[NSRCA-discussion] How I became an expert Snap Judge (TIC)
Budd Engineering
jerry at buddengineering.com
Tue Oct 13 18:43:50 AKDT 2009
The Answer: No, not even close...
Jerry
Sent from my iPhone
On Oct 13, 2009, at 7:26 PM, "Vicente \"Vince\" Bortone" <vicenterc at comcast.net
> wrote:
> Chris,
>
>
>
> I am copying from the first sentence FAI rule book: " 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" The question: Is 1-2 degrees consider a good
> amount to define a high angle of attack?
>
>
>
> Vicente "Vince" Bortone
>
> ----- Original Message -----
> From: "Chris Moon" <cjm767driver at hotmail.com>
> To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
> Sent: Tuesday, October 13, 2009 3:07:01 PM GMT -06:00 US/Canada
> Central
> Subject: Re: [NSRCA-discussion] How I became an expert Snap Judge
> (TIC)
>
> I think what this goes back to is the erroneous belief that you need
> to see an exaggerated pitch departure or it should be severely
> downgraded. Keep reading the maneuver description. It needs "A"
> pitch break, and depending on the current aoa (angle of attack) that
> can be a difference of just a degree or 2 if you are near the
> critical aoa. Please don't tell me guys, you are looking for MORE
> than a simple exceeding of the critical aoa and resulting stall. An
> exaggerated pitch break just to prove to naysayers that you make a
> break is wrong, wrong, wrong. It says it needs "A" break. Please
> keep re-reading it. Same for spin entry. It needs to stall, not go
> 30 degrees nose up to "prove" a stall. We are getting wound up over
> a misunderstanding of the mechanics of a stalled condition. As Don
> and Verne are alluding to, it really is not that complicated.
>
> Chris
>
> verne at twmi.rr.com wrote:
>
> Or you could just write in "DNO".... I always seem to see the break
> as in, nose up, tail down, and my 56 year old eyes are lousy. Verne
> ---- "Vicente "Vince" Bortone" <vicenterc at comcast.net> wrote:
>
> Verne, Following AMA description: if we don't see the break is 5
> points downgrade. That is 1/2 of the snap roll maneuver.
> Therefore, if we see the snap roll but don't see the break the judge
> has the right to write down 5 points score assuming that all other
> components are perfect. Therefore, base on the rule book the snap
> roll without a break has a value of 5 points. Vicente "Vince"
> Bortone ----- Original Message ----- From: verne @ twmi . rr .com
> To: "General pattern discussion" < nsrca -discussion at lists.
> nsrca .org> Cc: "Don Ramsey" <don. ramsey @ suddenlink .net> Sent:
> Tuesday, October 13, 2009 2:14:02 PM GMT -06:00 US/Canada Central
> Subject: Re: [NSRCA-discussion] How I became an expert Snap Judge
> (TIC) Is there anybody involved in this discussion that honestly
> can't recognize a snap when they see one? I'm just asking..... Verne
> ---- Don Ramsey <don. ramsey @ suddenlink .net> wrote:
>
> Vince, What about the next sentence in the FAI definition, “If the
> stall/break does not occur and the model aircraft barrel rolls arou
> nd, the manoeuvre must be severely downgraded (more than 5 points).”
> How about if the break does not show and the model does NOT barre
> l roll around. Do you still downgrade by 5 or more points? I don’t
> know what the intent of the rule was but I can tell you for a fact
> that the judges that only score FAI in Europe do not downgrade it by
> 5 or more points. I believe they use the “If it’s not a barrel
> and not an axial roll then it’s probably a snap, so judge it that wa
> y” because they have been instructed in the past to do it that way.
> Don rom: nsrca -discussion-bounces at lists. nsrca .org [mailto
> : nsrca -discussion-bounces at lists. nsrca .org] On Behalf Of Vicente
> "Vince" Bortone Sent: Tuesday, October 13, 2009 12:10 PM To: General
> pattern discussion Subject: Re: [NSRCA-discussion] How I became an
> expert Snap Judge (TIC) Matt, I am copying the snap description
> from the current FAI and AMA manuals. I don't see the AND you menti
> on in the FAI rule book. See the important portion in bold. I see
> that the AMA description is better in this respect. You are correc
> t in regard the downgrade in FAI . 5 or more points if you don't se
> e the break and the model barrel rolls. Therefore, what is the downg
> rade in FAI if the judge does not see the break and there is autorot
> ation? I will say 5 points since it says 5 or more points if the mo
> del barrel rolls. Again, it appears that AMA down grad descriptions
> are better. FAI : 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 st
> op of the rotation, and constant flight path through the manoeuvre i
> s concerned. At the start of a snap-roll, the fuselage attitude must
> show a definite break and separation from the flight path, before t
> he rotation is started, since the model aircraft is supposed to be i
> n a stalled condition throughout the manoeuvre, If the stall/break d
> oes not occur and the model aircraft barrelrolls around, the manoeuv
> re must be severely downgraded (more than 5 points). Similarly, axia
> l rolls disguised as snap-rolls must be severely downgraded (more th
> an 5 points). Snap-rolls can be flown both positive and negative, an
> d the same criteria apply. The attitude (positive or negative) is at
> the competitor’s discretion. If the model aircraft returns to an un
> stalled condition during the snap-roll, the manoeuvre is severely do
> wngraded using the 1 point/15 degree rule. AMA: Snaps: A Snap roll
> is a simultaneous, rapid autorotation in the pitch, yaw and roll ax
> es of flight in a stalled wing attitude. The following criteria appl
> y: 1. Since the maneuver is defined as a stalled maneuver, initiated
> by a stall of the wing induced by a rapid change in pitch attitude,
> the nose of the fuselage must show a definite break in pitch attitu
> de from the flight path in the direction of the snap (positive or ne
> gative) while the track closely maintains the flight path. The lack
> of a discernable pitch break is downgraded by 5 points. Large deviat
> ions from the flight path, indicative of a delayed stall, are to be
> downgraded using the 1 point per 15-degree rule for each axis of the
> excursion before stall. For example, it the model pitches 15 degree
> s nose up and the wings rotate 15 degrees before the stall, the mane
> uver should be downgraded 1 point for pitch and 1 point for roll. 2.
> The track visualized as the path of the Center of Gravity (CG) shou
> ld closely follow the geometric flight path of the maneuver while th
> e nose and tail auto rotate through opposite helical arcs around the
> flight path. Lack of these helical arcs (or coning) is indicative o
> f an axial roll and is scored zero. 3. If a stall does not occur and
> the model barrel rolls, the score is zero. A barrel roll can be ide
> ntified when the CG, the nose, and tails scribe the same helical pat
> h through the required rotation of the maneuver 4. Snap rolls have t
> he same judging criteria as axial rolls as far as start and stop of
> rotation, constant flight path through the maneuver and centering on
> lines. 5. If the model returns to an unstalled condition during the
> maneuver, such that the autorotation is not visible and the model r
> olls or barrel rolls to complete the maneuver, it would be downgrade
> d using the 1 point per 15 degree rule. 6. Airspeed is not a criteri
> a which should be used to judge this maneuver. The wing of the model
> is stalled during this maneuver; therefore a significant decrease i
> n speed may occur and is not a cause for downgrade. Vicente "Vince"
> Bortone ----- Original Message ----- From: "Matthew Frederick" <mjfrederick at cox.net
> >
> To: "General pattern discussion" < nsrca -discussion at lists.
> nsrca .org> Sent: Tuesday, October 13, 2009 9:47:30 AM GMT -06:00 US/
> Canada Central Subject: Re: [NSRCA-discussion] How I became an
> expert Snap Judge (TIC) ? While speaking with Don Ramsey about the
> nuances of judging snaps at a recent contest I found that he agreed
> with my interpretation of the FAI snap rule. The severe downgrade
> should only be applied if there is no break AND there is no
> autorotation (this is exactly what the rule says). Basically, lack
> of a break is not substantial grounds for the severe downgrade in
> FAI . If the break is not seen and autorotation still occurs at some
> point during the roll the one point per 15 degree rule applies.
> Since the snaps happen so fast, for me it's usually not more than 1
> or 2 points unless it was blatantly obvious that the plane rotated a
> while before the snap truly began. It's the same as if you stop the
> snap before completing the rotation and do an axial roll to finish.
> This nonsense of people being so quick to apply a severe downgrade
> has gone too far. One element of a maneuver (because I can't think
> of any sequence that has just a snap roll) should not ruin a whole
> flight, or eve n that one maneuver unless it just wasn't a snap. I
> like the idea of "if it's not a barrell roll and not an axial roll,
> it's probably a snap." Matt ----- Original Message ----- From:
> Vicente <mailto:vicenterc at comcast.net> "Vince" Bortone To: General
> pattern discussion <mailto: nsrca -discussion at lists. nsrca .org>
> Sent: Monday, October 12, 2009 5:12 PM Subject: Re: [NSRCA-
> discussion] How I became an expert Snap Judge (TIC) I believe that
> the current downgrade is severe. AMA 5 points. FAI 5 or more
> points if my memory is correct. In local contest I have been
> using 3 points downgrade. I know that is wrong but it has been my
> best way for me to take into account the break issue. It used to be
> zero and it was changed to 5 points (IMAC still a 10 points
> downgrade or nada). Therefore, Ron is correct. Probably makes
> sense to go 2-3 points downgrade if the judge can not see the break
> before rotation. Vicente "Vince" Bortone ----- Original Message
> ----- From: "John Fuqua" <johnfuqua at embarqmail.com>
> To: "General pattern discussion" < nsrca -discussion at lists.
> nsrca .org> Sent: Monday, October 12, 2009 1:51:00 PM GMT -06:00 US/
> Canada Central Subject: Re: [NSRCA-discussion] How I became an
> expert Snap Judge (TIC) Ron makes valid observation which I came to
> many years ago at the TOC when Mr. Bill graciously funded for full
> scale pilots like Patty Wagstaff do demo flights to entertain us.
> The one thing that I came away with in comparing full scale to our
> airplanes is the speed of the snap/rotation. In the full size
> aerobatics types that I observed there was plenty of time to see the
> nose pitch and then after somewhat of a hesitation yaw and rotate.
> In our pattern planes, especially when using a snap switch, it all
> gets to be a blur due to sheer speed. I have no solution to this
> issue but to MAKE the pilots show a break by having severe
> downgrades. Otherwise the concept of a snap will be ignored. Yes
> it's hard to see which makes it incumbent on the pilot to present it
> to the judges. -----Original Message----- From: nsrca -discussion-
> bounces at lists. nsrca .org [mailto: nsrca -discussion-bounces at lists.
> nsrca .org] On Behalf Of
> ronlock at comcast.net
> Sent: Monday, October 12, 2009 1:26 PM To: General pattern
> discussion Subject: Re: [NSRCA-discussion] How I became an expert
> Snap Judge (TIC) Here is a description that shows technically
> correct snap execution, and valid, consistent judging is possible.
> (Half of the District One guy need not read this, they have already
> heard it) <G> At a small airport airshow, one of demos was an in-
> trail formation of four full scale AT-6 Texans. As each plane got
> to stage center, it did a single positive snap roll. Spectators saw
> four snap rolls in a row, about 5 seconds apart. The flight of
> four went around, and repeated the maneuver. Some spectators are
> getting bored - even a pattern guy could get bored with a string of
> 8 nearly identical maneuvers. And then, they did it yet again!!
> What's in this for us? The snap maneuver by each AT-6 appeared to
> take a second or so, from initiation to completion. By the time the
> fourth plane did a snap, you could start seeing.... - there is a
> nose pitch up, - then a yaw, - then plane rolled in direction of
> yaw, - plane returned to straight and level flight. By the time
> the flight came around for another four snaps, you could see more
> details.. - there is a nose pitch up, (somewhat sudden, at least
> sudden for an AT-6) - then a large amount of yaw, - then rapid
> roll in direction of yaw, (rolling faster than it could with
> ailerons) - plane returned to fairly close straight and level, nose
> slightly high. By the time the flight positioned for yet another
> four snaps, (Yawn, spectators headed for cotton candy) the four
> distinct elements of the snap roll maneuver were easy to see, and
> there was time to evaluate (judge) each element. 1. there is a
> nose pitch up, (somewhat sudden, at least sudden for an AT-6, with
> little rise in altitude) 2. then large amount of yaw, (the yaw
> proceeds the upcoming roll) 3. then autorotation at rate faster
> than it could do an aileron roll) 4. plane returns to level flight
> track, with nose lowering to level flight attitude. We can all be
> expert Snap Roll Judges! Ahhh, at least for AT-6 snaps. What I
> take from all of this- The problem is not snap descriptions.
> It's the application of them; observation, discrimination and
> judging of elements in the split second observation time we have.
> Is the task beyond reasonable expectations of most of us as a
> judging community? I suppose we will continue work started over 10
> years ago to improve in these areas. In the meantime, shall we
> reduce the impact of inconsistent judging of snaps by limiting the
> downgrade of the snap portion of a maneuver to say..two points2?
> Ron Lockhart _______________________________________________ NSRCA-
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