[NSRCA-discussion] basic judging question

[Bill Glaze]

The stall turn descriptions seem to be consistent throughout, with no exceptions.  It is,   of course, apparent that the actual drift direction of the airplane, when it is in a zero airspeed, or near zero airspeed, condition, cannot be controlled.  In that "zero" condition, control surfaces have little (or, at best, highly diminshed) effect on airplane attitude. In IAC competition, effects caused by wind drift are to be ignored, because the pilot, not standing on the ground, has little idea of the direction the wind is taking his airplane.  In this case, we have the advantage. 
Is this discussion going somewhere?  Or just confusing us?
  ----- Original Message ----- 
  From: Joe Lachowski 
  To: NSRCA Discussion List 
  Sent: Wednesday, October 07, 2009 1:52 PM
  Subject: Re: [NSRCA-discussion] basic judging question


  The description of stall turns does refer to Figure-M's and the like. 
   
   

  Stall Turns: Stall turns consist of lines and partial loops as well as stall turns. The following criteria apply to all maneuvers containing stall turns (e.g., Figure M, Stall Turn with Half Rolls, etc.). 

  1. Lines must have exactly vertical and horizontal flight paths. 

  2. Entry and exit must consist of partial loops with equal radii. 

  3. Length of the vertical line is not a criterion. 

  4. All rolls must be placed in the center of the lines. 

  5. Maximum pivot radius is one-half (1/2) wingspan. A pivot radius of more than one and one- half (1-1/2) wingspan should be considered a major defect and be downgraded by at least two (2) points. 

  6. If the model shows a pendulum movement after the pivot, the maneuver is downgraded by one (1) point. 

   
   


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  Date: Wed, 7 Oct 2009 10:12:41 -0700
  From: bob at toprudder.com
  To: nsrca-discussion at lists.nsrca.org
  Subject: Re: [NSRCA-discussion] basic judging question

        Jim,

        What you said is exactly how I remember the judging discussion presented at the Youth Masters re: IMAC stall turns. And I remember thinking to myself that this is not the way we did it in pattern in the '90s. Oh, well, I did not want this to turn into a pattern vs IMAC discussion again. :-\

        Getting back to my original question, I think the stall turn should be wind corrected as much as possible through the stall turn itself. However, that is not how the maneuver description is written for the Figure M or the Double Stall Turn. The language used for the regular Stall Turn w/ or w/o Rolls should be duplicated, IMHO.

        Bob R.


        --- On Wed, 10/7/09, Woodward, Jim (US SSA) <jim.woodward at baesystems.com> wrote:


          From: Woodward, Jim (US SSA) <jim.woodward at baesystems.com>
          Subject: Re: [NSRCA-discussion] basic judging question
          To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
          Date: Wednesday, October 7, 2009, 11:02 AM


          Bill – I can see where the confusion is -  as I perfectly relayed the information as taught in the SE judging seminar and confirmed in the practical judging practice held on Sundays.  The IMAC judging committee interprets the definition to mean that the attitude (fuselage) must be in the vertical plane during the rotation.  They further back this up by stating that if the plane were to be in the “wind-corrected” attitude (not perfectly vertical) during the rotation, that it would be subject to the 0.5 pt per 5 degree rule.  I’ve been in the room 3 times when Wayne M. has explained this and answered many questions from it.



          Lots of discussion took place over this in the judging seminar.  Basically they are teaching that for “yaw” you can remain wind corrected, but for the pitch axis, you must be in the vertical plane.  Sorry if this seems to contradict the rule, but this is what is being taught and practiced in the South East.  

           

          I think it looks funny, and I would prefer for the interpretation to allow “wind-correction” for any time, but I must fly what they teach as the scoring criteria SE.  On the other hand, I would love to know if this has changed as well. 

          Thanks, 

          Jim 

           



           

          From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Bill's Email
          Sent: Wednesday, October 07, 2009 9:48 AM
          To: General pattern discussion
          Subject: Re: [NSRCA-discussion] basic judging question

           

          Woodward, Jim (US SSA) wrote: 

           

           

          However, this dovetails into the recent IMAC & Pattern comparison threads.  In IMAC, the plane is supposed to be brought into the “vertical plane” prior to the stall-turn(pivot) taking place.  This is mostly evident if you are flying in a strong headwind where you are wind correcting the vertical line.  Just prior to the stall turn, the pilot hast to pitch the plane into the vertical plane, then yaw around the pivot, then return to the wind corrected down line. 

           

           Not sure where you got this about IMAC, but it is incorrect. This may be the cause of your confusion (from Rule 8.5):

          The wings must remain in the vertical geometric plane throughout the turnaround, and the aircraft‘s attitude before and after the turnaround must be absolutely vertical (unless wind correction is required), with no extraneous tail movement. There must be no rotation around the pitch or roll axis. If there is movement around any axis other than the yaw axis, often referred as "torquing" (Fig. 25), there is a deduction of 0.5 points per 5 degrees of axis.

          At no time in IMAC is the actual attitude of the plane judged, it is ALWAYS the track of the theoretical center of mass. You are not required to alter the pitch of the plane at the point if the rotation starts if the pitch attitude in not vertical due to wind correction.





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