"maximum usage time" for canopies?

[mostwanted 0]

i just read that it seems that in my country (austria/europe) there is something like a "maximum allowed usage time" for canopies: 20 years.

could this be possible? (is that true?)

it is also mentioned that the maximum usage time is 20 years, unless the manufacturer determines something else.

[ryoder 1,388]

You just had to start this thread again, eh?
For the record, I'm all for it. As a rigger, I have seen several reserve canopies just over 20 years old, that looked like new, but tore like tissue paper.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[darkwing 4]

Yes, it is true, and as a rigger I'm against it. There are much better ways to determine airworthiness.

-- Jeff
My Skydiving History

[mostwanted 0]

Quote

You just had to start this thread again, eh?
For the record, I'm all for it. As a rigger, I have seen several reserve canopies just over 20 years old, that looked like new, but tore like tissue paper.

i don't think i have already posted this question...?

[ryoder 1,388]

Quote

i don't think i have already posted this question...?

Just kidding; This has been a hotly contested topic several times in the past.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[mjosparky 3]

There is only one way to determine if a canopy is airworthy. That is to jump it and see what happens. Very few riggers are willing to do that, so they come up with a variety of other methods to tell you your reserve is garbage.

Sparky

My idea of a fair fight is clubbing baby seals

[stratostar 5]

Quote

For the record, I'm all for it. As a rigger, I have seen several reserve canopies just over 20 years old, that looked like new, but tore like tissue paper.

For the record I have amassed one of, if not the largest collections of jumpable retro rigs anywhere in the USA
and have many mains and reserves well over 20 yrs old that pass tensile strength with flying colors.
And we jump them regularly, I have been jumping my 1965 MK-1 paracomander since I got it in 1984.
As with many of the others in the collection it hasn't blown up yet!


I have also had a few people send me PC's that were pulled tested by others who ripped the shit out of the taffeta and called it unairworthy when in fact they just didn't know what the hell they were doing and the canopy would have been fine had thay not trashed it doing the pull test.
I have also seen plenty of sun rotten canopies tear like tissue paper, some more then 20 years old and plenty that were less the 20 years old.
So it would depend on who is doing the tensile test as to how relible the test is.
And how well cared for the rig/canopy has been over the years.

~

you can't pay for kids schoolin' with love of skydiving! ~ Airtwardo

[mattjw916 2]

What's the "proper" procedure for doing a "pull-test"?

I've heard a few different methods over the years but never really discussed it at length before.

NSCR-2376, SCR-15080

[councilman24 36]

The current and best reference is PIA TS-108. http://pia.com/piapubs/TSDocuments/ts-108.pdf

But up for debate, including within the PIA technical committee, is the force that should be used. Many think that 40lbs is too high. PISA always maintained that for F-111 type fabric 35lbs should be used. The spec strenght is 45lbs. Also for type 3 30-50cfm Lo-Po fabric spec strength is 45lbs. Type 1, 1.1 ounce fabric used in military canopies the spec strength is 42lbs. So 35lbs is appropriate.
Zp is in general 43 lbs. Reference, FAA "Parachute Rigger Handbook" PD's reserve manual specs 30 lbs.

I usually test to most things to 35 lbs. I've had a few fail over the years. The ones that have failed have failed at less than 10 lbs.

PIA Technical committee would like to gather more data from fabric manufacturers and revise this specification. But, we don't have a volunteer at this time. PIA is a volunteer organization. Without a champion projects like this don't happen.

Key considerations, placement of clamps, tightness of clamps, and pull force used. The clamps need to be pulling directly in line with the threads, whether warp or fill. Also the clamps need to be tight enough not to slip. If they slip they may very well damage good fabric. Then you need to use a quality scale. Or at least one that you know won't be reading too low. The difference between test and spec isn't very great.

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

[stratostar 5]

Quote

What's the "proper" procedure for doing a "pull-test"?

well start by reading your poynter manuals if you have them, but the answer is on page 72 of vol-2.
paragraph 3 and you need to see illustration #2 as well.

But in short, clamps 3 inch apart and a load of 40lbs (18kg) for 3 seconds, this is what I use to test a canopy in a non destructive method on old shit.
And then there is always the old school "thumb test" not as good but it works.
Or do what Terry say's

Read the the poynters manuals lot of good stuff to read about.

~

you can't pay for kids schoolin' with love of skydiving! ~ Airtwardo

[councilman24 36]

If you fill in your profile then we'll know where your from.

Some countries have mandated a parachute equipment service life. The U.S.A. hasn't. Some individual manufacturers have mandated various lifetime. PD requires factory inspection of their reserves at 40 pack jobs or 25 rides. GQ Security imposed a 15 year life on their pilot rigs.

I've been told most manufacturers will specifiy a service life for military contracts because the military requires one.

About 7 or 8 years ago PIA proposed imposing a 10 year service life. This was widely critisized in and out of PIA. We all know that a canopy on the shelf (well controlled shelf) for 10 years is practically as good as new. And a canopy can be trashed after a few days in the sun. Time is not a good measure of equipment airworthiness.

But, beside the pull test, (see above) and factory permiability tests it's difficult to test gear. We can't really test harnesses in the field. And if we could we'd very like damage them by testing. So some/much of the airworthiness determination is subjective and opinion. I'm pretty conservative. But I've jumped some junk.

The good news is that with a very few specific exceptions, harness don't come apart if design properly, manufactured properly, and not damaged.

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

[mattjw916 2]

Stratostar, et all...

Thanks!!!

NSCR-2376, SCR-15080

[riggerrob 558]

I have pull-tested close to 1,000 canopies and can count on one hand the number that failed.
It does not matter whether they are made of MIL-SPEC fabric (i.e. new-production C-9s from Mills), Lo-Po fabric (i.e. Strong LoPo) or F-111 (i.e. Phantoms), 99 percent of them passed 40 pound pull tests.
I pulled holes in a couple of faded, frayed and filthy military surplus rounds. They were old and ugly and should never have been packed into pilot emergency parachutes.
I pulled a hole in one Start-Flyer made of pre-F-111 fabric.
I also pulled a hole in a round reserve built by a long-defunct SoCal manufacturer. One panel was made of F-111 and easily passed a 40 pound test, while the panel that resembled tent fabric failed at slightly over 20 pounds.
I have only seen one PD reserve fail a pull test. An embarrassed Senior Rigger brought it to me to patch. I patched his hole and concluded that his only problem was doing a second pull-test too close to an earlier test. I also did pull-tests on several other panels, all of which passed.