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Fordy

Tandem equipment after malfunction

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A very experienced TMI had a very difficult situation to contend with after a tension knot malfunction on his main canopy.

I am posting this for TMI'so to read and it maybe avert the same incident happening again. I am not naming manufacturer but from the detail in the description you may make your own deduction.

TMI deployed main canopy after uneventful drogue fall at a normal altitude and had tension knots on one set of break lines, tried clearing but made the decision by 4000ft that it was not landable so initiated correct emergency procedure for this particular equipment.

Upon cutting away, part of the cutaway cable delaminated and left a strand of wire in the 3 ring release stopping the 3 ring from doing its job and releasing the main completely. This resulted in the reserve opening and immediately flying forwards and during inflation looping completely around the TMI and student entanglingredients reserve lines with the TMI at the ankle and the student on one hand.

The TMI worked the problem but could not see the issue with the 3 ring whilst being inverted under the mostly inflated reserve whilst the main spun behind on the single riser attached to the container. The TMI managed to pull the riser free without use of the knife on the student harness but said that it was incredibly difficult and disorientating with the reserve entanglement.

Once the main was freed the TMI was able to release the line group from around his ankle and then cut a line free on the student to allow a full inflation of the reserve at approximately 900ft, reserve landing was uneventful and apart from some small line burns both TMI and student were unhurt.

The BPA have issued a safety notice 1-16 stating that all cutaway cables used in sport parachuting must be coated. (This is a UK only safety notice not a manufacturer product bulletin)

The manufacturer was very helpful and communicated directly with the TMI about the issue.

The equipment had a cutaway cable that has no teflon coating on the cables although newer models come with a transparent coating.

The equipment was thoroughly checked at the servicing and has regular 100 jump checks as in accordance with the BPA regulation with no issues with the cables.

This post is not meant to invite or incite any form of scaremongering but to be informative to TMI'so that may jump equipment with bare cutaway cables and hopefully prevent an issue like this from happening again.

The TMI in the incident has over 12,000 tandems and did very well to avoid further injury to either himself or his student.

Stay safe

Regards

Fordy

[/url]http://www.bpa.org.uk/assets/Stay-safe/Safety-Notices/82.-Notice-1-16-29-07-16-SportParachuteEquipmentCutawayCables.pdf
Fordy

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Interesting.
I got a little mixed up when you said 'delaminated' as I interpreted that as meaning it was a coated cable, when I guess it wasn't.

To be clear, correct me if I'm wrong:

-- The jump happened with a rig that has a bare cable style cutaway cable (ie, must be a Strong Tandem unless there's some European rig I don't know of)

-- The cable had a broken strand
The bulletin said:
Quote

it was discovered that an individual strand of wire, which broke off from a metal cutaway cable, had caught around the small ring release on the right hand riser, preventing the rings from operating in the correct manner, at the point of initiating the cutaway.



-- The BPA subsequently banned non-coated cable for all rigs not just tandem

The BPA didn't seem to say anything about the age or maintenance of the cable or describe the manufacturer's response or suggest any preventative measures or investigate the frequency of these incidents. (Or is that stuff hidden in one of their rigging meeting minutes, that are available on the web?)

[Edit: I checked the BPA site; the minutes for the last 2 rigging meetings are not yet available. So there seems to be no public explanation of their action?]


If there's scaremongering going on, it's the BPA:

One nasty incident = Ban something!

That being said of course we're interested in any failures that occur to a cutaway system.

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***
I got a little mixed up when you said 'delaminated' as I interpreted that as meaning it was a coated cable, when I guess it wasn't.

No, it wasn't coated.

Delamination: a mode of failure for composite materials and steel. In laminated materials, repeated cyclic stresses, impact, and so on can cause layers to separate, forming a mica-like structure of separate layers, with significant loss of mechanical toughness. the closest word that came to mind when i typed the post.

And yes, The BPA have decided that without identifying one particular manufacturer the practice of having non coated cables may not be the best idea for safety as the non coated cables are an older design and have been "updated" to clear coated but not been part of a PSB by a manufacturer.

How many nasty incidents that could have been fatal do you need to ban outdated equipment when even the people making it have moved on to a different process. Not scaremongering by the BPA, common sense.

If you have a system with these older style non coated cables then i for one would rather you were aware of the incident.

regards

Fordy
Fordy

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Their new rule would suck for some people with vintage gear.

For example, I know a guy with an Eastern European Talka rig with square main and Rogallo reserve from the early 1980s with uncoated cable.

Or my buddy sometimes jumps a UT-15 round canopy & rig, and it uses uncoated cable. But I'd be OK if I jumped with Capewells or R-3's on a Paracommander rig?

Would my friends be shit out of luck in the UK, or would it be easy to get a waiver?

Plus of course there were the early rigs with 3 rings that used what looked like clothes line cable -- I'd be far more wary of that stuff 40 years later, even if it technically was allowed by the BPA.

You aren't the BPA so don't speak for them but I gotta wonder about these things.

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Legally, Strong Enterprises covered their butts years ago.
Strong Enterprises installed bare steel cables for a few years. We all knew they were delicate and prone to linking. A few years ago, Strong introduced new cables with tougher clear coating and Strong recommended replacing old bare metal cables with new clear-coated cables.
Cutaway cables have always been high-wear items and no-one expects them to last more than 1,000 jumps.
Sounds like the tandem owner was trying to save a few dollars by keeping old cables in service after they cracked/de-laminated/broke a strand. When you factor in medical bills ..... how much money did the rig owner really save???????

Worn-out cutaway cables are not exclusive to Strong. For example, a few years back, Racer had problems with red Teflon coating cracking and sliding off the inner steel cable. Racer solved the problem with tougher, orange coated cables. Anyone still jumping a Racer with red cables is behind the times.

On a similar note: The three largest Ametican tandem manufacturers have all issued Service Bulletins on cracked or worn-out flex pins. Most of the failed flex pins had more than 1,000 jumps.

As for pchapman's question about Telka rigs with bare metal cables ..... no need to ban them, just ask your rigger to thoroughly inspect them at every repack.
Users can also learn how to inspect and clean and lubricate cutaway cables. Ideally cutaway cables get pulled and cleaned once a month.

Moral of the story, good tandem owners and riggers keep a few spare flex pins and handles on hand and replace they when they start to wear out, but BEFORE they fail in the air.

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How long ago did strong switch to the clear coated cables.

It must be at least 10 years ago, because I don't remember the uncoated ones being common when I first started in the sport, a we were a dual hawk dz.

I wouldn't be thrilled about that dzo's level of expenditures on mx and upgrades.:S

"The restraining order says you're only allowed to touch me in freefall"
=P

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