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peanutgallery

Tension knot??

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Had my first cutaway yesterday and am still trying to figure out what exactly it was. I've been having some off heading openings on my Pilot 150. I opened 90 to the left, no big deal, collapsed my slider, it hasn't righted itself yet. still turning slow left. I have a square canopy over my head, no obvious line over, broken line, pinching or anything that I can see that would be causing it. I grabbed both toggles (which were perfectly stowed) and both came out of the keepers. Which immediately cause the canopy to dive hard to the left. When I went to flare to try to clear whatever it was, my left toggle only wanted to come down to about my chin, it had a ton of pressure like a spring that wanted to go back up, it felt like it was stuck on something, now I'm in a diving spin that's getting faster (not super fast but enough for me) I pumped a few more times with the same result, a springy, tension feeling. 2 grand, chopped it. Beautiful reserve ride right over the dz. The canopy was a mess when we found it and all the lines were a tangled ball of shit but there was no obvious issue. I'm happy with my decision to chop, in hind sight I could have maybe corrected with my right toggle to work with it a little more, but it being my first malfunction...I had enough and wanted it gone. I'm just a little perturbed that I'm not exactly sure what it was that caused it...i.e. how to prevent it in the future. It was my second jump of the day, first jump was no problem, on heading and perfect. I untwist my break lines every fifteen jumps or so and just did it a few jumps ago. People are saying it sounds like a possible tension knot, what do you think?

and for the record...i threw on someone else's rig and completed the last two jumps of the four way scrambles :)
I used to have a handle on life, but it broke

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A tension knot can happen fairly easily if the brake lines are never untwisted. I untwist mine after every jump and this is part of my packing procedure. Some people do it once a day and some people don't do it at all. I don't know your technique but this might be something to consider.
Think of how stupid the average person is and realize that statistically half of them are stupider than that.



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Do your risers have little hammer head stoppers for the slider to stop? My first cutaway was caused when I unstowed my brakes and the brake line caught and tied into the soft link at that point, slow turn on opening, and faster turn when I unstowed the brakes. If you are stowing your brakes by pulling the loop through the soft link and back down to the toggle with those stoppers, this will more than likely happen again. I talked to my rigger and he fixed the problem. Hope it helps:S


-Evo
Zoo Crew

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Do your risers have little hammer head stoppers for the slider to stop? My first cutaway was caused when I unstowed my brakes and the brake line caught and tied into the soft link at that point, slow turn on opening, and faster turn when I unstowed the brakes. If you are stowing your brakes by pulling the loop through the soft link and back down to the toggle with those stoppers, this will more than likely happen again. I talked to my rigger and he fixed the problem. Hope it helps:S


-Evo



You're stowing your brakes through your connector link? Or am I missing something here?

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Read before giving advice



I think Chute Me read the post, and I did too. OP is asking about tension knots and how to prevent them and then bitching because he got a response about it?? Damn.

A tension knot in the brake line will feel springy as the captured line is pulled down but will feel heavy because of the relative weight of the parachute. Line length will allow the captured steering line to be pulled only so far.

Tension knots from wound-up brake lines are not uncommon. Untwisting the brake lines regularly and keeping the lines taut while packing and stowing are ways to manage the issue.

Nova
"Even in a world where perfection is unattainable, there's still a difference between excellence and mediocrity." Gary73

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I did, until my cutaway...really without the slider stoppers at the top of the risers I dont think there would have been a problem. I have a couple loops now lower on the riser I stow the loop through. Only reason I had a problem was because of those stoppers, the loop got caught on the corner of one and knotted up. Ya live you learn :P
Zoo Crew

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Will, "rlucus" asked you if you were sure about where you were stowing your brakes because of the terminology you used.

"Stowing your brakes" refers to pulling the "cat's-eye" down below the metal guide rig and inserting the narrow part of the toggle, then fastening the toggle in some manner to the riser.

You were talking about "stowing your excess brake line", which is what a person does after stowing their brakes.

It is considering best to have a specific place to stow your excess brake line than to loop it through anything not designed for that.

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Do your risers have little hammer head stoppers for the slider to stop? My first cutaway was caused when I unstowed my brakes and the brake line caught and tied into the soft link at that point, slow turn on opening, and faster turn when I unstowed the brakes. If you are stowing your brakes by pulling the loop through the soft link and back down to the toggle with those stoppers, this will more than likely happen again. I talked to my rigger and he fixed the problem. Hope it helps:S


-Evo



You're stowing your brakes through your connector link? Or am I missing something here?



........................................................................

Stowing excess brake line through connector links fell out of fashion - a couple of years ago - after a couple of them jammed.

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I was not at all bitching that I got a response, just asking if he read the post being that he suggested untwisting the break lines when I clearly said that I do that regularly. Thanks for the response.



Boy you complain a lot. ;)

When I saw your jitters, I figured you'd be done for the day. Good on you for hopping right back in the saddle. You were a pro. I was impressed.

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Read before giving advice



That is good advice. Now here is some for you. Of course I did read your post BEFORE posting my response.

Think about what you are posting or some people may think you are an asshole. Of course if that is the intent of your post then please continue with what trips your trigger.
Think of how stupid the average person is and realize that statistically half of them are stupider than that.



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I was not at all bitching that I got a response, just asking if he read the post being that he suggested untwisting the break lines when I clearly said that I do that regularly. Thanks for the response.



OK - it seemed a bit harsh to comment on a helpful reply, that's all. ;)

Tension knots can form even if the lines are untwisted. It can happen if there is slack in the line which allows it to wrap or twist around another line and when the load is applied a knot can form.

Your problem sounds like a tension knot and you might have decided to re-stow the right brake and fly with rear risers but there's no heroism in that. You handled the problem and you made the right choice - if it's not safely landable, get rid of it.

Blues. Nova
"Even in a world where perfection is unattainable, there's still a difference between excellence and mediocrity." Gary73

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Read before giving advice



That is good advice. Now here is some for you. Of course I did read your post BEFORE posting my response.

Think about what you are posting or some people may think you are an asshole. Of course if that is the intent of your post then please continue with what trips your trigger.



oh boy,oh boy, i'm getting blasted for a comment I didn't make, if you scroll back up I didn't say "read before giving advice," c10edges did. I aksed if ChuteMe read the post with a :P face like I was playing. Hope this clears it up, I'm not an asshole, I appreciate any input. thanks.
I used to have a handle on life, but it broke

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So if I do untwist the brake lines frequently and this was a tension knot, is there anything else I should be doing to prevent it from happening again or is it probably just a random "it happens" kind of thing? I did try to correct with the right for a while to see if I could clear it, but it was pretty bad and at my experience, I didn't even consider trying to land it like that.
I used to have a handle on life, but it broke

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Yes. Clear your lines before packing, keep them taut while packing, and stow them evenly, tightly and securely.

It's the most important aspect of proper packing.

Nova
"Even in a world where perfection is unattainable, there's still a difference between excellence and mediocrity." Gary73

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One thing to keep in mind is that after a canopy is chopped there isn't a lot you can reliably tell looking at the trash. If both brakes are still set that's something. If there is evidence of burns that's something. Brakes don't always stay set as it flutters down, tension knots don't always stay in. I'm not even convinced that twisted lines give you a significantly higher chance of a mal.

-Michael

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Good points, Michael. In the absence of burns or other evidence, it's often best-guesswork as to what was happening after deployment. If it's just not known what happened, a clear description of the symptoms/actions and appearance of the malfunction narrow the list of suspects.

Since you brought it up, I guess I'm not convinced twisted lines give a higher risk of malfunction, either - but IMO it's an unneccesary risk. ;)

Blues. Nova
"Even in a world where perfection is unattainable, there's still a difference between excellence and mediocrity." Gary73

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Since you brought it up, I guess I'm not convinced twisted lines give a higher risk of malfunction, either - but IMO it's an unneccesary risk. ;)


Don't different types of lines have more "memory" than others? For instance, Spectra lines, when remaining twisted for long periods of time retain the twisting if left untreated. Would this not attribute to a less-than-normal opening?

I, for one, always untwist my lines before my weekend jumps. Not to mention it's a good way to clean out your parachute from all the junk inside the cells (if you jump in a dusty DZ, like me).
"Fail, fail again. Fail better."
-Samuel Beckett

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I'm not aware memory in the lines of a main is significant.

I believe (and answered to the point) the twisting that Michael referred to isn't the twisting like we see in brake lines but the twisting of line groups.

Example: Some always use their fingers to separate the line groups as they run up the lines to the parachute for packing. Others just pull the lines tight and start packing.

I'm a firm believer in separating the line groups.

Nova
"Even in a world where perfection is unattainable, there's still a difference between excellence and mediocrity." Gary73

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Just to be clear I was referring to some minor twists in brake lines, not attach to a drill and put 500 turns in it twisted, just a couple here and there.

Whenever I attach a main to risers and especially when I attach a reserve the lines will always be 100% twist free and exactly in the proper order - no exceptions.

With respect to twists in the lines increasing the likelihood of a mal, a properly staged opening keeps a reasonable amount of tension on the lines so I don't think some twists will matter a great deal. If it did you would see a corelation between those who untwist and do not untwist, especially on something like tandem gear! I believe maintaining your elastics would be far more important.

-Michael

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Two of my 4 malfunctions, all in the 80's, were tension knots. One is on video, old VHS and I'm too ignorant to try to up load it through my PC 105.

But, they weren't necessarily obvious under canopy but very obvious in the video.

Tension knots, IMHO, were a major cause of malfunctions in the old days with dacron line. I firmly believe that spectra, with it's 'slicker' surface just doesn't hold tension knots as well and that if as many form they come out more often.

No, if the knot is there your not going to fix it and all you can do it get rid of it.

And I have never FOUND a tension knot in a cutaway canopy. They are called 'tension' knots for a reason.

You did good, probably had a tension knot, and other than trying to keep lines straight, tight, and stowed neat nothing to do.

Well, unless you want to go back to the old days and start rubbing you lines with wax.;) JUST KIDDING, DON'T do that now. But I've seen wax, soap, and who knows what else used.
I'm old for my age.
Terry Urban
D-8631
FAA DPRE

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Thanks! Really I just wanted to know what other people thought it could be based on the description of the mal. Nothing was found in the canopy as expected but based on what everybody here is saying, tension knot seems most probable. I appreciate all the input. I'll keep untwisting my brakes as I do now and be more careful stowing. It's nice to have one out of the way though :P at least I know I won't panic :)
I used to have a handle on life, but it broke

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