Jan 3, 2009, 4:59 PM
Post #1 of 48
A hair-raising experience.
The recent incident of the wingsuiter falling from his harness got me thinking to a small instance I had a few weeks ago that definitely got my hair standing up.
My buddy and I do a freefly jump, him sitflying, and me backflying. Everything was normal until it was time to break.
As I went to my belly, tracked off, and slowed, it felt as if I didn't have a rig on. I felt nothing on my back, and was relieved when I felt the hacky behind me. The resulting opening was normal.
Now under canopy, I feel very loose in my harness. I look down to my horror, that my chest strap was completely loose. Not undone, but loosened all the way.
Now I'm a very OCD guy about gear checks, and I can assure you all that the chest strap was routed correctly, had tension on it, and was securely in the locking band. In fact, it may have been the locking band that prevented the strap from completely coming out, despite it being routed correctly.
What could have caused this situation? I was wearing a t-shirt during the jump, so maybe the t-shirt didn't have enough baggyness against the strap? I'm completely baffled, but glad it hasn't happened since.
It just scares me to think that if I was in a high-speed track for a long duration, such as during a tracking or atmo jump, that I could have possibly slipped out from my shoulder straps. Which btw, with the chest strap loosened all the way, I can easily shrug my rig off. I have no doubts the wind can do that even easier.
sometimes people forget. Have you ever forgotten? I'll bet you have. You can search for an excuse all you want but I'd be willing to bet that you won't find one. I have a lot of jumps. My chest strap has never just loosened on its own.
Never heard of one loosening up, but I haven't been around that long.
How tight do you normally have it?
You were backflying right? Try tightening the chest strap normally, then lay on your back and see of it is as tight then. If there is slack in it, could the turbulence in your burble have fluttered it enough to loosen it??
I don't know if this is possible or not. It's just a scenario that jumped into my head. Feel free to contradict it or just laugh.
My buddy and I do a freefly jump, him sitflying, and me backflying.
It's the backflying that did it. When you arch and fly on your belly, you push your chest out and put tension on your chest strap, loading the friction adapter and keeping your chest strap in place.
When you fly on your back, you reverse the arch, and end up pushing your main lift webs closer together, removing tension from the friction adapter, and you know the rest.
What you need to do is use additional elastic bands, arranged around the chest strap and friction adapter in such a way that they lock the chest strap in place with or without tension on the strap. The trick in doing this safely is making sure that you can still accurately check the strap is properly threaded during your gear check. Some jumpers have devised an over/under/around method that makes a visual check of the strap difficult or confusing. Avoid this.
Additionally, this is the sort of thing you need to address with your local instructors/riggers immediately after the jump in question. Do not jump the rig again, nor alter it's configuration until the situation has been investigated, and the cause and solution have been explained to your satisfaction.
Jumping a rig that behaves in a way that you do not understand is asking for trouble. Remember that accidents are usually the end result of several bad situations coming together all at once. What seems like a minor problem today could easily add to another minor problem tomorrow, and that will be the day your buddy does something stupid right under you, and you can imagine the rest.
Sorry to ask, but what does OCD stand for? When I tighten my leg and chest straps I usually make sure they're really, really tight. People usually say "You don't need to tighten it that much cause it's not comfortable". I for one don't care if it is comfortable or not. I'd rather have my straps to be uncomfortable than to fall out of my rig or in other words, I chose saftey before comfort. Btw, my straps always loosen a bit during freefall anyway.
(This post was edited by elias123 on Jan 4, 2009, 7:30 AM)
You have learned a very important lesson. Glad it all worked out in the end!!!
I bet you will never be one of the people that say "that could never happen to me"
I am sure that before that jump you never thought in a million years that you would forget something so basic as doing up your chest strap. Now..... dont let anyone else do it. Check your buddies on the plane. Be looking out for other problems with yours and others gear. Dont be afraid to say something to a fellow jumper if you dont think it looks right. You may save a life, or learn something in the process.
I think the burble while backflying makes the most sense.
Do this, to help determine if this is what could have been the cause:
- With the rig off you, and laying on "its back" (Laterals and handles and chest-strap up/facing you), route and set the chest-strap about where you think it usually is when it's on you.
- Then, by grasping the laterals on each side just below the mud-flaps, shake vigorously up & down on the laterals WITHOUT tension (without pulling apart the laterals at the same time) being placed on the cheststrap. Or with VARYING tension being applied to the cheststrap while you do it / it "flaps".
- Do this with your "normal" keeper on the excess.
- Do this with (an) extra band(s), as Davelepka has suggested to you.
Does it work its way (shake/flap) "full slack" under the 1st scenario? Then the second one?
Chances are, that there is nothing wrong with the friction adapter itself, as it sounds like it normally does its job for you as it is supposed to, and as it is designed - under load/tension. If you know you are planning on back-flying again for instance - adding the extra keeper band(s), or rubber-bands, or changing the way you stow the excess may be all that you want to do and be aware of. It all comes down to being aware of how your gear functions, then - applying it and configuring it however correctly as may be necessary, for your planned jump/situation.
As others have already now said in here as a result of this - I think this can be an "eye opener" for people to consider. Not just for you, and not just for this specific isolated condition either -but overall too, in how they process maybe a little bit more, what they are doing, and how their planning for their specific jumps may be impacted as well.
Which btw, with the chest strap loosened all the way, I can easily shrug my rig off. I have no doubts the wind can do that even easier.
Sounds to me like your harness is too big. I realise without a chest strap ona jump, there is a high chance you'll come out of the harness, though the way you say it sounds like it can come off real easy. I think people underestimate the importance of having a harness that fits you properly.
Also, with regard to doing up the legstraps super tight, keep in mind that this wont necessarily keep you in the harness. If your harness is too big for you its surprisingly easy to pull your rig over your head no matter how tight the leg straps and/or chest strap is.
Is your chest strap made of one layer of webbing or two? Old school, belly-flying harnesses usually only had one layer of webbing and that was enough because they were under constant tension, ergo the buckle never slacked off.
Nowadays, modern sit-flyers (head-downers,e tc.) prefer chest straps made of two layers of webbing to "bulk out" the buckle and reduce risk of slack.
Remember that most parachute hardware was originally designed for bulky cotton webbing, far bulkier than modern nylon webbing.
It is easy for your local Master Rigger to sew an extra layer of webbing onto your chest strap (look at a Javelin or Dolphin) to increase the bulk and reduce the chance of slippage.
(This post was edited by riggerrob on Jan 8, 2009, 3:04 PM)
My rig has fit me very well up to this point, but so I can get your perspective on it, here's a picture from when I first got my rig.
How much of a gap do you have between your main lift webs and your shoulders when under canopy? I've jumped Paulagc's rig that was too small lengthwise, where the hackey was about as far up on my back as I could reach. That one didn't bother me quite as much as Bruce Johnson's rig that was way too long. Even with the legstraps tight there was 4 inches between the top of my shoulder and the harness after I opened. That could've been a problem with finding handles if the Spinletto would've given me problems.
One interesting thing I saw while in florida this year is that a number of jumpers were stowing their extra chest strap on the wrong side of the buckle. This has a tendency to pull the buckle into the unloaded position so the chest strap can loosen. I had to demonstrate this to a few people before they realized that what they'd been doing for years could have caused a dangerous situation.