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BMAC615

A License on >1:1 WL?

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I understand a higher wing loading matters less for a "big guy" like me or the example than it does for an average sized or smaller person. So the decision for me to fly at 1.1 or 1.2 is probably more analogous to a smaller person deciding to go to 0.9 or 1.0

I thought it was a pretty common concept that smaller canopies tend to be more sensitive to given inputs.

This all goes way back, for example being part of Brian Germain's wing loading chart and all sorts of stuff he has written. Accompanying his chart:

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While a 170 square foot canopy may perform in a docile manner at 1.0 lbs
per square foot, a 107 of the same design will be much more responsive at
the same 1.0 wingloading. Therefore, the Chart skews the data in a non-
linear nature, suggesting a more gradual downsizing progression for
lighter pilots and a more aggressive paradigm for the heavier jumpers.

But: I also recall that he (and others like me) say not to take things too far -- All that isn't supposed to be an excuse for a big guy to start loading up his canopy excessively 'because it's more docile for me'.

So one is still free to agree or disagree with the exact numbers in that quote at the start of this post, about a 1.2 loading for the poster being like 1.0 for a smaller person.

Edited by pchapman
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I actually had heard that before, too. Two factors: one is that a 20 sq ft reduction in size is a smaller percentage at the higher wingloading, and the other because canopies below about 150 sq ft have shorter lines, and therefore are more sensitive to inputs. 
But people can easily read what they want in there, and forget the “don’t hang your cap on this.” 
To the OP, this is a discussion between you and more than one instructor at your dropzone. More than one simply because that reduces the chance of relying on the judgment of a single point. 
Wendy P. 

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2 hours ago, wmw999 said:

canopies below about 150 sq ft have shorter lines, and therefore are more sensitive to inputs. 

That's true, but I wouldn't try to bake that into wingloading to say a big guy at 1.2 is equivalent to a small guy at 1.0. 1.2 is 1.2, and 1.0 is 1.0. If you happen to be on a 150 or smaller, there will be additional things to consider, but that's separate from wingloading. Just like rectangular vs. elliptical--another thing that greatly affects performance that I would not try to bake into wingloading.

To put it another way, when someone recommends a wingloading for you, if that were to put you at 150 or below you'd want to have some more dialogue about it. It absolutely does not mean that if you're above 150, that he's actually recommending 0.2 higher. It just doesn't work that way. 150 and below is the special case--above that is the normal case and you don't need to adjust anything.

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10 hours ago, sfzombie13 said:

the whole article, i just read it.  i had never heard it either. 

Ok I've read the article now, and I don't see anywhere an implication that wing loading matters less for a bigger jumper, or that a bigger jumper at 1.2 is analogous to a smaller one at 1.0. In fact, the author refutes that notion directly from the very start:

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It’s possible for two jumpers with widely different exit weights to get the same performance, but the lighter jumper must load their canopy a little more lightly. True/False?

[...]

The above statements are all false.

 

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I started loaded at 1.2 on a 190.  It's definitely more docile than 1.2 on a 120.  But probably not the recommended route. I was stupid.

I would suggest you not take advice from random people on the internet who don't understand basic canopy dynamics, and take advice from a canopy coach that does.  It's important in this sport to have mentors that you personally know and trust for advice.

FWIW almost a decade and about four canopies later I'm still (again) on a 190, although thanks to COVID weight it's loaded a bit heavier.

Edited by lyosha

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15 hours ago, nwt said:

Ok I've read the article now, and I don't see anywhere an implication that wing loading matters less for a bigger jumper, or that a bigger jumper at 1.2 is analogous to a smaller one at 1.0. In fact, the author refutes that notion directly from the very start:

 

well, one person read it and got that, then i did the same thing, but you didn't.  i'd say you are the outlier here, without any other opinions on it.  it seems to imply that downsizing by large folks is different than for small folks, and that is very true.  it also seems to me that the whole small canopies being high performance could change significantly by lengthening the lines, since that is what most say makes the difference.  i have mentioned that before and was told there is no market for it, yet we are still talking about how dangerous it is for smaller folks to downsize due to the canopy size, when that is only half the equation if line length makes that much difference.  i am sure there would be a market for it if we still have students who are smaller start jumping, then need to downsize canopies without sacrificing safety.  granted it isn't a huge market, but neither is skydiving in general.  sometimes we have to do things for safety, and not just profits, but i guess the canopy manufacturers have yet to reach that conclusion.

Edited by sfzombie13

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(edited)

It’s not just shorter lines, it’s air resistance and drag as well. A smaller canopy has a lower profile and less drag/air resistance. It accelerates faster and takes longer to slow down.

What we have to understand is this whole WL conversation is not linear. In fact, it’s chaotic.

Most people giving advice regarding WL or canopy size or canopy type almost never ask: WHY. Why do you need a smaller canopy or a different model? What are you trying to accomplish? What are your short-term and long-term goals?

For example, If someone comes to me and says, “I started skydiving because I want to fly wingsuits” or “I started skydiving because I want to BASE jump,” my WL and canopy recommendation would be much different for them than someone who said, “I got into skydiving because I want to have fun.”

What’s funny, is a lot of people don’t know they want to “downsize” until they see their instructor or the other “bad asses” of the DZ swoop in. They see the top of the totem pole wearing little rigs and flying tiny canopies and emulate them.

Before giving anyone any advice, ask yourself, “what are they trying to accomplish and how can I help them accomplish that goal?”

Don’t force your aspirations and goals on them.

Edited by BMAC615
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