Long - Snaps, setup, technique, and "tells" (Was Re: Snap Rolls.....are they legitimate/ RE: displacement during snap rolls discussion)

[George Kennie]

   WOW !!!!!!!, Dave.

David Lockhart wrote:

> 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 can
> 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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