Displacement during snap rolls (was Why is it so quiet?)

[David Lockhart]

More than 1 pilot was awarded 1 or more zeros in the 2004 US NATs F3A final on snap maneuvers.  The "average" snap in subsequent flights in the finals showed more break / displacement (of course, any break / displacement is infinitely more compared to none, ahem.....).

A stalled entry is a required element of spins - no stalled entry, score equals zero.  No different for snaps.  Judges are required to judge what they actually see (not what they think may have happened), and pilots are required to show / demonstrate / complete all required elements to avoid downgrades (which may be a downgrade to zero).

To specifically answer Bob's question - my opinion - if the geometry of the manuever is not compromised, then no downgrade.

Another question(s) - In a given maneuver involving a snap, the exit track of the plane is 15 degrees different than the track prior to the snap.  What is the downgrade if the change in track is abrupt?  What is the downgrade if the change in track is smooth?

Regards and Happy Holidays,

Dave Lockhart
DaveL322 at comcast.net



----- Original Message ----- 
  From: Ed Alt 
  To: discussion at nsrca.org 
  Sent: Tuesday, December 28, 2004 11:04 PM
  Subject: Re: Displacement during snap rolls (was Why is it so quiet?)


  Good topic Bob.  If the model really did a snap roll, it had to displace somewhat.  If not, and if you could actually tell that it did not, that could be an indicator that a snap roll did not actually happen. Generally, the model has to displace to a new track, however slight, from the yawing and pitching moments introduced.  The criteria should perhaps be that you are able to able to maintain the new track exactly in parallel to the pre-snap track.  How much offset is OK is hard to say, but things generally start looking suspicious whan it's much more than a couple of wingspans.  You would generally start to see other obvious problems, such as barrel rolling, if the displacement were really large.  For another perspective, I think the Scale Aerobatics Flying and Judging Guide does a decent job of describing how to grade a snap.

  Ed
    ----- Original Message ----- 
    From: Bob Pastorello 
    To: discussion at nsrca.org 
    Sent: Tuesday, December 28, 2004 10:31 PM
    Subject: Re: Why is it so quiet?


    It can be very, very bad.
    Or not.

    Let's talk about displacement of the flight track during snap rolls.  Whatcha y'all think?  Is it downgradeable, and if so how much, and what is the criteria?

    Bob Pastorello
    NSRCA 199  AMA 46373
    rcaerobob at cox.net
    www.rcaerobats.net


      ----- Original Message ----- 
      From: Mike Hester 
      To: discussion at nsrca.org 
      Sent: Tuesday, December 28, 2004 9:21 PM
      Subject: Re: Why is it so quiet?


      Ya well, it's definitely not going on the primary bird. For that I have a trusty OS 160FX with vp30 pump. I know it will run when I want it to run.

      Just like me "testing" a new design, testing my feather cut, testing my composite skillz (or lack of), so far so good. Of course I didn't make the YS, so that one is more of a massochistic tendancy methinks. I'm not skeert to spend a buck. Plus it wouldn't take too much to drop in an OS if it comes to it. I've gotta see for myself if the fire is as hot as it looks. I usually suffer 3rd degree burns right after one of these moments.

      Classic last words: "How bad could it be?"  =) 

      -Mike

      PS Ok ok NEXT year.
        ----- Original Message ----- 
        From: Bob Pastorello 
        To: discussion at nsrca.org 
        Sent: Tuesday, December 28, 2004 9:47 PM
        Subject: Re: Why is it so quiet?


        You have less than 3 days, then.  Could be tricky for you.
        Besides, how does one "try" something that costs $700+  ?  Sounds a bit like "testing" the $3500 plasma tv.....

        Bob Pastorello
        NSRCA 199  AMA 46373
        rcaerobob at cox.net
        www.rcaerobats.net


          ----- Original Message ----- 
          From: Mike Hester 
          To: discussion at nsrca.org 
          Sent: Tuesday, December 28, 2004 8:38 PM
          Subject: Re: Why is it so quiet?


          YS SUCKS!!!!!!!!!!

          Better?

          =)

          -Mike

          P.S. I am actually going to try a DZ 160 some time this year. This could mean the apocalypse is near.
            ----- Original Message ----- 
            From: William C. Harden 
            To: discussion at nsrca.org 
            Sent: Tuesday, December 28, 2004 9:33 PM
            Subject: Why is it so quiet?


            I know someone out there has something interesting to say.  So stir something up!

             

            Bill

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