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

 

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pchapman  (D 1014)

Aug 21, 2011, 6:26 AM
Post #1 of 114 (3316 views)
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Tandem tension knot - Just because it flies OK doesn't mean it lands OK Can't Post

This is a pretty basic lesson when it comes to a "minor" malfunction, but I'll make it anyway since I've got photos.

Just because a canopy is controllable while up high, and it seems to flare - giving you that 'pulling up' feeling - doesn't mean it is actually smart to land it.

Especially if the ground winds are weak, you are doing a tandem with a paying customer, and the customer is elderly. (And she's another jumper's mom.)

In this case, the instructor couldn't plane out fully on landing, hitting with some forward speed and a little descent rate, would have been OK for a healthy young solo jumper but which caught the leg of the student, who broke her femur and ankle.

Two camera flyers (for later tandems on the same load), including myself, had flown by the tandem to gawk in wonder at the clearly visible problem. (And given that I opened at 3500' on my Protrack and flew just over the tandem 1 min 40 sec later, that suggests a lowish pull too...)

The instructor involved thought he had the canopy under control without too much opposite toggle, and had landed a tandem with a tension knot at another DZ last year.

(For some reason the cops this year are really picky. They came in addition to two ambulances. The gear had to be left in the field until some forensics guy came to inspect it and release it back to the DZ. I know everything gets confiscated at DZ's if there's a fatality, but I didn't expect that kind of analysis for just a rare injury & ambulance call.)

Canopy: Sigma II 370, Vectran lines. Looks like a stabilizer slider stop caught on an A line 3 cells over. (So it wasn't actually a line vs. line tension knot. Things related to lines were still caught due to tension, so I hope "tension knot" is still a reasonable category to put this under?)
Attachments: tension knot - on final.JPG (98.6 KB)
  tension knot - aerial.JPG (63.6 KB)
  tension knot - aerial - beneath.jpg (82.6 KB)


normiss  (D 28356)

Aug 21, 2011, 7:29 AM
Post #2 of 114 (3233 views)
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Re: [pchapman] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

That was not a smart decision on his part IMO.
Unsure
That is clearly a chop in my book.


aerialcameraman  (D 27629)

Aug 21, 2011, 8:01 AM
Post #3 of 114 (3214 views)
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Re: [normiss] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Gone in my book.


chuckakers  (D 10855)

Aug 21, 2011, 8:41 AM
Post #4 of 114 (3189 views)
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Re: [pchapman] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

choppy choppy


Rover  (D 241)

Aug 21, 2011, 2:13 PM
Post #5 of 114 (3094 views)
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Re: [pchapman] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Chop the TI's rating as well!


kd5xb  (Student)

Aug 21, 2011, 2:46 PM
Post #6 of 114 (3077 views)
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Re: [pchapman] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

That's bad news. The canopy has one cell turned completely VERTICAL. There's no way THAT will flare and land properly.


stratostar  (Student)

Aug 21, 2011, 3:23 PM
Post #7 of 114 (3058 views)
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Re: [pchapman] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

You've got to be kidding...... rolling eyes......Crazy


catfishhunter  (D 28796)

Aug 21, 2011, 3:36 PM
Post #8 of 114 (3050 views)
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Re: [pchapman] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

if it was my mom I'd be stomping a new mud hole in that dumfucks ass. He should never be allowed to be put in charge of someone else's life ever again. Shit happens but that borders on criminal negligence.


Squeak  (E 1313)

Aug 21, 2011, 5:47 PM
Post #9 of 114 (3011 views)
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Re: [catfishhunter] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

In reply to:
if it was my mom I'd be stomping a new mud hole in that dumfucks ass. He should never be allowed to be put in charge of someone else's life ever again. Shit happens but that borders on criminal negligence.

Hi John, not directed at you per-se, but its very easy to judge from hind sight.
as the TM, his view of the mal would have been different, and I'm assuming he did a full controlabilty check up high. He made a judgment call based on said check and chose to land, hind sight shows it was the wrong choice, a mistake.
All of above is based on assumption.


Rover  (D 241)

Aug 21, 2011, 5:56 PM
Post #10 of 114 (3004 views)
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Re: [Squeak] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Quote:
He made a judgment call based on said check and chose to land, hind sight shows it was the wrong choice, a mistake.

Yes, he made a 'judgement call' and on that he will be judged. I think it is fair to say that the judgement made was poor to say the least, and the inevitable happened. No excuses for this in my opinion.


skydivingchad  (D 28984)

Aug 21, 2011, 6:09 PM
Post #11 of 114 (2998 views)
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Re: [pchapman] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

This is one of the basics. Is it there? Is it SQUARE?....


Premier billvon  (D 16479)
Moderator
Aug 21, 2011, 6:45 PM
Post #12 of 114 (2977 views)
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Re: [Rover] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

>I think it is fair to say that the judgement made was poor to say the least . . .

Had a friend who cut away from a tension knot on his (Strong 520) tandem main. He later remarked it was probably landable. His reserve opened with a lineover. The outcome would likely have been worse than the one in this case, except he impacted in a mud puddle (rare in San Diego; he was very lucky.) Minor injuries to the student.

Was his judgment poor?


VideoFly  (D 25621)

Aug 21, 2011, 6:51 PM
Post #13 of 114 (2972 views)
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Re: [billvon] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Is it possible that in the case you presented, the questionable judgment was in the choice of rigger? I know there are many variables involved, but when I choose a rigger to pack my reserve, I do so with the expectation that I will have a good reserve overhead when needed.


Liemberg  (Student)

Aug 21, 2011, 7:02 PM
Post #14 of 114 (2967 views)
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Re: [pchapman] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Though 'monday morning coaching' IS easy, I find it hard to see any merit in the TI's judgement when he decided to land this - even if he has gotten away with something similar in the past.

The canopy is clearly deformed.

There was absolutely no guarantee that it wasn't going to take a 'turn for worse' closer to the ground where turbulence may be lurking...

Though I hate chopping canopies as much as the next person, when it's gotta go, it's gotta go.

Square, Stable, Steerable.

Pretty basic - almost 'square' just isn't good enough with modern canopies...

Even if it had been a solo jumper and he had walked away unhurt, someone should discuss with him the grim possibilities of canopies collapsing close to the ground during landing manoeuvres when configured like that.


firemedic  (D 29776)

Aug 21, 2011, 7:14 PM
Post #15 of 114 (2959 views)
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Re: [billvon] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

In reply to:
>I think it is fair to say that the judgement made was poor to say the least . . .

Had a friend who cut away from a tension knot on his (Strong 520) tandem main. He later remarked it was probably landable. His reserve opened with a lineover. The outcome would likely have been worse than the one in this case, except he impacted in a mud puddle (rare in San Diego; he was very lucky.) Minor injuries to the student.

Was his judgment poor?


As someone said earlier here, everything is always clearer in hindsight. So in hindsight did he make a bad decision? Yes.
I think the more important question to ask is why he did not know it was a bad decision to land it.


Premier billvon  (D 16479)
Moderator
Aug 21, 2011, 7:24 PM
Post #16 of 114 (2950 views)
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Re: [VideoFly] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

>Is it possible that in the case you presented, the questionable judgment was in the choice of rigger?

Quite possibly. But that doesn't help the guy up there trying to make the best decision.

No parachute is 100% reliable. Should you take the (moderate) chance of injury that is incurred by landing a main with a problem vs. the (tiny) chance of nearly certain death that you incur by having a reserve mal? We get somewhat complacent because reserves work so very often - but it's worthwhile to note that they do not _always_ work.


firemedic  (D 29776)

Aug 21, 2011, 7:38 PM
Post #17 of 114 (2936 views)
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Re: [billvon] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

 

No parachute is 100% reliable. Should you take the (moderate) chance of injury that is incurred by landing a main with a problem vs. the (tiny) chance of nearly certain death that you incur by having a reserve mal? We get somewhat complacent because reserves work so very often - but it's worthwhile to note that they do not _always_ work.
Very good point BV.
Just guessing but I would think there are tens of thousands of main deployments every year that have no problem. So, reserve deployments are much much lower in number. I wonder what the reserve malfunction rate is.

ETA: I've had several tension knots on tandems, most of which I was able to clear quickly. A couple did not. They seemed to be stable and appeared to flare ok. I felt a "urge" to just stay with them but I chopped them because I just didn't know for certain if they were landable. I don't think anyone can know for certain that a canopy that appears to be stable and landable is stable and landable when you're at 4000'.


(This post was edited by firemedic on Aug 21, 2011, 7:58 PM)


VideoFly  (D 25621)

Aug 21, 2011, 7:42 PM
Post #18 of 114 (2934 views)
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Re: [billvon] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Really? A line over on a reserve? I know things happen and a perfectly good pack job can open improperly due to many other variables, but as I watch my rigger meticulously pack my reserve, he often explains why and how he places the lines and fabric to specifically avoid a line over as well as other potential problems.

While I can appreciate that the decision to cut a main canopy away may include thoughts of the reserve not performing properly, a tandem instructor must make a quick and deliberate decision without second-guessing a reserve’s performance. In the situation you described, I believe your friend made the correct decision. It was unfortunate that there was a problem with his reserve, but his good decision to cut away and the fact that the reserve “opened with a line over”, or should I say, may have been packed to open with a line over are two completely separate issues, which affected a single skydive.

I have seen tandem instructors land compromised main canopies, usually with satisfactory results, but that gamble may also place students into an unsatisfactory situation.


davelepka  (D 21448)

Aug 21, 2011, 7:50 PM
Post #19 of 114 (2929 views)
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Re: [Squeak] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Quote:
its very easy to judge from hind sight

The condition of that canopy was easy to judge fron any sight. I read the OP, and had pictures in my mind of what was happening. When I got to the end and opened the first pic, that was all I needed to see. Much, much worse than what I had pictured, and not even close to a 'landable' canopy for any tandem on any day. Not even close.

The fact that three other jumpers did a 'fly by' to see the mess, and more than one person found it noteworthy enough to take pictures says a lot about the situation.


normiss  (D 28356)

Aug 21, 2011, 7:51 PM
Post #20 of 114 (2928 views)
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Re: [Liemberg] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

This.
1000%
Repeatedly.
Wink


VideoFly  (D 25621)

Aug 21, 2011, 8:12 PM
Post #21 of 114 (2918 views)
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Re: [davelepka] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Having a tandem student injured while landing a compromised reserve is in my opinion, more tolerable that if the injury occurred while landing under a compromised main.

I know this may sound terrible, but I am just posing several questions. Might it be possible that in some instances, the decision to not chop a compromised, but possibly landable main, may involve thoughts of avoiding expenses of repacking a downed rig and the possible loss an expensive main canopy? Could an instructor fear ridicule for cutting a possibly landable main away? Might an instructor lack the experience and/or training to be comfortable cutting a compromised main canopy away?


davelepka  (D 21448)

Aug 21, 2011, 8:33 PM
Post #22 of 114 (2907 views)
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Re: [VideoFly] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

Quote:
thoughts of avoiding expenses of repacking a downed rig and the possible loss an expensive main canopy? Could an instructor fear ridicule for cutting a possibly landable main away? Might an instructor lack the experience and/or training to be comfortable cutting a compromised main canopy away?

As to the costs, be it loss, repacks, or down time, any instructor or DZO who let's that be a part of the equation should not be in the tandem business. If you cannot afford the loss/repack/down time, then you cannot afford the lawsuit that could ensue from an injured passenger.

As to the ridicule, if you're not past the point in your life where the opinions of others matter so highly to you that it effects your decision making while dealing with malfunctions, then you lack the maturuty to be an instructor, and quite possibly a skydiver in any respect.

As for the training, every TI is required to have at least one cutaway as a prerequisite for the rating. Even without that, again, if you lack the fortitude to pull the handles, you should not be instructing or skydiving.

I understand the points you're making, but this is remedial stuff here. Like others have pointed out, the criteria of 'square' is taught during the FJC with regards to identifying a good canopy. This canopy clearly did not meet that criteria, yet this jumper chose to fly it to the ground, with an eldery passenger in the harness.

Between this, and the recent fataility in Uruguay, I have to wonder what the hell people are thinking. There should be page after page of posts, speculation, and what-if's in the wake of any incident. Simple obvious things like we see here and in Ururguay should never come into the equation.

It's like I said, when I read the OP, I had a picture in my mind of what the canopy looked like. It was similar to a canopy with one brake stowed, and the other pulled down to counter it, like a knot in the steering line alone. When I opened the pic, I was shocked at the condition of the canopy, and that anyone would think to land it. It's just dumb, and if you're going to do dumb things, this is what happens.

Where the hell did common sense go?


Premier billvon  (D 16479)
Moderator
Aug 21, 2011, 10:50 PM
Post #23 of 114 (2855 views)
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Re: [VideoFly] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

>Really? A line over on a reserve?

Yes. Even when properly assembled, maintained, packed and deployed, parachutes can malfunction.

>While I can appreciate that the decision to cut a main canopy away may include
>thoughts of the reserve not performing properly, a tandem instructor must make a
>quick and deliberate decision without second-guessing a reserve’s performance.

Definitely not. Any instructor (AFF or tandem) MUST understand and consider the additional risks incurred by deploying a reserve when it is not absolutely needed. They are not foolproof.

>I have seen tandem instructors land compromised main canopies, usually with
>satisfactory results, but that gamble may also place students into an unsatisfactory >situation.

Agreed - and that's true both ways. There is no one correct answer that covers all situations.


Rover  (D 241)

Aug 21, 2011, 11:31 PM
Post #24 of 114 (2840 views)
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Re: [billvon] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

In reply to:
>I think it is fair to say that the judgement made was poor to say the least . . .

Had a friend who cut away from a tension knot on his (Strong 520) tandem main. He later remarked it was probably landable. His reserve opened with a lineover. The outcome would likely have been worse than the one in this case, except he impacted in a mud puddle (rare in San Diego; he was very lucky.) Minor injuries to the student.

Was his judgment poor?

The fact that it was 'probably landable' means that it wasn't definitely landable. If there is shit happening, move on, and then deal with the hand you've been given. The fact that you have used this as a defence to what happened in the original post means that I question your judgement if you think that what occurred was justified.


(This post was edited by Rover on Aug 22, 2011, 1:27 AM)


BrianM  (D 661)

Aug 22, 2011, 12:14 AM
Post #25 of 114 (2827 views)
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Re: [davelepka] Tandem tension knot - Just because it flies OK doesn't mean it lands OK [In reply to] Can't Post

In reply to:
As for the training, every TI is required to have at least one cutaway as a prerequisite for the rating.

The rest of your post is great, but that statement is incorrect. It varies with manufacturer. Strong and Jumpshack require one, UPT does not. I'm not familiar with other manufacturers.


(This post was edited by BrianM on Aug 22, 2011, 12:14 AM)


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