Wing Loading vs Jump Numbers Guideline

[karlm 0]

I have read all the posts and replies to all the forums about wing loading etc.

All Students up to 100 jumps on Skymasters 285, 235 & 200's

After that no higher than the follwoing.

100 - 200 Jumps 1.1 Wing Loading (Square only)
200 - 300 Jumps 1.2 Wing Loading
300 - 400 Jumps 1.3 Wing Loading
400 - 500 Jumps 1.4 Wing Loading
500 and above your own choice.

Feel free to PM me if you want to.

Better never to have met you in my dream than to wake and reach for hands that are not there.

[vt1977 0]

I agree with the rest of your post, but I have to take issue with this part:

Quote

All Students up to 100 jumps on Skymasters 285, 235 & 200's

With somewhere between 50 and 60 jumps, I started jumping my first rig which contained a PD170 main which I was loading at a little over 0.8.

I had downsized from a student 220 (wing loading of approx 0.65). I felt safer under the 170 because I wasn’t always backing up in very moderate winds, it felt easier to fly and I was (comparatively!) more in control.
I see what you’re saying, but there have to be exceptions for lighter jumpers. Perhaps nothing smaller than a 170 (or even a 150 in very exceptional cases) up to 100 jumps.

Otherwise, there is a flaw in your system – my exit weight was approx 145lbs. Following your system to the letter up to 100 jumps I could only jump a Skymaster 200 but at jump 101 there would be nothing to stop me having a square 135. This is clearly not a good idea.

Vicki

[karlm 0]

You are correct on the lighter jumper vs wing loading issue, and it would have to be adjusted to make allowances for it. Under wing loading a canopy can be just a dangerous as loading a canopy.

I used the standard that an average jumper with gear would have an exit weight of around 176 to 187 pounds.

Thanks for your input.

Better never to have met you in my dream than to wake and reach for hands that are not there.

[nacmacfeegle 0]

What about currency considerations?
Would you do anything to manage AGL effects?
Finally planform and performance considerations.

I'm not knocking you for having a go at trying to address a serious issue, that in itself is admirable, its just that it could be a little more complex than wingloading alone.
Have you seen the Dutch way of looking at this?

--------------------

He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. Thomas Jefferson

[j3zz 0]

Although that would be a great table I think it is a bit to conservative to be feasible.

Lets face it most people buy thier first rig within 100 jumps and probably intend to use if for maybe a 200 jumps or more,

I was jumping a 170 loaded at 0.95 from about 50 jumps, and never had a problem even with some major canopy errors.

So yes if we all could change canopies irrespective of cost I think it is a good table but in reality people are going to looking at something with a bit more milage. Also the modem semi-eliptcal canopies are probably fine for a first canopy, eg, sabre2,pilot,hornet,spectre

I have seen the dutch system and it seams pretty good.

I think as mentioned before wing loading is not everything plan form has a lot to do with the choice.

Also I think that 500 in not enough to make your own choice entirely do you really want A 500 jump wonder jumping a 2.4 loaded cross-braced rocket ship. I think as a rough guide this table has some merit but as a whole I think it is a little limited.

Just my .02c

Jeremy

"Now I know why the birds fly"
Hinton Skydivers

[Stumpy 256]

Brian Germain has a similar guideline in his book - WNE (Wingload never exceed) table.
He also talks about the smaller canopy issue - i.e., you cannot directly scale canopies. ie. a 135 does not fly like 135/170ths of a 170 (Sorry if that doesn't make any sense, i know what i am trying to say but work is numbing my brain!) He also talks about altitude and a number of other factors.

WELL worth a read if you get the chance - chapters on psychology, canopy design, tchnique and a host of other stuff. I spent 4 hours on weather hold yesterday reading it and now i want to read it again because there was SO much info.

Never try to eat more than you can lift

[BIGUN 1,050]

For as long as I've been back in the sport, people have been saying "Educate, don't regulate." And yet, most every rule in our BSR's is a result of someone getting injured, killed, or because someone saw the potential for these two things happening. For example, the PLF. Been around 60+ years and still the best method for preventing injury.

You are to be commended for instituting a mechanism of pause on your DZ. It may not be perfect, but it's a baseline for people to at least ask for more information.

Perhaps prior to purchasing something based on bad information or the casual "you can handle it" or "It's going to be a little hot, be sure to come in wings level for the first few jumps," you will be given the opportunity to have an in-depth discussion with someone whcih may prevent injury or death.

Nobody has time to listen; because they're desperately chasing the need of being heard.

[WrongWay 0]

I agree with all of them except maybe the 0-100 jump category. Maybe it should be clarified as 1.0 or less?

As far as "Educate, don't Regulate"......I have one thing to say about it.....

Perhaps it should be "Educate.........educate.........educate........educate some more.......if they still haven't listened to a word, regulate".

Wrong Way
D #27371 Mal Manera Rodriguez Cajun Chicken Ø Hellfish #451
The wiser wolf prevails.

[karlm 0]

Thanks for the replies and some real valid points.

- Currency has no bearing on wing loading, we have seen worldwide that even current jumpers, kill or injure themselves on canopies, no matter of wing loading.

- Our DZ is 5000ft MSL, so it's a quick canopy DZ, we have an average temp of around 25 to 30 degrees celsius and that adds to be effects on the canopies.

- Under such a system a jumper would most likely not go to a 2.4 WL after 500 jumps, as the first 500 would have educated him. Also our DZ requires CI permission to downsize.

- Hornets, Sabres and Pilots are seen as square, even if they are marketed as semi elliptical. And these are great canopies for a student and can be flown with alot of fun.

- I agree that wing loading is not the only criteria when looking at this, but to the average student or 100 jumper wonder, thats the best way to explain it to him and keep him safe and educated.

- Our DZ has three sizes of student Skymasters, all first jumpers use the 285's, and the progress to 235 and 200 for throw out conversions. Some of our students tip in over 220lbs exit weight, so when they down size to the throw outs it's a 1.1 WL, but the canopy is designed to be docile and idiot proof.

Where can I get info on the dutch system? i would like to take a look at it.

Better never to have met you in my dream than to wake and reach for hands that are not there.

[dragon2 0]

Quote

- Currency has no bearing on wing loading, we have seen worldwide that even current jumpers, kill or injure themselves on canopies, no matter of wing loading.

The idea is, if you´re not current, you can´t downsize (with the Dutch system, you have to stay within your category).
Usually people will be allowed to jump their own canopies after a layoff, however smart or not smart that may be, we don´t regulate that.

***Where can I get info on the dutch system? i would like to take a look at it.

There are a bunch of threads about this, but this is the one that started it:
http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=404784;search_string=dutch%20canopy;#404784

ciel bleu,
Saskia

[billvon 2,384]

>- Currency has no bearing on wing loading, we have seen worldwide that
>even current jumpers, kill or injure themselves on canopies, no matter of
>wing loading.

Currency has a huge effect on safe wingloading. A jumper who can safely land a 2 to 1 loaded canopy may not be able to land it safely after a year layoff. He would be well advised to switch to a larger canopy until he is current again.

[Reginald 0]

PD has recomended wing loadings. they are much more consertative than yours. ;-)

Check out the recomendations for the Sabre 2 http://www.performancedesigns.com/sabre2.htm

And "A license' is generally considered a novce, "D" and expert.

"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

[pilotdave 0]

Quote

And "A license' is generally considered a novce, "D" and expert.

I wouldn't agree with that. It's about canopy control experience, not jump numbers or licenses. Someone with 1000 jumps only on accuracy canopies isn't an "expert" at canopy control... at least not for flying anything other than accuracy canopies.

And until recently 200 jumps would get a D license. I doubt anyone would consider someone with 200 jumps on "novice" canopies to be an expert.

Dave

[karlm 0]

Sorry I see my comment on currency was not well put.

I believe that if your uncurrent it is a big issue to safety while under canopy, and one should be current before being allowed to downsize or move from one type o fcanopy to the next.

I also believe that even current jumpers with low jump numbers should not be allowed to fast track to downsizing either.

Better never to have met you in my dream than to wake and reach for hands that are not there.

[Reginald 0]

Quote

Quote

And "A license' is generally considered a novce, "D" and expert.

I wouldn't agree with that. It's about canopy control experience, not jump numbers or licenses.

I don't think you got my point. I was simply saying that it is a generally accepted way to translate the PD recommendations to quantitative jump numbers and defined skills that are required for a particular license. I agree it is not a good way to do it but it is frequently used and it is easily measurable.

"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

[FrogNog 1]

I follow you. I'm now jumping a Sabre 2 and I noticed their labels have that table of exit weight for the canopy size and "skill level" of the jumper.

The tables I have seen on some PD canopies seem conservative when looking at the terms they use (e.g. "Expert"), but when compared to USPA A/B/C/D licenses, don't seem overly conservative. So I don't know what I think.

I don't think this question has any easy answer. Many previous posters have pointed out many holes.

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Pull.