[NSRCA-discussion] Snap

[Ed Alt]

Your statement that any use of rudder or aileron = no snap is what is wrong.  I'm aware that you can snap an airplane simply by stalling it. I've got a full scale license too.  So the key is, the wing MUST stall.  No stall, then no autorotation (the wiffle snap).  The use of rudder is required so that one wing advances and the other retreats rapidly as the critical angle of attack is reached.  This allows you to control the direction of the snap.  The advancing wing tends to not stall, or not stall as deeply as the retreating wing, which does stall.  This is due to the drop in airspeed of the retreating wing, and to some extent on some airplanes, the blanking effect of the fuselage on a section of the retreating wing.  

Adding ailerons is necessary on a lot of models because they are so lightly loaded, you can't get much of a presentable snap without it.  It's got to do with how fully developed the stall is, and since we tend to have a difficult time getting the kind of potentially life changing stall condition that you can get in a more heavily loaded airplane, pattern models and IMAC style models tend to need help with the ailerons so that it doesn't look like a complete train wreck.  Personally, I wish we would just eliminate snaps in precision aerobatics. This is a never ending debate and a never ending problem with bad judging.

Ed

----- Original Message ----- 
  From: rjo626 at aol.com 
  To: nsrca-discussion at lists.nsrca.org 
  Sent: Sunday, October 11, 2009 7:46 PM
  Subject: [NSRCA-discussion] Snap


       I am not wrong. I've done it. With a tail heavy airplane with too much elevator throw. Before I knew how to fly, 
  my father would hold the radio down so that I could pull the elevator stick back to do a loop. I pulled back all at
  once instead of gradually. The Sportmaster did a TRUE snap roll in straight and level flight. Scared the bejeezum
  out of both of us! No aileron; no rudder.

       Later!
              RJO


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