Current thinking - getting out of line twists

[kleggo 145]

For Discussion

Hi.

Assume a wing suit jump. And assume that a lightly loaded square parachute is flying flat / straight, but there are multiple line twists between the canopy and the jumper.

What is current thinking on getting out of line twists prior to decision altitude?

Squeeze risers together and reach up to untwist to bring twists down to the risers?

Pull risers apart and?

Other?

 

Thank you

Edited December 3, 2021 by kleggo

[BMAC615 209]

This

[Kenzdik96 26]

Yes, exactly as described in that video, squeeze risers together and attempt to bring the linetwist as low as possible. That will help keep the canopy level, and once the line twist gets low enough, enable you to have some control of the parachute even before the line twist is fully resolved. This is the second best method of dealing with linetwists on all parachutes (square, elliptical, crossbraced), where the best method is, of course, preventing them in the first place. As for prevention methods, semi stowless bags help somewhat, so does packing technique (on some canopies), and having your gear sized properly and suited to the activity you are doing (wingsuit options for your rig if you are flying a wingsuit etc). But by far the best prevention method is having a proper body position on opening. A 360 camera can be a very useful tool when investigating body position errors. 

A useful anti-line twist tip (although I am not sure how applicable it is to wingsuit) is to keep your hands on your chest and rest your chin on your fists immediately after throwing your PC, while simultaneously getting your legs together and touching your knees and ankles together. This does several things: makes sure your body is as symmetrical as possible, keeps your hands away from grabbing the risers prematurely (preventing your hand or finger from being caught in a line twist, can lead to broken bones), and as your chin is resting on your fists it forces you to look at the horizon instead of at your deploying canopy, which in term boosts your situational awareness and gives you proper warning when your canopy is beginning to turn during the opening and enables you to correct the turn with your harness before a violent line twist fully develops. 

[chuckakers 426]

On 12/3/2021 at 10:43 AM, kleggo said:

Assume a wing suit jump. And assume that a lightly loaded square parachute is flying flat / straight, but there are multiple line twists between the canopy and the jumper.

What is current thinking on getting out of line twists prior to decision altitude?

Squeeze risers together and reach up to untwist to bring twists down to the risers?

Pull risers apart and?

Other?

Important topic. Following.

[Divalent 139]

"Squeeze risers together and reach up to untwist to bring twists down to the risers?"

This worked for me every time, although the "squeeze risers together" is not part of it; it's twisting the twisted section to lower it that is the important element. Usually it will also get your body rotating in the correct way so that it untwists on its own. But by lowering the twists, you can also then reach to the lines above the twists, which allow you good leverage to get your body rotating.

This is illustrated pretty well in the compilation video that BMAC615 posted above. (And in the last one shown in that video, apparently you can use your feet, lol!)

The old "kick-em out" method in the SIM is pretty poor. They really should replace it with this one.

[wolfriverjoe 1,523]

Random thought that just popped into my head (and an honest question that I don't know the answer to):

Squeezing the risers together brings the twisted section lower.
That means the canopy spreads out more and there's a longer length of lines above the twist. (this part isn't the question)

Does that wider canopy spread and longer length of line above the twist give better leverage for the twist to be undone?
Put slightly differently, does the lower twist see a greater 'untwisting' force from the lines and canopy?

A long time ago, when I was a student, I learned on direct bag static line gear. 
That setup almost guarantees line twists on opening. 

I got pretty good at getting out of line twists. It was under a 288 Manta, so it never gave me any issues other than the untwisting part.

I found that once I started spinning out of the twists (sometimes had a lot of them), I would keep untwisting and even go faster as the 'pull' on the lines added force to the untwisting.

[BMAC615 209]

 

2 hours ago, wolfriverjoe said:

Squeezing the risers together brings the twisted section lower.
That means the canopy spreads out more and there's a longer length of lines above the twist. (this part isn't the question)

Does that wider canopy spread and longer length of line above the twist give better leverage for the twist to be undone?

 

It’s not that the wider canopy spread and longer length of line above the twist gives better leverage for the twist to be undone (or undo itself) so much as it gives you the ability to have leverage to spin yourself in the opposite direction of the twists.

@chuckakers, if you’re following for potential updates in line twist procedures, consider teaching “riser control” as in reach up and spread risers apart during opening sequence. This video demonstrates good riser control. It allows the pilot leverage to keep the body from creating line twists during opening sequence. Another consideration is “feet and knees together” once the pilot transitions to vertical during deployment to keep your leg wing from becoming a propeller and rotating the pilot under the canopy.

If you find yourself in line twists, do not unzip your leg zippers and do not try to release the brakes. Simply reach up, squeeze risers together and twist the risers in the direction of the twists so the twists themselves transfer down to the risers as demonstrated in This video. At that point, you can make heading changes by pulling on rear line groups or just push off the line group to rotate yourself in the opposite direction of the twists.

This procedure works equally well for non-wingsuit canopies not flying straight or level as demonstrated in the video referenced above.

Edited December 5, 2021 by BMAC615

[meteora 2]

I like this method: https://www.skydivemag.com/new/lacs-line-twist-remedy/ 

This was explained to me at a wingsuit competition in Germany about two years ago. On a rainy day everyone tried it in the training harness. For me it works just perfect.

[kleggo 145]

bmac, thanks for the vimeo = very clear.

 

meteora, thanks, I haven't watched the viddy yet, but I'm guessing it's the one where the guy is a proponent of swinging his lower torso and legs to untwist. Might be a good solution if one can't reach the risers for some reason.

 

Cheers

Craig