Basejumper.com - archive

Heard about this but the video has just come online, props to the jumper for putting it in the trees and coming away unhurt. Seems it was a problem with the slider grommet cutting the lines!

https://www.youtube.com/watch?v=7LLmUGV7MOA

Yikes. I recently replaced a slider grommet because of a small nick in it.

Does anyone know what strength/type lineset he was jumping? 400/600lb Dacron? Spectra?

Edited to add: With minimal internetting, the youtube video says it was a Mayhem 280, and the Bad Seed website says Mayhems are built with 600lb Dacron (Black/Red as an option).

Factory slider?

The jumper posted the video on FB and has been commenting on it. From what he has said so far.

Canopy had small mesh slider with direct control.

Lines broke before the "splices"

new line set with 33 SD and 2 SU

Slider was new from bad seed and put on correctly

Slider only had 2 jumps on it

This is all just the info that I have retrieved from the facebook page that was posted by the jumper.

Do we know which lines broke, exactly?

And does "before the splices" mean above (closer to the canopy) or below (closer to the jumper) the cascade?

I dont know as of yet. I sent the jumper a link to this incident report so he can get in and fill in all the blanks. Looks like the front 2 lines from the video and he said before the "splices" so im guessing before the cascades closer to the jumper. Tom I PM'd you a link to the FB page if you would like to contact him directly

Any relation with this?

http://www.basejumper.com/...rum.cgi?post=2974199

I'm gonna bet it is below the cascade at the end of the finger trapped line.

He said one of the grommets was a "bad crimp". Poorly made slider cutting lines perhaps?

hello,

looking again on the video, do you think that the opening position helped to this part?

i see he was still quite steep while opening and this would put a lot of stress on the lines / canopy. i haven't broken anything on my canopy, but i had a few hard openings due to steep position / packing and i know it can add more stress to the equipment.

have a nice day,
a

The slider grommets do not ride against those lines, only the outside lines.
Take care,
space

In theory, yes. But I feel like a parachute opening is WAY too chaotic to say that the inside lines are *never* touched by the grommet.

I believe I have seen mayhem's with 2 bar tacks on top of each other at the cascade junctions, I wonder if that has anything to do with this. I'm trying to think of things that he does differently than every other manufacturer and I can't think of anything other than that, and I doubt that would substantially weaken the lines. It was a pretty brutally hard opening, with a heavier jumper, and I wouldn't necessarily be surprised if that happened on a blackjack/flik/fox/troll/osp etc.

More info will come I'm sure.

I didnt say that. I said The mechanics do not add up to the 2 lines being cut by anything considering the points of line separation and the lines which separated.
Take care,
space

I think your centre A's are going to have more contact with the slider than you would expect.

Not more than I expect. I know they get a spanswise load after the outerlines do assuming the slider is correctly dimensioned.By that I mean not narrower than the centercell.

But that is beside the point in this case. Those were not the lines that separated. That would have to be one heck of an intellgent and precise slider grommet to pick 2 inner lines out of a group of 5 dontcha think?
Take care,
space

hello,
the canopy are ship to bad seed,I await their comments.
the lines are broken just below the splices :

Y
X <===

and sorry for my bad english

thank's
tim.

To the thread.
For those who think that it was the slider.
Is it a coincidence that the lines separated at the weakest point? Think about. Not one but 2 lines.
Take care,
space

yes, probably
the slider is perhaps not the main cause

That was my thought too. If both lines are broken at their weakest point i'd assume they were damaged by shock rather than being sliced by the slider.

a point which may cast doubt,
In slow motion, the lines broken When the slider arrives at the heights of breakage...

One question for those with more experience/knowledge than me.

Seeing as the spanking occurred before the slider descended, would a line dump be the most probable cause of the hard opening?

Packing with the nose fully open and exposed? But in that case wouldn't the slider have raced down the lines and get more of a 'canopy just exploded' type spanking when insta-pressurizing? Something more simple like a head-low deployment? Gremlins?

Have you got a photo of the slider grommet? Is the 'defect' on the inside of it?

Some very knowledgeable people asked you on FB for some of these, they would be the best bet to help you get to know why it happened, and hopefully they'll be around here soon.

no i don't have picture,I ship the slider with canopy.
three eyelet have a ridge in friction with lines

Don't be silly. The grommet could be damaged and could still be causing excessive wear in that line group without the other lines breaking too.
PS. Not saying that is what happened.

No. It's a well known fact that finger trapping lines creates a wear point at which a line will commonly break.

Pictures would be nice but ridges on poorly set grommets are not uncommon. If that was the case then that could easily cause excessive wear.

Edit to add: Just read that it only had 2 slider up jumps so it obviously couldn't be from excessive slider wear.

I've "inspected" the canopy after the jump, i write some things i've noticed but i leave the answer to more experienced people.


Yes, it is before the cascade closer to the jumper.

The cascade part (so the part of the line closer to the canopy from the brake point) show signs of burning.

Only the broken line shown these burns, the other lines of the canopy (even the same lines on the left part) were totally fine.

The slider was showing an explicit sharp edge on the inner side of the grommet on the same part of the broken lines.

To me and other jumpers on the place seemed a problem caused by the slider but nobody of us is so experienced to be sure.

In skydiving I have seen tension knots cause extremely hard openings, broken lines, and burns to the broken line as you described. Did you notice any where else along the line that was burned? Like the line may have been looped back on itself in a knot.

I had a skydiving canopy that occasionally opened VERY hard and broke the A and B lines below the cascades twice. The canopy still flew OK, but I cut them away anyway because I was worried about the thing wrapping up on landing if there were any turbulence.

It was always the center lines, and always below the cascades. For some reason the thing would just go Bang and damn near rip my head off.

It is amazing how a canopy can fly when damaged, though. I used to be a cameraman for a 4 way team and used a worn out old main the opened slowly. Cameras were heavy then, and a hard opening really hurt.

You know how an old pair of jeans will get so worn out that you can finally basically poke a finger through it? This canopy was like that. One time I was packing and noticed torn cloth. I opened it up and the bottom skin was ripped from nose to tail. You could walk through the hole but the top skin was fine. I was jumping so much that I got lazy. The damn thing blew up and I didn't even notice it with a quick glance canopy check.

Anyway, super hard openings can break lines. It doesn't have to be the slider grommets. It was the center two lines both times. It was 550 flat Dacron lines.

hi!

when (properly made) lines rip due to too high load, they break at the start/end of the splice where the inner line ends. (see attached picture)
the point where the (outer) line goes from thick to thin is a stress point, to ease this stress point the end of the line (the one inside) has to be cut at an angle.

what interesting here is that not both a/b center lines broke, but the left center and the next one further out. and it reallly seems that they break when slider is approximately at the cascade.
is there a higher quality video available? maybe even more frames?

todd from apex did some video cutting lines on base canopies during flight:
https://www.youtube.com/watch?v=KcLQoO_x52E

maybe "smaller" 9 cell skydive canopies handle better in this scenario? (higher internal pressure, and on a 9 cell you still have a higher ratio of good lines if 2 are gone...) can anyone confirm this?

btw. a skydiver here broke quite a few bones after he broke both center a lines on his nitro. he thought it flies well, but realized that its actually sinking faster and not flaring that good anymore when he was about to land...
i suppose if youre still hundreds of meters up it can be hard to judge how fast youre really going at what angle.

New from Bad Seed :

http://badseedbase.com/wp-content/uploads/2012/10/Service-Bulletin-BSB-001.pdf

clickified

I also posted it in the general forum and stickied it.