Tension knots malfunction.

[macey 0]

Has anyone here had/seen/heard of one?

[lazerq3 0]

Seen one on "BREAKAWAY"...dont know if that counts!!

jason

Freedom of speech includes volume

[Casch 0]

While I was in Eugene, I saw one of the Tandems have a tension knot mal. I was on the ground watching the abnormally long snivel and then the subsequent cutaway. Oddly enough though, the lines were fine when it finally landed. The TM was absolutly positive that it was a tension knot though so...Anyway, all was well, the main and freebag were stuck together and landed at a local golf course

[VanillaSkyGirl 6]

I had one on my 11th jump. It looked like closed end cells at first, but then I peeked around the slider (I'm small), and I was startled at what I saw. I didn't know what it was at the time as it had never been in any of our class malfunction pictures. The whole front right side of the lines were all stuck together as one and slightly twisted from the slider to where they met with the parachute ends. The parachute front end was not and would not open completely on that (front right) side.
I knew that this definitely wasn't normal, and that I couldn't fix it. Therefore, I calmly cutaway and pulled my reserve. It was when I got home and reviewed a "Breakaway" malfunction video that I had bought that I knew what it was exactly. It looked almost identical to the video, except it was a little worse (more heavily closed front end).
The video claimed that it was a packing error. I was jumping rented, DZ-packed gear (huge 280 main) at the time. The packers there were awesome, but I guess that this stuff happens sometimes.
I hope that this helps.

[Casch 0]

What is it that you want to know? Just wondering if it's a very common mal? As far as I know it's not very common. I think most common way to cause it is to have poor line stows, messy and disorganized. Otherwise they shouldn't happen.

[VanillaSkyGirl 6]

I think most common way to cause it is to have poor line stows, messy and disorganized.
Yes, what Casch wrote is very true. At the time, my old DZ was training new packers. I figured that this happened because of that.

[Casch 0]

ick...I would feel sorry for the packer... When I first started packing, there was NO way I would let anyone else jump my packjob. At least when I jumped it, I truely expected the worst and was 100% ready for it...if I had packed a mal for someone else...oh I would feel terrrrible

[tombuch 0]

Quote

Has anyone here had/seen/heard of one?

Sure. It used to happen frequently on some of the older square parachutes.

Back in the day squares opened really, really, really fast, so manufacturers and jumpers looked for ways to slow them down. We learned about sliders, trim, and a few packing tricks.

Unfortunately sometimes we slowed the opening so much that the parachute would snivel for a long time before filling with air. As the parachute sniveled the lines would be flopping around with very limited control.

Older parachutes tended to have big fat cascades where lines split, usually created with knots. I had several tension knot malfunctions when the cascades of the steering lines snagged on the "A" lines, and wouldn't pull free or allow the slider to descend.

The smaller cascades on modern parachutes have reduced the problem, but not eliminated it. That's actually one of the big problems with the contemporary parachutes that are designed or packed to open slowly. As the parachute is sniveling, the lines remain uncontrolled, and they can snag or wrap on just about anything.

When I hear jumpers laughing about their 1,000 foot snivels I kinda cringe and know that at some point they will probably have tension knots.

So, imagine you are smiling and sniveling under your cool and groovy parachute that always takes 1,000 feet to open. As you get to the lower end a couple of lines thrash around and knot on each other below the slider. It's no big deal because your parachute always opens slow, so you give it just a bit more time, then you start pulling on steering lines or doing whatever magic-making you can think of.

Of course you are already low and moving fast, so time is running out. Finally, you realize it's not a correctable problem and you cutaway. Unfortunately you are just a bit unstable so you struggle to arch and then reach for the silver handle, but you run out of time and slam into the ground, wishing you had a faster opening parachute, wishing you hadn't waited so long for the stupid tension knots to clear, wishing you hadn't tried to get stable, wishing you were more altitude aware, and wishing you had left the RSL on your rig.

Tension knots are real.

Tom Buchanan
Instructor (AFF, SL, IAD, Tandem)
Senior Parachute Rigger

Tom Buchanan
Instructor Emeritus
Comm Pilot MSEL,G
Author: JUMP! Skydiving Made Fun and Easy

[councilman24 37]

Two of my four malfunctions (all before 1988) were tensions knots. This used to be a very common partial malfunction. I believe, without any evidence, that the use of the slicker microline has help decrease tension knots. I have one on video, from underneath. Sorry, it's VHS and I don't have capture capability.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[SkyDekker 1,465]

yup, so far that has been my only malfunction (knock on wood). My 3rd jump ever on a giant old 300 sq ft parachute, with static line deployment.

[Remster 30]

My only cutaway was a tension knot on a Sabre 210.. circa 1996

Remster

[rigging65 0]

They happen, not all that often, but they happen. Some of them you can "ping" with a riser and get out of (load and unload the riser rapidly to allow enough slack in the line for the knot to slip out). Sometimes they clear, sometimes they don't.

It's generally agreed that worn out lines are more likely result in tension knots than good, non-fuzzy lines.

Stow your lines in some ordered manner, make sure they're going to pay out in order, and keep them fresh and in trim...you'll reduce lots of possible Mals just by doing these few things.

"...and once you had tasted flight, you will walk the earth with your eyes turned skyward.
For there you have been, and there you long to return..."

[lippy 918]

My only chop to date was tension knots. Before I had it, I'd stuff the slack on the lines into the cigar roll while packing, so that my line stows would be cleaner. I tried to shake it out with the risers, but it started turning right as I was shaking the left, so I said byebye. In retrospect, popping the brakes may have cleared it, but it's too late for that now.

I got nuthin

[Casch 0]

Quote

In retrospect, popping the brakes may have cleared it, but it's too late for that now.

That may not have been a very good idea. Depending on altitude...what if you were to try, it didn't work, and you weren't able to get the toggles off your hands before pulling silver...then you risk a possible entanglement. If I ever get a tension knot, I hope that I don't hesitate to cut away

[sducoach 0]

Tension knots can be reduced by simply "milking" your brake lines down from the cascades towards the toggles.

With your brakes un-stowed, pick up the brake line at the cascade. Make sure the cascade is straight, pinch the brake line and slide your fingers down towards the toggle. You will notice the lower line begin to curl. That is the start of a tension knot. Now continue holding the line and "un-twist" the toggle. Repeat on the other side.

We don't notice is very often when we pack but we put these twist into the lines by leaving the toggles un-stowed as we walk in, or setting the toggles and twisting the line one way or the other to stow the toggles. After repeated twists when the line attempts to extend under tension, its just like winding up the old rubber band, it twists upon its self and without releasing the tension, you're stuck.

Blues,

J.E.

James 4:8

[iohn 0]

hi all

anybody ever heard that tension nots can cause really fast turns under ellipctical canopies ?
in my case spring 160 wingloading 1.25

thx
Iohn

[slotperfect 7]

I have had a couple, but cleared them both by pulling down on the entire line group (riser) and letting it "snap" back into place. The momentary change in tension on the knot took care of it.

Mind you, this was with big, square, F-111 canopies, not highly loaded ellipticals.

IMHO the best way to avoid tension knots is careful packing, including taking the twists out of your brakelines routinely when you pack. There's really nothing to it, and it saves a lot of problems in the long run.

Arrive Safely

John

[mr2mk1g 10]

I had a tension knot mal (no cutaway) about a month ago.

Jumping a borrowed Saber 170 in a Vector II because some one else wanted to borrow my rig.

When I unstowed the breaks the canopy dove hard to the left - right toggle pressure returned me to level flight.

On looking up I can see that the left break line is all twisted round the left hand rear line set and no ammount of pulling would clear it.

I was now at 1000ft and under a big square canopy which I was flying in about 3/4 breaks. I decided to keep it because I could control it and could predict how it would land.

I therefore flew with essentially flat turns by inceasing or decreasing RH toggle input. Only just made it back to the DZ because of the fairly deap break setting I had to use to maintain level flight.

The final flat turn I used to turn back into wind actaully turned out to be more of a hook turn (again cos of the fairly deap breaks), but I was nice and high.

On landing I gave a really hard flare, whilst keeping the toggles at thier relative hights they were at for level flight.

I guess because of the hard flare the damn tension knot came free and the left hand side of the canopy surged a little on landing before I could compensate with more toggle pressure.

A good PLF to finish and I was down safely if a little roughly.

The guy who packed this is a very good packer used to jumping radical, highly eliptical canopies and I would trust his pack jobs any day. What had apparently happened was someone had stepped over the lines half way through the pack job and kicked them by accident. (we've all been on the receiving end of that right?)

My friend had just pulled the lines straight again and continued with the pack job (again I'm sure we've all done that before). We figured this must have caused the break line to become wrapped arround some of the suspension lines, or at least some ammount of confussion in the lines to be created.

The result was the offending tension knot. Interesting experiance.

[matttrudeau 0]

A good friend of mine had tension knots on a small Jedei. He's a videographer so it was all on video. His canopy was defintely diving to the right. Before he cutaway, you can see the left riser come in front of the camera and then disappear to the right.

[marks 0]

i had a tension not malfunction on an 87 vx on the right side d lines...

if i didnt chop it right away i was going to black out because it was spinning soo fast.

[bch7773 0]

A guy at our DZ had some tension knots once. It caused his chute to start spinning, and so he had to cut away pretty fast. On the video, it looked like a normal canopy except for one side was just a tiny little bit distorted. actually, we weren't sure it was tension knots, but there wasn't a better explanation. (one brake unstowed had already been ruled out)

MB 3528, RB 1182

[iohn 0]

I also go with Tension Knots, cannot find a better explanation.
Thx for the replies!
Iohn

[JackR 0]

There are a lot of good reasons to clear the brake lines. Avoiding tension knots is only one of them.

I haven't thought about tension knots for quite some time. Reading through this thread reminded me of a lot of "legends" that I heard as I was learning to skydive.

There was a rash of tension knot malfunctions on tandems in the mid-90s. Based on some of the input from this thread, a lot of thouse were probably caused by worn lines. That was a time when tandems were becoming more and more popular and DZs were seeing the money rolling in. It was also a time when those tandem canopies were getting more use (=wear) between maintenance.

When I was being trained to pack parachutes as a student, my instructor, Scott Chew (sorry if I got the spelling wrong.) showed me how tension knots could develop. He took a brake line in hand and twisted it while it was slack. I think he may have put two full turns in it. He pushed the turns together and flicked one of the twists with a finger. Then he put tension on the line. A knot developed and only got tighter with the more tension that was added. On a brake line the slider would not have passed over this without some serious pumping of the lines. Given some of the other posts here, imagine yourself going through that around 1,500 feet.

At the time is absolutely amazed me how quickly and easily he was able to get the knot into the line. I pulled and pulled on the line, like you would with your toggles, and couldn't get it to undo. Ever since I've paid attention to twists in the brake lines.

I can't say I've been committed to this though. I only check it every few jumps on my own gear, but I always put my toggles back on the Velcro after I land and have the canopy collapsed behind me. If I notice that one has fallen off on the way back to the packing area, I clear that brake line for sure and usually clear the other one.

I show my packing students how to clear the brake lines, but don't take the time that Scott did to explain why it is important. I usually just rely on the "'Cause I said so" reason and move on to flaking and bagging the canopy.

I pack at our drop zone and don't clear the brake lines as often on that gear either. I've found myself a lot of times looking back down the lines after laying the canopy on the ground, thinking, "I should clear those brakes the next time this rig gets jumped." At that point I don't want to have to redo all of that work. Maybe I should be saying, "It is a lot easier to clear the brake lines now than have a student cutaway from tension knots."

There is one time I always clear the brake lines. That is during the repack. As part of the reserve inspection I always walk the brake lines to verify no twists. I also inspect and pack the main as a free service and I clear the brake lines at that time as well. I just spent 4-5 hours on the reserve. The 2 minutes it takes to clear some brake lines is worth it to give my customers cleared brake lines again since the last time they did it.

I have written a lot so far and I thank you for staying with me. Let me leave you with this thought. Many of the comments about tension knots were from "back in the day." I'm sure you've enjoyed many of these stories around the campfire after a good day of jumping. These "back in the day" canopies had Velcro toggles and most everyone was taught to put their toggles back on the Velcro anytime you took your hands off of the toggles. Now more and more jumpers have Velcro-less toggles. How many times have you seen that toggle flipping and twisting as they walk back to the packing area? How many of those times did the packer take the time to clear the lines? The best thing I've seen with the Velcro-less toggles is to tuck them into the toggle keepers on the riser, again, as soon as you land. Even if you do this, check them ever so often and prove to yourself that you're doing a good job of this.

Packin' Jack
42nd Lost Prairie: The Ultimate Answer to Life, the Universe, and Skydiving
25 Jul - 3 Aug 2009
2007 photos: http://www.skydive.com/prairie/pages/prairie.htm

[jumpgod 0]

I haven't seen one per say, in fact, most malfunctions that i have witnessed were due to packer error....being rushed maybe....uncocked pilot chutes, broken lines, line-overs, but no tension knots ever witnessed.

I think it might have to do with tensioning your lines while flaking and stowing. if you leave that mess at the tip of the nose when you start cacooning, it's an accident waiting to happen.

"dude, where's my main?"