[NSRCA-discussion] BS about snaps!

seefo at san.rr.com seefo at san.rr.com
Fri Oct 16 12:21:13 AKDT 2009


Bill,

Back when people were flying with reeds, I believe this WAS possible. My Super Kaos back in the late 70's would snap just fine as well with rudder/elevator. I don't believe a current generation F3A airplane will however.

-Doug



---- Bill Glaze <billglaze at bellsouth.net> wrote: 
> Doug:
> It IS possible--that's all we used to have, even with multi-channel reeds. 
> Input full elevator, and rudder simultaneously.  Snaps looked just fine, as 
> well as spins, with no aileron input; (You couldn't get but 2 channels at 
> the same time).  It was, however, more difficult to control the exit point.
> Bill Glaze
> ----- Original Message ----- 
> From: "Doug Cronkhite" <seefo at san.rr.com>
> To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
> Sent: Friday, October 16, 2009 12:52 PM
> Subject: Re: [NSRCA-discussion] BS about snaps!
> 
> 
> >
> > There is a BIG difference between a basic stall (such as on landing) and 
> > an accelerated stall (snap roll). I agree that people are getting too 
> > wrapped up in the wording though.
> >
> > One thing I disagree with is your assertion that the ailerons are only 
> > functioning as spoilers once the stall happens. In full-scale aerobatics 
> > that's true, but with F3A airplane wing loadings being what they are, I'm 
> > betting that most simply can't 'snap' without ailerons. If that's true, 
> > then the snap SHOULD be possible with elevator and rudder only.
> > -Doug
> >
> >
> >
> >
> > shinden1 at cox.net wrote:
> >> Matt perfect explanation. common Sense prevails! its SET UP SET UP SET 
> >> UP!!
> >> We have tried to over complicate fundamentals of Model snaps  for years
> >> I know every one has stalled an airplane on landing before ..did you see 
> >> a pitch break? No, the first thing you "saw"  was one wing drop and the 
> >> rest occurred immediately after. If you have the room, flying speed is 
> >> the only thing that helps recover it.
> >> Anything else  you add speeds it up and worsens it.,,,,,Oh!!! I have just 
> >> described a perfect spin entry too!
> >> A snap is no different from a spin it`s a stalled "condition" the speed 
> >> and  inputs are the only difference in mantaining or stopping both 
> >> maneuvers. it`s why you cant do a pos spin with a neg spin input.
> >>  Im Sorry Guys, but trying to legislate the perfect wording to judge poor 
> >> snaps only worsens the problem, the description in place is all we need. 
> >> the more we try to describe it ,the higher the scores will be for the 
> >> guys performing it already. a perfectly performed FAI snap looks like A 
> >> perfectly performed AMA snap.
> >>
> >> The bottom line is, it initially only takes one wing halve to stall 
> >> before the chain reaction of events occur.  the ailerons act as Spoilers 
> >> after each  wing half looses lift as it rotates pos and neg. the rest is 
> >> predicated on  CG position, the actual amount of throw in the remainder 
> >> { including throttle ,,or Speed} of the surfaces that will mantain , over 
> >> do, or perfect the rotational yaw,pitch , entry, and fuse angle at exit 
> >> of the maneuver. Now,figuring out what causes each effect  and how to 
> >> adjust it is the teachable moment.
> >> I submit the Guys who can Snap consistatly have the best trimmed 
> >> airplane.
> >>
> >> The reason it`s the highest  k-factor is, it`s the hardest to learn do 
> >> correctly
> >> the reason it`s not in the lower classes is because each class should 
> >> teach the pilot how to advance in his airplane set up and trimming skills 
> >> You just can`t pic up a airplane giver it the control inputs and expect 
> >> good results  If you put effort in the perfecting of all Snaps  ,it can 
> >> teach you more about set up and trimming of your model than any other 
> >> thing we do with our airplanes. The Snaps Define wether your model is set 
> >> up correctly Period.
> >>
> >> The good designers hang their collective hats on this maneuver when 
> >> finalizing a design ,,Because this maneuvers will perfect the design or 
> >> break it. When you get the snaps Perfect Every thing else in the flight 
> >> demands improve ,when its not perfect you will have a few Maneuvers that 
> >> suffer from the incompletion of the setup.
> >> The demands of each class schedual should teach whats required ,,,if you 
> >> are willing to take the time to experiment and learn.
> >> There have been non engineers performing this maneuver correctly for 
> >> decades Although the Explanation of the terms is help full ,,the proper 
> >> execution of the snap is a better school master.
> >> I submit the guys having to do the most selling on their snaps .( leading 
> >> with  up ,down,Elevator) are the ones trying to continually redefine it.
> >> They just dont think it`s possible to perform the maneuver with no 
> >> displacement  ,,Hog Wash
> >> Next year in the F11 pattern we have 2 versions of a 1.5 snap one from 
> >> inverted and one from up rite . I promise you if we perform this maneuver 
> >> to show a pitch leading break like some of what I saw judging the Nats 
> >> this year  the airplane will rise 2-5 meters before the rotation happens 
> >> ,,, this is not a snap it`s a sell job. and the same guys doing that 
> >> version on a 45 down line will severly downgrade ours.
> >> there is no supper raidio super human input trickery to do a proper snap 
> >> ,just a perfect setup.
> >> FAI has to perform up line, downline and level snaps the same set up 
> >> rules apply to all these if the airplane is set up right ! there will be 
> >> the same input to do them all save if you have brakes on for the Elec 
> >> guys LOL.
> >>
> >> So the guys that figure out how to do it with no departure will earn the 
> >> Best scores Why ,because it`s precision in the setup delivers the best 
> >> and  the most consistent execution.
> >> Fake stalls in the spins(switching from High to low rate trick) always 
> >> produce a poor non predictable  spin as well because you cant tell the 
> >> "airplane" that it`s not stalled  .sure you can get By ,But there will 
> >> always be the Guy who can do it better with a better set up.
> >> Try two spins in opposite directions with a fake entry Or for that Matter 
> >> ,,two snaps opposite  with a poorly set up airplane  ,,,( Ask Beniot or 
> >> Seba about this)Very poor results. when the airplane is completely set up 
> >> it will have NO weak Maneuvers. You cant tell me Seba don`t know how to 
> >> throw two stick in the corner  for an inverted Snap LOL,,, no ,,,,He just 
> >> cant  Lead the Fake as well inverted. A Keen observer picked two snaps 
> >> reversed from inverted at the Worlds because he could see the Forgery in 
> >> the pos snap previos  ,Seba  fooled the Judges But not the Pilots .
> >> The Judges applied the Rules ,,,the Pilots applied knowledge and common 
> >> sense.  saw the weakness in his set up and called him on it
> >> I must tell you it made me happy to see it.
> >>
> >> So ,if you have consistent problems keeping a snap on line during the 
> >> execution But see someone who can ,ask them about their setup.
> >> but be prepared to change your "Whole" set up because like I said before 
> >> Trim your airplane to fly all snaps and it will perfect the total setup 
> >> demand and reduce the needs for rates, condition switches and the Like of 
> >> the airplane ,Then force you  to change your bad Habits in "every" 
> >> Maneuver.
> >> do you have the courage?
> >>
> >> Bryan
> >>
> >>
> >> ---- rcmaster199 at aol.com wrote:
> >>> Jerry Budd explained pretty well the fact that pattern planes are so 
> >>> lightly loaded that a?large amount of?force in pitch must exist to cause 
> >>> a stall. Stalls, accelerated and/or assymetric,?I don't think are what 
> >>> happens in a pattern snap.
> >>>
> >>>
> >>> ?
> >>>
> >>>
> >>> I believe an?assymetry in lift does however. Think of the the wing as 
> >>> two halves (fancy that) where one sides lifts the equivalent of its 
> >>> whole area and the other side only a small percentage. Neither panel is 
> >>> stalled per se....one simply lifts less than the other. Yaw will induce 
> >>> the differential lift once the wing has been loaded in pitch. Assymetric 
> >>> lift will cause the wing to autorotate in roll axis.....we accelerate 
> >>> that autorotation with ailerons (duh!!). Some planes will snap with yaw 
> >>> command alone once pitch loading has happened. Most pattern planes will 
> >>> not because, as Jerry pointed out, it doesn't take a whole lot of lift 
> >>> to keep a pattern plane flying
> >>>
> >>>
> >>> ?
> >>>
> >>>
> >>> My 2c
> >>>
> >>>
> >>> ?
> >>>
> >>>
> >>> MattK
> >>>
> >>>
> >>> ?
> >>>
> >>>
> >>> ?
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> -----Original Message-----
> >>>
> >>> From: Martin X. Moleski, SJ <moleski at canisius.edu>
> >>>
> >>> To: General pattern discussion <nsrca-discussion at lists.nsrca.org>
> >>>
> >>> Sent: Fri, Oct 16, 2009 6:43 am
> >>>
> >>> Subject: Re: [NSRCA-discussion] Suggested New Snap Roll (Brake Roll) 
> >>> Description
> >>>
> >>>
> >>>
> >>>
> >>>
> >>> Keith Black wrote:?
> >>>
> >>>
> >>>> How about this definition:?
> >>>>
> >>> ?
> >>>
> >>>
> >>>> 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 maneuver ...?
> >>>>
> >>> ?
> >>>
> >>> That what Vicente (and others) are arguing is a bad?
> >>>
> >>> definition for our purposes.?
> >>>
> >>> ?
> >>>
> >>> I agree with those who want to remove all references to?
> >>>
> >>> stalling from the definition of the maneuver.?
> >>>
> >>> ?
> >>>
> >>> The model must depart (break away) from all three?
> >>>
> >>> axes. Saying that the first departure must be separated?
> >>>
> >>> from the other two does not make good sense to me.?
> >>>
> >>> ?
> >>>
> >>> Demonstrating the kind of "stall" that leads to a?
> >>>
> >>> spin entry is very different from the assymetric stall?
> >>>
> >>> required for autorotation--at least in my own understanding?
> >>>
> >>> of what accelerated stalls are like.?
> >>>
> >>> ?
> >>>
> >>> ? Marty?
> >>>
> >>> _______________________________________________?
> >>>
> >>> NSRCA-discussion mailing list?
> >>>
> >>> NSRCA-discussion at lists.nsrca.org?
> >>>
> >>> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion?
> >>>
> >>>
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