USPA downsizing guidelines proposal

[packing_jarrett 0]

I wouldn't vote for it. the chart says I need to be at a 170 when I've already jumped a 120!!!

Na' Cho' Cheese

[bob.dino 1]

The fact that you've jumped a 120 and survived doesn't make it a good idea...

[kelel01 1]

Anybody have the document in a PDF format?

And anyone want to buy a Mac?

[Superman32 0]

This chart seems much more reasonable, i.e. have real life effect than previous charts that were way too conservative.

There are however alot of "MUST"s. Is this chart intended to serve as merely a guideline or a rule that "must" be followed?

Inveniam Viam aut Faciam
I'm back biatches!

[Eule 0]

Here you go. If anyone has both Word and Acrobat, they can check to
make sure I am honest. :)

Eule

PLF does not stand for Please Land on Face.

[bob.dino 1]

Download OpenOffice. It's free, works on Macs, and opens Word docs just fine.

Or buy Office for Mac. Cheapskate .

[faulknerwn 38]

I completely agree with you about the small women. I understand the small canopy thing too - its ok for someone with an exit weight of 200 lbs but not for someone with an exit weight of 135? That's goofy - small people are completely hosed here..

Just because you go smaller doesn't mean you have to go radical. I absolutely adore my Triathalon 99 - in fact I just bought a second one cuz my old one is getting so worn out. Given the choice I'd rather jump my Tri 99 than _any_ elliptical 120. The Spectres and Triathalons certainly feel safer at a smaller size than the larger ellipticals - but there's not even any options on your chart for a smaller person to jump a smaller "safer" canopy.

Just because its smaller does not mean its unsafe - it can actually be more docile than the larger canopies.

[Eule 0]

All,

I haven't seen any previous discussions on this, so I might repeat
points that have been raised in other forums. Also, I have low
jump numbers. But here goes. Some of these are user-acceptance
kinds of things - how do you convince people to accept what the
chart says - and some are more technical.

- The weights are "weird" - i.e., not round numbers. It's easy to
check that this started out in kilograms - 50 to 120 kg in 5 kg
(11 pound) steps. It might be better to have 10-pound steps,
although this would add one column to the table and it would
end at 260 pounds. This may not be good, in light of my next
comment.

- IMO, the table has too many numbers in it. People are going to
look at it and their eyes are going to glaze over. The main thing
affecting this is the 20-jump step for the rows - I think this may
be too small. A 200-jump step is too much and a 100-jump step
is probably too much. I think something like 40 or 50 should be
better. The way it is now, a particular weight person stays on the
same canopy size for 80-120 jumps, so I don't think it's a big
deal to have them on a bigger canopy for another 10 jumps or so.
It might also be desireable to have two separate tables for midrange
and minimum, instead of one big one.

- The chart should probably start at 30 or 40 jumps, and there
should be some supporting text that it's not for students.

- The fact that this chart isn't for reserves should be right up at
the top, like "USPA Main Canopy Downsizing Chart." This info
is in there now, but it's down at the bottom.

- The 'average' weight of a rig was pretty obviously 10 kg, but that
probably doesn't matter much.

- It may help to mention that the chart is for MSL and that the
"every 2500 feet" refers to MSL. Stranger things have happened...

- Do any other national associations have a chart like this, or is
Sweden the only one? Or is Sweden considered the 'best' of the
alternatives?

- The "midrange" numbers have been made to fit some popular
canopy sizes: 135-150-170-190-210-230-260. But the "minimum"
numbers haven't. Saying that "since you have 20 more jumps,
you can now jump a main that's 5 square feet smaller" is a little
silly.

- Probably a typo: somebody that weighs 220 pounds and has 100
jumps gets to downsize from a 230 to a 220 to a 210 as he goes
to 140 jumps. Nobody else gets to use a 220. "220, 221, whatever
it takes."

- If you calculate the wingloading using the weights and the midrange
canopy sizes, the results are "notchy". The WLs always go up as you
go down the columns, but sometimes go up, down, up again as you
go to the right in the rows. This is probably caused by the limited
number of standard parachute sizes. The goal is to be safer, not
to have a "pretty" chart, but I thought it was interesting. Maybe
somebody will use this as a knock against this chart.

- If you calculate the wingloading using the weights and the minimum
canopy sizes, the results look a lot smoother. On the other hand,
the minimum sizes aren't made to fit "standard" canopy sizes.

I have made an Excel spreadsheet (attached) which tries to back up
some of the above comments. The midrange WLs are shown on a
colored table and on a 3D surface chart to help show the notchiness.
The minimum WLs are also shown on a colored table. These colors
were done by hand, so they won't update if you change the numbers.

On the last tab "Attempting a 'smoother' chart", I have it set up so
I can play around with the WL values. Basically you enter the four
'corner' WL values, shown in bold, and the WL values for the rest
of the chart get linearly interpolated (table 2). These WLs are then
used with the weights to get a "raw" canopy size (table 3) and
fitted to the 135-150-170-190-210-230 sizes (table 4). Finally,
the actual WL obtained is computed (table 5). Tables 4 and 5 have
automatic colors that will change as the numbers change. Excel limits
you to 3 colors, though. The cut-offs for table 4 are set at 210 and
169, while the cut-offs for table 5 are adjustable.

As an example of the last tab, I set it up so that at 20 jumps, 110-
pound people start at 0.70 and 265-pound people start at 0.90. This
goes up to 1.20 and 1.40 respectively by 500 jumps. The results are
that this starts the skinny person off on a 150 and takes them to a
135 by the 120th jump, and a big person starts off on a 230 and goes
to a 210 at 320 jumps and a 190 at 440 jumps. The WL chart is
still "notchy", but maybe not quite as bad as the original data. Maybe
something other than a linear interpolation would help.

Again, the goal is safety, not a "pretty" chart. But I feel that if the
chart doesn't quickly make sense to people, they will tend to disregard
its recommendations, IMHO.

As to whether these should be "recommended", "strongly
recommended", or "required" - that's a political debate that I don't
much care to comment on.

Before someone asks: Yes, I have absolutely no life whatsoever. :)

Eule

PLF does not stand for Please Land on Face.

[peckerhead 0]

Does this assume all canopies are ZP?

[phoenixlpr 0]

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Do any other national associations have a chart like this, or is
Sweden the only one? Or is Sweden considered the 'best' of the
alternatives?

Here is the Hungarian regulation. All weight is exit weight.
Authoried canopy sized is documented in the jumper's logbook by his/her mentor.

Canopy Nazis of the world unite!

[speedy 0]

I still say education and training will save far more lives than regulation in this case.

It is not known that any of the low/hook turn, landing fatalities in the last years would have been prevented by such regulation. It is just assumed that they would.

Even with regulation you're still going to get people jumping stuff way out of their experience level. Skydivers do not always follow the rules.

Regulation just shifts the responsibilityfrom people looking after themselves and listening to the DZ operators. We are adults and you would think that staying alive is high on our priorities. Why do we need rules for the vast majority to save a minute minority, that should have more sense?

Dave

Fallschirmsport Marl

[TaylorC 0]

If this goes through what would happen to people from outside of the US who have a smaller canopy than what is mandated by the chart and want to jump in the US?

[RossDagley 0]

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If this goes through what would happen to people from outside of the US who have a smaller canopy than what is mandated by the chart and want to jump in the US?

Yah bingo. I'm jumping a 190 atm, which according to that chart, I'm not allowed to jump... On the other hand, it wouldn't stop me hooking in a 230 if someone loaned me one...

Are these 'guidelines' or is there a plan to enforce these somehow? and how would this affect 'tourists' visiting the US?

[phoenixlpr 0]

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If this goes through what would happen to people from outside of the US who have a smaller canopy than what is mandated by the chart and want to jump in the US?

I'm not an USPA member, why should be this requirement be applied on me?

[mr2mk1g 10]

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If this goes through what would happen to people from outside of the US who have a smaller canopy than what is mandated by the chart and want to jump in the US?

I'm not an USPA member, why should be this requirement be applied on me?

I've highlighted the important part for you. If you go to the states to a USPA DZ you HAVE to join the USPA if you want to jump. Then the requirement might have to be applied to you.

If you don't want to jump in the states at a USPA DZ then it wont apply to you... but then if you don't want to travel to the states there wasn't really a lot of point in replying to his question about travelling there.

[RossDagley 0]

Edited to remove my post - Matt cleared it up just above :)

[Spatula 0]

Here's a question...

Lets say that this proposal is approved and put into effect. What will happen to those jumpers who for example should be jumping a 210 and are jumping a 190? Would they be banned from jumping that canopy? Just curious how this would be enforced and what would happen in a situation like this?

Thanks!

[Nutz 0]

I haven't read what everyone is saying but this is my $.02. I weigh 250 out the door and started jumping a 190 at jump 30. (That is 1.3) Before that I jumped a 280, 260, 230 and a 205. I did this under the advisement of the AFFI/DZO/S&TA. I jumped that same size canopy until I quit jumping last year. (About 300 jumps) All without incident. I think it is safe to say that I think that you cannot apply all people to some chart. You have to judge on a case by case basis. If I had been forced to stay at a 230 until 500 jumps then I never would have continued jumping. This is a bad idea and not the solution to the problem.

[rasmack 0]

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I've highlighted the important part for you. If you go to the states to a USPA DZ you HAVE to join the USPA if you want to jump...

No. IIRC a GM just has to require USPA membership for US jumpers. Quite an important difference.

HF #682, Team Dirty Sanchez #227
“I simply hate, detest, loathe, despise, and abhor redundancy.”
- Not quite Oscar Wilde...

[mr2mk1g 10]

edit - I misread your post. I've not been to a USPA GM DZ that did not require USPA membership despite the fact that I'm not a US national. I confess though I don't know the actual letter of the law... but that certainly is the practical reality of the situation.

[Nutz 0]

The fact that I am under a 230 is not going to stop me from hooking it into the ground.

Education will.

[weekendwonder 0]

Hmmmmm....

I think the chart is resonable as a recommendation/information resource, but a hard and fast regulation?

Based on what I've seen, most canopy accidents aren't directly related to size, but to the pilot's skill and ultimately, judgement. Certainly, size does impact the degree of skill required, but wing loading (which basically, this boils down to) should be the choice of the individual jumper. You would hope that anyone looking to downsize would gather info such as this, talk to other SKILLED jumpers at their DZ, and demo different canopies before making the move. I know I did.

Me? About 220 out the door, and jumping a Diablo 150. Plenty fast for me, but would hate to be REQUIRED to stay there is I chose to go smaller in the future.

Eagles may soar, but weasels don't get sucked into jet engines.

[Remster 30]

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I've not been to a USPA GM DZ that did not require USPA membership despite the fact that I'm not a US national.

Eloy accepts both CSPA and BPA memberships. The Ranch and Perris accepts CSPA memberships (and maybe others, but never had to check into it).

Remster

[BrianSGermain 1]

The trouble with smaller jumpers with smaller canopies is, little canopies fly more radically, even with a fairly light wing-loading. A Lotus 120 with a 1.0 lb/sf wing-loading turns faster than a Lotus 190 with a 1.0 wing-loading. The smaller canopy also has a diminished glide ratio.

So we cannot compare apples to apples, in other words. If we are to achieve the same kind of performance, the lighter jumper needs to be on a larger parachute. It may be possible to change the small canopies to have longer lines and a taller airfoil, but this has not been done yet. Nevertheless, the smaller wing will still be more radical due to its size.

This is why it appears that smaller jumpers are losing out on this chart. The truth is, they are getting their hands on a more radical parachute earlier.
+

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[174fps 1]

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I've not been to a USPA GM DZ that did not require USPA membership despite the fact that I'm not a US national.

Eloy accepts both CSPA and BPA memberships. The Ranch and Perris accepts CSPA memberships (and maybe others, but never had to check into it).

Betsy just posted a list of nationalities that require USPA membership
to jump at Eloy (in the Holiday Boogie thread), BPA third party insurance does not cover the US so USPA membership is required for Brits.
USPA temporary membership is $15 for a month.