Slider Down Line Twists

[guest]

Seen a couple of them now, sometimes in conjunction with 90deg+ off headings, one of them multiple twists but with a bang on heading opening.
All seem to have come about by the jumper being turned or spun during the opening sequence.
Anybody got any ideas on what contributes to them happening and how to reduce their occurence?

[bps]

Hi Dizzy -

I've seen about a dozen slider-down line twists from jumpers who had uneven / poor body position during the deployment sequence.

It appeared that the hard opening combined with an asymetrical body position on deployment literally swung the jumper into line twists on opening shock.

Here's an interesting trend that I'm starting to notice with vented canopies:

As we all know, canopies with bottom skin inlets, like the Black Jack and the V-tec, pressurize significantly faster, resulting in a more forceful opening, especially in the 2 to 3 second range.

From what I've seen, this increased opening shock may increase the possiblity of spinning the jumper into line twists, especially if the jumper has an asymetrical body position.

The first and only time that I had line twists on a jump was a slider-down jump on a vented canopy at the Perrine. It was a standard 2 second delay and my body position was good throughout deployment.

Like most off-headings, it occured from canopy extraction to line stretch. (it was a 90 left) The opening force spun me to the left, past the direction of canopy flight and into a half line twist. I was in no immediate danger of striking anything, so I kicked out and landed uneventfully.

Recall of the jump led me to believe that my body position was fine and it was the added force of the opening that "spun" me into the line twist. Video review confirmed this.

So my thought is that increased opening forces may contribute to the likelyhood of line twists if the jumper's canopy heading or body position is asymetrical.

Something to consider...

Bryan