Wing loading

Talk about anything hang gliding.

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mario
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Wing loading

Post by mario » Wed Mar 19, 2014 9:01 am

Much to the joy of some here, I was looking at buying a newer (used) hang glider to replace my almost 30 year old GTR. I'm hoping to find a Sport2 or U2 type HG. I know, good luck, right! I would like to get some idea of what wing loadings people are flying at Kagel and hopefully their thoughts on the matter. I realize that this is a personal preference, for instance, I'm sure Joe probably likes under 1lb/ft2 and Rob is probably over 2lb/ft2. It's obvious to me that the newer medium to higher performance wings are more efficient than they used to be and so can handle a higher wing loading.
So if you've never figured out your wing loading, here's how you do it:
Take your hook in weight (you, harness, etc) and add that to the weight of your glider. Divide that by the area (ft2) of your wing, and that's it.
So for me on my 148 GTR, it would be:
175lb hook in wt plus 53lb (that's right!) glider = 228lb divided by148 = 1.54lb/ft2
So, I showed you mine, let me know what your wing loading is and what you're flying. Thanks!
Mario

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OP
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Post by OP » Wed Mar 19, 2014 5:32 pm

I think wing loading and the associated performance varies greatly depending on the glider. So the comparison of loading isn't that useful.

Examples:
Joe G. flying the Northwing 215 Foot tandem glider solo is no problem @ less than 1lb/ft^2. Joe G. flying a T2 Topless 144 > 1lb is a problem.

Erica can soar the 300ft^2 condor at the beach.
Australian Jodi on the small 135 Sport2 uses diving weights for ballast. Both females about 100lbs without harness.

I have reason to believe there are both 135 and 155 Sport2s available for you to try in our community.

I hook in around 210 depending +/- a camel-back and bags.
Falcon 195 is great. Great sink and I can control it easily.
Falcon 170 is okay, the added response isn't really needed on a falcon. Ridge soaring I was the lowest in the stack with the 170.
Sport2 155, awesome for my weight. Ridge soaring on top of the stack. At funston 200 feet above most all the other flexwings. Making the crossing to west lake a lot easier.
T2 144, I can fly it well enough, haven't had a ridge soaring comparison.


Notice the loss of performance when flying with children:

Image

mario
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Post by mario » Wed Mar 19, 2014 8:51 pm

"I think wing loading and the associated performance varies greatly depending on the glider. So the comparison of loading isn't that useful"

Thanks OP,
I agree with you on the above and that is why I asked to know which wing you are flying when giving your wing loading. Having said that, I find your weight and glider info very useful. The reason I got on this subject is because I was recently offered a nice Discus which has only 125 sq ft of area. Now I know I would probably love it when I'm zooming around high above the ground, but I was a bit scared thinking about landing it due to the higher stall speed a higher wing loading would give. Then there are the high alt flying sites to consider. For me, it's more about controllability, land-ability and then sink rate. So, I did the math and came up with almost 1.85 #/ft^2. At first I thought, no way would anyone fly at that wing loading without owning a lot of broken down tubes. But times and gliders have changed and as I discovered by searching online (although there is very little info on the subject), that a wing loading of 1.9+ on a topless is common, and a few have said they like flying their S2s or U2s at about that same wing loading.
I know that the only way I will know what size glider to get is by test flying, but I was hoping this post would give me a clue on what to keep my eyes out for and maybe even get me to try that mini glider...
Thanks

BTW, I've only noticed a loss of performance flying with young kids on my back when they start to do that choke hold or hands over the eyes stuff! I now just stick them in that pouch that normally holds my parachute and find that the wing loading stays about the same and there is no loss of performance.

Greg Kendall
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Post by Greg Kendall » Wed Mar 19, 2014 9:19 pm

I'm at 2.0 lbs/ft^2 (Litespeed RX 3.5). It seems about optimum on average.

Greg

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chadness
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Post by chadness » Thu Mar 20, 2014 12:29 pm

I think I am also right about 2.0 on my T2 154:
glider = 75, hookin = 230 (195 body + 35 harness, gear, gauges, bags, etc)

mario
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Post by mario » Thu Mar 20, 2014 3:57 pm

Thanks everyone! I also got a PM saying:
1.7 - Sport 2 155
1.9 - T2C 144

Anyone that flies a U2 or the like care to show and tell?

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Malury
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Post by Malury » Fri Mar 21, 2014 12:52 am

I fly the small U2. I am a bit heavy for it, hooking in at about 215 lbs.
I calculate between 1.86 to 1.95 per sq ft. And I enjoy great authority over the glider. Bottom of the stack, but thats just me.

I think I am right in the sweet spot on my Sport 2 155 at about 1.83 lb/ft.

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BudRob
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Post by BudRob » Fri Mar 21, 2014 9:23 am

As stated by Mario in his first post, I fly a high wing loading of about 2.15 lbs per sq ft. on my Moyes LS 3.5 RX. As with Malury, I also enjoy great handling authority over the glider and I am usually NOT on the bottom of the stack. Having a glider what you can put exactly where you want in the thermal (as opposed to where the thermal wants to put you...) more than cancels out the very small sink rate difference in flying the higher wing loading. I also find it easier to land than the larger gliders. I flew the larger gliders for years but do not plan on going back unless I relocate to a flatland site or gain a whole lot more weight.

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Ken Andrews
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U2 wing loading

Post by Ken Andrews » Mon Mar 24, 2014 2:06 pm

According to my bathroom scales and the glider manual, my U2-145 wing loading is:

Me: 158 pounds
Gear: 38 pounds (harness, helmet, parachute, camelbak, etc.)
Glider: 64 pounds
Total: 260 pounds

Sail area: 145 ft^2

Wing loading: 1.79 lbs/ft^2

To me, my U2 seems just the right size, and I love the way it flies and handles. I also fly a Falcon 195 (1.26 lbs/ft^2) and a T2C-144 (1.88 lbs/ft^2). While this T2C is probably the right choice, I seriously considered the T2C-136 (1.99 lbs/ft^2).

Even as an engineer who loves numbers, I have to agree with others that a wing loading number isn't very helpful. To quote George Stebbins, the great thing about a Falcon (or any single-surface glider) is that pretty much whatever happens, two thirds of the wing is always flying. The drawback with a Falcon is that only two thirds of the wing is ever flying. Naturally, this means that one needs more wing area on a single-surface glider.

If one is heavier on a glider, one pays in minimum sink rate, but there's no cost in glide ratio, the handling is better, and speeds are higher all around. My belief is that Kagel air is bumpier than most, and on typical flying days, we need handling more than sink rate. On the other hand, I would think you would find a 125 ft^2 Discus awfully small, particularly when facing a no-wind launch.

Rather than size, the harder question is deciding between the Sport2 and the U2 (or Discus). I think one under-appreciated factor is that it's more fun to fly whatever glider your friends are flying. Beyond that, there are the usual factors: the Sport2 is a recreational glider that's fun to fly and forgiving of mistakes, while the U2 is a thoroughbred that will bite back if mistreated. I believe one has to fly at least once every couple weeks to stay safe on a U2, but in exchange, it does offer an impressive amount of performance.

mario
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Post by mario » Mon Mar 31, 2014 11:02 pm

Thank you everyone, as I found your numbers and experiences very helpful in choosing my new glider!!!!
I've decided to get a single surface glider because I just can't seem to get out to fly enough. I also went for 170ft^2 and a wing loading of 1.39lbs/ft^2 because of the inefficiency of an SS wing and so I have a chance at staying up.
My brother made it, so if it is too big, he can just keep cutting a bit off the trailing edge until it's just right for me.
http://i.imgur.com/DV2aCst.jpg
http://i.imgur.com/N02gQf4.jpg
http://i.imgur.com/3ZckY1o.jpg
I hope to see you all in the sky this April!!!

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JD
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Post by JD » Mon Mar 31, 2014 11:15 pm

mario wrote:....I've decided to get a single surface glider because I just can't seem to get out to fly enough....My brother made it, so if it is too big, he can just keep cutting a bit off the trailing edge until it's just right for me....April!!!
Image
At 225'^2 and a 1.20#/'^2 wing loading, I will be out on Thursday for a Battle of the Bowsprit Gliders!
Image

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BudRob
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Post by BudRob » Tue Apr 01, 2014 6:45 am

This is an April fools joke, right?

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JD
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Post by JD » Tue Apr 01, 2014 9:58 am

BudRob wrote:This is an April fools joke, right?
Didn't know that. Must have lost track of time. Recovery is going slow. That's why I've resurrected the monster floater along with a supine harness.

mario
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Post by mario » Tue Apr 01, 2014 2:27 pm

"I think one under-appreciated factor is that it's more fun to fly whatever glider your friends are flying."

I don't know Ken, sometimes it's nice to be flying something different, don't you think?
Okay, truth is I am coming to to the conclusion that I will be looking for a Sport 2 135 unless I feel completely comfortable on the small U2 and manage to fly more often.

For those that were not born yet, the glider in the photos are of an Aolus that my brother Carlos designed, built (everything-frame to sail making) and flew more than 30 years ago! Don't worry Rob, I will not be flying it off Kagel, but I will bring it out to the beach if we ever have that event again. By coincidence, J D designed and made a very similar design at about the same time but some 2000 miles away!
The Aolus flew very well for its day. I know that My brother used to fly from Kagel to JPL and back often. Once he landed it in a Lowe's parking lot in Chatsworth, if I remember correctly. As a teenager I would drive chase in the Owen's and one flight in '81 or '82 he flew from Walt's point to almost Tonapah and back to Bishop AP at sunset! Not bad for a single surface glider! Of course Carlos was a good pilot, something I can't claim. I can however claim to have made the first concept sketch for the design in about '75 or 6 in the then LZ off Polk(?). It was an attempt to make something that looked more like a bird and to deal with the then common divergent tendencies that the gliders had back then. Those were exciting times.
Apologies if my April fools joke caused alarm or if I blabbed on too long!
Beautiful skies today!!

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dhmartens
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Post by dhmartens » Wed Apr 02, 2014 5:55 pm

Image
Image
I fly the Falcon 2 225

200 lbs Current Body Weight
38 lbs Estimate Equipment
59 lbs Glider Weight
297 Total

225 sail

297/225

1.32 Wing loading

1.45 @ 230 lbs Wing loading at historical maximum body weight

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