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View Full Version : Wing loading vs Span


Jonathan St. Cloud
December 20th 16, 09:04 PM
In days of old the phrase was "Nothing beats wing span". Now it seems as if these short wing "open" birds, i.e., JS1C are beating the long wing birds.. Rarely even see a 23 meter bird in the open class. Having almost half my glider time in the open class I miss the long beautiful wings and at the end of a dying day a 6.2 pound wing loading.

https://www.youtube.com/watch?v=tt9VfoN2kTA&t=44s

Never having flown a 21 meter bird, but I cannot imagine they are as efficient at dolphin flying as a bird with more span.

So the question is, does span still beat wing loading or does 21 meters at 12 pounds beat 26.5 meters at 9.2 pounds? I realize there are many assumptions and variables, but damnit I miss the beauty of the long wings.

December 21st 16, 03:00 AM
On Tuesday, December 20, 2016 at 4:04:59 PM UTC-5, Jonathan St. Cloud wrote:
> In days of old the phrase was "Nothing beats wing span". Now it seems as if these short wing "open" birds, i.e., JS1C are beating the long wing birds. Rarely even see a 23 meter bird in the open class. Having almost half my glider time in the open class I miss the long beautiful wings and at the end of a dying day a 6.2 pound wing loading.
>
> https://www.youtube.com/watch?v=tt9VfoN2kTA&t=44s
>
> Never having flown a 21 meter bird, but I cannot imagine they are as efficient at dolphin flying as a bird with more span.
>
> So the question is, does span still beat wing loading or does 21 meters at 12 pounds beat 26.5 meters at 9.2 pounds? I realize there are many assumptions and variables, but damnit I miss the beauty of the long wings.

IMHO...it depends on the weather you would encounter. If your are continuously flying in weak weather I'd go 26.5/9.2. If weather was expected to be consistently better than 4 knots, then 21/12. You could always order a Binder EB-29R and go 29.3/11 and self launch to boot. Think of all the fun you would have getting that aircraft carrier out of the trailer and ready to launch. Your new 29Es would pay for about 1/2 of that new EB 29R.

Steve Leonard[_2_]
December 21st 16, 05:28 AM
On Tuesday, December 20, 2016 at 9:00:38 PM UTC-6, wrote:
> On Tuesday, December 20, 2016 at 4:04:59 PM UTC-5, Jonathan St. Cloud wrote:
> > In days of old the phrase was "Nothing beats wing span". Now it seems as if these short wing "open" birds, i.e., JS1C are beating the long wing birds. Rarely even see a 23 meter bird in the open class. Having almost half my glider time in the open class I miss the long beautiful wings and at the end of a dying day a 6.2 pound wing loading.
> >
> > https://www.youtube.com/watch?v=tt9VfoN2kTA&t=44s
> >
> > Never having flown a 21 meter bird, but I cannot imagine they are as efficient at dolphin flying as a bird with more span.
> >
> > So the question is, does span still beat wing loading or does 21 meters at 12 pounds beat 26.5 meters at 9.2 pounds? I realize there are many assumptions and variables, but damnit I miss the beauty of the long wings.
>
Just my opinion after about 300 hours racing a Nimbus 3 at 25.5 meters and about 9 psf. If the day is good, you can't keep up on a head to head run if you have more span but less wing loading. But, if you make some decisions better then them, you can for a race. You don't have a significant edge in mass, so Kinetic Energy is not significantly different. You have more wetted area, and lower wing loading, so in strong stuff, they can probably keep right up on the pull ups while dolphin flying. And out-glide you on the run.

When it gets weak, we all get light. I can get down to about 7.2, they can get down to about the same. You gain a span loading advantage, so maybe a bit on climb. But, I find the Nimbus handles worse dry than wet, so my climb doesn't go up as much as I would hope when I get light. Then, when you leave the thermal, you feel like you are a feather.

20 years newer aerodynamics does make a difference. But, like you, Jonathan, I do love span. To quote Platypus: "There is no Substitute for Span. Well, there is. It is called talent. But, you can buy span." So, I bought 25.5 meters of it. And I love every minute of flying it!

Steve Leonard

Dave Nadler
December 21st 16, 12:27 PM
On Wednesday, December 21, 2016 at 12:28:10 AM UTC-5, Steve Leonard wrote:
> 20 years newer aerodynamics does make a difference.

And 40 years makes an even bigger difference.
Nimbus 3 first flew more than 35 years ago!

I guess we're getting old...
See ya at the Seniors,
Best Regards, Dave

Steve Leonard[_2_]
December 21st 16, 03:33 PM
On Wednesday, December 21, 2016 at 6:27:34 AM UTC-6, Dave Nadler wrote:
> On Wednesday, December 21, 2016 at 12:28:10 AM UTC-5, Steve Leonard wrote:
> > 20 years newer aerodynamics does make a difference.
>
> And 40 years makes an even bigger difference.
> Nimbus 3 first flew more than 35 years ago!
>
> I guess we're getting old...
> See ya at the Seniors,
> Best Regards, Dave

I could only go as a guest, Dave. But, yes. We are getting old. And, I assumed that Concordia and initial JS1 Aero is pushing 10 years old now, too. So, it is closer to 20 than 40 years of Aero Evolution.

Maybe at Cordele,
Steve

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