Weight rules discussion ( my opinion)

[David Lockhart]

Buddy,

I agree with your thought process regarding wing loading.  100 squares per pound is a very good standard to use.

I agree the most competitive monoplane that fits in a 2x2m box will have no problem being under 11 lbs (but many are apparently having a problem achieving this).

I agree that the monoplanes are dominant in IMAC.

However -
- In IMAC, there is no (practical) weight limit or size limit, so neither the monoplanes or bipes are restricted in any meaningful way - so the swing is back to monoplanes - no real surprise.
- In pattern, the bipe that is competitive with the good monoplanes is very close to 11 lbs (as we have seen with the Double Vision bipes) and appear to be relatively fragile at that weight.  The reason the bipe hasn't been accepted (my opinion) is the average guy knows how difficult it would be for him to achieve and maintain a DV (or similar sized bipe that is competitive with the best monoplanes) under 11 lbs.

Raise the weight limit in pattern, and the 2x2m monoplane will get bigger and more costly (and the most competitive examples will still probably be under 11 lbs, but the "average" plane won't be).

Raise the weight limit in pattern while leaving unlimited displacement and the 2x2m box, and the 2x2m monoplane will no longer be the most competive design - the most competitive design will be a purpose designed pattern bipe that will be substantially more expensive (money, time, maintenance) than the current day designs.

If you don't think a purpose design pattern bipe would be the best, ask Chip.  He will tell you without reservation he would not have flown his Double Visions in the past few years if he did not think it was the best plane.

Regards,

Dave
  ----- Original Message ----- 
  From: BUDDYonRC at aol.com 
  To: discussion at nsrca.org 
  Sent: Friday, February 25, 2005 1:02 AM
  Subject: Re: Weight rules discussion ( my opinion)


  In a message dated 2/24/2005 9:11:03 PM Central Standard Time, DaveL322 at comcast.net writes:
    Buddy,

    Do the rules of aerodynamics include things like wing loading and power loading?  Both of those will be dramatically effected by a change in the weight limit (up or down).  With unlimited displacement and 2x2m maximum dimensions available, weight is very much a design factor.

    Dave



    "Lance 
    In my evaluation the rules need to apply to Pattern as a whole. With the two meter size limit builders will utilize the rules of aerodynamics to achieve the optimum design and weight becomes a moot issue for all classes.
    Buddy "
      ----- Original Message ----- 
      From: BUDDYonRC at aol.com 
      To: discussion at nsrca.org 
      Sent: Thursday, February 24, 2005 8:56 PM
      Subject: Re: Weight rules discussion ( my opinion)


      In a message dated 2/24/2005 7:25:59 PM Central Standard Time, patterndude at comcast.net writes:
        Buddy,
        One good idea that I didn't see in your list was the onelwhere the weight limit for the Advanced-thru-FAI classes remains the same but the limit for Sportsmand/Intermediate is raised.  This really makes sense to me.  We are all comfortable with advancing difficulty in sequences.  Well, building light is also a learned skill and sometimes requires more $$ comittment.  Pilots grow in flying, building, trimming skills.  Why subject sportsman to FAI building rules?
        --Lance

          ----- Original Message ----- 
          From: BUDDYonRC at aol.com 
          To: discussion at nsrca.org 
          Sent: Thursday, February 24, 2005 1:33 PM
          Subject: Weight rules discussion ( my opinion)


          Since the whole message was to large to post following is my opinion.

          After a thorough weighted comparison of the items listed in my previous post I have arrived at the following conclusions.

           It is most important that we strive to make pattern an inclusive sport, which I feel is necessary to increase participation in the future. In order to do that one of the first item that should be addressed is that of eliminating the illegitimate double standard in the weight rule. There are two possible solutions; the first would be to enforce all rules, which many agree in this case would not be in patterns best interest. That leaves us with only one solution and that is to change the rule.        

           In doing that we must consider the overall impact of such a change to insure that it serves to protect all the other aspects concerned as much as possible. After careful review and acknowledging that maintaining the two-meter rule is in fact the limiting design criteria for pattern I suggest that a change in the rule upward to twelve pounds or in light of current FAI considerations, to 5.5K would be an appropriate solution.

          This change could possibly effect other aspects of pattern design in the future but given the known requirements some of which are listed in my previous post that are necessary and practiced extensively today I have little fear that this change will result in any major design changes that would present a problem or afford anyone an unfair advantage in the near future.

           If you study the items in my previous post it will also become apparent that there are many listed that offer the potential to increase our participation and make pattern more inclusive. 

          Should anyone have any other items to offer that I should include which may require further evaluation concerning my conclusions and suggested weight change please forward them to me.

          Buddy Brammer

           



      Lance
      In my evaluation the rules need to apply to Pattern as a whole. With the two meter size limit builders will utilize the rules of aerodynamics to achieve the optimum design and weight becomes a moot issue for all classes.
      Buddy 
  Dave
  I agree considering optimum design within the two meter limit, performance will be determined by the design. Optimum weight is included in the equation. If weight is increased the design must change to obtain optimum performance. Today design weight is in the neighborhood of one pound per one hundred square inches of wing area. In the past patterns dictated an eleven hundred square inch wing area. Optimum design is now at about nine hundred and eighty square inches due to requirements brought about by the current patterns we fly, and in reality that is the driving force in the current design equation required to obtain optimum performance and always will be.
  Considering a twelve pound weight limit, a two meter maximum size limit and the fact that power requirements increase exponentially as size, drag and weight increase, I don't see how a designer would attempt to purposely consider such a challenge and expect optimum performance with the possible exception of a biplane design and that option has always been out there, tried a few times and excluding Chip's effort has never been accepted. 
  In fact look at IMAC where anything is possible and the swing is back toward monoplanes and away from biplanes, I wonder why?
  Considering all the possibilities I still think a weight change is the way to go.     
   Buddy
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