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riggerrob

Max. wing-loading per model

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What is the maximum wing-loading per canopy model?
For example, lift to drag ratios seem to peak at about:
1.5 Sabre Mark 1
1.5 Diablo
1.7 Stiletto
We are discussing the heaviest you can load a specific model and still get decent glide and flare.
Maybe we should re-phrase this question: What is the maximum wing-loading per canopy model that will score well at a blade running meet?
Let's be clear here. We are not talking about the maximum wing loading you can jump and survive.
Let's limit discussions to canopies that you have jumped or observed closely at blade-running meets.

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Stilettos are used by lots of the itermedites if I remember correctly.... The Pro class is where X-braced canopies are used a lot. Who would have ever thought a Spectre would be in, and do well in a Blade Running meet?
Cause I don't wanna come back down from this cloud... ~ Bush

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The Spectre kicked a lot of peoples butts.....
She was swooping that Spectre further then most casual jumpers are their Extreme Pocket Rockets.... I think Bridgette did the Pood Swooping Nationals under the Spectre too. A Spectre is a good swoop canopy in the hands of a good pilot.
Cause I don't wanna come back down from this cloud... ~ Bush

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Gen Chuck Yeager had an argument w/ another pilot one day. The other pilot thought that the airplane was more important than the pilot. Chuck thought that the pilot was more important. So they got two aircraft, one that was vastly superior to the other and went up and dog fighted. Yeager won. They landed and switched aircraft. Yeager won again.
Give the ten best canopy pilots in the world Spectres and let everyone else have whatever they want, they would have a very hard time beating all/some/any of the Spectre's.
Hook

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Not to steal your thunder phree, cause you are right, but give yeager the best aircraft and he is unbeatable, or was....I guess....you know what I am trying to say. Give the best canopy pilot out there the best thing on the other end of the Vectran and he/she will win every time.
Hook

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Totally true... but so many people nowdays are getting smaller canopies since hey offer an immediate improvement in proformance compaired to building skills that transfer to other canopies. Give the best pilot the best plance/canopy and they will win, give a so-so pilot the best plane/canopy and I bet they won't out do a great pilot on a so-so plane/canopy.
Cause I don't wanna come back down from this cloud... ~ Bush

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For example, lift to drag ratios seem to peak at about:
1.5 Sabre Mark 1
1.5 Diablo
1.7 Stiletto

Is this some theoretical based on swoop distance? Because -clearly- L/Dmax has little to do with wingloading from an aerodynamic point of view.
I will agree that there must be some point at which wingloading per specific canopy reaches it's optimum for swoop distance based upon (1/2rho)*V^2*Cl*S vs mass (kinetic energy) and drag.
Essentially, if you're wingloaded too lightly you'll bleed more drag than your kinetic energy can overcome for the distance desired and if you're loaded too highly you'll run out of lift sufficient to sustain level flight too quickly. This, of course, would not only vary according to wing design, but also according to specific wing size within the same design.
Nothing scales -exactly-.
quade
http://futurecam.com

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quade,
Theory and fancy formulas are nice, but every canopy has an envelope that it performs well within, and performance suffers when you exceed that envelope. I asked people where the edges of the envelope are for each canopy model.
I am trying to figure out at what wing loading a canopy starts sinking out of the sky.
We all know that under-loaded (say 100 pound student) Mantas just mush around the sky. Mantas don't really fly like wings when they are under-loaded.
By the same token, over-loaded canopies don't really fly like wing seither. We all know that you can overload most ZP canopies and survive. But when you near the edge of the envelope, glide and flare performance suffer.
The original question was: what is the heaviest practical wing-loading for each model?

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One of our pro swoopers has a XAOS 69 loaded at near 3. He has used it well in competition, but feels it is overloaded, so he is backing off to likely use only the 77 in competition, even for the speed portion.
Nothing Scientific, but that would put him saying that 3.0 is too heavy, and the 77 at about 2.7 is more the upper range of the sweet spot on the XAOS-21.
On my XAOS at 2.1, it is not overly radical, for that kind of a landing. It comes withing 10 feet of a full stop at the end of the swoop (meaning I have to slide/run out those ten feet). That on no wind, and if I shut it down the way I am supposed too.

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I am trying to figure out at what wing loading a canopy starts sinking out of the sky.

Agreed. However, it's not going to be definitive point since the mass, skill and knowledge of the canopy pilot has a lot to do with it as well.
My comment about things not scaling comes into play here as well.
For instance, let's look at a fairly light individual in fairly good shape -- Eli of the Flyboyz for instance. His body should be able to accept/absorb a slightly higher sink rate than can a person twice his weight. So the sink rate that to me might be "falling out of the sky" to him may just be a normal landing.
And there's also an issue about kinetic energy v drag not scaling as well.
Take Luigi at a loading of 1.7:1 and J.C. on the same model of canopy also at 1.7:1 and as far as swoop -distance- is concerned I think J.C. is going to win just because his body carries more energy.
Anyway, I think you get the idea.
quade
http://futurecam.com

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quade,
I was trying to ask a technical question that ignored pilot technique.
As for your implication that J.C. would fly better at the same wing loading as Luigi ...
Sorry dude, but I have to disagree. Luigi is short and muscular. J.C. has almost the opposite body type: tall and lanky. J.C.'s longer limbs crate more drag.

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Thanks guys,
We are now getting some serious input.
quade,
I was trying to ask a technical question that ignored pilot technique.
As for your implication that J.C. would fly better at the same wing loading as Luigi ...
Sorry dude, but I have to disagree. Luigi is short and muscular. J.C. has almost the opposite body type: tall and lanky. J.C.'s longer limbs crate more drag.

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"Take Luigi at a loading of 1.7:1 and J.C. on the same model of canopy also at 1.7:1 and as far as swoop -distance- is concerned I think J.C. is going to win just because his body carries more energy."
I disagree. That would put Luigi under a much smaller canopy. At the same wing loading, a smaller canopy has less drag, a higher top speed to trade for altitude in a swoop. This is why small girls get plenty of performance at lower wingloadings than their larger male counterparts. A VX-60 will go faster than a VX-120, all other things being equal. Swooping is trading altitude for airspeed and then airspedd for altitude as efficiently as possible.
Hook

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A VX-60 will go faster than a VX-120, all other things being equal.

Again, I'm ONLY talking about a swoop distance competition.
It doesn't matter which is faster -- it matters which has the most kinetic energy at the entry gate and how much drag will be created over the course.
If we use a factor of 2 for L's and J's weight and canopy size and have all other things equal, then J probably should win distance since his canopy -shouldn't- create twice as much drag.
Just look at the actual results of the last few pro swoop distance competitions and I think you'll see they favor the heavier guys rather than the light ones. Obviously, there's some variation for piloting technique.
quade
http://futurecam.com

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I think it is a complicated issue. Take two jumpers, one under a 100 and one under a 200. Both have a 1:1 wing loading. assume same technique and ability. Which one can swoop farther? At the same speed the 200 pound jumper has twice the kinetic energy than the 100 pound jumper, but the 100 sq ft canopy will go faster, creating more kinetic energy, but probably not twice as fast. the 200 lb jumper will slow down faster than the 100 jumper because he has more drag. So its a trade off. Too many variables, fat jumper, muscular, etc...We probalby won't figure this one out completely:-)
Hook

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I think that most of the reply are very intresting but are not to the point .
First we have to say what gliding angle or sink rate do we want in full flight and the test it with a different wingload (suspendent mass) and that would be the Max wing load for that glid angle per model per size canopy
my 0.02 Euro cent
AM67

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