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billbooth

Is Your Hand Deploy Pilot Chute Correctly Made?

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If you guys don't cut this out, we may have to go negative. Bill

That's all I've got Captain, I can't give you any more or she'll fall appart!!!
Seriously Bill, you make a great product and I have trusted my life to you more than a thousand times. I love the Sigma Tandem and think the V3 series is great.
Blue Skies
:::OK, Canopy is Open, No Traffic Around, .. Why are these "Extra" Lines Draping Down??, Damn!

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What should I do?

I can't tell you what to do, but your knowledge and advice is invaluable to me. Thank you for bringing it to these forums. Maybe you've saved the life of one or more of us with this thread alone!
Frank
"There's nothing new under the sun"

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I think I have the distintion of being the only skydiver w/ 2700+ jumps, regularly fly a canopy at 3.1:1 wingloading and have never been injured.

Whew... easy on the shit-talking karma, man! You'd better go knock on some wood, or at the very least go appease the beer gods. It's one thing to say something like that while playing foosball, but damn. ;)
Jason

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Frank;
When I first started making gear, I actually thought I could make it so good than no one would ever die jumping it. I still remember how devastated I was the first time someone bounced on my gear. Since then I've learned to live with the reality that I can do nothing about most fatalities. That's up to each individual jumper, every time they leave an airplane. However, I have spent the last 30 years trying to make sure that no one ever dies because their gear wasn't up to the task. So it means a lot when someone tells me I'm headed in the right direction. By the way, I love your screen name "Iflyme". I wish I had thought of it.
Thanks, Bill Booth

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Bill:
Wish I had that info on pilot chutes about a month ago. I would have saved myself a reserve ride. I'm going to print out your post and hang it up at my DZ.
For what it's worth, your willingness to share information has made me consider a Vector 3 for my next rig purchase.
-Sandy

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>I have two children, a staff of 50 people, and an ex-wife who depend of me for their livings. What should I do?
I would guess that people advising you to stop posting have to retake their Marketing 101 course.
Most containers sold now do function well. By having that litlle better secret details in Vector - you will not win many new customers. By having your reputation as a guru well known, you will - too much is based on trust and perception in this area.
Personally, I definitely will have much bigger chance to select or recommend Vector, because of your posts here - I did not even know who you are, and why I should trust your worksmanship previously. (Chose Mirage ;) - really nice rig, drool over this new unisyn rings now, have not had them.. Vektor was second choice.. just little less sexy, for whatever reason.. Marketing?)
And besides that - if you advice saves single live - karma will pay off. It will. Shutting up would not. ;-) Your reputation is an asset as valuable as your actual knowledge, when it come to selling..
Just my $0.02
Sincerely.

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Well I just checked the pilot chute of my Mirage G3, bought in August of 2000, and guess what, according to Bill's aritcle up top, they put the support tape on the mesh on wrong (that is, not on the "bias") and it stretches below the apex. This kind of pissed me off. A company like Mirage doing this??? That is surprising. damn, this sucks.
My openings, ever since I got my rig, have almost always had a delay from when I throw out to when I feel the pin get pulled.
I emailed Mirage about it today, we'll see what they say.

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...the pilot chute of my Mirage G3, bought in August of 2000...

You have the same main PC that you had in August of 2000? I don't know about you, but that's time enough for about 500 jumps for me. Have you considered that the kill-line may have shrunk? Considering that Jeff Johnston was the long-time product manager for RWS, I'd like to think that Mirage knows how to make a pilot chute.
Jason

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Some people dont do 300 jumps a year...

Yeah, that's why I said, "I don't know about you...."
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I dont see how a shrinking kill line could change the sewing direction on the mesh....

I wasn't suggesting that... I was just asking if Krishan had considered that the kill-line may have shrunk as well.
Jason

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Yes, every manufacturer is capable of making mistakes, including RWS. But maybe other manufacturers simply have different design considerations. Maybe some use a mesh that has a bias that is parallel to the stitching. Is that not possible? Maybe not, but I'm not going to jump to conclusions just because I can see one small piece of the puzzle.
Jason

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>Well I just checked the pilot chute of my Mirage G3, bought
>in August of 2000, and guess what, according to Bill's
> aritcle up top, they put the support tape on the mesh on
> wrong (that is, not on the "bias") and it stretches below the
> apex. This kind of pissed me off. A company like Mirage
> doing this??? That is surprising. damn, this sucks.
> My openings, ever since I got my rig, have almost always
> had a delay from when I throw out to when I feel the pin get > pulled.
Personally, I would not get overly worried about the mesh direction. Apex sounds like a bigger deal.
On the other hand - some "delay from when I throw out" to the pull of the pin is probably a good thing, is not it?

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I really do not like any delay between throwing out and the pin getting pulled. I'm not worried about hard openings, cause I have a pocketed slider.
I just like to know that things are happening as soon as I let go of the pud.
I've had at least a couple of pc's in tow that lasted 2-3 seconds. Sure that's not a long time, but it sure feels like it when it's happening.

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>I've had at least a couple of pc's in tow that lasted 2-3 seconds
Hm. My Mirage's PC felt going out pretty fast, compared to the rental rigs.. Is it THAT much slower then other rigs? Cause it maybe the way you throw it, or pack your bridal, or 100 other thing that we really need Bill Booth to tell us about..
Even though we do not jump Vector ;-)) But we may order a PC from him.. ;-)

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Guys;

Use some simple logic here. A collapsible pilot chute is designed to collapse when the kill line pulls the apex below the skirt. Right? Well then, if your centerline or kill line (see the definitions at the beginning of this string) is so short that it pulls the apex below the skirt (or any portion of the skirt), when your pilot is fully cocked, then how the hell can it work correctly? Every time someone has asked me why their pilot chute wasn't working very well anymore, the problem has been an apex pulled too far, with support tapes not sewn on the bias. EVERY TIME!
Think of the mesh on your pilot chute as the suspension lines of a round canopy. If the suspension lines are all different lengths, then the parachute is not going to work very well is it? We sew the support tapes on the bias (the direction the mesh stretches the most) to stabilize the mesh so that the whole skirt of the inflated pilot chute, especially that part which is between the support tapes, is roughly the same distance from the base. If the support tape is not sewn on the bias, and the apex is pulled to the junction of the support tapes and the skirt, when the pilot chute inflates, the mesh halfway between the support tapes (on the bias) stretches a lot, allowing that portion of the skirt to get way above that apex, spilling a lot of air, and lowering the pilot chute's drag. How much drag is lost depends on how much the apex was pulled in the first place. Why would a manufacturer not sew the support tape on the bias? Well...1. They either they don't know any better, or 2. it's really hard to sew tape on the bias, 'cause the damn mesh keeps stretching.
Whether a pilot chute made this way is "safe" or not depends on how big it is compared to how much your canopy weighs, and how fast you are going when you deploy. And don't forget, pilot chutes made this way tend to loose drag as they get older and the mesh stretches. In other words, a poorly made pilot chute might work OK, for a while, if you always deploy a light canopy at terminal or above. Yet, that same pilot chute might be considered "unsafe" with a heavier canopy, or at lower airspeeds (like an emergency hop-n-pop at low altitude), or after it gets older.
The point here is; While there are many ways to make a pilot chute, I want each one I make to be as efficient as possible, and have an exactly predictable amount of drag, at any airspeed, for its entire useful life. Isn't that the definition of quality control?
Bill Booth

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"I've had at least a couple of pc's in tow that lasted 2-3 seconds. Sure that's not a long time, but it sure feels like it when it's happening."
Kirshan;
A pilot chute in tow for "2 or 3 seconds" is terrible. If your pilot chute is correctly made and matched to your canopy weight, and if you throw it cleanly out of the burble, at terminal velocity, the time from pilot chute release to line stretch should be no longer the 3/4 of a second. NO LONGER. Do not jump a pilot chute that hesitates for even a second a the end of the bridle. Please!
Bill Booth

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This is one of the things that concerns me with people jumping with 22-24" Dia. pilot chutes. They are so small to begin with, that any loss in efficency will certainly result in a less than desirable situation. IMO, 28" is a great all around size.

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A pilot chute in tow for "2 or 3 seconds" is terrible. If your pilot chute is correctly made and matched to your canopy weight, and if you throw it cleanly out of the burble, at terminal velocity, the time from pilot chute release to line stretch should be no longer the 3/4 of a second. NO LONGER. Do not jump a pilot chute that hesitates for even a second a the end of the bridle. Please!

I just wanted to say that the "mine hesitates for 2-3 seconds" sounds a HELL of a lot like the "10 second /thousand foot snivel" stories that frequently come up in the canopy discussions.
I think we're so tuned in and paying attention at pull time that any delay seems like forever. I used to think I had a 2 second delays until I saw the video, then I realised it was pretty much instantaneous.
Incidentally, my pilot chute passed all your tests. The patch on the bridal says Jim Cazer, and references your patent no 4,399,969
_Am
ICQ: 5578907
MSN Messenger: andrewdmetcalfe at hotmail dot com
AIM: andrewdmetcalfe
Yahoo IM: ametcalf_1999

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Kelly;
You're absolutely right. Construction details are much more important on small pilot chutes, just like they are on mini 3-ring risers. You can probably make a 36" pilot chute any way you want, but a 24" must be made exactly right. Relative Workshop offers a 34", F-111, non-collapsible, and a 28" ZP collapsible. Because we can't really control where our pilot chutes go, we don't sell anything smaller to the general market. We do offer a 24" ZP for people with canopies below 97 square feet, but you have to "beg" for it and promise you won't sell it to some unsuspecting newbee with a 280 square foot canopy. I wouldn't go any smaller than that 24". Remember, some day you may have to do a hop-n-pop.
Bill

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I don't know if this has been mentioned yet, but isn't kevlar a better material to use for a kill-line since it doesn't shrink? I understand that it may fail and break sooner, but that just results in a fully opened pilot chute. It seems to me that Spectra is a poor choice of material for a kill-line. I would want something that doesn't shrink before something that breaks.
I have a pullout with a kevlar kill-line and kevlar lined bridle. Everytime I pack, I grab the apex of the pc and the bridle and pull to see if the centerline is tight inside (I have no sight window on the bridle). If it is, its cocked so I put it in the container and close it.
-Jon
"Sous ma tub, Dr. Suess ma tub" :S

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