Self induced line twists (youtube video) - Was: Fatality in Rockmart, GA

[BillyVance 34]

Mark, could you have held both toggles in one hand so you could pull your goggles off with the other hand?

"Mediocre people don't like high achievers, and high achievers don't like mediocre people." - SIX TIME National Champion coach Nick Saban

[Andy9o8 0]

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I watched the video linked above by BlueHaze several times, and what I saw was:

Normal main deployment.
Release brakes.
Canopy flies normally.
Hard left toggle turn around 360 degrees.
Immediate right toggle turn, without waiting for the canopy and jumper to return to straight flight.
Canopy flies into line twists.
Jumper tries to kick out.
Jumper decides that it's time to cutaway.
Jumper cuts away.
Typically fast SkyHook reserve deployment.
Normal reserve flight and landing. (Though I'm not sure I would have made that left turn just before landing. Looked a little low!)

This problem can happen even on lightly loaded student canopies. Any time you're making a hard turn, let the canopy return to straight flight before turning the other direction.

That is not what i saw at all. I never saw a right hand turn period. I saw canopy already open..toogles released then an immediate left 360 in which appeared to be too aggressive and he spins up and and it looks as if he pulls both handles at same time. thats what I saw.

Looked that way to me, too.

[LeapingGnome 0]

I saw something completely different, while at the end of his left turn the horizon rises as if in a turn stall and the left end cells are collapsed. Just as it starts to go into the spin he has slack in the right riser group over the back of the left risers, then it starts to spin. If he started a turn to the left and while in the turn pulled the right toggle the canopy could try to "helicopter". And then throw slack in the line group.....know what I trying to say?

Falcon 74, Eagle 110, NFS 407, GW-2945, DW-1641, DDW-1151, "Inga... elevate me"

[Gato 0]

This all was addressed (with the video) in a 14-page thread Marko put up a few months ago - the discussion, then, was about him flying a 135.

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3119923;search_string=markovwgti;#3119923

By the way, kudos to you, Marko, for upsizing to a Safire2 149!!!

T.I.N.S.

[LeapingGnome 0]

Thanks i didn't know. I was just addressing what Gary73 saw.

Falcon 74, Eagle 110, NFS 407, GW-2945, DW-1641, DDW-1151, "Inga... elevate me"

[Gato 0]

Doh!!

Sorry, Gnome!!!

I wasn't directing that specifically at you - just the whole damn thread!

I need to watch my mouth sometimes, or at least where it's pointed.

T.I.N.S.

[markovwgti 0]

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Mark,
Thanks for the info; I guess I saw something that wasn't there. I honestly didn't think a canopy like that would twist up with just a single turn. Glad you got out of it okay!

Hey man its all god..hey im glad i got out of it too!! :)

[markovwgti 0]

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This all was addressed (with the video) in a 14-page thread Marko put up a few months ago - the discussion, then, was about him flying a 135.

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3119923;search_string=markovwgti;#3119923

By the way, kudos to you, Marko, for upsizing to a Safire2 149!!!

i never had a 135...and will not get a 135 for a while....i was just changing my profile every week wiriting different canopy sizes to be a asshole and make everyone else think that lol...sorry about that!

[markovwgti 0]

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Mark, could you have held both toggles in one hand so you could pull your goggles off with the other hand?

i havent thought about it and dont really want to try...maybe they can get entangled or something...who knows what can happen!!

[fergs 0]

Aren't we all getting lost in off-the-subject items. This thread is about Mark experiencing a toggle induced line twist and spin. Whether he had fogged goggles or had let go of his toggles or wanted to brew a coffee is irrelevent for the main lesson we all should be learning from his expeience.

The main thing to learn, in my opinion, is that a TOGGLE INDUCED TWIST and spin is a possibility on each and every jump we make.

If this happens to you, how you deal with the situation is dependent on a number of things. Your altitude at the time is an important one.

I estimate Mark's altitude at cutaway to be around 400 to 450 ft. At this height, his only real option was to chop. Had he been a lot higher, he'd have had other options if he chose to use them (kicking out, opposite toggle, etc). Had he been lower, his chances of a nice stand up landing on his reserve would reduce with the altitude down.

His chances of a successful cutaway and long reserve ride (if you can call 40 seconds a long reserve ride?!!) were drastically increased due to the rig being skyhook equipped.

From chop to being suspended under a fully open reserve was between 1 and 2 seconds. This is an outstanding feature of a skyhook controlled cutaway. Let me say those important numbers again - between 1 and 2 seconds. Think that through for a moment.

So ladies and gentlemen - for those who want to debate loosening chest straps, cleaning goggles and the like - take those to another thread. Focus on the issue. Be aware of how (easily) a toggle induced twist can happen. DO NOT DO THIS lower than any height you are comfortable chopping at.

If you were unaware of how fast a skyhook gets reserve nylon above your head after a cutaway, go back to the vid and watch it frame by frame. Be impressed with how reserve deployment borders upon instant.

OK, are we focussed?

Be safe.

f

[markovwgti 0]

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Aren't we all getting lost in off-the-subject items. This thread is about Mark experiencing a toggle induced line twist and spin. Whether he had fogged goggles or had let go of his toggles or wanted to brew a coffee is irrelevent for the main lesson we all should be learning from his expeience.

The main thing to learn, in my opinion, is that a TOGGLE INDUCED TWIST and spin is a possibility on each and every jump we make.

If this happens to you, how you deal with the situation is dependent on a number of things. Your altitude at the time is an important one.

I estimate Mark's altitude at cutaway to be around 400 to 450 ft. At this height, his only real option was to chop. Had he been a lot higher, he'd have had other options if he chose to use them (kicking out, opposite toggle, etc). Had he been lower, his chances of a nice stand up landing on his reserve would reduce with the altitude down.

His chances of a successful cutaway and long reserve ride (if you can call 40 seconds a long reserve ride?!!) were drastically increased due to the rig being skyhook equipped.

From chop to being suspended under a fully open reserve was between 1 and 2 seconds. This is an outstanding feature of a skyhook controlled cutaway. Let me say those important numbers again - between 1 and 2 seconds. Think that through for a moment.

So ladies and gentlemen - for those who want to debate loosening chest straps, cleaning goggles and the like - take those to another thread. Focus on the issue. Be aware of how (easily) a toggle induced twist can happen. DO NOT DO THIS lower than any height you are comfortable chopping at.

If you were unaware of how fast a skyhook gets reserve nylon above your head after a cutaway, go back to the vid and watch it frame by frame. Be impressed with how reserve deployment borders upon instant.

OK, are we focussed?

Be safe.

f

Ive been waiting a few hours for a post like this....thanks man!

BTW names Marko!

:)

Blue Skies

[fergs 0]

Marko,

Well you handled what many would find a very stressful situation very well. From the vid, you recognised that you had a big problem - then you did not hesitate to take the correct action. Congratulations.

How did you find the Skyhook? Anyone seeing your vid should now understand their huge benefit in situations like your.

All power to you, Marko.

Cheers and blue Skies,

fergs

[lethargic8 0]

I am a new jumper so I was wondering if anyone could answer this for me. I was under the impression that with an un-landable canopy below 1000ft the eps are different?

[popsjumper 2]

Certainly so. This is a case of a low cutaway WITH A SKYHOOK.

I personally would be reluctant to cutaway at that low altitude without one. There's other things that could be done instead.

YOU have food for thought...and discussion with more experienced people that you know and trust.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[jumpwally 0]

glad they made it,,,but it is the dumbest move i've seen in quite a bit................

smile, be nice, enjoy life
FB # - 1083

[rave4funn 0]

Wow! That made my butthole pucker. I want a skyhook. However, I pray I am never in a position to have to rely on it especially that low.

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http://www.myspace.com/rave4funn

[chrismgtis 0]

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Here is a video of self induced line twists at a low altitude, cutaway, and use of the skyhook. Posted for learning about this accident.

http://www.youtube.com/watch?v=QECtqCRNKxs

That was scary. Someone has some balls!

Rodriguez Brother #1614, Muff Brother #4033
Jumped: Twin Otter, Cessna 182, CASA, Helicopter, Caravan

[markovwgti 0]

thanks.....

[SkymonkeyONE 3]

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Cos the brake line could have wipped round another line or produced a tension knot.

I don't understand this. There will be no slack in the brake lines. The canopy PULLS them up...no slack to get tangled in other lines.

That's sort of accurate, at least in most cases. For example, on both of my sport canopies the brake lines are let out very long and the excess loops out back behind the canopy in full flight. The only tension on the toggles in full flight is because of the drag to the rear created by the airspeed. The tail of my canopy in no way pulls "up" on my toggles. Even on "non-swoop" canopy setups, the brake lines should not be pulling down on the tail of the canopy at all during full flight.

Chuck

[popsjumper 2]

Of course, as always, you are correct Chuck. But here, we were talking about letting go of the toggles after you had pulled them to some degree of extension, not full flight.

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[erdnarob 1]

Some basic physics law here would explain what happened. It is the conservation of the angular momentum. In other word, what I have seen on the video is a quite sudden deep input on the left toggle inducing immediately severe line twists.
Explanations:
In such a case, the canopy which weights say 6 pounds is quite fast to react while the jumper's body and equipment which should be at a total of 200 pounds (a reasonable guess) has the tendency to stay at zero rotation for a little while. The jumper's body was in late to start a rotation with respect to the canopy and therefore line twists occured. The canopy is about 30 times less massive than the jumper but is wider. On the other hand the lines near the jumper are just 2 feet apart or so then easily subject for twisting. Even though the canopy is wider it is maybe 10 times faster to turn than the jumper who has zero angular momentum before the turn and whom mass have a tendency to stay as it was.

How to avoid it: When doing a fast turn, start applying pressure on toggle progressively to allow the canopy to start the turn and bank and allow your body to follow the rotation. Once you have the rotation of the canopy, the bank and the rotation of your body, everything should be OK about line twists not likely to occur. Or you also can kick your body while applying a sudden input on your toggle. That way you help your body to follow up with the canopy which starts to turn. Swoopers at 400 feet are doing it by using their legs to do so.

Years ago, in the eighties, I had a Nimbus canopy having an aspect ratio near 3:1. On my 3rd jump with it and at a 1000 feet I gave that parachute a sudden medium imput and got an immediate line twists. People at the ground saw it and I even heard their OOOOHHH!!. Fortunately I had only one and half line twists and managed easily to get rid of that. It was a lesson for me to remember. When you drive a car, you don't turn the steering wheel suddenly especially when slippery.

Learn from others mistakes, you will never live long enough to make them all.