Brake line break possibility

[katzurki 0]

So far I have had the impression that, if they do at all, the lines break on opening.

Has it ever happened / how likely is it that a brake line can break when you pull it for a toggle turn, or worse yet, when you pull on both during your flare?

(The question arose when I rented a rig that had somewhat rusty, sharp-feeling grommets (those small metal rings through which the brake lines pass)... the canopy was hooked up after it had been chopped and spent some time in a puddle a few months back then. It was inspected and I was told I could jump it for today, and they would fix those rusty rings the next day.

[GeordieSkydiver 0]

I read an incident somewhere (safety and training?) where exactly that happened.

Some dude came in to land, flared, one brake line snapped and he went into a turn until impact, luckily he was almost down, and survived.

I also saw a guy in California land on rears because one of his brake lines broke on his 'steerable' checks.

So, yes. It can and does happen.

Lee _______________________________

In a world full of people, only some want to fly, is that not crazy?
http://www.ukskydiver.co.uk

[ryoder 1,590]

The brake lines are the only components that can, (and do), fail well after opening shock. Any portions of the lower steering lines that come into contact with the keeper rings are subjected to wear during toggle maneuvers. Also note that the point where the toggle attaches to the steering line does not experience load during opening shock, so if it was improperly attached, it would most likely fail after releasing the brakes.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[riggerrob 643]

Steering lines breaking AFTER opening is a recent phenomenon.
The latest, heavily-loaded canopies open so soft, but can pull so many Gs tuning onto final approach, that they experience grater loading during turns than opening shock.
Mind you, only already frayed lines are likely to fail on final approach.

[billvon 2,991]

> how likely is it that a brake line can break when you pull it for a
> toggle turn, or worse yet, when you pull on both during your flare?

It has happened and can happen in a few ways.

1. The lower line (below the stow) can break during brake release or the flare. Note that this line is not loaded at all during opening, and gets much of its wear by having the catseye or finger trap sliding through the guide ring constantly.

2. The toggle can come off. Again, it's not loaded during opening, and a problem (like an unsewn/un-knotted toggle fingertrap) may well show up during release or flare.

3. The flare can just be the final straw that breaks a very worn line.

A factor compounding this is that Vectran doesn't show wear as readily as Spectra so it's easier to miss an impending problem.

[johnny1488 1]

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A factor compounding this is that Vectran doesn't show wear as readily as Spectra so it's easier to miss an impending problem.

I have to say that is wrong. Vectran shows a lot of wear before it breaks. In fact it looks like shit. Spectre doesnt show much wear, but its major fault has been shrinkage, not breakage. HMA on the other hand, shows very little wear prior to breaking. One of the reasons, I'm sure, that the manufacturers that use it, have since stopped putting it on brake lines and used dacron instead.

Johnny
--"This ain't no book club, we're all gonna die!"
Mike Rome

[DancingFlame 0]

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Vectran shows a lot of wear before it breaks.

Not always. My control line seemed to be in good shape but after a BANG opening i've got that line broken...

[johnny1488 1]

Which line broke and how many jumps did the set have on it? Where was the canopy packed and jumped (conditions).

Even though my brake lines still looked jumpable, I always changed them at 300 jumps. My concern has always been a brake line breaking on flare. A broken line on opening has never been a concern for me.

And whether or no vectran can brake was not what I was relying to. It was the fact that vectran shows more wear than spectre or HMA.

Johnny
--"This ain't no book club, we're all gonna die!"
Mike Rome

[nicknitro71 0]

I raccomand making the lower control lines of 600 LB flat dacron.

Memento Audere Semper

903

[DancingFlame 0]

Loop where lower control line attaches to upper one. Lineset had more than 500 jumps. Packed only indoors on packing carpet (I love my canopy). Jumped in heavy conditions, weather sucks here

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I always changed them at 300 jumps

Good idea. I'll follow this one too.

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It was the fact that vectran shows more wear than spectre or HMA

Agree with HMA. Do not agree with spectra. However spectra-lined canopies go out of trim faster that lines get worn out.