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20_kN

Reserve PC Hesatation?

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I came across an interesting Friday Freakout video in which the PC of a reserve gets stuck in a jumper's burble. My understanding is that most (all?) reserve PCs have a spring that's intended to help prevent that from happening. I dident really see the PC spring out much when he pulled his reserve and I am curious why. How common is this on a reserve?

https://www.youtube.com/watch?v=2D3b4U-4eRk

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20_kN

I came across an interesting Friday Freakout video in which the PC of a reserve gets stuck in a jumper's burble. My understanding is that most (all?) reserve PCs have a spring that's intended to help prevent that from happening. I dident really see the PC spring out much when he pulled his reserve and I am curious why. How common is this on a reserve?

https://www.youtube.com/watch?v=2D3b4U-4eRk



It's always a possibility, but fortunately it seems rare. Or at least, with that much hesitation. There was probably some additional burble/turbulence from the bridle he had bouncing around up there, maybe it interfered. Being belly to Earth for a reserve deployment means there's a chance you can launch it right into the burble. They usually clear it even in those cases, but not always, which is why I was taught as part of my EPs to look over both shoulders (check right, check left) after the reserve ripcord is pulled. If there's a pilot chute caught in a burble that check will tilt your body and will hopefully expose the pilot chute to relative wind and the reserve deployment sequence will continue.

Watch this video: https://www.youtube.com/watch?v=wCrvQ_xy_LA

Go to settings and set it to .25 speed. You'll see the guy in frame, his reserve hesitates for a split second in the burble, which probably saved them both as they ended up deploying at two (very slightly) different altitudes instead of wrapping in each other's shit.

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All uses of he are for convenience (and because I'm an old fart) and imply only a reference to another person of any gender or no gender. :P

If you have your own rig the next time you take it to your rigger to have it inspected and repacked tell him you want to pull the reserve. Best is to do it in a hanging harness set up to simulate a cutaway but even just standing on the floor will be educational. Do it with the main STILL PACKED. Your rigger should want you to do this. If he can't be bothered find another rigger. If you don't have your own rig make arrangements to watch a DZ rig being opened. I'm somewhat concerned that with an A license you don't seem to have a basic understanding of gear. (That all skydiving reserves have a spring loaded PC)

If you can do it in front of mirror will see the spring in your reserve PC open the flaps of the reserve container and 'launch'. Or have someone video it on your phone. Do NOT do it without your rigger present. He should want to see how it launchs also and would rather have the rig opened in his presence. It may do anything from barely get out and fall to the ground at your feet to spring out hard and hit the floor 10 to 15 feet away. The videos posted in the one reply that are main spring loaded PC's are not completely representative because the main bridles are much shorter.

After the PC gets out of the container it has to inflate. In the video you posted at 1:23 the PC launchs but hits the trailing main bridle and is stopped. It falls back to the container upside down and has to have wind hit it to turn it back around, inflate and leave. The jumper was lucky there wasn't a permanent bridle entanglement. But without the main bridle in the way reserve PC's can and often spring out, fall back and then fall off sideways to leave. I don't know if this student was just too used to holding on do his dummy PC or it was stuck on his hand.:S

PC hesitation is not un-common but is usually fast enough on reserves that you don't realize it. It is more common on mains with spring loaded PC's because the bridles are shorter and often the springs are wimpier. Also when deploying a main you are more likely flat and stable causing a symmetrical burble (low pressure area) behind your back. In emergency procedures you are often tipped one way or another. Experienced jumpers, especially those who jumped spring loaded main PC's a lot may very well 'sit up' for reserve pull to get air across their back for a cleaner launch. You don't want to do anything that might get you unstable and flip over but being flat stable and happy is the worst case for a quick reserve PC launch. The training mentioned above of looking over you shoulder is good because it helps disturb the burble and get the PC off you back. Waiting to recognize a PC hesitation and then looking may be too late.

Get with a rigger, understand your gear.
I'm old for my age.
Terry Urban
D-8631
FAA DPRE

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>How common is this on a reserve?

It's not that uncommon when you are flat and stable; there's a burble right above your reserve (which is one reason throwouts got so popular.) When I teach AFF I emphasize looking above you after a reserve pull by twisting hard at the waist; this both lets you see what's happening above you and disturbs the burble if the PC is there.

During most cutaways (i.e. something out) it's not an issue.

BTW the spring isn't nearly long enough to get the PC out of the burble; it extends several feet above the jumper. It's main purpose is to push open the reserve flaps and launch the PC up to where the air is a bit clearer - and with luck it finds its way out of the burble.

Back when we had main ripcords on student rigs I got a very closeup view of burbles, and they happened about 30% of the time. (i.e. the PC would bounce at least once.) For level 1's we took to rotating the student upright as the PC launched, both to clear the burble and reduce the opening shock.

Final note - I still have a video from an AFF level 2 I did years ago. Student pulled, I turned to leave, got about 5 feet away. The PC launched, arched over him towards me, landed on my back, then finally caught air and deployed. All I felt was a little tap. PC's do strange things.

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20_kN

My understanding is that most (all?) reserve PCs have a spring that's intended to help prevent that from happening.





councilman24

I'm somewhat concerned that with an A license you don't seem to have a basic understanding of gear. (That all skydiving reserves have a spring loaded PC)



So he did not assume that it was a universal constant, and this concerns you?

Ok.

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GoGoGadget

*** My understanding is that most (all?) reserve PCs have a spring that's intended to help prevent that from happening.





councilman24

I'm somewhat concerned that with an A license you don't seem to have a basic understanding of gear. (That all skydiving reserves have a spring loaded PC)



So he did not assume that it was a universal constant, and this concerns you?

Ok.

Yes, because he should know that by now. This gear is what saves your life. Relying on a rigger or an AAD may be required by law or DZ rule but you need to know as much about your gear as you can. The basics of how it works is .. well basic. Knowing that you may have a PC hesitation that you have to blow off by rolling a shoulder or setting up my save your life. And it's YOUR responsibility to know what to do to save your life. I've know jumpers with hundreds of jumps who didn't know how to hook up a 3 ring. This means that they didn't know if it was wrong. At drove me nuts.
I'm old for my age.
Terry Urban
D-8631
FAA DPRE

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councilman24

****** My understanding is that most (all?) reserve PCs have a spring that's intended to help prevent that from happening.





councilman24

I'm somewhat concerned that with an A license you don't seem to have a basic understanding of gear. (That all skydiving reserves have a spring loaded PC)



So he did not assume that it was a universal constant, and this concerns you?

Ok.

Yes, because he should know that by now. This gear is what saves your life. Relying on a rigger or an AAD may be required by law or DZ rule but you need to know as much about your gear as you can. The basics of how it works is .. well basic. Knowing that you may have a PC hesitation that you have to blow off by rolling a shoulder or setting up my save your life. And it's YOUR responsibility to know what to do to save your life. I've know jumpers with hundreds of jumps who didn't know how to hook up a 3 ring. This means that they didn't know if it was wrong. At drove me nuts.

Totally agree. There is no excuse nor reason for ignorance. Ultimately, your life is your responsibility.

People need to wake up. This is not tiddlywinks we are playing.
My computer beat me at chess, It was no match for me at kickboxing....

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I think there are a couple of important things to point out here:

1) The original poster knew enough about their own gear to ask a question about spring loaded pilot chutes and hesitation. I think it shows they're thinking about safety and asking good questions. They're clearly thinking about these things and developing a better understanding. This is, utterly, entirely, and without question a good thing.

2) I don't think it's fair to expect a newly license jumper to know everything about all sport gear. Clearly they know their gear has a spring loaded reserve pilot chute. It looks like they're a fairly new jumper (A license), not a rigger. We need them to know their gear, and more importantly, their EPs. And given the questions they're asking, they're thinking about EPs.

3) By admonishing the poster in this manner we risk discouraging the asking of questions by creating toxic environment. An environment where people are fearful of asking a questions because someone with a lot more experience (and maybe has forgotten what it's like to be new at this) says "they should have already known it" or some other admonishiment. Maybe they should have known, maybe not (in this case I don't think they should have), but either way it's far better to address it than to admonish it. We want to cure ignorance, not encourage it.

Because a toxic environment where people are discouraged from asking questions, quite simply, is a recipe for death. We aren't playing tiddlywinks.

When we stamp their foreheads many of us tell them it's a license to learn. Let's not discourage that.

So original poster, keep posting these questions. You're asking good questions (don't forget to ask you instructors, generally they're a better resource than message boards). But these are important questions. Keep it up.

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shadeland

I think there are a couple of important things to point out here:

1) The original poster knew enough about their own gear to ask a question about spring loaded pilot chutes and hesitation. I think it shows they're thinking about safety and asking good questions. They're clearly thinking about these things and developing a better understanding. This is, utterly, entirely, and without question a good thing.

2) I don't think it's fair to expect a newly license jumper to know everything about all sport gear. Clearly they know their gear has a spring loaded reserve pilot chute. It looks like they're a fairly new jumper (A license), not a rigger. We need them to know their gear, and more importantly, their EPs. And given the questions they're asking, they're thinking about EPs.

3) By admonishing the poster in this manner we risk discouraging the asking of questions by creating toxic environment. An environment where people are fearful of asking a questions because someone with a lot more experience (and maybe has forgotten what it's like to be new at this) says "they should have already known it" or some other admonishiment. Maybe they should have known, maybe not (in this case I don't think they should have), but either way it's far better to address it than to admonish it. We want to cure ignorance, not encourage it.

Because a toxic environment where people are discouraged from asking questions, quite simply, is a recipe for death. We aren't playing tiddlywinks.

When we stamp their foreheads many of us tell them it's a license to learn. Let's not discourage that.

So original poster, keep posting these questions. You're asking good questions (don't forget to ask you instructors, generally they're a better resource than message boards). But these are important questions. Keep it up.



You got the wrong end of the stick here. I was not specifically criticising the OP.

My comments were aimed at the general skydiving population who take no interest in finding out about their gear.

Asking questions is the best way to do that. There are no stupid questions.

However.

I would expect an A licence holder to know enough about their gear to be able to pack it, untangle it, inspect it properly, assemble the 3 ring, and give good gear checks.
And also have an understanding of how the AAD works, and how the deployment system works for both main and reserve.

There is plenty of downtime while earning an A licence to find out these things. I guess some people just spend their downtime sitting on their arses with their brain switched off.

And THEY are the ones my comments are aimed at.
My computer beat me at chess, It was no match for me at kickboxing....

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billvon

>How common is this on a reserve?

It's not that uncommon when you are flat and stable; there's a burble right above your reserve (which is one reason throwouts got so popular.) When I teach AFF I emphasize looking above you after a reserve pull by twisting hard at the waist; this both lets you see what's happening above you and disturbs the burble if the PC is there.

During most cutaways (i.e. something out) it's not an issue.

BTW the spring isn't nearly long enough to get the PC out of the burble; it extends several feet above the jumper. It's main purpose is to push open the reserve flaps and launch the PC up to where the air is a bit clearer - and with luck it finds its way out of the burble.

Quote

Back when we had main ripcords on student rigs I got a very closeup view of burbles, and they happened about 30% of the time. (i.e. the PC would bounce at least once.) For level 1's we took to rotating the student upright as the PC launched, both to clear the burble and reduce the opening shock.



Final note - I still have a video from an AFF level 2 I did years ago. Student pulled, I turned to leave, got about 5 feet away. The PC launched, arched over him towards me, landed on my back, then finally caught air and deployed. All I felt was a little tap. PC's do strange things.



I might just add that a few of us started jumping before hand deploy came into widespread use - I first saw a hand deploy rig in 1976, after having started two years earlier. In those days, we regarded hesitations as a fact of life and frequently talked about them and our own methods of avoiding or dealing with them. Today's generation of jumpers know only hand deploy and never even pull a ripcord until they're already in trouble. There is a real knowledge gap in the art of ripcord deployment that needs more attention.

Your humble servant.....Professor Gravity !

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