Snaps

[JOddino]

I believe we are saying the same thing if you define the critical angle of attack as the point where an increase in angle of attack does not increase the lift.  So it would seem that the task is to rapidly change the angle of attack from near zero and have it exceed the critical angle before the plane changes its flight path.  This is tough for a pattern plane because they are very responsive especially when they have relatively high airspeed.  The big high inertia IMAC planes have a much easier time achieving a high angle of attack before the flight path changes just like an airliner.
Jim  

----- Original Message ----- 
  From: Ed Alt 
  To: discussion at nsrca.org 
  Sent: Tuesday, April 13, 2004 11:36 PM
  Subject: Re: Snaps


  Jim:
  The wing is stalled when the critical angle of attack is reached, which can happen at any airspeed, starting from any flight attitude. This is most easily seen & felt if you go up in a light plane and gradually work the yoke back, increasing the angle of attack and holding altitude as airspeed bleeds off before the stall.  This can go on for many seconds.  The total lift is staying the same before the stall, but the wing doesn't stall until the angle of attack gradually increases to the point that the critical AOA is reached.  In that example, the critical AOA will be reached at a lower airspeed due than if the pilot had done an accelerated stall by yanking the yoke rapidly back.
  Ed
    ----- Original Message ----- 
    From: JOddino 
    To: discussion at nsrca.org 
    Sent: Wednesday, April 14, 2004 1:15 AM
    Subject: Re: Snaps


    How do you stall a wing that is not producing any lift, as in the case when the plane is on a vertical up or down line?
    My definnition of stall is when an increase in angle of attack does not produce an increase in lift.  Another might be when the lift does not exceed the weight.  I've got to believe we know a snap when we see it and we ought to quit trying to describe it in words.
    Jim
      ----- Original Message ----- 
      From: Patternrules at aol.com 
      To: discussion at nsrca.org 
      Sent: Tuesday, April 13, 2004 6:13 PM
      Subject: Re: Snaps


      In a message dated 4/13/2004 8:06:56 PM US Eastern Standard Time, rcsteve at tcrcm.org writes:
         Don't stop reading as so many do, this is the next sentence.
        
       1. Since the maneuver is defined as a stall maneuver
      (initiated by a rapid stall of the wing induced
      by a change in pitch attitude), the nose of the
      fuselage should show a definite break from the
      flight path in the direction of the snap (positive
      or negative) while the track closely maintains
      the flight path.
       


      Steve Maxwell
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.f3a.us/pipermail/nsrca-discussion/attachments/20040414/1d3be7fe/attachment.html