Tandem tension knot - Just because it flies OK doesn't mean it lands OK

[-ftp- 0]

In your opinion, what causes tension knots?

[phoenixlpr 0]

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And being multi rated, I can also say that all three were on the same brand system.... So really it is 3 chops in ~300-400 Tandems on that system.

On what system?

[Ron 10]

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In your opinion, what causes tension knots?

In no order... Packing, Maintenance, Design, It just happens.

Since all of mine are on the same system, different rigs, different packers, different DZ's..... And that I have not had one yet in 200-300 jumps on another system, I'd tend to think design plays a part.

Just like how a Stiletto is known for line twist chops, I personally think the Strong rig is more prone to tension knots.

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[phoenixlpr 0]

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I personally think the Strong rig is more prone to tension knots.

With the classic spectra lines or with the new Vectran lines?

[Ron 10]

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With the classic spectra lines or with the new Vectran lines?

Never paid attention to be honest. My last Strong chop was in 2009.

If I had to guess, I'd say spectra.

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[tkhayes 348]

No exaggeration, 20+ reserve rides in 2500-2600 tandems. I have not had one for a long time. I started tandems in 1991, and I did a lot, I do not do so many nowadays. I had 3 in one weekend, 2 of them back to back a long time ago. I have several streamers, one seriou sbag-lock that did not cutaway, many tension knots, and I blew up two canopies. I have jumped (and cutaway) Master 425's, Master 500's, PD421, EZ384 and SET400's.

Anyway, a little off the subject again, so I do not actually have to (once again) re-justify my experience to make my point.

A tandem Instructor is carrying a passenger/student for hire. You have a far higher level of responsibility using far more complex gear so my argument stands:

"The decision to cutaway a partially controllable canopy on a tandem is not black and white. And just because someone chose NOT to, even if an injury results, is not necessarily a sign of negligence."

I would not hesitate to pull a cutaway handle on my own gear, not ever. That's largely because I have never had a problem doing that.

I will very much hesitate to pull a handle on tandem gear if, after some testing, I maybe decide that I can land this thing.

What is happening in this thread is that people are looking at a few STATIC photos, making a DEFINITIE judgement call on the decision making process and declaring NEGLIGENCE, prior to even having all the facts. I hope none of you work in law enforcement, I would not want to be on the receiving end of your investigation.

TK

[-ftp- 0]

I completely respect your view, experience, and opinion.

However, do you think a) a practice flare/controlability check would reveal that the canopy (come to find out) was not performing to standards? and b) if it did pass, how can one predict the condition will not change when they are too low to take apporpriate action?

[peek 21]

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Just like how a Stiletto is known for line twist chops ...

I think you should say "was known". When the Stiletto was new, people were experiencing this for the first time, so a lot of people seem to remember it. Many other canopy models are deploying with unrecoverable twists now.

But anyway, on to my next question. Which models of Strong tandem canopies are you thinking are known for tension knots? Newer ones or older ones?

[Ron 10]

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I think you should say "was known"....so a lot of people seem to remember it.

If "a lot of people seem to remember it".... Wouldn't that make it "is known" still???? Heck remember the nickname Spinetto? The point being that it had a reputation... Earned or not, currently used or not.... It had one that was pretty well known and those of us around then remember it.

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Which models of Strong tandem canopies are you thinking are known for tension knots? Newer ones or older ones?

As I said, my last Tandem chop was on a Strong in 2009, since then I have mainly been jumping UPT. My best guess is SET400's with spectra lines.

And I only brought it up to back TK's tandem "jump to chop ratio" was not unheard of and that real or not, earned or not, Strong seems to have a higher malfunction % than the UPT system. At least in personal observation and beer fed campfire discussions.

I would be very interested in seeing some hard data.

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[peek 21]

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I would be very interested in seeing some hard data.

I don't think we are ever going to get that. People just don't report things to the manufacturers like they should. I have yet to have a tandem reserve ride. I have had a couple of canopies damaged on opening but they were landable. I hope I never get tension knots.

(Why look at that, this thread has come full circle.)

[tkhayes 348]

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a) a practice flare/controlability check would reveal that the canopy (come to find out) was not performing to standards?...

My point exactly. define "performing to standards". "Can I land this?" has a wide range of subjective decision making, not just the parachute, but the dive, the weather, the wind/temperature, the passenger, the gear, and the experience, to mention a few.

I had a bag lock that turned into a main reserve entanglement ending up with a wildly spinning reserve with a main hanging off of it. In the end, the situation actually IMPROVED and I did a stand-up landing in the peas with a passenger and a main partially inflated still in tow. In that situation, I had no choice.

On a blown up canopy, I failed to react because I did not see the top skin blown out until we were at 2400', I cutaway at 2200' and ended up with a Cypres fire and a short reserve ride, and pounded the guy in, but we walked away from it. Having my time back, I would have and SHOULD HAVE landed it, the canopy was not flying that badly.

On a A/B line entanglement in high winds, I decided to chop, and I ended up with a C/D line entanglement on the reserve and basically pounded in again. Luckily we walked away, but again, i wish now that I had just decided to and the main. It was not that bad.

People seem to forget, when you pull the cutaway handle, you are actually limiting your options. I am not saying 'Don't do it', I am just saying that the decision is neither negligent nor correct, it is simply a decision to be made with possibly severe or at least serious consequences. Yes the odds of a problem are low, but you have to ask yourself , "If I land this, are the odds of a problem JUST AS LOW?"

It is a subjective decision. The guy made the decision. In this case someone got hurt. Whether or not someone got hurt does not necessarily make his decision 'negligent'.

But in this thread, he was convicted of wrongdoing by his fellow skydivers within 6-10 posts. I call bullshit and that is why I said "Shaddup!"

[Birdguy 0]

Just a sidenote, that the Tandem Passenger did struggle to lift her legs. The TM was trying to aid her to no avail. She is still extremely happy with her Skydive and does not lay any blame on the TM. HER QUOTE was " I thoroughly enjoyed the Skydive, but need to work on my Landings!" She also raised $40,000.00 for her Charity (Lou Gehrigs Disease) or ALS! A remarkably strong spirited and happy 70+ year old!

[mjosparky 4]

First of all I am not a TI. But I do know a little bit about canopies. Ram Air canopies by their design want to open. When they don’t it is almost always caused by human error or input. It is rare for a malfunctioning square to improve and there is a good chance it will get worse. You can point out all the anecdotal exceptions you want but in 20+ years of test jumping I found this to be true.

From the pictures it looks as if he was going to have little if any flare. All three pictures appear to show the canopy was in a right hand slip. Trying to keep the wing level, flare using differential brake input while trying to control the slip greatly increased the chance of injury for the paying customer. That is if the left side did not roll under at 200 feet.

This was a malfunction and should have been dealt with as such. The fact that he had made a similar decision before raises a red flag about his judgment. Pulling his rating may be a little harsh but he needs to understand there are consequences for repeatedly make poor decisions. Maybe some remedial training and a 30 day set down would wake him up.

Here is a quote the fits this situation to a T.

Sparky

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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)

My idea of a fair fight is clubbing baby seals

[jumpwally 0]

...and thats a perfect way to put this thread to bed !

smile, be nice, enjoy life
FB # - 1083