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<DIV><FONT face=Arial size=2>This is a great thread on the anatomy of a snap!
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What I'd like to hear are techniques for
executing good positive and negative snaps. I'm interested in things like
what's the best direction to snap (left?), what are the necessary stick
movements for positive and negative snaps, timing of stick movements, what
should be done differently on down-line vs. horizontal vs. up-line snap, etc.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I've heard that the top fliers don't just jam the
sticks at the same time but they break the snap into multiple components to keep
it true and on heading. This is a complete mystery to me and I'd love to
understand it more.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Also, of great interest to me is how much throw is
necessary for good snaps and how to fly smoothly with that much throw. Obviously
each plane will vary but I'm looking for some basic guidelines on throws, maybe
with specific planes just as a idea. And how do the top level fliers deal with
having enough throw to execute snaps AND keep their other maneuvers from
being jerky? Dual rates, huge expo, snap switch, or just REALLY steady fingers?
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>This weekend at the Nederland, TX contest FAI flew
F03 in the sixth round. All of us mortals sat around in amazement watching snap
after snap in every conceivable attitude and direction. And Earl you're correct,
these snaps looked nothing like a lot of snaps in the other classes. They were
extremely crisp, quick and solid. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>So please, someone share your secrets so we can
improve on those mediocre snaps that everyone keeps referring to!
:-)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks,</FONT></DIV>
<DIV><FONT face=Arial size=2>Keith Black</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=EHaury@aol.com href="mailto:EHaury@aol.com">EHaury@aol.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, June 23, 2003 10:03
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Snap rolls (long)</DIV>
<DIV><BR></DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2
FAMILY="SANSSERIF">With the Nats fast approaching I thought it might be useful
to review / discuss the snap roll and its proper judging. My observation is
that there is a lack of quality demonstrated by many snaps. There seems to be
some tendency for folks that fly the maneuver poorly to judge it leniently, or
worse yet, judge well executed snaps harshly because they look unfamiliar. No
other maneuver is executed so quickly, making it even more demanding to
judge.<BR><BR>Please refer to page 78 of the rulebook under "Snaps." Consider
Item 1 carefully. <BR>"the nose should show a definite break" and "while the
track closely maintains the flight path" are key criteria for judging the
entrance to the snap. A rapid pitch attitude change, simultaneously or closely
followed by a yaw attitude change will create a stalled wing in the direction
of the snap and rapid autorotation rotation generated by the opposite wing.
The track will "closely" follow that established before the snap.<BR><BR>I ask
that you consider the often seen snap entrance. The aircraft pitches, yaws,
and rolls quite a bit off track before the stall occurs. The aircraft then
stalls and maintains that track, finishing with considerable offset from the
initial track. In my opinion, the rules require the change in track during the
snap iniation to be downgraded. Typically the changes are 15 to 30 degrees in
the vertical and horizontal plane, so 1 or 2 points for each plane. At the
same time, due to concurrent application of aileron, some 15 to 30 degrees of
roll occurs before the stall. Another point or 2 off for lack of proper snap
rotational angle <B>at the entrance.</B> At the same time, please realize that
there will be some small change of track as enough attitude change occurs to
initiate stall. This is recognized in the rules i.e. "track <B>closely
</B>follows." Certainly this is another one of the approximation words that
shouldn't be in rules. I believe, however, that "closely" better defines 5
degrees or so of track change and certainly does not allow 15 to
30.<BR><BR>Observe also that some pilots will change the track horizontally
(yaw) opposite the snap to accommodate the poor entry and facilitate exit on
the desired track. This change of entry track should also be downgraded at 1
point / 15 degrees.<BR><BR>Item 2 describes a barrel roll (zero). If the
events described in the discussion of Item 1 occur without an eventual stall,
the maneuver is a barrel roll. It may be fairly tight and still be a barrel.
This is tough to call, I've video taped a number of snaps that appeared fine
but were clearly barrels when viewed in slo-mo. The trick in judging this is
to look for the CG to stay on the original track, as stated in the rules. In
my opinion, so many snaps are barrels that this look may be becoming the
standard, with true snaps on track are being judged as axial
rolls.<BR><BR>Item 3 deals with wing position at start and stop and seems well
understood.<BR><BR>Item 4 mentions that snaps may be either positive or
negative. Look for the proper horizontal break direction.<BR><BR>Item 5 "If
model returns to an unstalled condition" "such that autorotation is not
visible" "model rolls to complete" indicates that rolling to finish a snap
must be severely downgraded. I suggest that 1 point / 15 degrees is
appropriate, as most of these rolled finishes will be 45 to 90 degrees which
results in a 3 to 6 point downgrade. As per Item 1 there should also be a
severe downgrade for unstalling early. <BR><BR>Item 6 discusses airspeed as
not being a criteria.<BR><BR>OK, recognize that there is a lot going on in a
snap in very short period of time. Look for all the elements to be there,
clean break, with the nose and tail autorotating in an attitude different from
the track, and a unstalling and rotation stop at the proper point. Please be
aware that there are many details to be considered beyond "it is or isn't" and
"the wings finish in proper plane." Also recognize that well performed clean
snaps may look a bit different depending on technique and aircraft.
<BR><BR>These interpretations are my own and outside of any official capacity.
I welcome discussion, addition, and disagreement.<BR><BR>Good
flying<BR><BR>Earl</FONT> </FONT></BLOCKQUOTE></BODY></HTML>