New Lines? How do you know?

[Zeppo 0]

I recently purchased a new rig, PD 9 Cell 260. I had this inspected and was told that it is in good condition, but I have a question about the lines.

When do they need to be replaced and how will I know?

I know that lines can stretch, and become out of trim, but how will this affect the performance of the canopy? Is this something easily noticeable?

Is there a recommended number of jumps between each new set of lines?

What goes up, must come DOWN!!!

[phoenixlpr 0]

You could have ask the person inspected your gear.

What type of lines do you have?

[chanti 0]

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I know that lines can stretch, and become out of trim, but how will this affect the performance of the canopy?

Spectra actually shrinks rather than stretches due to friction from the slider grommets coming down on opening. If the brake lines shrink a lot your canopy will fly slower due to almost being in quarter brakes all the time. You will also flare with less input than usual. Also if the canopy is out of trim you will have funny/off-heading openings.

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Is this something easily noticeable?

Yes, I've just had my brake lines adjusted and it's a HUGE difference!

-Chanti-

[ZigZagMarquis 9]

If you can... find out how many jumps the canopy has on it, total... find out if the lines on it now are original... if not... find out how many jumps on on the canopy since it was last relined. Then, with this info, go talk to the rigger that inspected the canopy. He or she will know more about the specifics of your situation then folks here...

... but generally speaking, when a canopy needs a re-line depends on a lot of things... type of canopy, size of canopy, type of lines, number of jumps, environment jumped in... to try to name a few, not necessisairly all of the factors... if we're talking Spectra here, its pretty safe to say, that generally you're looking at a line kit every 500 to 800 jumps... maybe more, maybe less... I'm sure someone will have something to say about that, because it all "depends"...

Good luck. Good on you for asking questions here, but talk to your local riggers too.

[fcajump 164]

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I recently purchased a new rig, PD 9 Cell 260. I had this inspected and was told that it is in good condition, but I have a question about the lines.

When do they need to be replaced and how will I know?

I know that lines can stretch, and become out of trim, but how will this affect the performance of the canopy? Is this something easily noticeable?

Is there a recommended number of jumps between each new set of lines?

Your Rigger, with the aide of the line spec sheets available from PD's web site, should be able to assist you with measuring the lines to determine how far "out" they are. As to condition, (s)he will be able to tell that from a fairly quick inspection.

JW

Always remember that some clouds are harder than others...

[riggerrob 643]

First off, ask your local rigger has Dacron or Spectra suspension lines.

If it has Dacron suspension lines, the center A lines will be the first to stretch. Also steering lines will fray. Dacron lines last 500 to 800 jumps, about the same life as F-111 fabric.

If the canopy has Spectra lines, the most obvious wear will be the outer A lines shrinking. Less obvious will be the steering lines shrinking. You need a Master Rigger - who understands the subtlties of trim charts from different manufacturers - to measure steering line shrinkage. If the canopy is tapered/elliptical, you REALLY need a Master Rigger who understands the dark art of trim charts.

In conclusion, the quickest way to measure suspension line stretch/shrinkage is to grab all the A lines - from one front riser - pull them tight and measure the difference. When the difference approaches 3 inches, you are due for a new line kit.

[Zeppo 0]

I'll talk to my rigger and get his thoughts on my line condition. I'm sure they're still good for now, but at least now I know what to look out for.

Thanks.

What goes up, must come DOWN!!!

[masterrigger1 2]

***
In conclusion, the quickest way to measure suspension line stretch/shrinkage is to grab all the A lines - from one front riser - pull them tight and measure the difference. When the difference approaches 3 inches, you are due for a new line kit.

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Rob,
Some canopies are now built with a couple of inches of differential already in them.
Examples:
Stiletto
Crossfire 1
Crossfire 2
Katana

The method that you described only works on certain canopies today.

Some of the ones that it works are (Not all are listed):
Colbalt
Sabre1
Monarch
Ariel


Cheers,
MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

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