ROLL with the application of ailerons. This is
probably not a true autorotation that would occur with rudder and
elevator only if we were on the "stalled" side of the curve, but the
resulting airframe response looks the
same.<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">I rest my case,
Jim<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">I am not an aeronautical engineer. Where
is Jim Alberico when we need him?<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">On Oct 15, 2009, at 6:23 PM, Ron Van Putte
wrote:<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">I was busy when this came in and didn't sit
down to read it until tonight. I'm an aeronautical engineer
and EVERYTHING Jerry wrote made sense to me and I'm a picky
engineer. I hope everyone was able to wade their way through
it and understood what Jerry wrote. He used some technical
stuff that may have slowed some down, but it was presented in such a
way that most R/C aerobatic pilots should understand the
logic.<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE
type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">Well done
Jerry.<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE
type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">Ron Van
Putte<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE
type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">On Oct 14, 2009, at 5:12 AM, Budd
Engineering wrote:<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE
type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">So what are we doing to make the plane
present what appears to be a snap roll when we can't actually be
stalling the wing asymmetrically to induce autorotation like many
claim?<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite"><BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
<BLOCKQUOTE
type="cite">_______________________________________________<BR></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<BLOCKQUOTE type="cite">
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