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I have to confess that I'm having some problems here. There is nothing
"smooth or graceful" about a snap executed in the manner required
to satisfy the powers that be who have expressed their judging standards
on this forum. I would submit that if you were to perform a snap
that met their criteria for "smooth and graceful", you would probably earn
a reward of zero ( claiming it didn't snap).
<BR>A snap is, by nature, a violent maneuver and the lines approaching
and exiting same are just lines and may be considered precise, but I would
have difficulty classifying a line as graceful, after all it's only a line.
Smooth,..........maybe.
<BR>As far as the C.G. staying on track,......that's what the AMA video
portrays, but it's a physical impossibility. Just by virtue of the pitch
break the C.G. will be wrenched from the flight path and when the rudder
kicks in the lateral displacement will be added. By skillful manipulation
the pitch line can be restored, but the lateral displacement is a much
tougher correction to master even when utilizing leading opposite rudder.
<BR>Remember that you can't increase the AOA without also increasing lift,
which will in turn break the flight path vertically.The same is true when
the rudder enters the equation and you can't correct for it's lateral displacement
by inputting opposite rudder without screwing up your heading.
<BR>Like somebody said, it's a subjective thing and we're never going to
get everyone on the same page on this one.
<BR>IMHO, if there's a pitch break and the nose and tail cones are visible
"IT'S A SNAP" and you can pretty much disregard the lateral displacement
(unless somebody wants to make the effort to get it inserted in the book).
<BR>I do seem to remember that there were a couple of guys in the finals
at the Nats that were able to get that center up-line snap to come back
to the vertical track consistantly so I would have to guess that there
is something significantly aerodynamically different going on when the
wing is unloaded............Hmmmmm.
<BR>Georgie
<P>Dean Pappas wrote:
<BLOCKQUOTE TYPE=CITE> <STYLE></STYLE>
<SPAN class=137421122-29122004>Jerry,</SPAN><SPAN class=137421122-29122004>I
have no problem with a dead slow snap, as long as all the elements are
there.</SPAN><SPAN class=137421122-29122004>An outside snap at the top
of an inside loop may be very slow, if the plane is decellerated to near
the level flight stall speed, at the top.</SPAN><SPAN class=137421122-29122004>If
you do a snap at just above landing speed, how fast is the rotation? Relatively
slow, I'll bet.</SPAN><SPAN class=137421122-29122004></SPAN><SPAN class=137421122-29122004>Not
zeroed, but downgraded. 1 point per 15 for the extra yaw, and a downgrade
for loss of smoothness/gracefulness.</SPAN><SPAN class=137421122-29122004>The
snap itself may be violent, but the approach and departure should be graceful.</SPAN><SPAN class=137421122-29122004>Regards,</SPAN> <FONT FACE="Times New Roman">Dean
Pappas</FONT>
<BR><FONT FACE="Times New Roman">Sr. Design Engineer</FONT>
<BR><FONT FACE="Times New Roman">Kodeos Communications</FONT>
<BR><FONT FACE="Times New Roman">111 Corporate Blvd.</FONT>
<BR><FONT FACE="Times New Roman">South Plainfield, N.J. 07080</FONT>
<BR><FONT FACE="Times New Roman">(908) 222-7817 phone</FONT>
<BR><FONT FACE="Times New Roman">(908) 222-2392 fax</FONT>
<BR><FONT FACE="Times New Roman">d.pappas@kodeos.com</FONT>
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<DIV class="OutlookMessageHeader" dir="ltr"><FONT FACE="Tahoma">-----Original
Message-----</FONT>
<BR><FONT FACE="Tahoma"><B>From:</B> discussion-request@nsrca.org [<A HREF="mailto:discussion-request@nsrca.org">mailto:discussion-request@nsrca.org</A>]<B>On
Behalf Of </B>Jerry Voth</FONT>
<BR><FONT FACE="Tahoma"><B>Sent:</B> Wednesday, December 29, 2004 4:21
PM</FONT>
<BR><FONT FACE="Tahoma"><B>To:</B> discussion@nsrca.org</FONT>
<BR><FONT FACE="Tahoma"><B>Subject:</B> Re: Displacement during snap rolls
(was Why is it so quiet?)</FONT></DIV>
How would you judge a snap that meets all the criteria that has been mentioned
in this thread that constitutes a good snap but takes almost a full second
to complete? I also was at the T.O.C. when the guy that won used opposite
rudder just prior to his vertical snaps-as I recall it was a very quick
move. Wouldn't they be zeroed using the current thinking because the initial
break was sideways before the up break? kJerry
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<DIV style="FONT: 10pt arial">----- Original Message -----</DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A HREF="mailto:d.pappas@kodeos.com" title="d.pappas@kodeos.com">Dean Pappas</A></DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A HREF="mailto:discussion@nsrca.org" title="discussion@nsrca.org">discussion@nsrca.org</A></DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, December 29, 2004
3:10 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: Displacement during snap
rolls (was Why is it so quiet?)</DIV>
<SPAN class=323240221-29122004>After re-reading the post, it occurred
to me I should clarify:</SPAN><SPAN class=323240221-29122004>I was writing
about what I thought a good standard might be.</SPAN><SPAN class=323240221-29122004>For
right now, the book is it, and as Bob pointed out, there is no specific
track downgrade.</SPAN><SPAN class=323240221-29122004>Anyone have an IAC
judges' guide handy? I'm curious.</SPAN><SPAN class=323240221-29122004>By
the way, the full scale guys do horrible things to snaps, including completely
unstalling the plane (particularly during consecutive snaps).</SPAN><SPAN class=323240221-29122004>That
don't make it right!</SPAN><SPAN class=323240221-29122004>Archie has a
good point, not only does the standard need to be better nailed down, but
some people may never be trained to "see fast". </SPAN><SPAN class=323240221-29122004>Add
in some "tired from 4 hours in the chair" and you have mush.</SPAN><SPAN class=323240221-29122004></SPAN><SPAN class=323240221-29122004>This
is a good discussion!</SPAN><SPAN class=323240221-29122004></SPAN> Dean
Pappas
<BR><FONT FACE="Times New Roman">Sr. Design Engineer</FONT>
<BR><FONT FACE="Times New Roman">Kodeos Communications</FONT>
<BR><FONT FACE="Times New Roman">111 Corporate Blvd.</FONT>
<BR><FONT FACE="Times New Roman">South Plainfield, N.J. 07080</FONT>
<BR><FONT FACE="Times New Roman">(908) 222-7817 phone</FONT>
<BR><FONT FACE="Times New Roman">(908) 222-2392 fax</FONT>
<BR><FONT FACE="Times New Roman">d.pappas@kodeos.com</FONT>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class="OutlookMessageHeader" dir="ltr"><FONT FACE="Tahoma">-----Original
Message-----</FONT>
<BR><FONT FACE="Tahoma"><B>From:</B> discussion-request@nsrca.org [<A HREF="mailto:discussion-request@nsrca.org">mailto:discussion-request@nsrca.org</A>]<B>On
Behalf Of </B>Dean Pappas</FONT>
<BR><FONT FACE="Tahoma"><B>Sent:</B> Wednesday, December 29, 2004 1:15
PM</FONT>
<BR><FONT FACE="Tahoma"><B>To:</B> discussion@nsrca.org</FONT>
<BR><FONT FACE="Tahoma"><B>Subject:</B> RE: Displacement during snap rolls
(was Why is it so quiet?)</FONT></DIV>
<SPAN class=217444617-29122004>Hi All,</SPAN><SPAN class=217444617-29122004>before
I crawl back to the lab ... and see what's on the slab ...</SPAN><SPAN class=217444617-29122004></SPAN><SPAN class=217444617-29122004>While
I agree that some displacement is inevitable, I wouldn't want to see a
rule that says that if you don't see any, then it's not a snap.</SPAN><SPAN class=217444617-29122004>The
very best high energy snaps will displace so little that it will be really
hard to say that it's there.</SPAN><SPAN class=217444617-29122004></SPAN><SPAN class=217444617-29122004>1)
My guess would be that most really good snaps probably displace about 1/2
wingspan, both up and to the side.</SPAN><SPAN class=217444617-29122004>Gravity
will possibly kill any evidence of the UP part. Try doing an inside snap
from inverted, or try a snap from knife edge. You'll see the UP displacement! </SPAN><SPAN class=217444617-29122004>2)
As the elevator throw is reduced, from that needed to do a good snap, the
airplane displaces worse and worse, as it takes longer for the plane to
stall deeply enough, to make little enough lift to continue changing the
airplane's course appreciably.</SPAN><SPAN class=217444617-29122004>3)
If the elevator throw is further reduced, the displacement goes away! Hmm.</SPAN><SPAN class=217444617-29122004>4)
Leading the elevator reduces the necessary amount of throw, for a good
snap. </SPAN><SPAN class=217444617-29122004></SPAN><SPAN class=217444617-29122004>Here's
the aesthetic question behind the argument:</SPAN><SPAN class=217444617-29122004>Do
we all agree that when you see a snap with an "in your face" break that
it really is a thing of beauty?</SPAN><SPAN class=217444617-29122004>Or
do some of us think it's untidy, and not"on a line"? I had a judge ask
me (back in '91) "What's with the twitch before the snap?"</SPAN><SPAN class=217444617-29122004></SPAN><SPAN class=217444617-29122004>I'm
as confused as anybody. I guess that's as good a way to start the new year
as any.</SPAN> <FONT FACE="Times New Roman">Dean Pappas</FONT>
<BR><FONT FACE="Times New Roman">Sr. Design Engineer</FONT>
<BR><FONT FACE="Times New Roman">Kodeos Communications</FONT>
<BR><FONT FACE="Times New Roman">111 Corporate Blvd.</FONT>
<BR><FONT FACE="Times New Roman">South Plainfield, N.J. 07080</FONT>
<BR><FONT FACE="Times New Roman">(908) 222-7817 phone</FONT>
<BR><FONT FACE="Times New Roman">(908) 222-2392 fax</FONT>
<BR><FONT FACE="Times New Roman">d.pappas@kodeos.com</FONT>
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