Parachute 20 year limit

I have a security chute that is older than twenty years of
experience. Are you guys finding that the repackers are refusing to
recertify past twenty years? Seems the manufacturers have put out
service bulletins recomending twenty year service limits. I am
interested in getting this chute repacked if possible. Please let me
know of anyone that might inspect this chute. Preferably near
Atlanta, GA.

On Dec 3, 8:34*am, wrote:
I have a security chute that is older than twenty years of
experience. *Are you guys finding that the repackers are refusing to
recertify past twenty years? *Seems the manufacturers have put out
service bulletins recomending twenty year service limits. *I am
interested in getting this chute repacked if possible. *Please let me
know of anyone that might inspect this chute. *Preferably near
Atlanta, GA.

The thing is, while it is not an FAA mandate, (the 20yr thing...) the
individual packer who certifies it as airworthy has their butt almost
as much on the line as yours is while wearing it, and studies have
shown that 20 yrs of normal use/exposure is approaching the safe
working life limits of the materials. I've heard of 20 yr old
containers that look perfect, with perfect looking canopies that you
can easily jab a finger through. IMO parachutes are just jot a good
arena to skimp in...

-Paul

sisu1a wrote:


The thing is, while it is not an FAA mandate, (the 20yr thing...) the
individual packer who certifies it as airworthy has their butt almost
as much on the line as yours is while wearing it, and studies have
shown that 20 yrs of normal use/exposure is approaching the safe
working life limits of the materials.

That's not what Strong parachute says, or my rigger, so I'd like to see
these studies for myself. Do you have a link to them?

Mostly, I'm puzzled by the idea that an emergency parachute has a
"working life limit" because it doesn't work: it just sits there. I
would think it's only a matter of how long the materials last, and nylon
and metal will last indefinitely in a cool, dry place.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

sisu1a wrote:
studies have
shown that 20 yrs of normal use/exposure is approaching the safe
working life limits of the materials.

That's not what Strong parachute says, or my rigger, so I'd like to see
these studies for myself. Do you have a link to them?

Eric Greenwell - Washington State, USA


I do not, I was passing along hearsay from a trusted source, and after
searching the best I could find was this article on the subject form
1958, http://tinyurl.com/6b5bca (.pdf file...) which admittedly does
not really support my point much being as old as it is. After talking
with a prominent rigger today while I was picking up my National, I
asked him about it to find the answer so I could provide such data. He
could not point me to any sources either, although he of course agrees
with the 20 yr thing. His suggestion was to ask some higher ups at
Parachute Industry Association, which I have done, and I will share
anything I turn up from that avenue. Also, here is a link to the PIA
rigger's newsgroup, where I'm sure you could get more useful info
there if you are motivated enough on the subject to post/search the
http://www.websitetoolbox.com/mb/rig...ool/mb/riggers

Mostly, I'm puzzled by the idea that an emergency parachute has a
"working life limit" because it doesn't work: it just sits there. I
would think it's only a matter of how long the materials last, and nylon
and metal will last indefinitely in a cool, dry place.

Poor choice of wording on my part I suppose. I didn't mean time spent
'working' when I posted that, but rather the length of time it is
still fit to work if it needs to. According to the same rigger, the
older nylons (like what would have been used in the 1958 study linked
above...) actually held up longer than the newer materials, but was
lower performing in actual use. Much like today's high performance
optics, today's high performance parachute materials have special
coatings that affect the physical properties and such, but on chutes
they supposedly degrade and rub off over time, even under the best of
conditions. 20 yrs is even thought to be optimistic to some for this
reason...

-Paul

What is this about round vs ram/square? I thought it was generally
accepted that ram/square give more control and lower descent rates,
but are less suitable for glider emergency chutes because they work
reliably only if you are the right way up etc. when you pull them.

Whereas it used to be said that round ones may give no or less control
and a higher descent rate (for a given area), and you may get broken
ankles, but they are better life savers because they deploy more
quickly and reliably when used by untrained glider pilots in emergency
when you may deploy them in far from the best attitude.

True, false, or what?

Chris N.

False. I believe squares are (slightly)more reliable. Only problem with
squares is that an untrained jumper can hurt/kill themselves landing one.
Square parachutes accelerate when turning(think glider without pitch
control) hence turning low to the ground and impacting while the parachute
is descending is the issue. I believe there are two companies selling
square pilot rigs: Paraphenalia and Rigging Innovations. Rigging
Innovations has two versions one is a standard square reserve for
experienced jumpers or folks willing to get training and the other has a
detuned square that still gets better descent rates than rounds. I don't
work for either company but being an exskydiver I use(well wear) a square
parachute. They are more expensive by probably $700-$1,200. take good
care of them and they should last more than 20 years...
At 12:20 05 December 2008, wrote:
What is this about round vs ram/square? I thought it was generally
accepted that ram/square give more control and lower descent rates,
but are less suitable for glider emergency chutes because they work
reliably only if you are the right way up etc. when you pull them.

Whereas it used to be said that round ones may give no or less control
and a higher descent rate (for a given area), and you may get broken
ankles, but they are better life savers because they deploy more
quickly and reliably when used by untrained glider pilots in emergency
when you may deploy them in far from the best attitude.

True, false, or what?

Chris N.

On Fri, 05 Dec 2008 04:20:16 -0800, cnich15000 wrote:

What is this about round vs ram/square? I thought it was generally
accepted that ram/square give more control and lower descent rates, but
are less suitable for glider emergency chutes because they work reliably
only if you are the right way up etc. when you pull them.

My chute, which was put together by John Rix (Southern Parachutes) is now
old enough that he's repacking it on a year-by-year basis. He's willing
to replace the canopy when the time comes if he can find one, but says
round canopies are becoming very hard to find. So, I asked him about
replacements. He suggested the Rigging Innovations Aviator model. It has
a square, 7 bay canopy that can't be stalled, and so needs no more
training than a round parachute. They're not cheap ($US 2300 on the web
site, compared with £1250 for a Strong from AFE).



--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

true....almost any parachute manufacturer will tell you the same...Round
parachutes are tested in order to pass TSO standards and have to be able to
successfully deploy when: packed wrong, deploy even when pilot is in any
position, when the parachute is soaked, dirty, even damaged and
more...Square sport parachutes must also be "flown" and even student squares
which are tamed down so they cannot fully stall or high speed take some
training and knowledge as well as an astute pilot who is fully aware of what
is happening, not always the case when the pilot is bailing out of a mid air
or disabled aircraft...knowing full well that many glider pilots may not
have even read the operators manuals for their emergency parachutes and have
little of no knowledge of how to use one if the occasion shows itself makes
for a far better choice of a round emergency parachute than a square for
90%+ of the potential users...
yes....you might hit the ground with a bit of an aaaarrrrrgggghhh with an
emergency parachute..but you'll have enough adrenalin pumping you won't even
feel it....if you happen to land wrong as you may well ...you could even
bust an ankle though you probably won't unless osteoporosis has already set
in...but you'll likely live to write the story and fly another day...
tim

Please visit the Wings & Wheels website at www.wingsandwheels.com


wrote in message
...
What is this about round vs ram/square? I thought it was generally
accepted that ram/square give more control and lower descent rates,
but are less suitable for glider emergency chutes because they work
reliably only if you are the right way up etc. when you pull them.

Whereas it used to be said that round ones may give no or less control
and a higher descent rate (for a given area), and you may get broken
ankles, but they are better life savers because they deploy more
quickly and reliably when used by untrained glider pilots in emergency
when you may deploy them in far from the best attitude.

True, false, or what?

Chris N.

Cris and all

Some stories on chutes.

I'm retired AAF/USAF and punched from a jet over Greenland in a snow
storm in the middle of winter and walked. I'm a member of the
Catapiller Club (It's still in existance so anyone who bails out can
join and get the pin).

Military chutes at that time were 24 foot round. Prior to and during
WWII they had two diameters. 28 foot if you weighed over 190lbs and 24
foot for us skinny guys. Idea was to reduce landing accidents cause by
descent rate. History showed that the landing injuries didn't go up
very far with heavy pilots using the 24 foot so system was changed and
only 24 foot became standard. It was cheaper to only have one style
and the 24 foot fit better in the small fighter cockpits.

After the War and due to the possibility of high speed bail out, they
started enclosing the canopy in a 'bag'. When the chute was deployed
the canopy stayed in the bag until the shroud lines had fully extended
at which time the pilot chute pulled the bag off the canopy and it
deployed. This reduced the whip lash problems with canopy deploying
and the pilot falling away from canopy until the shroud lines were
full out (snap, crackle and pop).

There were two shroud lines on right and left rear that were flagged
in red. These shrouds could be cut after canopy was deployed and the
canopy then distorted and had some forward motion. By pulling on the
right or left shrouds you could turn the canopy and this gave you
some rudimentary steering ability.

Prior to landing you rotated the canopy so that you would touch down
facing forward downwind. Upon touch down you executed a parachute
landing roll like the Para Troopers use. You then dumped the canopy to
prevent dragging in the wind.

My advice is to use the MOST RELIABLE chute under ALL conditions
(round) and get some rudimentary training in its use.

Merry Xmas and good and safe flying. (No chutes please )

Big John


************************************************** ******************************

On Fri, 5 Dec 2008 04:20:16 -0800 (PST), wrote:

What is this about round vs ram/square? I thought it was generally
accepted that ram/square give more control and lower descent rates,
but are less suitable for glider emergency chutes because they work
reliably only if you are the right way up etc. when you pull them.

Whereas it used to be said that round ones may give no or less control
and a higher descent rate (for a given area), and you may get broken
ankles, but they are better life savers because they deploy more
quickly and reliably when used by untrained glider pilots in emergency
when you may deploy them in far from the best attitude.

True, false, or what?

Chris N.

wrote:
What is this about round vs ram/square? I thought it was generally
accepted that ram/square give more control and lower descent rates,
but are less suitable for glider emergency chutes because they work
reliably only if you are the right way up etc. when you pull them.

Be sure to select a canopy type and size the matches your weight. Check
the manufacturer's charts or talk to them. I bought a Softie sized so I
was at the bottom end of it's weight range, giving me an impact speed
about like jumping off a table.

The wind and terrain will make a much bigger difference in your landing
the difference in descent rate between properly sized round or square
parachutes. A soft landing is likely important for someone doing 10 or
20 jumps a day, but not for emergency use.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org