Mar 19, 2001, 5:18 PM
Post #1 of 20
Collapsible Pilot Chute
I was reading a copy of Parachutist the other day (I think it was February's issue) and noticed something about collapsible kill-line pilot chutes. I knew they needed more frequent inspection than a "regular" PC. However, this article stated that if a kill-line was manufactured to just the right length, it would "soon start to shrink..." etc. How soon is soon? If I cock the PC and see green isn't that OK? If it starts to become difficult to acutally get some green? I am going to ask my rigger this weekend anyway, but I wanted the opinions of some of you beforehand...particularly because I am going to repack my main this week (thanks for the pack job Merrick...but those statements about some 180-deg. off heading openings made me nervous!) and I would like to know what to look for when I inspect it myself...I have only made about 20 jumps on this new rig so I wouldn't think it would need anything yet, but better safe than sorry!
As far as I'm, concerned; if it's green, it's green.
You can also check for kill line shrinkage by looking through the mesh of the pilot chute. There are usually three or four lines that run between the hackey and bridal attachment point inside the mesh. These lines should pull tight. If they're loose you're kill line is too tight.
Here is a way to check a collapsible PC. Sorry I cannot remember where I came across the literature on it. Susupend the PC by the bridle where it attaches to the pilotchute itself. Locate the reinforcing tapes on the mesh of the PC that run bridle to nylon. Now compare them to the center length of the PC. My understanding is that the center hanging 1" lower than the edge tapes is optimum but this may vary with gear. You should be thinking about re-placing the PC when the center where the hackey attaches and edge tapes are the same length. I have a Collapsible PC made by Jim Cazer (ordered with my Dolphin) which seems to be good construction, it is zero-p also. What you would start noticing if using a worn PC, either increased prosity of the nylon or shrinking apex line would be less snach force, or softer openings than what you would have usually had. It would be a gradual change so I am not sure that it would be noticible really. What you might try to do is pull your main out and start collapsing your PC until it is right on the edge of the colored portion, then see where the apex hangs like I mentioned above. Personally I would think that if you can see color in the window, the PC should be OK to use. The manufacturers probibally take in to account the shrinkage of the microline due to the heat generated from the movement inside your bridle and color the center line accordingly. I'm not a rigger though and this is just what I have came across when I was buying my gear and deciding if I wanted a collapsible pilotchute YMMV.
I don't have that little green line to let me know when my pilot chute is cocked. To check it, I just wave it in the air and drop it, if it catches air and sort of floats to the ground its cocked. If it drops straight down hackey first, then its not. I would say, when it gets hard to cock, its time to replace it. Mine is getting to that point after about 500 odd jumps, but it still works. Anyway, I'll be replacing mine soon, because it is sort of worn and I have a new canopy, so I think its only right to have a new p/c to go with it.
Its a great idea to ask your rigger to SHOW you exactly what the article was referring to and see if yours is OK. Just like skydivers in general, most riggers are very approachable and willing to answer questions and help out.
I did the marker trick on mine and it doesnt work all the time...sometime the line twists and the marker is on the other side and it is a bitch to fix. I usually look at the P/C and make sure that it is cocked at least twice to ensure that it is cocked (the last time being right before I put the P/C in the BOC) So that may not work for you all the time. I have been told by a rigger that a P/C will work within 3 inches of the green line. That is the margin of error. Can anyone else confirm or deny this??? Definately ask your rigger and let us know what he says...thanks!
Well when I'm packing I check it several times several ways. I'll cock it and then toss it a couple of times during the pack job. For me the green in the window is for double-checking after everything's packed.
If you don't have any green line, you have no way of checking after the pack job whether thing thing is cocked or not. Thus the marker idea.
As far as the kill line twisting. Yeah, you'd probably have to mark all the way around the thing to make sure.
I also have the problem that the marker can sometimes fade...so the best thing to do is to make sure that you cocked it several times. Thats what gives me peace of mind. It sounds like you may be ready for a new P/C anyways so get one with a window indicator if you are that concerned about it.
"...but those statements about some 180-deg. off heading openings made me nervous!"
LOL - Well, That only happened that once but I'm still am nervous about other people jumping my pack-jobs. I mainly did it so you wouldn't have to cram it in your bag or pack it up before you went. Plus, I was bored.
As for the pilot-chute, I generally just check the window & do the floating test. If both are cool, I'm good to go.... Otherwise, I'd check with your rigger (as I'm sure you're already planning to do).
I got my complete rig used. The collapsible chute marker area is blue not green, but overtime, the blue area soemtimes gets pulled out of view. This is true even though the pilot chute is cocked. So I don't know what to think, except that everything seems to work fine. And yes, I do the floating test too, before I put it into the BOC pouch.
(Note the increasing use of Americanisms in my posts)
Right... the argument that the kill line will shrink comes from the fact that the line is in fact Microline/Spectra, which can shrink under repeated friction (running back & forth in the bridle).
Whether or not this is the case, when you cock your PC, look inside the netting! is the tape that runs from PC base (bridle) to PC apex taut? If so then your PC is cocked (regardless of what colour what bit of the line is!!). The coloured line & window (where fitted) is there for "Flight-line" checks & doesn't replace a check of the PC while packing!
A kill-line PC will most likely deploy your canopy even if its not cocked as long as your closing loop isnt too tight. Don't try it though. But it is possible. It has happened to me before a few times. Scary stuff.
Guess what folks? I have never heard of tossing the PC in the air to see if it floats before. I have not seen anyone do this. Interesting...I am going to start doing that. I also never heard of looking inside the netting...I was just told to look for green and go. I check it several times, but only that way. Now I have another method at my disposal!
Merrick...I am sure the thing would open fine. I was just messing around. I know you packed it so I wouldn't have to, thanks a million! I thought that was nice. My dad even said so. :)
Couple things to ad. First, as far as the green line is concerned, neither of my pilot chutes even have a window. If you cock the pilot chute then it is cocked. You can tell if it is cocked with your eyes closed. Just take some time to look at how it actually works and it will solve all your confusion and worries. Second I have seen several people deploy with uncocked pilot chutes. You will have a pilot chute hesitation, but unless you have a extremely tight closing loop it will eventually pull the pin. Nobody I know has had a mal. because of this. A good friend of mine went of the bridge with his pilot chute uncocked. He swears he cocked it(sort of shoots my "if you cock it it's cocked" theory down the drain) but there is video to prove it was not cocked. Blues, c
The guy I've been getting coaching from recommends that you check to make sure it's cocked again after getting the canopy in the bag, or if you want, while you're lieing on it getting the air out just before. He says that while messing with your canopy to pack it, there's a possibility of it coming un-cocked. Anyone find that to be true (if you cock it before you start messing with the canopy)?
I usually cock it right when I set the canopy down and then again before I put the D-bag in the container (carefully making sure that there isnt any fabric coming out of the grommet-thats how friction holes get burnt into the canopy.) But you are right...the P/C can become uncocked when you are messing around with the main.
Yes, it can get "uncocked", especially if you are a new packer and mess with the canopy a lot. I believe that happened to me the fist time I jumped my own unassisted pack job. Huge hesitation before opening.
So, while cocking my pc is on of the first things I do, I always check after it is in the bag, before I close my container.