[NSRCA-discussion] [F3A-Discussion] snaps

[rcmaster199 at aol.com]

I offer the following to hopefully initiate discussion:
?
Plane shows an abrupt, definite pitch change and abrupt departure from flight path, followed immediately by:
Rotation in Roll, and Yaw. 
?
Forget about whether the Yaw happened before the Roll or not...it's?nearly impossible to determine from a practical point of view. Pitch change is much simpler to determine. Not that it doesn't matter; it matters that Yaw and Roll are done serially BUT happen so quickly for autorotation to occur in a pattern plane,?they are practically superimposed commands. That's for pattern planes only
?
I urge you to forget about whether the plane is stalled or not...it doesn't matter from a practical point of view. If you want the rule changed such that better verbiage is crafted, go for it and make a proposal to the FAI.
?
If the model does not show the abrupt pitch change and departure, the snap should be downgraded. That should be straight forward for snaps in straight lines. Much more difficult to discern a pitch change in a curved line such as in Avalanches. This is where it becomes much more of a judgement call. Folks, that is why you are in the chair, to make the judgement call. 
?
Consider this: if the pilot desides halfway through the snap to simply roll it to exit, then severely downgrade it. I think you would be able to tell if this happens
?
If it shows a departure in Yaw and/or Roll first, before it shows the change in pitch, ?it should be downgraded. 
?
If the exit is missed in Roll axis, apply?1 pt per 15 degrees rule. If the exit is?missed in Yaw axis, apply the 1/15 rule. If the plane does not follow the same angle of line, entry to exit, apply 1/15 rule. Pay extra attention on exit to see if the model was commanded in pitch to achieve the same angle. If you see a pitch change to correct the line, downgrade. Try not to confuse line departure or displacement here with a visible correction in pitch. If the plane departed from the line to initiate the snap, the new, displaced line must be maintained.
?
Let the comments?roll
?
MattK




-----Original Message-----
From: Ken Thompson <kthompson56 at satx.rr.com>
To: General pattern discussion <nsrca-discussion at lists.nsrca.org>
Sent: Mon, Jul 5, 2010 9:13 am
Subject: Re: [NSRCA-discussion] [F3A-Discussion] snaps

Glad for that description...the way I originally understood it the plane was not supposed to deviate from the flight path...always said that was impossible...
?
Ken
----- Original Message ----- 
From: Dr Mike 
To: 'General pattern discussion' 
Sent: Monday, July 05, 2010 7:04 AM
Subject: Re: [NSRCA-discussion] [F3A-Discussion] snaps


Yes that is correct, thanks Matt.
Mike 
?
From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of rcmaster199 at aol.com
Sent: Sunday, July 04, 2010 6:22 PM
To: nsrca-discussion at lists.nsrca.org; f3a-discussion at lists.f3a.us
Subject: Re: [NSRCA-discussion] [F3A-Discussion] snaps

?
The F3A maneuver description may be inadequate and/or inaccurate, however?that doesn't much matter for the judge who has the ardeous task of deciphering the snap. The description stands as is for this cycle and that's how the World's judges will judge them to the best of their ability next year. I urge all judges that judge F3A Semis and Finals at this year's Nats/Team Selection contest to take heed of?FAI description (not AMA) and judge accordingly.

?

In essence, Snaps?should not zeroe'd as easily as they once were; far cry from where it was just a?couple years ago. I believe that's the main reason the rule was written as indicated. 

?

Mike's point I think deals with bringing the Snap back out of hibernation such that folks get a chance to re-read it and re-hash just in time for the Team Selection; fresh in one's mind so to speak

?

Matt K

?

?

-----Original Message-----
From: Woodward, Jim R (US SSA) <jim.woodward at baesystems.com>
To: 'f3a-discussion at lists.f3a.us' <f3a-discussion at lists.f3a.us>; 'nsrca-discussion at lists.nsrca.org' <nsrca-discussion at lists.nsrca.org>
Sent: Sun, Jul 4, 2010 4:27 pm
Subject: Re: [NSRCA-discussion] [F3A-Discussion] snaps
Mike, I'm replying from a blackberry without the benefit of the rulebook in front of me. I thought these were called "Flick Rolls" now? I don't think any of us are equipped in the context of judging a 0.5 second manuever to determine if is "stalled" or "unstalled." I think Jerry Budd posted on the nsrca list the last dissertation on snaps, which from memory, pretty much proved the planes are not stalled.

Given you posted this, what do you want to see happen? Thx Jim W.

?

From: f3a-discussion-bounces at lists.f3a.us <f3a-discussion-bounces at lists.f3a.us> 
To: 'General pattern discussion' <nsrca-discussion at lists.nsrca.org>; f3a-discussion at lists.f3a.us <f3a-discussion at lists.f3a.us> 
Sent: Sun Jul 04 17:11:46 2010
Subject: [F3A-Discussion] snaps 

Given the abundance of snap maneuvers(7 maneuvers, 9 snaps) in the F-11 pattern, I feel compelled to give the exact description via the F3A rulebook:

?

A snap-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 I a stalled condition throughout the maneuver.? If the stall/break does not occur and the model aircraft barrel-rolls 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 competitors 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. 

?

?




_______________________________________________ NSRCA-discussion mailing list NSRCA-discussion at lists.nsrca.org http://lists.nsrca.org/mailman/listinfo/nsrca-discussion 


_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
_______________________________________________ NSRCA-discussion mailing list NSRCA-discussion at lists.nsrca.org http://lists.nsrca.org/mailman/listinfo/nsrca-discussion 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20100705/bbdb6609/attachment.html>