Kill Line Wear

[rushmc 18]

I am looking for some feedback regarding what looks to be excessive wear on the PC kill line of my rig.

While I was packing a local (I was visiting another DZ) came up and asked me about the kill line of my rig. He told me his had to be replaced after 100 jumps because of wear cause by the nut on the link that is inside the D-bag. My rig had 50 jumps on it at the time and it is showing considerable wear already.

So two questions come to mind. 1) Have any of you seen this and what have you done to fix it, and 2) He told me that the fix he used was to replace the link with a split ring like the ones on a key ring! What do you think about that?

I have e-mailed the manufacture and I have not heard anything back as of yet and before anyone wants to warn me .....I promise I will not do anything without comment from the manufacturer My rigger also wants to see what they have to say.

PS, I tried searching the forum and I did not find an answer. Sorry if I missed something

I look forward to your comments and thanks

"America will never be destroyed from the outside,
if we falter and lose our freedoms,
it will be because we destroyed ourselves."
Abraham Lincoln

[alan 1]

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So two questions come to mind. 1) Have any of you seen this and what have you done to fix it, and 2) He told me that the fix he used was to replace the link with a split ring like the ones on a key ring! What do you think about that?

Kill-line wear is a problem, I have had to replace several for customers that have broken. They also tend to shrink from heat generated by the friction from the collapse on opening. I apply a food grade silicone to mine to reduce wear and friction that will shrink it. A pc with a too short kill-line may not function properly. There have been several good threads about pc's here lately (although not addressing your question specifically), do a search. Bill Booth made a very detailed post about proper pc design. The split ring works very well and in fact, Rigging Innovations supplies them with their new rigs.....the latest Talons and Voodoos that I have assembled came with the split ring instead of the rapide link. The ring does not cause wear on the line, the two loops, or the grommet. I'd never use the rapide link again.

alan

[Hooknswoop 19]

Kill line pilot chutes wear at several points. The following is what to inspect and some suggestions for increasing the life span of your kill line pilot chute.

The Spectra kill line shrinks from the heat generated from sliding through the bridle as the pilot chute collapses and the bridle stretches over time, affecting the original calibration. Because the change is so gradual it often goes unnoticed until you begin to experience hesitations on deployment. To check for correct kill line length, cock the pilot chute and watch the kill line. Does it become taunt before the two white ribbons that run from the apex (the top of the pilot chute) to the bridle? If it does, then the kill line is too short, not allowing the pilot chute to completely inflate. When cocked, the two white ribbons should be taunt and there should be some slack on the kill line. Also, if the handle of the pilot chute being pulled through the small opening at the base of the pilot chute on deployment, the kill line is too short. Your rigger should be able to replace the kill line, or if the kill line was manufactured with enough excess line, your rigger can simply extend the kill line.

Check the stitching that holds your handle to the pilot chute. If the handle rips off, you would have a total malfunction. Check the bridle, especially where the pin attaches to the bridle. If any of the stitches have come out, have your rigger repair it. If the pin rips off of the bridle you would have a pilot chute in tow malfunction. As you fly your canopy, the deployment bag is free to spin around the bridle. Eventually the bridle will wear out and break at the grommet. Have your rigger use waxed nylon cord to tack both sides of the rapide link to the reinforced part of the deployment bag to prevent the bridle from rotating in the grommet. Some manufactures sew the pilot chute bridle to the deployment bag, eliminating this problem. The disadvantage of a sewn-in pilot chute is they are difficult to replace, usually a job for a rigger. Lastly, have your rigger install stainless steel rapide links instead of the plated links. They won’t corrode, reducing wear on the bridle.

Whether your pilot chute is a kill line or not, the Z-P or F-111 fabric wears just like the fabric on a canopy. The porosity of the fabric degrades with use, decreasing the drag of the pilot chute. Eventually the pilot chute will not have enough drag to deploy your main canopy, leaving you with a pilot chute in tow or a bag lock. An indication that your chute may have problems is a pause between throwing your pilot chute and the canopy coming out of the bag.

A patch on a pilot chute would be difficult to sew and could cause it to spin on deployment, creating lines twists. As the mesh wears, holes will develop. Once the mesh tears the hole will become larger quickly. Replace a pilot chute with holes in the fabric or mesh.

Checking your pilot chute every time you do your 30-day three-ring maintenance is simple and could prevent a malfunction. If you are not confident inspecting your pilot chute, have your rigger help you. An ounce of prevention is worth a pound of cure.

I haven't had any problems w/ using the rapide link inside the D-bag.

Hook

[rushmc 18]

Thanks for the responses. As always, I learn something every time I come here.

"America will never be destroyed from the outside,
if we falter and lose our freedoms,
it will be because we destroyed ourselves."
Abraham Lincoln

[wingnut 0]

bringing this thread back up from a search i did,

had a guy at the dz two weekends ago have his pilot chute and d-bag come off on opening. the kill line were it conected to the canopy was just broken, with about 3 inches of kill line still conected by the rapid link. any idea as to what may of caused this and how to tell if it could happen, i know the lines shrink but what about just breaking from pilot chute drag???

______________________________________
"i have no reader's digest version"

[ZigZag 0]

Most bridles have an additional lanyard between the d-bag and canopy to take the strain off the kill-line and some mfg's have the kill-line sheathed inside the bridle, which then extends through the d-bag to the canopy. In that case, the size of the grommet on the d-bag where the bridle passes through plays a major role. Too small, and it will pinch the bridle and create more friction on the kill-line.
Besides being a design issue, maintenance can help prevent some problems. Jumpers should get their mains and associated parts inspected frequently.

[rhino 0]

Even if the kill line brakes on opening won't the pilot chute still do it's job?

[ZigZag 0]

[wingnut 0]

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Even if the kill line brakes on opening won't the pilot chute still do it's job?

yes it would but in the case i'm asking about the kill line was the only thing conecting the pilot chute and dbag to the canopy... when it broke the pilot chute and dbag fell off.... good thing the canopy was ota the bag when this hapened or he would of maybe had a bag lock...

______________________________________
"i have no reader's digest version"

[ZigZag 0]

[wingnut 0]

Quote

Remember, the bridle is supposed to be sewn to the D-bag in that case

good point, didn't thinkof it like that..... don't think this guy liked his newly "made" main freebag though....lol....

______________________________________
"i have no reader's digest version"

[NWFlyer 2]

Quote

Kill line pilot chutes wear at several points. The following is what to inspect and some suggestions for increasing the life span of your kill line pilot chute.

The Spectra kill line shrinks from the heat generated from sliding through the bridle as the pilot chute collapses and the bridle stretches over time, affecting the original calibration. Because the change is so gradual it often goes unnoticed until you begin to experience hesitations on deployment. To check for correct kill line length, cock the pilot chute and watch the kill line. Does it become taunt before the two white ribbons that run from the apex (the top of the pilot chute) to the bridle? If it does, then the kill line is too short, not allowing the pilot chute to completely inflate. When cocked, the two white ribbons should be taunt and there should be some slack on the kill line. Also, if the handle of the pilot chute being pulled through the small opening at the base of the pilot chute on deployment, the kill line is too short. Your rigger should be able to replace the kill line, or if the kill line was manufactured with enough excess line, your rigger can simply extend the kill line.

Check the stitching that holds your handle to the pilot chute. If the handle rips off, you would have a total malfunction. Check the bridle, especially where the pin attaches to the bridle. If any of the stitches have come out, have your rigger repair it. If the pin rips off of the bridle you would have a pilot chute in tow malfunction. As you fly your canopy, the deployment bag is free to spin around the bridle. Eventually the bridle will wear out and break at the grommet. Have your rigger use waxed nylon cord to tack both sides of the rapide link to the reinforced part of the deployment bag to prevent the bridle from rotating in the grommet. Some manufactures sew the pilot chute bridle to the deployment bag, eliminating this problem. The disadvantage of a sewn-in pilot chute is they are difficult to replace, usually a job for a rigger. Lastly, have your rigger install stainless steel rapide links instead of the plated links. They won’t corrode, reducing wear on the bridle.

Whether your pilot chute is a kill line or not, the Z-P or F-111 fabric wears just like the fabric on a canopy. The porosity of the fabric degrades with use, decreasing the drag of the pilot chute. Eventually the pilot chute will not have enough drag to deploy your main canopy, leaving you with a pilot chute in tow or a bag lock. An indication that your chute may have problems is a pause between throwing your pilot chute and the canopy coming out of the bag.

A patch on a pilot chute would be difficult to sew and could cause it to spin on deployment, creating lines twists. As the mesh wears, holes will develop. Once the mesh tears the hole will become larger quickly. Replace a pilot chute with holes in the fabric or mesh.

Checking your pilot chute every time you do your 30-day three-ring maintenance is simple and could prevent a malfunction. If you are not confident inspecting your pilot chute, have your rigger help you. An ounce of prevention is worth a pound of cure.

I haven't had any problems w/ using the rapide link inside the D-bag.

Hook

Bumping this thread because I did a search and Hook's post is a nice summary of the types of things we should all be looking for in maintaining our gear.

I also thought about bumping up "Stupid Things I Have Done" since my kill line probably should have been replaced ... oh ... 50-75 jumps ago. Anyway, after a weekend of really noticing pilot chute hesitation, coupled with a very timely safety day reminder from the folks at Elsinore, I took a close look and realized my PC was a malfunction waiting to happen. I grounded it and it will not be jumped again till the kill line is replaced.

When's the last time you checked yours?

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[phoenixlpr 0]

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When's the last time you checked yours?

I have a spare PC and another with d-bag. I can replace it if it starts hesitating.

[DeNReN 0]

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When's the last time you checked yours?

everytime I pack

[NWFlyer 2]

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Quote

When's the last time you checked yours?

everytime I pack

Yeah, I look at mine - but not as closely as I should have. I don't just check for color, though - I always make sure the PC is cocked and catches air, but I haven't been checking the kill line length each time I pack.

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[DeNReN 0]

Quote

Quote

Quote

When's the last time you checked yours?

everytime I pack

Yeah, I look at mine - but not as closely as I should have. I don't just check for color, though - I always make sure the PC is cocked and catches air, but I haven't been checking the kill line length each time I pack.

I was taught to check and teach to check 3 ways....kill line slack being the most important...then check for catching air..then the window.

when packing I always keep a eye out for anything that dosent look right or looks different and will check with a rigger if I am unsure about something.

[everymansaved 0]

On the topic of kill line replacement, I have a question for you hook (and anyone else for that matter). What do you think about using Vectran for replacement of kill lines? I replaced mine a while ago and all I had on hand was Vectran. I only had the rig for another 50-75 jumps, but it seemed to work well. I imagine it would be like a line set, you might have to change it a bit more often than spectra, but it wouldn't shrink. Thougts?

God made firefighters so paramedics would have heroes...and someone can put out the trailer fires.

[Hooknswoop 19]

I prefer Vectran. Doesn't Shrink. Worst case is the PC won't collapse if the Vectran breaks and you get a normal deployment. Worst case with Spectra is a PC in tow because the PC can't inflate completely from the shrinkage.

Derek

[bodypilot1 0]

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Worst case with Spectra is a PC in tow because the PC can't inflate completely from the shrinkage.

I would HOPE jumpers are checking for inflation after they are cocking their PC.

www.WestCoastWingsuits.com
www.PrecisionSkydiving.com

[everymansaved 0]

Yeah, that's what I thought. I've done another one since and used Vectran for thsoe reasons. I wonder why it's not used from the factory, do you think it's a cost issue?

God made firefighters so paramedics would have heroes...and someone can put out the trailer fires.

[Hooknswoop 19]

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I would HOPE jumpers are checking for inflation after they are cocking their PC. Unsure

LOL, right. Keep hoping. Most people don't check for inflation with tension on the bridle, which, depending on the kill line length, can decrease how much a PC inflates.

Derek

[bodypilot1 0]

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LOL, right. Keep hoping.

I will

www.WestCoastWingsuits.com
www.PrecisionSkydiving.com