[NSRCA-discussion] Snap entry in FAI
Woodward, Jim (US SSA)
jim.woodward at baesystems.com
Mon Jun 16 09:37:43 AKDT 2008
Jon,
I'm shocked - you are totally wrong here. Do not equate "fuselage" to
"pitch" in the reading of this definition. As a judge you should NOT
apply a "pitch-assessment" pass/fail criteria to judging FAI snap rolls.
It is completely rejected. The plane and therefore "fuselage" must
autorotate about the flight axis, which means that the nose and tail of
the plane will move in a conical fashion. The pilot can initiate with
all 3 axis at one time.
It is the responsibility of the judge to determine if autorotation
occurred, and not determine how or in what order the pilot did it.
Thanks,
Jim
________________________________
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Jon Lowe
Sent: Monday, June 16, 2008 1:21 PM
To: nsrca-discussion at lists.nsrca.org
Subject: Re: [NSRCA-discussion] Snap entry in FAI
You are correct, as long as there is no roll induced at the same
instant. I overlooked that possibility. Not sure how rudder alone will
induce the "supposed to be in a stalled condition" though!! There are
many attitudes (e.g. 45 down on center) where a judge could not likely
see a rudder departure alone first, and thus conclude that departure did
not occur before the roll departure started. And a judge might also not
see a pitch departure first on a end box upline snap, but he could see
rudder first. It is VERY clear that simultaneous roll with either or
both of the other axes departures is NOT allowed as others have tried to
state here. I did say that pitch and yaw departure could happen
simutaneously, in my original post, as long as roll doesn't occur at the
same time.
Jon Lowe
-----Original Message-----
From: JShulman <jshulman at cfl.rr.com>
To: General pattern discussion <nsrca-discussion at lists.nsrca.org>
Sent: Mon, 16 Jun 2008 11:22 am
Subject: Re: [NSRCA-discussion] Snap entry in FAI
Jon,
I don't see where it says pitch break? Rudder first will show attitude
break and separation from the flight path. So if one uses rudder and
elevator first this is also correct.
Regards,
Jason
www.jasonshulman.com <http://www.jasonshulman.com/>
www.shulmanaviation.com <http://www.shulmanaviation.com/>
www.composite-arf.com <http://www.composite-arf.com/>
-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org
<mailto:nsrca-discussion-bounces at lists.nsrca.org?> ]On Behalf Of Jon
Lowe
Sent: Monday, June 16, 2008 12:11 PM
To: nsrca-discussion at lists.nsrca.org
Subject: Re: [NSRCA-discussion] Snap entry in FAI
I suggest people re-read the definition ofsnap-rolls from the
FAI sporting code. I did a few minutes ago. Here it is:
"5B.7.5. SNAP-ROLLS
A snap-roll (or flick roll/rudder roll) is a rapid autorotative
roll where the model aircraft is in a stalled
attitude, with a continuous high angle of attack
Snap-rolls have the same judging criteria as axial rolls as far
as start and stop of the rotation, and
constant flight path through the manoeuvre is concerned.
At the start of a snap-roll, the fuselage attitude must show a
definite break and separation from the
flight path, before the rotation is started, since the model
aircraft is supposed to be in a stalled
condition throughout the manoeuvre, If the stall/break does not
occur and the model aircraft barrelrolls
around, the manoeuvre must be severely downgraded (more than 5
points). Similarly, axial
rolls disguised as snap-rolls must be severely downgraded (more
than 5 points).
Snap-rolls can be flown both positive and negative, and the same
criteria apply. The attitude
(positive or negative) is at the competitor's discretion. If the
model aircraft returns to an unstalled
condition during the snap-roll, the manoeuvre is severely
downgraded using the 1 point/15 degree
rule."
Note that "the fuselage attitude must show a definite break and
separation from the flight path, before the rotation is started..."
That means that simultaneous pitch and rotation is specifically NOT
permitted. I would interpret it as meaning that pitch and yaw could
theoretically happen simultaneously, as long as no roll is involved.
Sorry Matt, the rules as written do NOT allow actuation in all three
axes simultaneously. The rule also states that a constant flight path
has to be maintained.
Let's face it, the only way to prevent severe downgrading from
EVERY judge, not just some judges, is to have a pitch break first.
Takes any question away.
Jon Lowe
-----Original Message-----
From: rcmaster199 at aol.com
To: nsrca-discussion at lists.nsrca.org
Sent: Mon, 16 Jun 2008 10:46 am
Subject: Re: [NSRCA-discussion] Snap entry in FAI
A "Flick" and a "Snap" roll are the same roll in full scale
aerobatics parlance and reference material.
Do these mean the same thing in model aerobatics? In my view,
they do
The latest FAI regs allow actuation of the three main axes
simultaneously...that is, the regs don't specifically differentiate
"Pitch Break" from other deviations. I don't think they specifically
require that the model must rotate about it's flight path either, I
don't believe (.....plane must rotate in a conical fashion about the
fight axis....). The model would probably present the best if that's
done, so pilots may want to consider that when executing the maneuver.
In my take, a rapid Pitch is desired to preload the wing.
Contrary to popular belief, both panels dot not have to stall for a snap
to occur. Quite the opposite. Upon rudder deflection, the port panel
will practically stall (lift much much less than the other panel) but
the starboard panel must be lifting to create the autorotation. If both
panels stall, the model will fall out of the sky for a distance and a
snap would not occur at the correct moment in time
MattK
-----Original Message-----
From: Woodward, Jim (US SSA) <jim.woodward at baesystems.com>
To: General pattern discussion
<nsrca-discussion at lists.nsrca.org>
Sent: Mon, 16 Jun 2008 8:47 am
Subject: Re: [NSRCA-discussion] Snap entry in FAI
Guys,
I thought the FAI changes explicitly allowed flick rolls? The
rule
reads, "... fuselage attitude must show a definite break and
separation
from the flight path."
It does not say, "MUST SHOW PITCH BREAK." Please DO NOT
ERROUNIOUSLY
APPLY A PASS/FAIL MAJOR DEDUCTION initial assessment to the snap
roll.
Watch the whole maneuver then render your score.
A break and separation from the flight path simply means that
the nose
and tail of the plane must rotate in a conical fashion about the
fight
axis. Yaw, roll, and pitch can all break at the same moment if
that is
how the pilot does it.
Hey :) some really handsome smart guy wrote some stuff at this
link
below about snap rolls to help clarify how they are done in
IMAC.
http://www.mini-iac.com/DesktopDefault.aspx?tabid=77
thanks,
Jim
_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
________________________________
Get the Moviefone Toolbar
<http://toolbar.aol.com/moviefone/download.html?ncid=aolcmp0005000000001
1> . Showtimes, theaters, movie news, & more!
_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
________________________________
Get the Moviefone Toolbar
<http://toolbar.aol.com/moviefone/download.html?ncid=aolcmp0005000000001
1> . Showtimes, theaters, movie news, & more!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080616/aae8e454/attachment-0001.html>
More information about the NSRCA-discussion
mailing list