reducing sigma tension knots

[skydiveoc 0]

any tips here on packing? Our packer is very experienced and in 4 years we have 12 sigma chops vs 0 Icarus. Recently had 2 in one day. I thought of attaching a stoe to the slider for the d lines or steering lines to reduce slack at the throwdown point.

[bclark 0]

We had an all Icarus fleet for years. We bought 3 Sigma 370's when we got the first of our Sigma tandem rigs. They kept getting cut away for the same reason (tension knots). After a couple of seasons of this we fixed them...by replacing them with Icarus 365's

[AggieDave 6]

Besides the obvious line wear inspection issues, a big issues is the cascade in the steering control lines. If the steering lines are not untwisted by the packers or the instructor, then it will cause more tension knots. Its a HUGE cascade and when it twists it turns out and flat then likes to catch the D/C line cascade.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[kenneth21441 0]

I totally agree with you. I have seen this countless times and I guess one of my pet peves is making sure that the lines are untwisted be it my own pack jobs or someone else is packing while I am supervisong them....

Kenneth Potter
FAA Senior Parachute Rigger
Tactical Delivery Instructor (Jeddah, KSA)
FFL Gunsmith

[johnny1488 1]

I've found that the guys at my dz that jump them (I jump Icarus) start getting tension knots when the line sets start getting old.

And Im pretty sure UPT would suggest flat packing.

Johnny
--"This ain't no book club, we're all gonna die!"
Mike Rome

[efs4ever 3]

Quote

Besides the obvious line wear inspection issues, a big issues is the cascade in the steering control lines. If the steering lines are not untwisted by the packers or the instructor, then it will cause more tension knots. Its a HUGE cascade and when it twists it turns out and flat then likes to catch the D/C line cascade.

He is correct.

1. UNTWIST.

2. Replace lines when they get rough.

I haven't chopped my personal rig since 2002. 2 in a hundred on "company" gear.

Russell M. Webb D 7014
Attorney at Law
713 385 5676
https://www.tdcparole.com

[Fledgling 0]

I have noticed that every one that mentions this problem seems to be talking about the Sigma 370's. I have just bought a brand new Sigma 340. Should I be expecting a similar problem as well?

[AggieDave 6]

Its not a canopy specific problem, its a line type specific problem. This is something that will and can happen to any main with dacron lines. It still comes down to proper gear maintenance. Even with the issues associated with Dacron lines, I prefer them for their ability to stretch a bit.

Any decent rigger could probably reline your Sigma with vectran or similarly appropriate line type, but I'm not sure what that would do for any amount of warranty with the company formally known as RWS.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[SkymonkeyONE 4]

You know, I can't recall a single instance of chopping due to tension knots on any of the Sigmas we had at Raeford. Actually, I think we made it like three years on them before the first cutaway.

Chuck

[jimjumper 25]

Untwisting the steering lines works to prevent tension knots. We are trying to find out why the lines are twisting to begin with. We are careful to stow the toggles immediately after landing and are still untwisting the steering lines after 3-4 jumps. Most of our canopies are new or just re-lined. We believe that the way the lines are manufactured (weave and tension) cause the lines to twist as they are stretched and then relax after opening. Any canopy designers out there have any ideas?

[skydiveoc 0]

I inspected the canopies and really didnt find alot of twists. Maybe 2-3 full twists coming down the cascade to the toggle. Am I missing something?

[camamel 0]

How many jumps per year, per canopy?

Richard

When you think you're good...this is when you become dangerous.

[camamel 0]

What is your e-mail?

We have 10000+ tandems on 370 here, and i understand!

Richard

When you think you're good...this is when you become dangerous.

[skydiveoc 0]

One canopy is new, others have 300 - 1000 jumps

[SLIPPYBLUEKNOBE 0]

Quote

Any decent rigger could probably reline your Sigma with vectran or similarly appropriate line type, but I'm not sure what that would do for any amount of warranty with the company formally known as RWS.

Has anyone done this?

[buff 0]

I'm not a TI but I pack the all of the "company rigs" which use Icarus canopies and one guy who has a Sigma with dacron lines.

I pack using a hook, untwist any of the control lines from the canopy down to the toggle, place the steering lines on top, and stow the excess in a band.

We have not had a chop or a tension knot in the 3 years I've been packing.

It's called the Hillbilly Hop N Pop dude.
If you're gonna be stupid, you better be tough.
That's fucked up. Watermelons do not grow on trees! ~Skymama

[SLIPPYBLUEKNOBE 0]

I was referring to replacing the dacron lines on a sigma canopy with something else. Interested to know how the openings were?

[SLIPPYBLUEKNOBE 0]

bump

[SLIPPYBLUEKNOBE 0]

Have also been noticing the loop that sets the brakes getting stuck between the cats eye of the steering lines and the metal ring.
I have cleared the toggles from the risers both the velcro and the buttons then the toggles from the loop and then when the steering line should slide off the loop and go into full flight nothing happens.
On one jump I had gone as far as to open the velcro covers that holds the excess steering line. Still nothing it wasn't till I had pulled out on the top of the ring that the canopy went to full flight.
Usually a little work with the toggle will do the trick. However I was interested to see were the problem was coming from.
Having chopped from tension knots a couple times and also having opened with them to successfully clearing them a few more times. I am under the believe that if you can get to the toggles quickly you can probably save yourself or the dz a repack.
Has anyone else noticed the loop hanging up?

[skydiveoc 0]

I seriously believe the 370 is a tension knot magnet. We have since switched to all 340's and one icarus 365 and have not had a single chop in 1.5 years or 3000 tandems. Same packer.

knock on wood here.

[theonlyski 8]

Quote

I seriously believe the 370 is a tension knot magnet. We have since switched to all 340's and one icarus 365 and have not had a single chop in 1.5 years or 3000 tandems. Same packer.

knock on wood here.

Maybe your packer just got better?

"I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly
DPH -7, TDS 578, Muff 5153, SCR 14890
I'm an asshole, and I approve this message

[tkhayes 348]

Tandem instructors can untwist the steering lines while they fly the canopy - just look up and spin the toggle on your hand a few times to undo it.

then it does not become a packing issue.