[NSRCA-discussion] Snap entry in FAI

[Matthew Frederick]

It is entirely possible (and expected) that you can show a pitch change 
without a deviation in the line of flight. It requires a reduction in 
throttle combined with the application of elevator. If it wasn't possible to 
show a pitch change without changing the line of flight we would see some 
horrible spin entries. Keep in mind, the snap and spin are essentially the 
same maneuvers with different entry speeds. Doing a proper snap according to 
the rules (both AMA and FAI from what I can see) is a matter of split-second 
timing of the control inputs. Nothing more.

Matt

----- Original Message ----- 
From: "Woodward, Jim (US SSA)" <jim.woodward at baesystems.com>
To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
Sent: Monday, June 16, 2008 2:05 PM
Subject: Re: [NSRCA-discussion] Snap entry in FAI


Jon,

I'm not sure if you are serious or not.  If a pilot is showing you such a 
"detectable" pitch departure first, they are actually flying "off" the line 
which is its own downgrade prior to the snap, subject to the 1 point per 15 
degree rule for line deviation.  The nose of the plane moving in a conical 
fashion is evidence of pitch departure.  You do not have to fly off the line 
to have that.  You can input all 3 at the same time and still achieve the 
highest score all things considered.
Thanks,
Jim

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org 
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of 
shinden1 at cox.net
Sent: Monday, June 16, 2008 2:39 PM
To: General pattern discussion
Subject: Re: [NSRCA-discussion] Snap entry in FAI

Assuming your airplane c/g is set correctly ,,
there will be a displacement during the Snap ,, but it will enter and exit 
,,on the same line  I.E.,,Pitch and Yaw will happen at the same time ..you 
will get a cone at the tail ,,,the airplane will displace during the input . 
and recovery will be a solid lock exit
if the airplane is "not stalled" during the snap ,,usually because your 
tail heavy,,,the airplane will exit on a different line than it entered,, 
Yaw ,and or Pitch
this includes up,down and 45`s,and
If you have to lead with any input ,,,your tail heavy

I hate to see the scores issued on the 1.5 knife snap :)
no judge will know what inputs are being applied .
If the airplane is tail heavy you don`t need elevator ,,, {most are not 
using this input} But I bet you can`t tell me who.

The harder we try to define and rewrite the rules ,,,the easier it will be 
for guys Like Jason to receive the 10`s
mortals like us will not be able to complete the definition.
and Andrew, Chip and Jason will laugh all the way to the top 4
Bryan

---- Jon Lowe <jonlowe at aol.com> wrote:
> Jim,
>
> I have no clue how you think all three axes can be initiated at the same 
> time. You keep forgetting the part of the RULE, quoted verbatim below, 
> that says the "fuselage break and separation from the flight path" must 
> happen "BEFORE THE ROTATION IS STARTED". I'm NOT equating fueselage break 
> to pitch break, it could break in pitch and/or yaw, if it doesn't start 
> rotation at the same time. If you initiate all three axis at the same 
> time, rotation WILL start at the same instant, and that is specifically 
> NOT permitted. READ THE RULE! The judge MUST determine if the fuselage 
> broke and separated from the flight path first, BEFORE the rotation 
> started. If it didn't, he MUST severely downgrade.
>
>
>
> Jon Lowe
>
>
> -----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 12:37 pm
> Subject: Re: [NSRCA-discussion] Snap entry in FAI
>
>
>
>
> 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
> 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]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. 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. Showtimes, theaters, movie news, & more!
>
>
>
>
>
> _______________________________________________
> SRCA-discussion mailing list
> SRCA-discussion at lists.nsrca.org
> ttp://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