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BillyVance

Tandem gear failure at Dublin, GA last week

By BillyVance, in Gear and Rigging

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BillyVance    35

BillyVance
I have looked through the forums to see if this had previously been posted and could see nothing, besides some people have been saying get the word out and warn those who have tandem rigs to check the affected parts, and hopefully prevent a similar occurrence from happening again... This was originally posted on the crwdog mailing list today by a crwdog who was doing tandems at the RoamingDZ boogie in Dublin earlier this month... I was there, but I did not see or know about this incident while there.
+++++++++++++++++
Hey gang, I have received numerous inquiries as to the incident that occured last week at the Dublin Boogie in Georgia. I was doing a Tandem on a borrowed Tandem rig. I experienced a malfunction on the main an elected to chop it. The reserve deployment and descent were uneventful until landing when the left front riser connector link " L-bar" completely seperated and the entire line-set fell off the reserve riser. There were no screws in the L-bar!! Apparently there was just enough tension to keep the link together until the landing when the connection catastrophically failed. I know I'm one lucky dude. It just wasn't mine or my passenger's time to go. Thanks for all the caring supportive e-mails. That's the story....
"Mediocre people don't like high achievers, and high achievers don't like mediocre people." - SIX TIME National Champion coach Nick Saban

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divnswoop    0

divnswoop
Quote

I have looked through the forums to see if this had previously been posted and could see nothing, besides some people have been saying get the word out and warn those who have tandem rigs to check the affected parts, and hopefully prevent a similar occurrence from happening again...




All that was needed to say about it has been said and the thread was locked. Let 'some people' know that the word is out. But here is the link if your interested.
Thread is http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=1544968#1544968.

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BillyVance    35

BillyVance
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Can someone explain the nutshell of an "L bar"?

_Am



Got this off of AggieDave's post on the other thread:

L-bar: http://www.paragear.com/...te.asp%3fgroup%3d193

Its item H359 SEPARABLE CONNECTOR LINK

Since RWS tandems don't have cascades on the reserves a rapid link won't work due to the amount of lines needing an attachment, so the L-bracket is used.
"Mediocre people don't like high achievers, and high achievers don't like mediocre people." - SIX TIME National Champion coach Nick Saban

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BillyVance    35

BillyVance
If there's ONE thing that could have prevented this incident from even occurring, may well be a checklist. I just mentioned this suggestion on the crwdog list. When it comes to complicated machinery and equipment, it never hurts to use a checklist to make sure everything is covered.

All branches of the military use them. All commercial pilots use them. Even astronauts use them. They’re even useful in private life. How many times have you packed up the family car for a trip to the beach, and then arrive and realize you forgot the surfboard, or swimsuits, or even toothpaste? One year, I took my ocean kayak with me to the beach. I had the life jacket and gloves with it too. But I left the freaking oars at home, a 5 hour drive away! I ended up buying a new pair at a nearby store…

Who knows? Some of the airplane crashes in our sport could have been prevented with a checklist when going over the preparations at the beginning of each day…

Just a thought…
"Mediocre people don't like high achievers, and high achievers don't like mediocre people." - SIX TIME National Champion coach Nick Saban

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mr2mk1g    10

mr2mk1g
I don’t mean to incite a further argument… but I remember sitting in on a rigging lecture given by Rick Boardman on a windy DZ last year.

He went through his “rigging box of horrors” and produced a set of links visually identical to those pictured under the paragear reference provided by Aggidave. Rick said that they were banned from use in the UK because they could be assembled without the screws in place resulting in a reserve that detaches on use.

Now my memory of this lecture is fuzzy so I may well be wrong. I also seriously doubt the model show by Rick was the exact same as that used here or the manufacturer surely wouldn’t still be fitting them for fear of loosing all gear sales to the UK - I only mean that they are visually the same to my memory.

Does anyone know if a similar item was indeed banned in the UK for this reason? Or is my memory playing tricks on me and it was actually a different reason the similar links were banned?

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AndyMan    7

AndyMan
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Lock this.



Please don't.

I still don't know what an "L bar" is, I saw the paragear description weeks ago and found it unhelpful.

Locking threads about real incidents where people can (and should) learn is the dumbest thing I've ever heard, and defeats the purpose of this and other forums.

What's an L bar? Why is it only used on RWS gear? Is it used on other gear?

What are the conditions that would allow one to come undone? Is tightening them recomended regular maintenance? Is inspecting them explicitly recomended?

Would someone intentionally undo one as part of standard procedures with RWS tandem gear?

Is it normal that one that is undone will hold togeather while under load? What about while not under load in the packjob?

What are the conditions that will cause one which is undone to fall apart?

I'm sure I'll have a ton of other questions, as will others. If this thread gets locked, knowledge will not pass. Not a good thing.

The other thread got locked before I got a chance to ask these questions. That was a travesty. Please don't repeat it.

_Am
__

You put the fun in "funnel" - craichead.

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AggieDave    6

AggieDave
Its common on many other types of gear, just not modern civilian gear anymore.

Think of two tetris L shaped pieces and how the fit together perfectly when one is upside down. Same thing here. Then on the short-legged tip of the L a machine screw goes through it and screws into the other L.

Once a tandem has been setup with that and has the screws tightened down properly...after the first repack cycle it takes a lot of grunting and cursing to pull the brackets apart. They stick together well.

The L-bars are used instead of a rapid link on the line attatchment on the reserve. Why you ask? The tandem reserves in RWS gear have no line cascades, so there's a shitload of lines coming to the attatchement point. A rapid link won't work, there's too many lines and it will crossload the rapid link. Thus the L-bracket.

The L-bracket isn't something that is normally dealt with doing tandems, you only see it on reserve rides and during repacks, a condition that would cause it to come undone is simply a rigging error. If the rigger doesn't insert the machine screws and tighten them to the correct torque setting, then its possible for them to come apart. However, like I said, if you set the L-bracket up correctly the first time, by the time the first repack cycle comes around, they are a BITCH to get apart, even with the machine screws removed. The last set we took apart at my DZ it took myself and another serious weight lifter a LOT of grunting and cursing pulling on opposite ends using suspension line with handles for leverage and it took us nearly 10 minutes of doing this on and off to pull the damned things apart. We were taking them apart to change a reserve to a new tandem container.

So the short answer is, no its not normal for a failure underload if they have been setup properly.
--"When I die, may I be surrounded by scattered chrome and burning gasoline."

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PhreeZone    20

PhreeZone
During times of maintence such as washing and shipping its common to remove the L-bars also. They will hold together for casual inspection on the ground with out the screws, but under tension they can release.
Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

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AggieDave    6

AggieDave
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They will hold together for casual inspection on the ground with out the screws, but under tension they can release.



Are you talking about during assembly or disassembly?
--"When I die, may I be surrounded by scattered chrome and burning gasoline."

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wmw999    2,589

wmw999
They were what was always used on rounds in the olden days. It's possible for them to be so firmly screwed together that you have to use a screwdriver and a lot of cuss words to separate them. Or at least I needed a lot of cuss words...

Checking for the screws was an extremely standard part of rigging when they were common. I'll bet it is for still, and I'll bet that no one is perfect.

Wendy W.
There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

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AggieDave    6

AggieDave
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Assembly. If its the same ones I've seen on Vector2 Tandems you can take the screws out and it will hold together still. You can hand squeeze thme together and it will start to set.



Yes, exactly. I was talking about disassembly and how the L-bars set together very tightly and they're hard to get apart if they were setup correctly in the first place.


However, for me this is simply an academic discussion since I'm a gear geek, but what I am not (and its well known on DZ.com that I'm not) is I'm not a licensed rigger.
--"When I die, may I be surrounded by scattered chrome and burning gasoline."

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chuckbrown    0

chuckbrown
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Checking for the screws was an extremely standard part of rigging when they were common.



It was one of the first things stressed as part of a reserve inspection at a course I took last year. You could count on an instructor loosening them to make sure you were inspecting every inch of the reserve system.


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riggermick    7

riggermick
Quote

Its common on many other types of gear, just not modern civilian gear anymore.

Think of two tetris L shaped pieces and how the fit together perfectly when one is upside down. Same thing here. Then on the short-legged tip of the L a machine screw goes through it and screws into the other L.

Once a tandem has been setup with that and has the screws tightened down properly...after the first repack cycle it takes a lot of grunting and cursing to pull the brackets apart. They stick together well.

The L-bars are used instead of a rapid link on the line attatchment on the reserve. Why you ask? The tandem reserves in RWS gear have no line cascades, so there's a shitload of lines coming to the attatchement point. A rapid link won't work, there's too many lines and it will crossload the rapid link. Thus the L-bracket.

The L-bracket isn't something that is normally dealt with doing tandems, you only see it on reserve rides and during repacks, a condition that would cause it to come undone is simply a rigging error. If the rigger doesn't insert the machine screws and tighten them to the correct torque setting, then its possible for them to come apart. However, like I said, if you set the L-bracket up correctly the first time, by the time the first repack cycle comes around, they are a BITCH to get apart, even with the machine screws removed. The last set we took apart at my DZ it took myself and another serious weight lifter a LOT of grunting and cursing pulling on opposite ends using suspension line with handles for leverage and it took us nearly 10 minutes of doing this on and off to pull the damned things apart. We were taking them apart to change a reserve to a new tandem container.



Easy way to seperate L bar links, Back both screws out 50%, hang on to one side of the link firmly and tap it with a rubber or plastic kinetic type mallet. Sometimes it takes a few whacks but it has never not worked for me.


Mick.

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meatbomb    0

meatbomb
Hey Mat,

I don't remember seeing those in Rick's box that day, but I'm pretty sure that L-bars are still legal in this country (at least for Round reserves). I packed a few under supervision 4-5 years back...I'll have a check in my Safety Notices tonight though and get back tomorrow...if some keen bugger doesn't beat me to it...;)

Beaten already...see the alternate thread (and explanation) from riggerrob
---
Swoopert, CS-Aiiiiiii!
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