Snap Article and the K-Factor

[George Kennie]

I'll second that!

Keith Black wrote:

> This is an awesome description. I believe that both Dave's and Earl Haury's
> posts should be included in the K-Factor. This is the type of information
> that I believe people really want to see in the K-Factor. Certainly I do.
> True that it will be a re-run for those on the mailing list, but those not
> on the list will benefit and it will increase the K-Factor's value for
> recruiting new members.
>
> I know that others are already pushing for more content in the K-Factor, I
> think that's great.  This may have already been mentioned, but I feel that
> every K-Factor should have at least one "how-to" article, judging article,
> and most importantly a flying tip article (maybe one beginner and one
> advanced). I know these flying tip articles are tough to come by, but my
> experience in pattern thus far has been that there are extensive discussions
> and articles on equipment and building but it's very tough to find
> discussions on flying techniques. I was disappointed when I joined the NSRCA
> that the K-Factor didn't have much in the way of flying tips that I
> DESPERATELY needed (and still need). I'm not sure if this is because people
> hold this info close to the vest or if most are just drawn to equipment
> aspect of the sport. Lately I've been impressed with some of our top caliber
> pilots such as Don S, Earl and Dave sharing some of their flying "secrets"
> with the list. And when speaking with people in person they all seem more
> than willing to give flying advice. So maybe it's simply that we don't focus
> on this in our discussions.
>
> I saw a post a while back asking Don S. about doing a monthly article. Let's
> also solicit the likes of Dave, Jason, Chip, Sean, Brian Hebert, Earl, etc.
> (not trying to leave anyone out, these are just people I know in my limited
> exposure). The info these guys can share will improve the caliber of our
> sport overall.
>
> Keith Black
>
> ----- Original Message -----
> From: "David Lockhart" <DaveL322 at comcast.net>
> To: <discussion at nsrca.org>
> Sent: Friday, December 31, 2004 10:08 AM
> Subject: Long - Snaps, setup, technique, and "tells" (Was Re: Snap
> Rolls.....are they legitimate/ RE: displacement during snap rolls
> discussion)
>
> > Chris,
> >
> > I think Bjorn made an extremely good point and analogy comparing the 3 pt
> > shot to a snap.  I think snaps are precision manuevers.  I don't think
> luck
> > with snaps is any different that luck with spin entry/exits or stall turn
> > entry/exits.  All are difficult to consistently perform without downgrade
> > (especially the snaps), and that is generally reflected in the KFactor
> > (oops, another can of worms).
> >
> > The reason stall turns are often performed conservatively is simple - a
> zero
> > for a flopped stall turn is death - the scoring is usually so close at the
> > top, that a single zero will take a pilot out of the running for the
> 1,000.
> > I would say at the top levels, most pilots are 90+ % to complete a tight
> > radius stall turn (the one that appears to rotate on the CG, and is not
> > subject to a downgrade).  The same pilots are 99.9% to complete the
> slightly
> > open radius stall turn that will get the minor downgrade.  If we as a
> > pattern community want to see less conservative stall turns, all we need
> to
> > do is increase the point deduction for the slightly open radius stall
> turn -
> > the risk has to equal the reward, so to speak.
> >
> > To specifically answer the 2 questions you posed (my opinions of course) -
> > 1)  If it is indeed a true snap (and not a twinkle roll or barrel roll),
> > then it does add to the capabilities of the pilot.
> > 2)  Until we can achieve a level of consistency in judging snaps, they
> > detract from the event.
> >
> > Now, the long part, including some of the "secrets".
> >
> > Airplane design -
> > In general, in the early/mid 1990s, most designs migrated towards
> increased
> > pitch stability and damping (which is often but not always synonomous with
> > long tail moment).  This was great for groove/lock in corners and lines,
> but
> > not good snaps - and perhaps not a bad bias considering the relatively low
> > number of snaps in the pattern.  The increased pitch stability made it
> more
> > difficult to setup a plane to do good snaps (and spins).  The same designs
> > also generally migrated towards increased yaw stability (actually good for
> > snaps, bad for spins, others will not agree).  My personal setups used as
> > much as 35 degrees of elevator to achieve consistent stall entries to
> snaps
> > and spins (and all of the elevator remained during the spin, but not
> during
> > the snap) and 40 degrees of rudder in spins (ele/rud only spins).  In
> recent
> > years, the number of snaps in patterns have increased, and the newer
> designs
> > have shifted towards less pitch stability (and less yaw stability, but
> that
> > change is a response to the combined rolling/looping and rolling circle
> > maneuvers).
> >
> > Airplane setup -
> > This is critical with any design, and when a snap is attempted, a couple
> > things can happen -
> > - a good snap.
> > - a twinkle roll (not a snap).
> > - a barrel roll (not a snap).
> >
> > The majority of the setups I see are not sufficient to consistently
> perform
> > nice snaps.  Consistently meaning the setup is not very tolerant of
> > differing weather conditions (hot vs cold, snapping in/out of relative
> > wind), pilot techniques, or entry airspeeds.  I have on more than one
> > occasion been asked to check a setup for snaps when the owner of the plane
> > was having problems with snaps.  In some instances, I've been able to
> > consistently snap a plane with no changes to the setup, but improvements
> to
> > the setup made it easier for the owner to consistently snap the plane.
> The
> > below descriptions are generalizations based on my experience flying a
> > variety of planes and observing a variety of planes and pilots from a
> > variety of perspectives (amazing how much differently snaps look from
> > different perspectives).  And, the below does not take into acount the
> > effects of wind on track and offer relative descriptions of control throws
> > (exact control throws are influenced by design, weight, pilot technique,
> > etc).  The most critical setup element is pitch - if enough pitch
> authority
> > is not available, the break can not be achieved - the adjustment to make
> is
> > more elevator throw, or a more rearward CG (and if neither work, the
> design
> > has too much stability in pitch to snap properly).
> >
> > - The "twinkle" roll - The plane that has too little elevator, a little
> bit
> > of rudder, and a boatload of aileron.  Very common.  The plane has little
> or
> > no displacement from track (or the path is an extremely tight barrel)
> during
> > the "twinkle" and returns to the original track with zero displacement or
> > deviation in track.  The rotation rate is probably equivalent to a full
> > stick deflection aileron roll (might be marginally higher due to a slight
> > assymetry in lift between wing panels caused by the minor amount of rudder
> > used).  The tail follows the nose exactly and no "cone" is inscribed.  The
> > advantage of flying a "twinkle" roll is that there is very little if any
> > loss in track, the entry is non-critical, airspeed loss in the "twinkle"
> is
> > minimal, and the only variable the pilot needs to concentrate on is
> getting
> > the wings level at exit.  As with the stall turn, it is a risk/reward
> > thing - why risk doing a real snap if the "twinkle" is getting scored?
> The
> > other benefit of the setup for a "twinkle" is that less elevator throw is
> > used, and that makes the plane smoother in all other manuevers.
> >
> > - The "barrel" roll - this one can be easy to see, or hard to distinguish
> > from a snap, and the setup that yields this result is often variable.  A
> > very tight diameter barrel roll is hard to distinguish from a good snap
> > because it will exhibit a pitching element on entry and the plane will
> > displace from track in pitch and yaw during the snap, but will generally
> > return to track for full snaps (1, 2, 3....rotations) and generally remain
> > displaced of the track (in pitch and yaw) by the diameter of the barrel
> for
> > 1/2 snaps (.5, 1.5, 2.5 ....rotations).  Very little if any cone
> inscription
> > is visible after the entry to the barrel.  The large diameter barrel has
> the
> > same characteristics of tight diameter barrel, but easy to see, simply
> > because of the large diameter alone.  Any change in the control inputs
> > during the "barrel" are generally very easy to see - because the plane is
> > not stalled and responds readily to any change in surface deflection.
> > Insufficient elevator to initiate the break is generally the cause of
> > barrels.  Adding aileron usually increases the rotation rate, and often
> > reduces the diameter.  Adding rudder may reduce the diameter of barrel,
> > increase the rotation rate, give the appearance of the inscription of a
> cone
> > (but it is only in yaw, and not in pitch, and the airplane is not in a
> > stalled condition), and may also add the look of a "cartwheel".  The
> benefit
> > of the "barrel" setup is that less control throw is used (smoother in
> other
> > maneuvers), the rotation rate is slow (easier to hit exit) and the track
> is
> > unchanged (but might be dispaced).
> >
> > - The "good" snap - I hope we know what it is in writing by now (actually
> > seeing it takes practice), so just some notes.  Theoretically, the break
> can
> > occur without displacement in pitch - but this never happens in practice
> > (angular acceleration, mass, and other physics properties are
> > real.........blame Newton).  A good clean break (very fast elev servo and
> > fingers) will reduce the amount of track deviation and displacement in
> both
> > pitch and yaw.  The rotation rate of the snap will be marginally effected
> > (if at all) by low / high rate aileron - ailerons don't work very well
> when
> > the plane is stalled.
> >
> > Piloting Technique and more setup -
> > To me, a good setup for snaps has a bigger "sweet" spot - the exact entry
> > airspeed and exact timing of the control inputs can vary and still yield a
> > good snap.  And the good setups "feel" the same whether snapping left or
> > right, positive or negative.  I fly with triple rates - normal flying is
> rud
> > on high, elev and ail on medium.  For spins, everything is on high.  For
> > snaps, I use a variety of rates setup to make the variety of snaps feel
> > balanced and I attempt to get the snaps from different perspectives in
> > different manuevers to "present" the same.  It takes a lot of time to
> setup.
> > The technique for all types (different rotations in different attitudes)
> of
> > snaps is similar (lead with elevator, then rudder, then aileron) but the
> > timing of each input usually varies a bit on both the addition and removal
> > of the inputs.  And each specific snap is usually a little different - I
> > "feel" the plane approaching the entry to the snap and try to gauge exact
> > airspeed, wind condtions, evaluate what the track is and if I want to
> change
> > the track, etc.....and then I make very small changes to the addition of
> the
> > inputs to get the desired effect (ie, I might use more elevator lead to
> > change the track in pitch if the plane was diving slightly in pitch track
> > prior to the snap, or lower than usual on airspeed).  During the snap
> > itself, I watch the progression of the snap and decide if I got the entry
> I
> > wanted (expected), and if I need to make any changes on the timing of the
> > removal of control inputs on the exit of the snap (ie, maybe hold the same
> > rudder or imediately go to opposite rudder on the exit to immediately
> > correct a deviation in yaw track).  The more I fly, the better I can make
> > these adjustments because I seem to see things better, the snaps seem to
> > take longer, my fingers seem to move faster, and I better know what the
> > mental image of the plane should be at any instant during the snap.
> >
> > "Tells" and "cheats"
> > One of the easiest snaps to judge is the 45 downline snap (airplane is
> > upright and executing a single positive snap).  The airplane is front and
> > center, and the break in pitch is easy to observe - and it is actually
> easy
> > to confirm.  Odds are, if you don't see a break, you will see the track of
> > the line steepen as the airplane passes through 90 degrees of rotation -
> > because the rudder is now "bottom" rudder (and the plane is still flying,
> or
> > if snapping, the break was in yaw, not pitch), and the track of the plane
> > will be steeper than 45 degrees at the finish of the snap.  Kinda of odd
> to
> > see a 45 downline get steeper after a positive snap??  Big tell, and
> pretty
> > common to see.  I see the same thing on 1.5 snaps on a 45 downline.  The
> > same thing also happens on 45 uplines when the line substantially flattens
> > out after the snap, but with an added variable - the flattening may be
> > partly due to reduced airspeed and gravity (but the plane will show the
> > initial loss in track at the 90 degree point in rotation).
> >
> > Exits - exits are generally judged more critically than entrances - for
> > snaps, rolls, and radii. A "cheat" to help with the exit of a snap is to
> > take out elev and rud before the snap is complete - such that all the
> pilot
> > is doing is completing a roll to level flight, and completing a roll is
> > easier than completing a snap - the tell is a substantial change in roll
> > rate (rotational inertia exists and for our models, the heavy wing monster
> > that appreciably demonstrates this is rare).  This type of cheat is also
> > employed on spin exists and on the exit of part and full rolls.  The roll
> > rate is slightly reduced as the rolling element nears completion to make
> it
> > easy to nail wings level.  Most judges will downgrade for the wings not
> > being level, fewer will catch the change in roll rate.  The same thing
> > applies to corner radii - they are often softer close to the exit to make
> it
> > easier to hit the line.  The reason the cheats are employed is because
> > downgrades are not being applied - "no whistle, no foul".
> >
> > How do some guys maintain distance during the entire flight (including
> stall
> > manuevers) when flying in a crosswind?  They don't.  They are just sneaky
> at
> > hiding the wind drift, and make corrections / allowances where they are
> the
> > hardest to detect.  Humans having pretty poor depth perception at 150
> meters
> > also helps.  This past fall, I had a trusted observer stand in the field
> > underneath my flight track and was told that the flight track was about
> 145
> > meters, +/- 3 meters (a bit more variation after spins).  And the observer
> > was surprised to see how visible the rudder corrections were - as the same
> > observer saw far fewer rudder corrections when viewing similar flights as
> my
> > caller.
> >
> > Prior to spins and stall turns, you will usually see a very small "cheat"
> > into the wind, and then a little drift with the wind allowed immediately
> > after the stall manuever, followed by a small "cheat" into the wind to
> > return to the original track.  A single 15 degree change in track is easy
> to
> > see and downgrade.  Very aggressive compensation for wind (difference
> > between attitude and track) while technically correct rarely scores well.
> > Three 5 degree changes in track are harder to see and harder to downgrade,
> > and present nicer (even if not as correct technically).
> >
> > With snaps - to hide the lateral displacement and yaw track change in a
> > snap, the "cheat" is normally opposite the direction of the snap prior to
> > the snap entry - 5 degrees nose in before a snap and 5 degrees nose out
> > after the snap is harder to detect than simply being 10 degrees off after
> > the snap.  And of late, there is no doubt in my mind that being 10 degrees
> > off before the snap will earn little or no deduction if the exit of the
> snap
> > is nailed.  All deviations in roll, pitch, and yaw track should be equally
> > downgraded whether before or after the snap - it is a goal that needs to
> be
> > achieved.  The change in track during a snap can often be hidden (or
> > mitigated) to a large extent by wind - this is simply smart piloting by
> > choosing to snap into (usually) the wind.  And in the instance of a snap
> at
> > the end of the box, where the displacement or loss of heading in yaw is
> > particuarly easy to see, a more pronounced and aggresive break in pitch ca
> n
> > be used to minimize the deviation in yaw, as the deviation in pitch is
> > harder to see (and thus harder to downgrade).
> >
> > Regards,
> >
> > Dave
> > DaveL322 at comcast.net
> >
> >
> >
> > ----- Original Message -----
> > From: White, Chris
> > To: discussion at nsrca.org
> > Sent: Thursday, December 30, 2004 4:11 PM
> > Subject: RE: Snap Rolls.....are they legitimate/ RE: displacement during
> > snap rolls discussion
> >
> >
> > Consistent snap rolls.....how much skill....how much luck?
> >
> > Do I read from the responses that the consensus is that snap rolls are
> > precision maneuvers?   I believe that may be true in full-scale aerobatics
> > particularly in slower snapping aircraft because you can actually see
> > outside and judge entrance timing based on real time entry speed (ASI) and
> > judge exit because of roll rate perceived via outside reference directly
> > relative to the horizon without any parallax as you would get from our
> > ground perspective.   I'm trying to say that the pattern airplanes that
> I've
> > flown snap differently and usually quickly.   I've seen very good pilots
> who
> > feel a real sense of accomplishment (or luck) when they hit the snap right
> > on....however, I still believe to a degree that it might be a little more
> > luck than precision to hit them consistently.  It seems a shame to have a
> > pilot miss an exit by 5 degrees to get a 1/2 point hit....particularly
> when
> > the perspective of a 5 degree bank at 150 meters away could vary with
> judges
> > and parallax considerations. (Or that a given judge may not see enough
> > conical rotation of the tail)
> > Please consider that I have nothing but admiration for the FAI pilots in
> the
> > finals when reading the following: Consider how conservative  stall turns
> > were performed during the FAI finals ( yes it was intelligent to fly them
> > that way)  you will notice that very few pilots flew great stall turns,
> they
> > were more like tight wingovers with the reason being obvious....who wants
> to
> > risk a flopped zero at the level where you have very few points separating
> > the standings.   Snap rolls seem to have more risk.
> >
> > I would love to see the consensus on the following questions:
> >
> > 1) Do snap rolls add or detract from the legitimacy of judging precision
> > aerobatic pilots capabilities?
> > 2) Do snap rolls add to the credibility of precision aerobatics?
> >
> > Respectfully submitted by a new guy,
> > Chris
> >
> > -----Original Message-----
> > From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
> > Behalf Of Bjorn Lehnardt
> > Sent: Thursday, December 30, 2004 2:04 PM
> > To: discussion at nsrca.org
> > Subject: Re: Snap Rolls.....are they legitimate/ RE: displacement during
> > snap rolls discussion
> >
> >
> > Bob,
> >
> > A good three point shooter in the NBA has mastered a maneuver that is
> > uncontrollable except for the first part, yet few question the validity of
> > his skill or it's part in the game.  Figuring out and mastering the
> > requirements for proper setup-entry under many different circumstances is
> > what makes a three point shot or a snap roll such an interesting part of
> the
> > game.
> >
> > I would seem a real shame to say that pattern and pattern flyers are not
> > capable is mastering the art and science of the stalled maneuvers.
> >
> > Snaps are still fairly new to pattern and so growing pains are to be
> > expected.  Resistance is natural and will go away with practice.  That
> both
> > flying practice and judging practice.
> >
> >
> > Bob Pastorello <rcaerobob at cox.net> wrote:
> > That is an excellent point, Chris.  And your modesty to not add
> > "Intermediate National Champion" to your credentials is noted.
> >     The issue of a virtually-uncontrollable maneuver EXCEPT for entry and
> > exit, does bring a valid question about it's place in our game.  I think
> Ed
> > Miller mentioned (sorry if wrong) that longer-duration maneuvers with more
> > easily-visible segments have their OWN level of difficulty.
> >     In '99, when I was working on the Rules Committee, and we were
> designing
> > new sequences one of the suggestions in Masters was a Center maneuver, a
> > square loop with 2/4 on U/D, 1/2 on horizontal legs.  We were TRASHED for
> > even suggesting such a thing!!!
> >     The reason I mention that is to consider difficulty and pilot
> challenge,
> > wouldn't most of us agree that the square loop I describe would be more
> > easily judged, and more challenging for the majority of pilots than the
> > downline SINGLE snap we have in '05 ???
> >
> > Since we're in a rules cycle year, maybe this is a good time to rethink
> the
> > "required elements" of every class, and look more for "what do guys WANT
> to
> > have in the sequence?"
> >
> > Great thread starter, Chris.
> >
> > Bob Pastorello
> > NSRCA 199  AMA 46373
> > rcaerobob at cox.net
> > www.rcaerobats.net
> >
> >
> > ----- Original Message -----
> > From: White, Chris
> > To: discussion at nsrca.org
> > Sent: Thursday, December 30, 2004 8:49 AM
> > Subject: Snap Rolls.....are they legitimate/ RE: displacement during snap
> > rolls discussion
> >
> >
> >
> > Please excuse me if I'm repeating, or committing a "faux pas" ( I think I
> > spelled that right:) ) ....but I am really interested in hearing opinions
> to
> > the following:
> >
> > 1) Do snap rolls add or detract from the legitimacy of judging precision
> > aerobatic pilots capabilities?
> > 2) Do snap rolls add to the credibility of precision aerobatics?
> >
> > I'm new to the game, but a "stalled" maneuver is a maneuver that is not
> > "flown on the wing" .  An overwhelming percentage of the other maneuver
> > segments in our patterns are flown on the wing and are able to be judged
> > accurately and with a minimum of "impression" influence.  Since the Snap
> > Roll it is not "flown" through it is not fully controlled....lack of
> control
> > indicates somewhat of a wildcard that penalizes capable pilots
> experiencing
> > a "bad" maneuver.
> >
> > I have seen many good snap rolls in competition, some done by great
> pilots,
> > some by new guys.....my question is: Should there be a "wild card"
> > allowance?  Is anyone capable of flying consistent snap rolls that are
> > consistently judgeable to clear and concise requirements?   I believe I'm
> > hearing an overwhelming "NO".  If the answer is no, then maybe they should
> > be removed.
> >
> > I fly RC pattern because in my opinion it is more graceful and precise in
> > appearance as compared to IMAC.... not that I don't respect IMAC pilots
> > capabilities and enjoy the show.  But, I sometimes I wonder how "Snap
> Rolls"
> > fit into RC Pattern....and it sounds as if I'm not the only one.   (I like
> > to see snaps....I just feel there are variables beyond the pilots control
> > which penalize inconsistently)  I think a pilot should be judged on
> > control....not inertial physics. (is that a real term????:) )
> >
> > Just my thoughts and question to the group....respectfully submitted,
> > Chris
> >
> > (as a CFII, airshow nut and pattern guy and whatever other credibility I
> can
> > throw in:) )
> > -----Original Message-----
> > From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
> > Behalf Of Ed Miller
> > Sent: Wednesday, December 29, 2004 7:11 PM
> > To: discussion at nsrca.org
> > Subject: Re: Displacement during snap rolls (was Why is it so quiet?)
> >
> >
> > Seems the never ending snap discussion was beat to death here last year
> too.
> > This will be long but hear me out. No doubt what I'm about to say will at
> > the very least be controversial. That's fine with me as I think we need to
> > think outside the box more often. My wife enjoys watching figure skating.
> > Being the "supportive spouse", on occasion I will watch for a bit with
> her.
> > It seems in figure skating, the multiple rotation jumps, triples and even
> > quadruple rotation variations is where all the judging ( and viewing )
> > emphasis is placed in a skaters routine. It also seems the judging is
> > focused on 2 things, the entry to the jump and "sticking" the landing.
> > Frankly, those that say they can see every element of the skaters rotation
> > are, IMHO, full of blank. It plain happens too fast. I have better
> eyesight
> > than most, in my younger days I could pick up the stitching and rotation
> of
> > a baseball thrown at 90mph. I'll admit, some of that sharpness is gone
> but,
> > I honestly cannot pick up all the rotation elements in a figure skaters
> jump
> > in real time ( we all can when they replay it in slow-mo ). Ever since the
> > snap roll was introduced into precision aerobatics, an oxymoron IMHO, we
> > have had the same problems judging snaps as professional figure skating
> > judges have judging triple toe loops. I have watched ( and learned some )
> > from the real snap masters, aka Lockhart and Pappas, yet, when in the
> judges
> > chair I look for departure in pitch ( entry ) and "the landing " of the
> > maneuver ( exit ) . So, to me, we've introduced snaps into precision
> > aerobatics to separate the wanna be pattern jockey hackers like me from
> the
> > gifted, talented folks like Lockhart, Pappas, Hyde, etc. but in fact what
> > we've done is actually dumbed down our judging criteria. These talented
> > flyers will find the setup and stick movements to present a maneuver such
> > that it defies the laws of gravity. However, most of us are only humans
> and
> > as judges, only judge what can we realistically see and honestly assess in
> a
> > snap roll. Most all snap rolls I've seen done and performed rotate at such
> a
> > speed that again, the exit is the focus. Once in awhile you can pick up
> the
> > obvious aileron roll exit. There are many more elements of a snap roll
> > besides entry and exit yet as I read/delete/read/delete, etc. the
> discussion
> > we are having here, it boils down to entry and exit positions. The
> > ex-masters maneuver of 2 rolls in opposite directions. It is a thing of
> > beauty when done properly  takes a lot of time to perform, especially
> > compared to our beloved snap rolls, has many more places for the pilot to
> > screw up that are EASILY VISIBLE to the judges besides the entry and exit
> > points. That's precision aerobatics IMHO. AMA pattern was always smooth
> and
> > graceful until someone decided as the FAI does, so must the AMA. Some will
> > say it's progress, new maneuvers, it's just raising the bar to let the
> cream
> > rise to the top. I'm on the side that the bar has sunk into the cream.
> Maybe
> > the some of the lost NSRCA members felt similarly.
> > Ed M.
> > ----- Original Message -----
> > From: Doug Cronkhite
> > To: discussion at nsrca.org
> > Sent: Wednesday, December 29, 2004 4:33 PM
> > Subject: RE: Displacement during snap rolls (was Why is it so quiet?)
> >
> >
> > The rules for family 9.9 are as follows:
> >
> > "Snap rolls represent one of the greatest challenges to judge. This is
> > primarily due to two factors: (1) the "snapping" characteristics of
> > different types of aircraft are unique; and (2), snap rolls are a high
> > energy maneuver that occur very quickly. Snaps happen so fast, in fact,
> that
> > is is virtually impossible for a judge to determine the exact order in
> which
> > events occur, especially at the beginning of the snap. There are no
> > criteria, therefore, for seeing nose and wing movement initiated at the
> same
> > time as with the other autorotation family, Spins."
> >
> > The rest of the paragraphs deal with snaps not autorotating through the
> > complete revolutions and so forth but there is no criteria whatsoever for
> > line displacement. This would be impossible to deal with actually since
> > aircraft snap so differently from one type to another. A top level
> unlimited
> > airplane like an Edge, Cap, or Sukhoi displaces very little, but people
> > flying lower classes in Decathlons, Clipped Wing Cubs and so forth
> displace
> > a great deal in a snap. There's just no way to fairly judge with a single
> > standard across all aircraft types.
> >
> > -Doug
> >
> >
> >
> >
> >
> >
> > From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]
> On
> > Behalf Of Dean Pappas
> > Sent: Wednesday, December 29, 2004 1:15 PM
> > To: discussion at nsrca.org
> > Subject: RE: Displacement during snap rolls (was Why is it so quiet?)
> >
> >
> > Thanks Doug,
> > You don't happen to have the piece of text in a form that could be pasted
> > into this forum, do ya'?
> >
> > Dean Pappas
> > Sr. Design Engineer
> > Kodeos Communications
> > 111 Corporate Blvd.
> > South Plainfield, N.J. 07080
> > (908) 222-7817 phone
> > (908) 222-2392 fax
> > d.pappas at kodeos.com
> > -----Original Message-----
> > From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
> > Behalf Of Doug Cronkhite
> > Sent: Wednesday, December 29, 2004 4:14 PM
> > To: discussion at nsrca.org
> > Subject: RE: Displacement during snap rolls (was Why is it so quiet?)
> >
> >
> > No track downgrade Dean. Since a snap roll is a yaw induced maneuver (or
> > should be at least) it's nigh-impossible to actually snap the airplane and
> > not displace the line a little. Especially when you consider the low
> weight
> > and inertia of our airplanes as compared to full scale.
> >
> > -Doug
> >
> >
> >
> >
> >
> > Do you Yahoo!?
> > Yahoo! Mail - Helps protect you from nasty viruses.
> >
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> > and follow the instructions.
> >
>
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