[NSRCA-discussion] Snap entry in FAI

Mon Jun 16 09:33:49 AKDT 2008

Perhaps everyone install an Eagle Tree logger with an Angle of Attack
sensor?

On Mon, Jun 16, 2008 at 12:21 PM, Jon Lowe <jonlowe at aol.com> wrote:

> 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
> www.shulmanaviation.com
> www.composite-arf.com
>
> -----Original Message-----
> *From:* nsrca-discussion-bounces at lists.nsrca.org [
> mailto:nsrca-discussion-bounces at lists.nsrca.org<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=aolcmp00050000000011>.
> Showtimes, theaters, movie news, & more!
>
> _______________________________________________
> NSRCA-discussion mailing listNSRCA-discussion at lists.nsrca.orghttp://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>
> ------------------------------
> Get the Moviefone Toolbar<http://toolbar.aol.com/moviefone/download.html?ncid=aolcmp00050000000011>.
> Showtimes, theaters, movie news, & more!
>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>

-- 

Keith Hoard
Collierville, TN
khoard at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20080616/9bf6b5ea/attachment.html>