Wet Reserves

[kkeenan 13]

Some speculation on the recent accident in CO centers on reserves getting wet in swoop meets and experiencing deployment/opening problems.
http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2345435;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread
The accident mentioned above was tragic, and my heart goes out to our friends at Skydive Dallas for their loss. The accident will have to be investigated fully and reach its own conclusions, so that we all may learn from this tragedy. The "Wet Reserve" theory may well have no connection with the cause of the accident. That being said, what are thoughts from the rigging community about this ?

1. Can wet lines get into tension knots easier than dry ones ?

2. What other problems can a wet reserve get into ?

3. How wet can a reserve get before a repack is required ?

4. Is it routine is it for swoopers to jump "totally wet" reserves on quick turnarounds in a competition ?

As our sport evolves, people are doing different things with gear than the people before them did. Sometimes gradual changes cause results that no one anticipated. People expect reserves to work all the time, and sometimes don't connect the long-term treatment of a packed reserve with the performance of that reserve in that moment when they need it.

Kevin Keenan

_____________________________________
Dude, you are so awesome...
Can I be on your ash jump ?

[BIGUN 1,049]

Even without any association with the recent incident, these are excellent questions that I hope some will address.

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

[Kimblair13 0]

I'm pretty sure a PD reserve that has gotten wet should be sent back to the manufacturer. That shows PD thinks something bad comes from getting wet.

*I don't know if the previous incident involved a PD reserve...just stating something I was told.

[AggieDave 6]

After the last swoop comp I had my reserve opened and repacked, since I had gotten wet at the end of two runs. What we learned is that even though I got pretty darned wet, the reserve hadn't gotten wet. The container was wet, the freebag had gotten damp from water creep (possibly), but the reserve was dry as a bone.

This really surprised me, seeing how I had gotten VERY wet.

I don't know if it has to do with the design of the reserve container, the material (parapack vs. cordura) and treatment of the material (i.e. heavy coats of scotchguard). Do you think that those factors would factor in, don't factor or perhaps they factor in but so slightly that it doesn't truely matter.

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

[mark 102]

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I'm pretty sure a PD reserve that has gotten wet should be sent back to the manufacturer.

From the PD Reserve Owner's Manual: "Fabric permeability must be tested if any of the following events occur:
"The canopy is completely submerged in water."

The manual continues with the 40 packs/25 jumps requirement that most folks are familiar with, plus some other conditions.

The reserve doesn't have to be returned to PD, though they recommend it. Another facility with a permeability tester could do the test if they were able to check for average permeability of 8.0 cfm or less.

Mark

[Kimblair13 0]

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"The canopy is completely submerged in water."

Does that mean the reserve itself being completely submerged in water or a swooper chowing and going completely in?

[riddler 0]

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1. Can wet lines get into tension knots easier than dry ones ?

I'd also like to know about how moisture affects Spectra vs. Dacron lines. No mention of what type of reserve lines yet, but probably Spectra or Micro?

Trapped on the surface of a sphere. XKCD

[psychoswooper 2]

1. Can wet lines get into tension knots easier than dry ones ?

2. What other problems can a wet reserve get into ?

3. How wet can a reserve get before a repack is required ?

4. Is it routine is it for swoopers to jump "totally wet" reserves on quick turnarounds in a competition ?


1st off, my condolences to all involved, this is sad.
Now, some thoughts that I have had:

Asymmetrical openings can cause all kinds of problems, including tension knots. Water is heavy & can be absorbed unevenly throughout the canopy causing a variation in permeability with some lines or parts of a wet canopy opening at different rates.(Think: heavier lines or fabric on 1 side vs the other for example)
IMHO a wet reserve pack job should be void until opened and inspected,. I would be interested in knowing what the manufacturers have to say about the airworthiness of their reserves when wet and whether or not it is permissible for them to be used as reserve parachutes in such a condition.

[mark 102]

From Poynter's:

"Wet nylon has less strength, but is fully regained once the nylon dries. The percent of strength reduction is as follows:
" Canopy fabric: about 22%.
" Webbing: about 15"
" Line: about 21%
...
"The water will also reduce the permeability of the fabric and cause a harder opening. This coupled with a reduction in the strength of the nylon could lead to canopy damage."

Mark

[base935 0]

Can we PLEASE take care of this within our community, and not involve the FAA to decide? Otherwise, the next rainstorm you belly fly through will require the reserve to be tested and repacked.

Gravity Research Institute

[krkeenan 0]

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Can we PLEASE take care of this within our community, and not involve the FAA to decide?

So far, you are the only one to bring up those three letters.

I don't see any reason why this can not be looked at within the jumper / gear industry community, and some answers be found. If it turns out that current practices are shown to be unsafe, then changes will be made, as they have in the past. There should be no need for regulatory intervention over an issue like this.

Kevin

======================
Seasons don't fear the Reaper,
nor do the Wind, the Sun, or the Rain...

[AggieDave 6]

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So far, you are the only one to bring up those three letters.

Nope, the media reports have shown that the FAA stated they are joining the investigation due to the reserve malfunction.

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

[MB38 0]

Consider how different untying one's shoes is when the laces are wet. The extra friction makes it trickier, but the fact that laces absorb water changes the act as well. When laces are untied, the water is effectively squeezed out of them as though they were peculiar-shaped sponges.

Obviously lines aren't shoelaces. But to me, it seems logical that wet lines [particularly fatter dacron lines] would want to stick together more through deployment.

Unfortunately, I don't have any dacron lying around to test my out-of-left-field theory with, so this post is effectively worthless. My packing tool has some microline that I could fiddle with, but that's not really relevant.

This is just pure speculation/food for thought with regards to the "wet reserves" question and not the incident. The incident is terrible news and I want to pass on my best to all involved.

I really don't know what I'm talking about.

[mark 102]

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it seems logical that wet lines [particularly fatter dacron lines] would want to stick together more through deployment.

If you tried hard, you might be able to convince me it would be harder to pull a wet toggle tongue from a wet brake-set loop or eye. I don't see how slightly fatter lines -- could they be any fatter than the lines going through a tandem rear grommet? -- would be an issue, nor do I see how water would activate some adhesive that wouldn't have been activated with just high humidity.

I'd like to hear from someone who knows what change in elasticity and elongation one might expect when nylon gets wet, but given how the lines are stowed, I'd be surprised if the effect was greater than one might get from an unstable deployment.

Mark

[BillPaine 0]

Call me old fashioned, but in a sport where the only thing standing between me and the grave is that rig on my back, I treat my equipment like a deity. I don't tolerate ANYTHING that may compromise its integrity. If there is ANY possibility that moisture can interfere with the process of getting a fully-inflated canopy over your head then don't jump it. Dry it out, re-pack it and live to jump another day. Is winning a swooping competition THAT important?

"We have met the enemy...and he is us." Pogo

www.mondo-fiasco.com

[waltappel 1]

The BASE community has a considerable amount of experience jumping gear with varying degrees of wetness. Personally, I have made at least a dozen BASE jumps into water in situations where we would dry out the canopies for a while, repack them, and jump some more. I've done it with rounds and squares and never experienced a problem, but that's just my experience.

Walt

[skybytch 259]

Reserve lines are stowed in a pouch on the freebag. It'd be interesting to find out how being wet affects how the lines feed out of the pouch. Would be more interesting to find out if what the freebag is made out of (different manufacturers use different materials) makes any difference too.

[sundevil777 93]

I would think that the most important consideration would be the friction of the lines and slider grommets - how that is affected by wet lines.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[peckerhead 0]

I would think it would be common sense to not jump wet gear.

Every time I made intentional water landings we opened up the reserve container and dried the canopy before it was repacked in a clean, dry container.

I know, I know, us old-timers don't get it.


We still think water is a hazard.

[caldwellbuilder 0]

I remember a friend , over 20 years ago, who made
a demo jump into a swimming pool. He repacked
the main while it was still wet and then made a
fun jump. His main malfunctioned, but his reserve
did not, however, everyone who witnessed what
happened was convinced that wet nylon does not
perform like dry nylon. Everyone also agreed that
they would not jump a reserve that had been
dunked.
Why risk it?

[kkeenan 13]

It would be incorrect to say that it is common for swoopers to jump wet gear. However, at swoop contests with ponds, people get wet, and wet gear is jumped on occasion. I've been around a few events, and I know this is done. I've never examined any equipment to see how wet it is. All I can say is that there is sometimes varying degrees of wetness, and it never seemed to be an issue to the swoopers as far as I could tell.

Kevin

_____________________________________
Dude, you are so awesome...
Can I be on your ash jump ?

[pchapman 261]

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The BASE community has a considerable amount of experience jumping gear with varying degrees of wetness.
Walt

When I recently searched the BASE forum I couldn't find anything on wet canopies, which surprised me given the detailed analysis that people try to do in BASE. But my search wasn't exhaustive, nor have I checked blincmagazine.

Bridge Day is one event where soaked canopies are commonly jumped without drying.

Perhaps a post in the BASE forum mentioning this thread might obtain some useful response?

[waltappel 1]

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Perhaps a post in the BASE forum mentioning this thread might obtain some useful response?

Done.

Walt

[freakydiver 0]

Thats a pretty far leap imho.

-- (N.DG) "If all else fails – at least try and look under control." --

[Bryguy1224 11]

When it comes to F-111 material the only problem i have heard of or seen is extra wear and tear due to wetness. Bridge day is a great example of why wet canopy's won't kill you. There are 100 or more soaked canopy's being jumped every year without incident. The only bad thing is the expansion of the stitching when it gets wet and the shrinkage when it dries. This can start to make you canopy asymmetric. After 50 or so water jumps in might be a problem. Just don't hand your canopy out to dry in the sun and that problem can be minimalized. But on the skydiving side of things I would worry about mold growing inside the reserve why it was left packed and wet sitting in your closet at home. That could cause a serious problem. Then I would definetly pull it out to dry and repack. If my base rig ever got soaked while it was packed I would unpack it and let it dry out. If I made a water landing at bridge day I would pack it right up and jump again, but at the end of the day I would let it hang and dry out of the sun.

Bryan

Bryan