[NSRCA-discussion] Snap entry in FAI
george w. kennie
geobet at gis.net
Tue Jun 17 06:41:02 AKDT 2008
Hey John,
Don't be sorry. Your challenging of the dogmas stated by me and others are
exactly what's needed. My reference to the down elev. mix in K.E. really got
me thinking after I wrote it. Of course this would be for a ship that pulls
to the canopy ( which most are the other way ), but it really got me to
thinking regarding the unloading of the 1G lift in K.E. I went to bed
thinking about it and awakened this A.M. wrestling some more and ultimately
had an epiphany regarding an effect that produces either pull to the canopy
or push to the belly. I had always felt that downwash from the wing AOA was
a major factor and while this may be a contributor I now feel that there is
a stronger contributing element. As this theory was formulating in my
noodle I grabbed my latest design and checked my postulate and discovered
that it bore out my deductions.
So don't ever be sorry. I need the stimulus.
Thank you John !
Georgie
----- Original Message -----
From: "John Pavlick" <jpavlick at idseng.com>
To: "NSRCA Discussion" <nsrca-discussion at lists.nsrca.org>
Sent: Tuesday, June 17, 2008 12:44 AM
Subject: Re: [NSRCA-discussion] Snap entry in FAI
> Sorry for the confusion. I know the wing is still producing "lift" during
> knife edge flight. It's just that the plane is "flying" on the fuse now
> too. Just wondering how that affects the dynamics of the whole thing.
>
> John Pavlick
>
> ----- Original Message -----
> From: <shinden1 at cox.net>
> To: <jpavlick at idseng.com>; "General pattern discussion"
> <nsrca-discussion at lists.nsrca.org>
> Sent: Monday, June 16, 2008 5:59 PM
> Subject: Re: [NSRCA-discussion] Snap entry in FAI
>
>
> Hey John
> the wings are still producing lift
> if not,, you would not be able to do a knife edge snap !!
> it`s just a reduced load on knife edge
> the wings are producing lift in verticle uplines,, and downlines also
> Bryan
> ---- John Pavlick <jpavlick at idseng.com> wrote:
>> Which axis do you need to show a "break" in for a knife edge snap? The
>> wing isn't really "lifting", the fuse is.
>>
>> John Pavlick
>>
>> "george w. kennie" <geobet at gis.net> wrote:
>>  My lip is becoming too painful from biting it, so I think I'm
>> going to stick my nose in here somewhere.
>>
>> I think I'm with Jon on this one.
>>
>> My logic, however flawed, tells me that if I am flying my plane
>> straight and level and I input rudder, no matter how much, there is no
>> way that this input will induce a stall to the airframe. Therefore, it
>> seems to me, that the necessary force required to stall the main lifting
>> surface must come from the elevator. It would further seem to me that
>> this input must, by it's very nature produce a pitching attitude to the
>> fuselage whether positive or negative. So I would have to conclude that
>> the attitude "break" referenced by the rule can only refer to a "pitch"
>> break and would be impossible to confuse with an attitude change induced
>> by the rudder seeing that the required result is to stall the main wing.
>>
>> And yes Jon, I agree that it would be necessary to lead with the
>> elevator in order to bring about this attitude change before rotation is
>> started, however miniscule the interval might be.
>>
>> Of course I'm still open to hearing other interpretations and their
>> validations as these observations are strictly opinions.
>>
>> G.
>>
>>
>>
>>
>> ----- Original Message -----
>> From: Jon Lowe
>> To: nsrca-discussion at lists.nsrca.org
>> Sent: Monday, June 16, 2008 2:10 PM
>> Subject: Re: [NSRCA-discussion] Snap entry in FAI
>>
>>
>> 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
>>
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152 P.MsoNormal {
>> FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman" }
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152 LI.MsoNormal {
>> FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman" }
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152 DIV.MsoNormal {
>> FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman" }
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152 A:link { COLOR:
>> blue; TEXT-DECORATION: underline }
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152 SPAN.MsoHyperlink {
>> COLOR: blue; TEXT-DECORATION: underline }
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152 A:visited { COLOR:
>> blue; TEXT-DECORATION: underline }
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152
>> SPAN.MsoHyperlinkFollowed { COLOR: blue; TEXT-DECORATION: underline }
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152 PRE { FONT-SIZE:
>> 10pt; MARGIN: 0in 0in 0pt;
>> FONT-FAMILY: "Courier New" }
>> #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152 TT { FONT-FAMILY:
>> "Courier New" } #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152
>> SPAN.EmailStyle19 { COLOR: navy; FONT-FAMILY: Arial; mso-style-type:
>> personal-reply } #AOLMsgPart_3_10dac3e0-4768-4b7d-9454-3fc24f6ce152
>> DIV.Section1 { page: Section1 } 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!
>>
>>
>>
>>
>> _______________________________________________ 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
>>
>> ---------------------------------
>> I am using the free version of SPAMfighter for private users.
>> It has removed 9842 spam emails to date.
>> Paying users do not have this message in their emails.
>> Try SPAMfighter for free now!
>> _______________________________________________
>> 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
More information about the NSRCA-discussion
mailing list