Tension knot or something more

[Binary93 65]

Hi folks,

A friend of mine had a cutaway yesterday (video below).

1. He didn't untwist the toggles for at least few weekends of jumping (the twists are visible on the video).
2. During packing, he flakes (pushes material between AB, BC  and CD outside and lines inside) but he doesn't clear stabilizers etc. During the opening, it looks to me as if stabilizer is trying to inflate while there are lines over it.

My question is, do you think the only cause for this is the twisted brake line (leading to a tension knot)? Do you think not clearing stabilizers during packing can also contribute towards this (or something else)?

I expect the answer to be "yeah, tension knot, untwist your brakes" but posting just in case I'm missing something and there's more to be learned.

Thanks!

 

 

 

[riggerrob 643]

Bill Booth likes to remind us that packing a ram-air canopy is basically about straightening out the strings. Once strings are straight, it will want to open.

Failing to clear stabilizers - outside of lines - was your buddy's first mistake.

Yes, twisted steering lines are more likely to create tension knots.

[CoolBeans 11]

How does one clear the stabilizers? Honest question. 

[Binary93 65]

29 minutes ago, riggerrob said:

Yes, twisted steering lines are more likely to create tension knots.

Thanks for the answer! Is there any other way to create a tension knot (I thought twisted steering lines were the only way)?

 

8 minutes ago, CoolBeans said:

How does one clear the stabilizers?

When you're packing, during/after flaking but before wrapping the canopy into a cocoon, you're supposed to pull the stabilizer material outside and leave the lines inside (in the video below, from 6:15 to ~6:23 for example). If you leave the lines over the material, they can burn the fabric during opening and damage your canopy. Not sure if there are any other possible side-effects.

 

[Westerly 61]

6 hours ago, CoolBeans said:

How does one clear the stabilizers? Honest question. 

Quickly because you have to catch the next load and that cute girl with the pink rig wont be impressed with you if you miss the load.

[CoolBeans 11]

1 hour ago, Westerly said:

Quickly because you have to catch the next load and that cute girl with the pink rig wont be impressed with you if you miss the load.

I think that's a guy actually, long haired guy rolling pink rig. 

Edited September 8, 2020 by CoolBeans

[Jaysus 1]

6 hours ago, CoolBeans said:

I think that's a guy actually, long haired guy rolling pink rig. 

Well I don't have long hair, but the rest is correct

[riggerrob 643]

The easiest way to keep suspension lines neat is applying a bit of tension.Gravity is your friend. PRO -packing helps as long as all the lines are evenly tensioned between your shoulder/hook and the harness.

 

A wise man can learn from even the village idiot.

Edited September 8, 2020 by riggerrob
add a sentence

[20kN 93]

Keeping things neat and straight can help, but only to a degree. Anyone who has watched even one single rear facing camera view of a parachute opening knows that once it hits the relative wind, shit goes flying everywhere and that nice art of perfectly executed folds turns into a ball of crap in a nanosecond anyway.

Edited September 8, 2020 by 20kN

[obelixtim 150]

On 9/7/2020 at 8:09 PM, Binary93 said:

Hi folks,

A friend of mine had a cutaway yesterday (video below).

1. He didn't untwist the toggles for at least few weekends of jumping (the twists are visible on the video).
2. During packing, he flakes (pushes material between AB, BC  and CD outside and lines inside) but he doesn't clear stabilizers etc. During the opening, it looks to me as if stabilizer is trying to inflate while there are lines over it.

My question is, do you think the only cause for this is the twisted brake line (leading to a tension knot)? Do you think not clearing stabilizers during packing can also contribute towards this (or something else)?

I expect the answer to be "yeah, tension knot, untwist your brakes" but posting just in case I'm missing something and there's more to be learned.

Thanks!

 

 

 

 Easy demonstration: Take a piece of line, hold it under tension, and introduce multiple twists to it. Then relax the tension. You will see it automatically kink up. Thats how many tension knots are born.

 I had a student canopy amongst my rigs that every now and then would be cutaway. I had 4 other identical canopies, but this one quickly showed itself as a rogue. I found the problem to be several lines which had been attached during manufacture that were twisted.  Easily solved, but had I figured it out earlier, it would have saved me a few reserve repacks, and a few students from an extra adrenalin rush. 

Untwist your brake lines.