Swept Leading edge vs Straight Leading edge

[Mike Griffin]

I sincerely appreciate all of the input on this post that I started.  Since I am not good in math and have zero education or training in aerodynamics, physics and engineering, I did not understand some of it.  I guess I was just looking for a simple answer as it pertains to flying our models.  Some designs have a barn door type wing with a straight leading edge and others have a tapered wing with a leading edge that is angled back.  Most of the top fliers (pilots) seem to prefer models with the swept back leading edges as compared to a wing with a straight leading edge.  My question was Why?  Is there any advantage of one wing design over another because the sweep or lack of on the leading-edge configuration.  If you take a Humongous and an SV11 and put it in the hands of a top stunt pilot flying the same pattern, will the design of the wing have anything to do with how the pilot scores or does it all depend on the skills of the pilot? 

Mike

[Scott Richlen]

  I am not good in math and have zero education or training in aerodynamics, physics and engineering, I did not understand some of it. 

Bottom line: just listen to what Brett says, and fly what Fitzgerald flies (or just copy it and change the shape of the rudder, move the canopy forward or back and then claim you designed it.)   

If you go back and read Gialdini's write-up for his Olympic way back when in American Modeler, take note of his dumbbell drawings and discussion.

This probably isn't quite correctly written: think of how a tapered planform wing has progressively less area per each inch of span as it moves out towards the tips compared to a constant chord wing.  In "upset" conditions it will roll less than a constant-chord wing simply because it has progressively less area.  It's an area times moment arm (from the center-line of your fuselage) thing.  You may have noted that, in general, constant chord wings fly pretty choppy in bad wind conditions.  Years ago at Brodaks I watched Dr. Reuben fly his Pathfinder in bad air conditions.  It was rolling, and hacking, and puking all over.  The next flight was his son, Stevey, flying a Cardinal Evo.  That thing came around the circle flying flat liike it was on rails.  Same wind conditions.  Staright chord versus tapered chord.
 

[Mike Griffin]

Bottom line: just listen to what Brett says, and fly what Fitzgerald flies (or just copy it and change the shape of the rudder, move the canopy forward or back and then claim you designed it.)   

If you go back and read Gialdini's write-up for his Olympic way back when in American Modeler, take note of his dumbbell drawings and discussion.

This probably isn't quite correctly written: think of how a tapered planform wing has progressively less area per each inch of span as it moves out towards the tips compared to a constant chord wing.  In "upset" conditions it will roll less than a constant-chord wing simply because it has progressively less area.  It's an area times moment arm (from the center-line of your fuselage) thing.  You may have noted that, in general, constant chord wings fly pretty choppy in bad wind conditions.  Years ago at Brodaks I watched Dr. Reuben fly his Pathfinder in bad air conditions.  It was rolling, and hacking, and puking all over.  The next flight was his son, Stevey, flying a Cardinal Evo.  That thing came around the circle flying flat liike it was on rails.  Same wind conditions.  Staright chord versus tapered chord.

Thank you Scott.   That helped.

Mike

[Brett Buck]

Bottom line: just listen to what Brett says, and fly what Fitzgerald flies (or just copy it and change the shape of the rudder, move the canopy forward or back and then claim you designed it.)   

    I note that the only thing I said of any consequence was to not use "personal preference" as a rationalization for doing something wrong or less-than-your-best. That is a classic trap, maybe the most insidious of the common traps you can fall into.

      What makes a good stunt plane, and how they fly, has converged to a narrow range. We still argue about stuff, but it's over minutia that are far more subtle than most people are concerned with - since almost everyone, including NATs qualifiers, has trim/power issues so profound that it just swamps the minor details.

     Otherwise there was a lot of very good information from everyone, and the basics of the question originally asked about wing planforms were answered long ago.
   
     Brett

[Scott Richlen]

the only thing I said of any consequence was to not use "personal preference" 

Oh no!  But my personal preference is to just listen to what Brett says....so now I'm in an unending conflicting do-loop!   

[Brett Buck]

Oh no!  But my personal preference is to just listen to what Brett says....so now I'm in an unending conflicting do-loop!   

      Yes, I can see your dilemma. Time to reboot.

    Brett