[NSRCA-discussion] 2007 Pattern Rules posted by AMA

[Ed Alt]

Hmm, I think I understand how to judge a snap based on the description on RCA-20 except for this:  It states "Large deviations from the flight path, indicative of a delayed stall, are to be downgraded using the 1 point per 15-degree rule for each axis of the excursion before the stall."  Then it follows with an example of a dual-downgrade due to a 15 degree nose up pitch and 15 degree roll before the wings stall.  

OK, there's two things that confuse me with this.  One is that it begins by stating that a deviation in the flight path can indicate a delayed stall.  I buy that, but then the example seems to muddy it.  The pitch-up angle shouldn't be a criteria for downgrade, the degrees of deviation from the correct flight path before the stall ought to be, right? I think I understand the intent, but the example doesn't match what I think that intent is.

The 2nd confusing thing is similar to the first, i.e., looking at the angle of bank achieved before the break.  Alright, on the one hand, it ought to be a downgrade that the model rolled before the stall, but the statement preceding the example talked in terms of flight path, not angle of bank.  Again, I think I understand that the intent is to apply 15% / degree of deviation from the flight path, but the example really seems to be referring to the bank angle alone.  

Can someone explain this better?  I think what it all means is that I should downgrade for as many as 3 things at that moment in time.  One is that the flight path may have departed excessively in the Y axis before the stall/autorotation, another is that it may have deviated excessively in the Z axis before the stall/autorotation, another is that the model may have rolled before the stall/autorotation.  But I don't see how I can possibly downgrade for excessive pitch attitude before the stall/autorotation, because it is the pitch break that initiates the whole chain of events.  That piece has to happen, as does some yawing motion, which is the other essential ingredient for autorotation.  

So if I've got this right, I use judgment to allow for a little bit of a flight path departure in the Y axis (being referred to as pitch in the rules) and also for a bit of path departure in the Z axis due to the yawing of the model to initiate autorotation.  No X-axis departure comes into the picture unless we have a cross box line with a snap someday.  Comments?

Ed
  ----- Original Message ----- 
  From: JShulman 
  To: NSRCA Mailing List 
  Sent: Tuesday, December 12, 2006 11:01 PM
  Subject: Re: [NSRCA-discussion] 2007 Pattern Rules posted by AMA


  I guess we can't zero snaps for not having a pitch break...lol. RCA-20, right side.

  And the landing zone is essentially a 30m box. But it is not a 0 if you don't land in it, just a downgrade. But don't go knocking parts off of it, or it'll become a 0. RCA-26

  Regards,
  Jason
  www.jasonshulman.com
  www.shulmanaviation.com
  www.composite-arf.com 

    -----Original Message-----
    From: nsrca-discussion-bounces at lists.nsrca.org [mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of JonLowe at aol.com
    Sent: Tuesday, December 12, 2006 10:47 PM
    To: nsrca-discussion at lists.nsrca.org
    Subject: [NSRCA-discussion] 2007 Pattern Rules posted by AMA


    Just noticed the 2007 Pattern rules have been posted by AMA.  They weren't there yesterday.

    http://www.modelaircraft.org/comp/0708rulebook/RC%20Aerobatics.pdf

    Jon Lowe



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