Wingloading versus other canopy factors

[peek 21]

There are a number of people who think that it would be a good idea for a particular national skydiving organization to create maximum wingloading "rules" for its members based on one of several criteria, like jump numbers or canopy training classes attended.

A while back I read a few comments that indicated that some enlightened people understood that there is more to a canopy being dangerous or not than mere wingloading, i.e., suspended weight to canopy size.

Factors that affect the relative "danger" of a canopy may also include its basic type, e.g., medium performance, high performance, rectangular, elliptical, semi-elliptical, cross-braced, air-locked, etc., (plus nearly any combination of these designs), and also its airfoil design.

I am no longer seeing such consideration. Has everyone forgotten about this aspect of canopy performance?

Why are so many people thinking that a "rule" related to _wingloading alone_ will be all that helpful?

In my research related to trying to find out why my friend's cross-braced canopy collapsed on a non-turbulent day during conservative canopy manuvers, I have been reminded that the manufacturers (and the highly experienced jumpers) of cross-braced canopies consider wingloadings that are too light to be more dangerous than those within a certain range.

Therefore, wouldn't a "rule" related to what type of canopy one could jump at a certain experience level need to include quite a few more specifications than just wingloading?

Folks, I just don't believe a simple wingloading rule is going to get it.

[Hooknswoop 19]

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Therefore, wouldn't a "rule" related to what type of canopy one could jump at a certain experience level need to include quite a few more specifications than just wingloading?

To be a more accurate rule, yes. But it would make the rule to cumbersome.

Same thing as minumum pull altitudes. There is more to having enough time to land safely than pulling by 2k. The altitude it takes for a canopy to open makes a huge difference. If you pull at 2k and it takes 900 feet for you canopy to open, that puts you at 1,100 feet, well below the recommended minumum altitude to decide to cutaway. If your canopy takes 200 feet to openn, that would put you at 1,800 feet, at the recommended altitude to decide to cutaway. By your opinion that the WL BSR shouldd include other factors, such as canopy type, then the minimum pull altitudes should be adjust for each person based on the amount of altitude for their canopy to open. Maybe each jumper's reaction times should be tested and that included in the calculation for their minimum pull altitude?

This isn't done and the minimum pull altitudes seem to work very well. Same thing for the WL BSR, if too specific it becomes to cumbersome and in-effective.

Derek

[billvon 3,080]

>Factors that affect the relative "danger" of a canopy may also include its basic type . . .

Agreed. However, wing loading is still the primary consideration. At lower experience levels it's safer for a newer jumper to try to land a Stiletto 150 than a Sabre 1 97.

>Therefore, wouldn't a "rule" related to what type of canopy one could jump
>at a certain experience level need to include quite a few more
> specifications than just wingloading?

If the rule was intended to "make everyone safe" then yes. But you'd need far more than that; you'd need to take into account density altitude (i.e. a canopy that's safe on a 32F day may not be safe enough on a 105F day) canopy size (larger canopies are more forgiving even at the same wingloading) terrain (landing in a forest clearing is very different than landing at Eloy) and winds (steady winds vs Perris in summer.)

However, the proposals we've been talking about are not "rules to make everyone safe." They are intended to keep people on more conservative canopies until they get education, at which point they can jump whatever they want. That education will include the info THEY need to decide what sort of canopy they want to jump, what density altitude is OK, what canopy is suited for them and their DZ. Rules alone can't make people safe canopy pilots; it is the education they have to get to be able to "place out" of the rules that will save lives.

[VectorBoy 0]

Not to mention that you can't buy a velocity 190 or a sabre 1 87. So dealing with a WL perspective may have an effect on other canopy design variables.

[pilotdave 0]

One of the reasons I don't like the idea of new rules is that they may not take into account future technology and training. Wasn't there a time, not all that long ago, that a sabre was considered a high performance canopy not suitable for beginners? Or when only experts were allowed to jump square canopies... And I bet someday there'll be a time when we can remember that stilletos were once for experts only.

I don't like the idea of setting a jump number required to jump an elliptical canopy or a cross braced canopy or whatever. Someone might develop an elliptical cross braced student canopy some day. Course that makes no sense... now. But maybe someday we'll have canopies that fly fast but land slow.

I think to do what you're talking about, we'd need canopy categories. Every canopy out there would be put into a category. A velocity might be a category A canopy. A sabre2 might be category C. So a BSR would limit both wingloading and category, separately.

We obviously have a problem now with people getting hurt under good canopies. I think in the future, canopy training will be very different from how it is today. It'll be a lot more like learning to fly planes. Much more "ground school" and studying. No amount of ground school can prepare a student pilot to solo a pitts special, but no rule is required to prevent low time pilots from flying them either. Pilots know better, most of the time, and also need a couple logbook endorsements. I think thats the direction skydivers need to go.

Dave

[larsrulz 0]

I recall seeing a great "downsizing chart" on here; it was used by some European country. It had 4 categories for canopy size, WL, type of canopy (HP, MP, etc.), and jump numbers. It allowed all those considerations to be included for canopy selection, where each jumper was in a certain sectino of the chart, which indicated their max WL, minimize size, etc.

That aside, I disagree with BSRs for canopy regulation...yeah, yeah, I know I only have 100 jumps. I think more control should be in the S&TA's hands, so they can be the ones that sign off a jumper for using a certain canopy. No two jumpers are a like, so basing canopy selection on jumper numbers and wing loading alone isn't logical.

I got a strong urge to fly, but I got no where to fly to. -PF

[diablopilot 2]

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A while back I read a few comments that indicated that some enlightened people understood that there is more to a canopy being dangerous or not than mere wingloading, i.e., suspended weight to canopy size.

Factors that affect the relative "danger" of a canopy may also include its basic type, e.g., medium performance, high performance, rectangular, elliptical, semi-elliptical, cross-braced, air-locked, etc., (plus nearly any combination of these designs), and also its airfoil design.

I am no longer seeing such consideration. Has everyone forgotten about this aspect of canopy performance?

No, but a wingloading BSR is a staring point. And a starting point is better than nothing, which is what we have now.

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Why are so many people thinking that a "rule" related to _wingloading alone_ will be all that helpful?

Because it is a start. And a 2.0 wingloading on a Sabre 2 is just as unsafe in the wrong (read:novice) pilots hands as a 2.0 loading on a Velocity.

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Therefore, wouldn't a "rule" related to what type of canopy one could jump at a certain experience level need to include quite a few more specifications than just wingloading?

First problem. Clasification of canopies.

What's eliptical? What's Semi-Eliptical? What's Tapered? What's Square?

You can't even get manufacturers to agree on this. Plus for example a Velocity is "less eliptical" than a Stiletto. So does that mean someone who has a velocity at 1.5 shouldn't beable to fly a Stiletto at 1.5?

Unless the USPA wishes to start evaluating and rating each product on the market then I think the canopy classification route is a dead fish. Heck many jumpers still believe the Crossfire and Stiletto are similar canopies.

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Folks, I just don't believe a simple wingloading rule is going to get it.

No it's not. There will still be people who get killed with 1000's of skydives on canopies they are not qualified to be flying.

Again, it's a starting point.

The pack opening altitude BSR doesn't eliminate the possiblity of someone dying because of an intentional low pull, but according to the fatality statistics the number of deaths due to low pulls has decreased markedly since it's implementation.

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You're not as good as you think you are. Seriously.

[Remster 30]

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recall seeing a great "downsizing chart" on here; it was used by some European country

Prety sure it was sweden. (or then again, maybe the NL)... but some of the canopies were placed in wierd categories... as I remember, the Spectre was in a category that was not adequate for beginers....

Remster

[diablopilot 2]

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but some of the canopies were placed in wierd categories... as I remember, the Spectre was in a category that was not adequate for beginers....

Weird is relative as are perceptions.

For example many people think a Diablo is a shit hot ride unsutible for beginers right?

Now lay a Spectre on top of one and see what the differences are.

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You're not as good as you think you are. Seriously.

[Ron 10]

WL is not everything, but it is a start.

Planform is important, but size equals speed at which things happen.

A newbie is safer under a Sabre 1 150 than a Stiletto 150, or a Velocity (If it was made) 150.

However a newbie is not safe under a Sabre 1 97 or any other 97.

You could take planform into account, but then you have to get the USPA to agree on classes and what fits into each class.

A Specter is elliptical... A Velocity is less.

So how would you put what into what class? And then what about new canopies on the market? Who could jump them till they are Approved, and who would approve them?

The W/L thing is easy to understand. A newbie is safer under a 1.1 loaded Specter, Stiletto, Sabre, Jedei 170 than a 1.5 loaded Specter, Stiletto, Sabre, Velocity 120.

And you don't need to classify the TYPES of canopies..WL is WL.

The USPA has already show no interest in doing anything...And if they have to do MORE they will want to do anything even LESS.

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[kallend 2,113]

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The USPA has already show no interest in doing anything...And if they have to do MORE they will want to do anything even LESS.
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I thought USPA just wanted to make sure the solution was the correct one.

...

The only sure way to survive a canopy collision is not to have one.

[Ron 10]

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I thought USPA just wanted to make sure the solution was the correct one.

You mean like the BIC that is gone now?

Down dumming the AFFCC?

The ISP that no one has to follow?

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[AggieDave 6]

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I thought USPA just wanted to make sure the solution was the correct one.

The only "solution" I've seen the USPA work towards the short 4 years I've been in the sport is money.

If they were serious about helping jumpers and protecting the sport, then something as simple as the BSRs would be actively enforced.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[dragon2 2]

dutch canopy rules

I don't agree with all the rules (ie a Spectre is okay at 25 jumps, for a tRiathlon you need 100, but you can jump a Sabre 1 from jump 1) but it's something...

ciel bleu,
Saskia

[tspillers 0]

An idea along that line, although time consuming to get to, would be to have canopies defined by class.

For instance, Class 1 being accepted student canopies like Navigators
Class 2 maybe Sabre 2
on to
Class Whatever being eliptical cross braced.

Then the rule could be more relevant and you could go from one class another and have different wingloadings (max or min) in each class.

Todd

I am not totally useless, I can be used as a bad example.

[quade 4]

The problem is who decides what canopy goes into what class.

Since wingloading is indicative of so many factors and is the greatest single influence on speed, to me, it makes the most sense.

quade -
The World's Most Boring Skydiver

[tspillers 0]

I think it would be better than nothing to have a wing loading.

That is why I said time intensive. It would have to be done as an industry....Maybe PIA, or a consolidation of PIA, manufacturers, USPA, etc.

Just a thought....In the perfect world ya know...

Todd

I am not totally useless, I can be used as a bad example.

[SkydiveNFlorida 0]

Honestly, I think that this goes a little bit too far. I've not flown a xbraced canopy, so I don't know how they perform and they may indeed be quite a difference... but, ime, ellipticals are not the death traps they are made out to be for low-timers who take the initiative to get canopy training (at low wingloading). Once you get used to the controls, it becomes second nature. You know where your flare is, how much toggle it takes to turn, etc. I got a Stiletto loaded very lightly (<1:1) at 44 jumps and I really enjoyed that canopy for quite some time while still maintaining a low w/l.

I'm not pro-w/l restrictions myself, but I can understand why some feel the need to enforce some rules when I see posts like the one incident with the 2.0+w/l velocity at 300 jumps. But, most people will stay within a reasonable margin I would think. Some pilots want to stay conservative, they don't desire performance enough to put themselves at risk of breaking bones/hurting themselves. Others understand the risks, and they find that the benefits of higher performance outweigh the assumed risk. But, I think that most people govern themselves fairly well. I love speed, but i'm not going to go out and buy an 80~sf x-braced canopy. I don't prefer to put myself at that level of risk. However, i'm willing to accept some risk in order to have fun, and so I don't fly a Spectre 170, either. I really think most people can and do govern themselves within their perceived skill level pretty well, and that most dz's will stop people with 300 jumps from loading a Velocity at 2.0+.

Yes, there are incidents... and there always will be, that's the nature of an extreme sport.

Angela.

[billvon 3,080]

>But, most people will stay within a reasonable margin I would think.

For the most part I agree. There are more and more people, though, who don't even comprehend the risk they are taking. After all, someone with 300 jumps can jump a VX90; if another new jumper is jumping a more conservative Xaos 104, why should they listen to a busybody who tells them they're being unsafe? Clearly they are being more safe than the first guy.

Things like minimum pull altitudes, rules on night jumps, demos etc are not to stop the 90% of jumpers out there with good judgement. It is to stop the people who do not yet understand the risks inherent in those things, to keep them alive until they learn that pulling at 700 feet is dangerous or that a demo needs special training. That's what any wing loading restriction is; just a way to keep people alive until they get the training they need to make intelligent choices.

[ianmdrennan 2]

Angela,

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ellipticals are not the death traps they are made out to be

In the right hands, no they aren't I agree.

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You know where your flare is, how much toggle it takes to turn, etc. I got a Stiletto loaded very lightly (<1:1) at 44 jumps and I really enjoyed that canopy for quite some time while still maintaining a low w/l.

Inexperience under these wings causes the "weaving landings" and other deployment issues. You say you were on a stiletto at around 44 jumps - didn't you also have to chop it because of linetwists or end up close to cutting it (can't remember the details)?

Landings aren't where the only problems come in on those types of canopies. There is really no reason whatsoever to be on that type of wing, the jumper will not be able to get the performance out of it with that little experience so there are better canopies that dont have the associated problems that are better to learn on.

It's not so much that it's impossible for a newer jumper to land them safely, it's more that the newer jumper isn't properly equipped (yet) to deal with everthing that comes along with them.

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I really think most people can and do govern themselves within their perceived skill level pretty well, and that most dz's will stop people with 300 jumps from loading a Velocity at 2.0+.

I thought so too but I've seen at LEAST one other case where a jumper with 400 jumps was on a vx93 loaded @ 2.2. There is a trend developing, there has been for many years, it's just getting more and more ridiculous now. I believe it's time to step in, by and large, people are showing that they are incapable of regulating themselves in a reasonable manner.

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Yes, there are incidents... and there always will be, that's the nature of an extreme sport.

Absolutely. But I hate seeing my friends die unnecessarily so until they have the maturity in the sport to make sensible decisions and to truely understand what they are getting into (a surprising amount don't because "it won't happen to them, they're heads-ip"), I support the regulation movement to do it for them.

Blues,
Ian

Performance Designs Factory Team

[Ron 10]

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I got a Stiletto loaded very lightly (<1:1) at 44 jumps and I really enjoyed that canopy for quite some time while still maintaining a low w/l.

And had line twists that didn't clear till 900 feet and ended up not being able to set up for a good landing and ended up landing near a plane that prompted you to get kicked off a DZ?

That easy to fly elliptical?

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[SkydiveNFlorida 0]

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I got a Stiletto loaded very lightly (<1:1) at 44 jumps and I really enjoyed that canopy for quite some time while still maintaining a low w/l.

And had line twists that didn't clear till 900 feet and ended up not being able to set up for a good landing and ended up landing near a plane that prompted you to get kicked off a DZ?

That easy to fly elliptical?

Calm down, Genius. I had line twists at 20~ jumps on a Sabre II 150.

I was kicked off a completely different dz than that one due to the fact that they didn't want me jumping an elliptical at 44 jumps.

I'm not really sure why I bother replying to you. You don't take anything that I have to say into account, you just try to slam people who don't follow Ron's rules.

Later.
Angela.

[SkydiveNFlorida 0]

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Inexperience under these wings causes the "weaving landings" and other deployment issues.

That's true. You need to be able to flare evenly to fly an elliptical. And, certainly need to pay more attention at pull time as well. But, these are not things that are impossible for anyone with less than 300 jumps, either.

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Yes, there are incidents... and there always will be, that's the nature of an extreme sport.

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Absolutely. But I hate seeing my friends die unnecessarily so until they have the maturity in the sport to make sensible decisions and to truely understand what they are getting into (a surprising amount don't because "it won't happen to them, they're heads-ip"), I support the regulation movement to do it for them.

Well, not everyone needs governing, although it is indeed evident that there are a small portion who do. But, to cut off the nose and spite the face may not be the way to go about this. Stiff regulations will suck for everyone, not just the few that might kill themselves under a challenging wing they are not ready for, (who might do so under a wing that falls within the guidelines anyhow).

Angela.

[SkydiveNFlorida 0]

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For the most part I agree. There are more and more people, though, who don't even comprehend the risk they are taking. After all, someone with 300 jumps can jump a VX90; if another new jumper is jumping a more conservative Xaos 104, why should they listen to a busybody who tells them they're being unsafe? Clearly they are being more safe than the first guy.

Stupidity does kill. And, certainly the longer time you spend in the sport, the more you understand risk. Of course, for some it takes longer than others, but it just sucks that because a couple of guys want to load a canopy they are not ready for extremely high, those that can competently set our their limits (which may not fall within the restrictions, but they are not completely radical) have to pay with tight restrictions.

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Things like minimum pull altitudes, rules on night jumps, demos etc are not to stop the 90% of jumpers out there with good judgement. It is to stop the people who do not yet understand the risks inherent in those things, to keep them alive until they learn that pulling at 700 feet is dangerous or that a demo needs special training. That's what any wing loading restriction is; just a way to keep people alive until they get the training they need to make intelligent choices.

I guess I just never really liked rules I trust my own judgement.

Angela.

[billvon 3,080]

>Of course, for some it takes longer than others, but it just sucks that
>because a couple of guys want to load a canopy they are not ready
> for extremely high, those that can competently set our their limits
> (which may not fall within the restrictions, but they are not
> completely radical) have to pay with tight restrictions.

Not with our plan. You can "test out" of any restrictions by demonstrating proficiency in front of a canopy coach or instructor. And if it turns out that they are jumping a canopy that they can't land well? They may not have chosen their own limits so well after all.

>I guess I just never really liked rules I trust my own judgement.

One of the purposes of rules is to keep people alive until they develop that good judgement.