Forums: Skydiving: Safety and Training:
Canopy Collision

 


Jimbo  (D License)

Apr 6, 2001, 5:48 PM
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Canopy Collision Can't Post

I was reading a local dropzone's online "student manual" when I came across this. It's filed under 'odd situations', and is in reference to two jumpers entangled in each others lines. Is this correct?

In reply to:
One or both of you may have to cutaway. The rule-of-thumb is for the high person to cutaway, fall through the lower person's lines, then deploy their reserve. This is just a rule of thumb and may not apply to all situations. Remember, you can't disconnect the RSL on XXX student rigs. Your reserve will start to deploy immediatly as you fall away from the mess. Will your reserve entangle with anything as it starts to deploy? It may be better for the other person to cutaway first.
This is a little disturbing as I thought that the LOW person cut away first. It seems dangerous having the high person cutaway and fall through the low persons lines, am I wrong? What are the situations in which the high person would cutaway first?

-
Jim



mountainman  (A License)

Apr 6, 2001, 11:04 PM
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Re: Canopy Collision [In reply to] Can't Post

from all of the literature I've read about it, the low person cuts away so the reserve doesn't catch on anything (as you've said). I don't see how the high person cutting away would be any safer. Also, I would think the high person would have a better chance of untagling the mess after the low had cut-away.

Just my thoughts!



Jimbo  (D License)

Apr 7, 2001, 1:12 AM
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Re: Canopy Collision [In reply to] Can't Post

In reply to:
rom all of the literature I've read about it, the low person cuts away so the reserve doesn't catch on anything (as you've said). I don't see how the high person cutting away would be any safer. Also, I would think the high person would have a better chance of untagling the mess after the low had cut-away.
My feeling exactly. Suggesting that the high person cut away is even worse when you realize that you cannot disconnect the RSL on the student rigs.

Any experienced CReW guys out there who can provide any insight as to why the high person would be encouraged to cutaway first?




Craig

Apr 7, 2001, 6:40 AM
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Re: Canopy Collision [In reply to] Can't Post

All the following just comes from what I have read and was taught.
On a wrap (i.e. your canopy wrapped around another jumper) the low person would want to cutaway first. You wouldn't want the high person to go into freefall all wrapped up in a canopy is the reasoning behind this. An entanglement might be a bit different. Lets say your canopy tangled in the other jumpers lines, so now you are hanging below the other jumper and the two canopies. If you just cutaway, there is a good possibility of your lines recoiling up into the other jumper causing more problems like them not being able to get untangled. Obviously a delay is important between the cutaway and reserve pull, but only if there is altitude to do so. If the RSL is not able to be disconnected, then the low person will have to cutaway and hope they do not entangle again. Of course, if you are getting too low for a cutaway then dump both reserves and hope for the best. Communication is important between the two jumpers so don't forget that either.
Just my .02
Craig



Stacy  (D License)

Apr 7, 2001, 2:40 PM
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Re: Canopy Collision [In reply to] Can't Post

Jim-

In my CRW stuff with Kruse he has always said the bottom cuts away first for seperation purposes and because the top person would obviously fall into the mess further if he were to chop. I'm racking my brain as to why womeoen would say what you read. hmmmm.


Stacy
http://astro.temple.edu/~sweeks


Jimbo  (D License)

Apr 7, 2001, 2:59 PM
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Re: Canopy Collision [In reply to] Can't Post

That's what I had thought. Having the top guy fall through the lower guys canopy just sounds dangerous. I would think that there is a good possibility of him snagging on the lower guys canopy and taking him down with him.

This just sounds like bad advice. I'd really love for an experienced CReW guy to comment on this.



Premier slotperfect  (D 13014)

Apr 7, 2001, 3:54 PM
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Re: Canopy Collision [In reply to] Can't Post

  I'm not an EXPERIENCED CReW guy; I have about 50 CReW jumps.

The theory behind the higher jumper cutting away first is that if the bottom jumper chops first, the higher jumper could be "fatally engulfed" in the lower jumper's jettisoned canopy. I don't particularly subscribe to that; I believe that those situations have so many possible variables that the two jumpers involved will need to keep a cool head and figure it out.

Of course the best way to deal with a wrap is not to get in one at all:

-learn how to flat track well so you get as much separation at break-off as possible
-clear left, right, above, and below as you wave-off
-keep your head on a swivel immediately after deployment, especially if your canopy opens off heading. Use your rear risers to make emergency turns to avoid anyone who shows up unexpectedly
-Bottom line: sometimes you have to look out for number one!

If you do have a collision/wrap (and you just might - I have had 2 collisions in 2447 jumps), two things are paramount: altitude awareness and communication!

-low-time jumpers should take guidance from the more experienced jumper in the wrap
-use your hook knife to clear yourself of the other canopy (you DO carry one, don't you?)
-remember that microline is very sharp when under tension, so check your rig out for damage before you make your decision (in case the other jumper's lines have sawed through part of the harness or reserve risers

In both of my collisions nobody was at fault . . . it was just "S**T happens." Neither resulted in a wrap, because each of us reacted IMMEDIATELY after opening. The canopies brushed off each other, and we were tipping a cold one shortly thereafter.

Two suggestions: 1) check out the canopy collision emergency procedures on the "Breakaway" video. That is a worthwhile film. 2) I attended a CReW seminar by Mike Lewis once . . . if you get the chance, he's the MAN!

Choose your CReW teacher carefully. CReW has a set of rules (discipline) just like RW. Follow them, and you'll stay safe.

Cheers,
SP



miked10270  (D 10270)

Apr 9, 2001, 11:37 AM
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Re: Canopy Collision [In reply to] Can't Post

Hi there,

Canopy collisions can fall into one of 3 distinct categories... Bounce. Wrap. Entanglement. Obviously "Bounce" (as in bounce off) is preferable, so...

If you ARE going to collide, GO BIG!!! Going into a star means that the chances of going through lines is minimised - & how hard can a nylon inflatable hit you anyway. Going big can spreads the load. So... Arms out (still holding the toggles so reduce speed) & legs open. Arch.

Assuming thathasn't worked, you're going to find yourself either "Entangled" in the other canopies lines, or "Wrapped" in the other canopy.

"Step 1" is DON'T PANIC!! Both jumpers check alti, & shout it out (in case the other can't see their alti).

"Step 2" is THINK!! One of you is almost certainly higher than the other. High man almost certainly still has a good canopy at the moment, so you have 2 persons under at least one good canopy. High man stow toggles (a loose toggle later on can complicate things). check & shout alti.

It's gonna be the high man who's entangled or wrapped. high man try to free himself or get view of his canopy.

If high man can't free himself, high man gets hold of low man's lines/canopy as high as possible & positive grip. get hold of as many lines as possible, ideally at the cascades, or get hold of 2 cells, well seperated. Check alti & shout it.

Low man chops (if there's the height) & as the load comes off the low man's main then it's gona do 2 things... First it's gonna want to go UP relative to the high man 'cos the load's gone off it. the idea behind high man having hold of the low canopy is so it doesn't foul the high canopy when low man chops. Secondly, now the load's off it, it should be amenable to collapse so high man should be able to get it under stowed to an extent.

The VITAL parts of this situation is THINK AND COMMUNICATE. "Positive" communication only please (imagine hearing only part of a negative message, like "Dont........" or "........cutaway").

Hope this helps,

Mike D10270.




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