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Continuing:<br><br>We can all agree what a loop looks like and all agree what an axial roll <br>looks like right? The problems begin when we get into the "stalled" <br>maneuvers -stalls, snaps,spins. Different planes behave and "look" <br>differently in the stall therefore there cannot be one standard "look" <br>for these maneuvers. Intuitively we know that different designs have <br>different airfoils and each plane has different wing loadings depending <br>on their weight and will stall differently. Back to aerodynamics 101 we <br>know that a wing stalls when you exceed it's critical angle of attack <br>and this angle does not change as far as that wing is concerned. <br>Different wings will of course have differing critical angles of attack <br>before they stall. So, differing wings designs must look differently as <br>they will reach critical angle at different times. The only thing that <br>changes is the speed at which the wing will stall if you try to maintain <br>level flight while reducing it's airspeed. So, does a plane need to <br>depart from it's original flight path to stall? NO. It just needs to <br>pivot around the c/g to take the wing past it's critical angle of <br>attack. The c/g of the airplane can absolutely maintain it's track <br>through the air. The speed of the rotation in a snap or spin will <br>depend on the airfoil and amount of control throws used as well as c/g <br>but the key is that you do not have to leave your c/g track through the <br>air to stall the wing. Period. Same for stalls at the entry to spins - <br>you can fly level and reduce airspeed while increasing pitch until you <br>bring the wing to and past it's critical angle of attack. This may be <br>15-20 degrees of nose up attitude - not some false 40-45 degree pitch up <br>designed to "show" the stall. Both wings are stalled and should count <br>as stalled. Period. They may look differently, but both are stalled and <br>correct. We need to get away from what "looks" right in a stalled maneuver.<br><br>Chris<br><br>fire away.......<br><br>chris moon wrote:<br>> George - you have made an excellent point in that the interval may by<br>> "minuscule" and not overly noticeable to everyone. It is absolutely<br>> wrong for some to claim that you must "show" them as judge an<br>> exaggerated pitch up just to satisfy a personal interpretation of the<br>> maneuver. Just as is is absolutely wrong for those judges to demand<br>> another overly exaggerated pitch up as a stall entry to a spin<br>> maneuver. It is never the job of the participant to exaggerate a<br>> portion of a maneuver just to prove it exists, therefore your usage of<br>> the term "minuscule" in terms of the time interval between pitch and<br>> rotation is something we need to keep in mind.<br>><br>> Chris<br>><br>> george w. kennie wrote:<br>>> My lip is becoming too painful from biting it, so I think I'm going to<br>>> stick my nose in here somewhere.<br>>> I think I'm with Jon on this one.<br>>> My logic, however flawed, tells me that if I am flying my plane<br>>> straight and level and I input rudder, no matter how much, there is no<br>>> way that this input will induce a stall to the airframe. Therefore, it<br>>> seems to me, that the necessary force required to stall the main<br>>> lifting surface must come from the elevator. It would further seem to<br>>> me that this input must, by it's very nature produce a pitching<br>>> attitude to the fuselage whether positive or negative. So I would have<br>>> to conclude that the attitude "break" referenced by the rule can only<br>>> refer to a "pitch" break and would be impossible to confuse with an<br>>> attitude change induced by the rudder seeing that the required result<br>>> is to stall the main wing.<br>>> And yes Jon, I agree that it would be necessary to lead with the<br>>> elevator in order to bring about this attitude change before rotation<br>>> is started, however miniscule the interval might be.<br>>> Of course I'm still open to hearing other interpretations and their<br>>> validations as these observations are strictly opinions.<br>>> G.<br>>><br>>> ----- Original Message -----<br>>> *From:* Jon Lowe<br>>> *To:* nsrca-discussion@lists.nsrca.org<br>>><br>>> *Sent:* Monday, June 16, 2008 2:10 PM<br>>> *Subject:* Re: [NSRCA-discussion] Snap entry in FAI<br>>><br>>> Jim,<br>>><br>>> I have no clue how you think all three axes can be initiated at<br>>> the same time. You keep forgetting the part of the RULE, quoted<br>>> verbatim below, that says the "fuselage break and separation from<br>>> the flight path" must happen "BEFORE THE ROTATION IS STARTED". I'm<br>>> NOT equating fueselage break to pitch break, it could break in<br>>> pitch and/or yaw, if it doesn't start rotation at the same time.<br>>> If you initiate all three axis at the same time, rotation WILL<br>>> start at the same instant, and that is specifically NOT permitted.<br>>> READ THE RULE! The judge MUST determine if the fuselage broke and<br>>> separated from the flight path first, BEFORE the rotation started.<br>>> If it didn't, he MUST severely downgrade.<br>>><br>>><br>>> Jon Lowe<br>>><br>>><br>>> -----Original Message-----<br>>> From: Woodward, Jim (US SSA)<br>>> To: General pattern discussion<br>>> Sent: Mon, 16 Jun 2008 12:37 pm<br>>> Subject: Re: [NSRCA-discussion] Snap entry in FAI<br>>><br>>> Jon,<br>>><br>>> I’m shocked - you are totally wrong here. Do not equate “fuselage”<br>>> to “pitch” in the reading of this definition. As a judge you<br>>> should NOT apply a “pitch-assessment” pass/fail criteria to<br>>> judging FAI snap rolls. It is completely rejected. The plane and<br>>> therefore “fuselage” must autorotate about the flight axis, which<br>>> means that the nose and tail of the plane will move in a conical<br>>> fashion. The pilot can initiate with all 3 axis at one time.<br>>><br>>> It is the responsibility of the judge to determine if autorotation<br>>> occurred, and not determine how or in what order the pilot did it.<br>>><br>>> Thanks,<br>>> Jim<br>>> ------------------------------------------------------------------------<br>>> *From:* nsrca-discussion-bounces@lists.nsrca.org<br>>><br>>> [mailto:nsrca-discussion-bounces@lists.nsrca.org<br>>> ] *On Behalf Of<br>>> *Jon Lowe<br>>> *Sent:* Monday, June 16, 2008 1:21 PM<br>>> *To:* nsrca-discussion@lists.nsrca.org<br>>><br>>> *Subject:* Re: [NSRCA-discussion] Snap entry in FAI<br>>> You are correct, as long as there is no roll induced at the same<br>>> instant. I overlooked that possibility. Not sure how rudder alone<br>>> will induce the "supposed to be in a stalled condition" though!!<br>>> There are many attitudes (e.g. 45 down on center) where a judge<br>>> could not likely see a rudder departure alone first, and thus<br>>> conclude that departure did not occur before the roll departure<br>>> started. And a judge might also not see a pitch departure first on<br>>> a end box upline snap, but he could see rudder first. It is VERY<br>>> clear that simultaneous roll with either or both of the other axes<br>>> departures is NOT allowed as others have tried to state here. I<br>>> did say that pitch and yaw departure could happen simutaneously,<br>>> in my original post, as long as roll doesn't occur at the same time.<br>>> Jon Lowe<br>>><br>>><br>>> -----Original Message-----<br>>> From: JShulman><br>>> To: General pattern discussion<br>>>><br>>> Sent: Mon, 16 Jun 2008 11:22 am<br>>> Subject: Re: [NSRCA-discussion] Snap entry in FAI<br>>> Jon,<br>>> I don't see where it says pitch break? Rudder first will show<br>>> attitude break and separation from the flight path. So if one uses<br>>> rudder and elevator first this is also correct.<br>>> Regards,<br>>> Jason<br>>> www.jasonshulman.com<br>>> www.shulmanaviation.com<br>>> www.composite-arf.com<br>>><br>>> -----Original Message-----<br>>> *From:* nsrca-discussion-bounces@lists.nsrca.org<br>>><br>>> [mailto:nsrca-discussion-bounces@lists.nsrca.org<br>>> ]*On Behalf<br>>> Of *Jon Lowe<br>>> *Sent:* Monday, June 16, 2008 12:11 PM<br>>> *To:* nsrca-discussion@lists.nsrca.org<br>>><br>>> *Subject:* Re: [NSRCA-discussion] Snap entry in FAI<br>>> I suggest people re-read the definition ofsnap-rolls from the<br>>> FAI sporting code. I did a few minutes ago. Here it is:<br>>> "5B.7.5. *SNAP-ROLLS*<br>>> A snap-roll (or flick roll/rudder roll) is a rapid<br>>> autorotative roll where the model aircraft is in a stalled<br>>> attitude, with a continuous high angle of attack<br>>> Snap-rolls have the same judging criteria as axial rolls as<br>>> far as start and stop of the rotation, and<br>>> constant flight path through the manoeuvre is concerned.<br>>> At the start of a snap-roll, the fuselage attitude must show a<br>>> definite break and separation from the<br>>> flight path, before the rotation is started, since the model<br>>> aircraft is supposed to be in a stalled<br>>> condition throughout the manoeuvre, If the stall/break does<br>>> not occur and the model aircraft barrelrolls<br>>> around, the manoeuvre must be severely downgraded (more than 5<br>>> points). Similarly, axial<br>>> rolls disguised as snap-rolls must be severely downgraded<br>>> (more than 5 points).<br>>> Snap-rolls can be flown both positive and negative, and the<br>>> same criteria apply. The attitude<br>>> (positive or negative) is at the competitor’s discretion. If<br>>> the model aircraft returns to an unstalled<br>>> condition during the snap-roll, the manoeuvre is severely<br>>> downgraded using the 1 point/15 degree<br>>> rule."<br>>><br>>> Note that "the fuselage attitude must show a definite break<br>>> and separation from the flight path, before the rotation is<br>>> started..." That means that simultaneous pitch and rotation is<br>>> specifically NOT permitted. I would interpret it as meaning<br>>> that pitch and yaw could theoretically happen simultaneously,<br>>> as long as no roll is involved. Sorry Matt, the rules as<br>>> written do NOT allow actuation in all three axes<br>>> simultaneously. The rule also states that a constant flight<br>>> path has to be maintained.<br>>><br>>> Let's face it, the only way to prevent severe downgrading from<br>>> EVERY judge, not just some judges, is to have a pitch break<br>>> first. Takes any question away.<br>>> Jon Lowe<br>>><br>>><br>>> -----Original Message-----<br>>> From: rcmaster199@aol.com<br>>> To: nsrca-discussion@lists.nsrca.org<br>>><br>>> Sent: Mon, 16 Jun 2008 10:46 am<br>>> Subject: Re: [NSRCA-discussion] Snap entry in FAI<br>>> A "Flick" and a "Snap" roll are the same roll in full scale<br>>> aerobatics parlance and reference material.<br>>><br>>> Do these mean the same thing in model aerobatics? In my view,<br>>> they do<br>>><br>>> The latest FAI regs allow actuation of the three main axes<br>>> simultaneously...that is, the regs don't specifically<br>>> differentiate "Pitch Break" from other deviations. I don't<br>>> think they specifically require that the model must rotate<br>>> about it's flight path either, I don't believe (.....plane<br>>> must rotate in a conical fashion about the fight axis....).<br>>> The model would probably present the best if that's done, so<br>>> pilots may want to consider that when executing the maneuver.<br>>><br>>> In my take, a rapid Pitch is desired to preload the wing.<br>>> Contrary to popular belief, both panels dot not have to stall<br>>> for a snap to occur. Quite the opposite. Upon rudder<br>>> deflection, the port panel will practically stall (lift much<br>>> much less than the other panel) but the starboard panel must<br>>> be lifting to create the autorotation. If both panels stall,<br>>> the model will fall out of the sky for a distance and a snap<br>>> would not occur at the correct moment in time<br>>><br>>> MattK<br>>><br>>> -----Original Message-----<br>>> From: Woodward, Jim (US SSA)<br>>>><br>>> To: General pattern discussion<br>>><br>>>><br>>> Sent: Mon, 16 Jun 2008 8:47 am<br>>> Subject: Re: [NSRCA-discussion] Snap entry in FAI<br>>><br>>> Guys,<br>>><br>>> I thought the FAI changes explicitly allowed flick rolls? The<br>>> rule<br>>> reads, "... fuselage attitude must show a definite break and<br>>> separation<br>>> from the flight path."<br>>><br>>> It does not say, "MUST SHOW PITCH BREAK." Please DO NOT<br>>> ERROUNIOUSLY<br>>> APPLY A PASS/FAIL MAJOR DEDUCTION initial assessment to the<br>>> snap roll.<br>>> Watch the whole maneuver then render your score.<br>>><br>>> A break and separation from the flight path simply means that<br>>> the nose<br>>> and tail of the plane must rotate in a conical fashion about<br>>> the fight<br>>> axis. Yaw, roll, and pitch can all break at the same moment if<br>>> that is<br>>> how the pilot does it.<br>>><br>>> Hey :) some really handsome smart guy wrote some stuff at this<br>>> link<br>>> below about snap rolls to help clarify how they are done in IMAC.<br>>><br>>> http://www.mini-iac.com/DesktopDefault.aspx?tabid=77<br>>><br>>> thanks,<br>>> Jim<br>>><br>>><br>>> _______________________________________________<br>>> NSRCA-discussion mailing list<br>>> NSRCA-discussion@lists.nsrca.org<br>>><br>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>>> ------------------------------------------------------------------------<br>>> Get the Moviefone Toolbar<br>>> .<br>>> Showtimes, theaters, movie news, & more!<br>>><br>>> _______________________________________________<br>>><br>>> NSRCA-discussion mailing list<br>>><br>>> NSRCA-discussion@lists.nsrca.org<br>>><br>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>>><br>>> ------------------------------------------------------------------------<br>>> Get the Moviefone Toolbar<br>>> .<br>>> Showtimes, theaters, movie news, & more!<br>>><br>>> _______________________________________________<br>>> NSRCA-discussion mailing list<br>>> NSRCA-discussion@lists.nsrca.org<br>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>>><br>>> ------------------------------------------------------------------------<br>>> Get the Moviefone Toolbar<br>>> .<br>>> Showtimes, theaters, movie news, & more!<br>>><br>>> ------------------------------------------------------------------------<br>>> _______________________________________________<br>>> NSRCA-discussion mailing list<br>>> NSRCA-discussion@lists.nsrca.org<br>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>>><br>>><br>>> ------------------------------------------------------------------------<br>>> I am using the free version of SPAMfighter for private users.<br>>> It has removed 9842 spam emails to date.<br>>> Paying users do not have this message in their emails.<br>>> Try SPAMfighter for free now!<br>>> ------------------------------------------------------------------------<br>>><br>>> _______________________________________________<br>>> NSRCA-discussion mailing list<br>>> NSRCA-discussion@lists.nsrca.org<br>>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>><br>><br>> ------------------------------------------------------------------------<br>> It’s easy to add contacts from Facebook and other social sites through <br>> Windows Live™ Messenger. Learn How. <br>> <https://www.invite2messenger.net/im/?source=TXT_EML_WLH_LearnHow><br>> ------------------------------------------------------------------------<br>><br>> _______________________________________________<br>> NSRCA-discussion mailing list<br>> NSRCA-discussion@lists.nsrca.org<br>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br><br><br /><hr />It’s easy to add contacts from Facebook and other social sites through Windows Live™ Messenger. <a href='https://www.invite2messenger.net/im/?source=TXT_EML_WLH_LearnHow' target='_new'>Learn How.</a></body>
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