Knotted Bridle

[Aylett2004 0]

I had a normal jump, landed, and while field packing discovered that my bridle was in a knot about halfway between the pilot chute at the canopy. The pilot chute had done it's job, collapsed properly, and it wasn't really a problem but i would still like to know what might have caused this. I know for a fact that it was not knotted when I packed it, so it must have happened on opening or while under canopy.

I jump a TalonFS, Spectre 150 loaded at 1.3 with a standard size ZP PC. Thanks.

Aylett

[Snowbird 0]

Okay, I'm really curious for this answer, cause the same thing happened on mine (non-collapsible) on Saturday.

Women and cats will do as they please, and men and dogs should relax and get used to the idea.
-Robert A. Heinlein

[Kris 0]

Spooky, that happened to me for the first time last Saturday as well. I looked at it, dumbstruck, for a couple of minutes. If I hadn't been with the rig every second I would have sworn someone was playing a joke, but it hadn't been out of my sight since I had landed.

The knot on mine was about 12-14 inches below the PC.

Sky, Muff Bro, Rodriguez Bro, and
Bastion of Purity and Innocence!™

[mjosparky 3]

FM, it is eveywhere!
Sparky

My idea of a fair fight is clubbing baby seals

[gus 1]

This has happened to me twice in the last couple of years but I've never found a concvincing explanation as to how.

p/c dancing around in your burble and knotting itself? Under canopy?

Gus

OutpatientsOnline.com

[BMFin 0]

Could it be that the knot was made when packing the PC ? It just tightened it self in the opening.

Normally when packing a PC. theres always some extra bridle left that people (me included) just shove in the pouch. If you shove it wrong, you could easilly make a knot waiting to happen.

[Genn 0]

Quote

p/c dancing around in your burble and knotting itself? Under canopy?

Gus

This is the explaination I got as well. A knotted bridle has happened to me on numerous occasions.

[darkwing 4]

I think the most likely time for it to occur is when you throw it out. Watch slow motion video of throw outs some time and you might agree with me.

-- Jeff
My Skydiving History

[Genn 0]

Quote

I think the most likely time for it to occur is when you throw it out. Watch slow motion video of throw outs some time and you might agree with me.

I definitely agree...I thought he implied that when he said burble, not sure though.

[bkdice 0]

This has happened to me once too. Not quite sure how though.

[rigging65 0]

I'd say it's pretty doubtful that it's happening during the initial throw out, as you'd more than likely see some major burn marks from the kill line on the bridle if it were killing itself through a knot. I suppose it could be happening during canopy inflation, as there is a bunch of tension taken off the p/c and bridle at that point...

I've seen bridles do this while the jumper was under canopy, twice. In both cases I saw first hand (we were bumping around with each other under canopy), the p/c wasn't totally uncocked. There was enough drag generated to cause the envelope to bounce around and hitch itself into the bridle. I don't see any reason why this couldn't result in a knot as opposed to a half-hitch, but I've not personally seen this happen.

I guess the end-all to this line, is that it's most likely happening after the p/c has done it's job, so it's probably not much of a threat...just an annoyance.

"...and once you had tasted flight, you will walk the earth with your eyes turned skyward.
For there you have been, and there you long to return..."

[riddler 0]

I agree with R65 - the pull force of a PC in good air is around 150 pounds. Unless it was packed that way, it's not gonna flip a loop and tie itself in a knot - it' s going to pull hard and straight as possible. Seems much more likely that as soon as tension is let off (when it starts to collapse), it's going to be erratic and could loop itself into a half-hitch. I've had this happen once. I was able to unhitch the knot easily by hand - I don't think it would be as easy if it was in a knot and subject to a 150-pound force - it would be too tight to easily undo. Once collapsed and trailing behind, it looks more erratic and could hapen there. But I'm not a rigger, so I'm only taking a wild-ass guess.

Ed to add - I've noticed this happen once on my 9-foot bridle. I've never seen it with my 5-foot bridle. Length of bridle may contribute here.

[skycat 0]

Derek has video of an AFP level 7 or 8 student give a weak throw and the pilot chute went strait into her burble. It danced around back there and actually hit her in the back of the head twice before it finally launched.

Fly it like you stole it!

[DJL 232]

I'd guess that it happened while under canopy, or landing, especially, since you said the PC was collapsed. I've done a bit of CRW on canopies with collapsable PC's and they really do dance around just because there's someone sitting in front of it making a burble.

"I encourage all awesome dangerous behavior." - Jeffro Fincher

[PilotMike 0]

I've seen mine with a knot in it once. I showed it around and some jumpers and I concluded that it probably happened when picking up my main in the landing area. I usually grab the bridle near the attachment point and tug to have the pilot chute come flying up to my hand. I think it's very possible for it to tie up at that point.

--------
Benefitting from the 'free capture of verticality.'

[jumpy 0]

There was an incident concerning this reported in ASM (Australian Skydiver Magazine) last year.

The picture attached explains there theory which I'm very inclined to beleive.

[billbooth 10]

If you want to avoid a knotted bridle, pack and throw your PC so that the envelope always stays "above" the bridle.The below instructions have been published in Wonderhog and Vector manuals since day one.

Lay your PC fabric side down. "S" fold your bridle between the apex and the skirt. Fold your pilot chute over the "S" folded bridle. Now do whatever you do to get the PC into the pouch. Throw your pilot chute firmly to the side, and do not hold onto it a split second longer than necessary. If you follow these simple rules, a knotted bridle will be very rare. They are caused by folding your bridle somewhere other than inside against the mesh, holding on too long, or a simple "lazy" throw. I'll say it again, you cannot have a knot unless you somehow allow the bridle to get "above" the envelope during deployment. A too long bridle will make this problem more likely. I spent a lot of time determining correct bridle length 30 years ago. By the way, a knotted bridle could be fatal if it half hitched around the PC itself.

[riddler 0]

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"S" fold your bridle between the apex and the skirt.

I was also told by one very good packer that it's better to make every bite of the s-fold shorter than the last. I'm not sure why, other than it seems harder for it to bunch up and knot. Any opinions on this?

[billbooth 10]

Won't hurt, but probably doesn't make any difference. Again, the important thing is to pack the bridle inside the pilot chute, up against the mesh.

[bschuyler 0]

I had a similar experiance this past weekend which resulted in a cutaway and reserve ride. The differance was that it was the pilot chute that tied in a knot, not the bridle. I know it happened after throwing out because the hackey was inside the knotted up part of the pilot chute fabric. As it was happening, I thought that I may not have cocked the pilot chute, but after inspection, found that it was still almost fully cocked, and noticed the knot. My guess is that a knot somehow formed before inflation, but it was not very tight at first and the pilot chute still had enough drag to open the container, but as it pulled the bag out of the container, the knot tightened up and totally collapsed the pilot chute which caused the bag to not open. I have packed my pilot chute the same way since I started jumping and have never had a problem, so I don't think that was a factor. It just goes to show you that anything can happen.