Low line twist fatality?

[jaymundo 0]

How in the hell did she induce line twists by turning her canopy.I havent had my sabre2 150 even come close to doing this by honking down on a toggle? speaking of the girl in the fatality section of parachutist.

[PhreeZone 20]

On a highly elliptical canopy this can be done fairly easliy. A stiletto and similar canopies can be wraped into line twists with just toggle input at any time if the pilot is not careful.
If once you start down the dark path, forever will it dominate your destiny, consume you it will....

[Jimbo 0]

We already know that it can done, that much is obvious. The better question is how? What forces work to make this happen?

[PhreeZone 20]

Rapid extreme toggle movements, uneven side to side loading of the canopy, stalling the canopy, extreme or rapid rear riser movements, Unloading the canopy in a rapid turn. All these are factors that can lead to self induced line twists. Many more factors help and I'll let some one that knows them better explain them.
I was able to give my self induced line twists under a Spectre 170 loaded just under 1:1 at 5000 feet once. An elliptical canopy just makes this easier for this to happen. I learned what a stall turn was on that jump....
If once you start down the dark path, forever will it dominate your destiny, consume you it will....

[billvon 2,991]

>The better question is how?
One way is to do a "stall turn" - bring both toggles all the way down, wait until the canopy stalls, then let one back up all the way. Another way is to do a hard turn, let the canopy recover, wait until it is going as slow as it will go in its recovery, and turn hard right there. All good things _not_ to do at low altitudes.
-bill von

[jaymundo 0]

Thanks yall,I will file this feedback and use it while under canopy.I just downsized to 1.56 and want to do things right.I skydive on the gulf coast where its fairly windy.The pd170 had me unable to fight the wind,so I went to the sabre2 150 and its been great.Thanks again

[AndyMan 7]

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A stiletto and similar canopies can be wraped into line twists with just toggle input at any time if the pilot is not careful

I wouldn't go that far. You can't spin up a stiletto just by burrying a toggle.
You can spin up an eliptical canopy by alternating very deep toggles. Deep into the right, then quickly deep into the left. I suspect this is true of your sabre2, too.
You can also induce a spin on an eliptical canopy by completely stalling it. As the canopy collapses there's a risk of it spinning if you're not even on the toggles.
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[riggerrob 643]

The theory behind self-induced line twists is that since the canopy weights less (has less mass) it can turn far quicker than the suspended weight (jumper). If you are vigorous enough with control inputs, then you can induce line twists. The heavier the canopy is loaded, the quicker it will twist. The scary part is when the lines twist tightly with one toggle down. Then you are into an un-recoverable line twist, like the one that killed my friend Bruce Geikie.
The only cure is prevention. It takes dozens of jumps to learn the edges of a canopy's envelope. How fast and how far can I move a toggle in this flight mode and still have a canopy overhead?

[wlie 0]

I'll have to agree with the rapid toggle input theory. Especially with today's high performance canopies, I think we need to paymore attention to our toggle inputs. Kind of like power steering - you don't want to apply the same force as you would on grandma's Buick.
I've heard about self-induced line twists, and it happened to me when I was trying flat turns on a Silhouette 190. I learned that I had I not let my turning toggle pass over the level of my braking toggle, and rapidly might I include, the line twists would less likely happen.
Also, I was just transitioning quiet quickly from a SkyMaster 290 (over 50 jumps) and different + smaller canopies when this happened.
And on my Diablo 170 (at 6th jump) I stabbed my toggle as I was coming in to land (about 10 feet off the ground) when another jumper overtook me and got pretty close. That move cost me a terribly sprained ankle. Then I read in Parachutist that a 28 yr old female jumper did something similar but at 50 feet. That spooked me.

[billvon 2,991]

>Then I read in Parachutist that a 28 yr old female jumper did something similar
> but at 50 feet. That spooked me.
Yep; she came as close to dying as you can come and still live. A year later she's walking again, and only needs one more surgery on her face. She was really lucky.
-bill von

[hookit 0]

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You can't spin up a stiletto just by burrying a toggle.

I disagree. When I was a newbie and had just downsized from a rented Fury 220 to my first canopy which was a PD 190 (loaded just under 1 to 1) I gave it line twists on the first turn I attempted to initiate.
I was used to having to bury a toggle to get the huge student canopies to turn. I was flying straight and buried the right toggle. This stalled the right side of the canopy while the left side continued to fly thereby spinning the canopy above me and giving me line twists. Not to mention scaring the crap out of me!
Fortunately I was plenty high and kicked out of the twists with no problems.

[cloud9 0]

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How in the hell did she induce line twists by turning her canopy

This is really fairly easy to do. I have seen it done twice in the last 6-8 months. Both times the jumpers were sasheying their canopy into the landing area. The first time under a stiletto loaded at about 1.4 it induced a 180 line twist at about 70 ft which he promply kicked out of by about 30 ft. The second time under a stiletto loaded at about 1.5 at about 800 ft he was in one full twist and neither of these jumpers were making radical inputs. Both landed fine but it got their attention.