Parachute 20 year limit

"Tuno" wrote in message
...
Base jumpers jump off clutching the drogue chute in their hand and
let it go to deploy the chute.

Right! And if a round opened faster than a square, they would do it
with a round at the other end of the "drogue" chute, which is not a
drogue chute, it's a *pilot* chute.


I am far from an expert on this subject. I have only used a chute once and
it was a round one. However, I live in Idaho not far from the "Perrine
Bridge." Having watched the base jumper I come to the conclusion that the
jumpers choose the "square" chute because of its' controllability. (You
don't want to end up in the water.)

The Perrine Bridge is one of the few places that is open to jumpers
24/7/365.
http://www.youtube.com/watch?v=9iYzChw0plc
http://www.youtube.com/watch?v=hU0q44RJsLg

Wayne
http://www.soaridaho.com/

Tuno wrote:

I would very like to know who you spoke to in March.

Unfortunately, I tossed my contact notes when I bought my parachute in
April, and my memory of who said what is poor. I can tell you I
definitely spoke to Strong, Paraphernalia, Tim Mara (who's offered
opinions here already), and I am pretty sure National, and I know I had
some contact with Allen Silver (but possibly not about ram-airs).

I also looked closely at this parachute:

http://www.parachuteshop.com/aviator..._parachute.htm

but this note (and also from reading the manual, as I remember), put me
off the idea:

"Because of the advanced characteristics of these canopy designs, the
Sport Aviator model may only be used by individuals who either have
ram-air jumping experience such as skydiving, or have received special
training in the use and performance of these canopies."

I also looked at Performance Design reserves, but they seemed to be for
even more experienced jumpers, and not people looking for "pilot
emergency parachutes".

Though I am not
surprised that a manufacturer would encourage you to stick with a
round chute -- they make money selling you either kind, and think that
they assume a liability risk if they do anything but tell an
"untrained jumper" to use a round parachute.

I can't assess that factor. They all seemed sincere, cautious, and
offered what seemed like sensible reasons for their recommendations.


The fact is, "square parachutes require training". But consider the
target audiences -- just about anybody can go make a parachute jump.
Licensed glider pilots have a FAR higher general compentency level
than your average yahoo. (At least in Arizona And I can assure you
that operating square *reserve* parachutes is an EASY thing for glider
pilots to do.

I believe you, but I'm not interested in learning, and I'm not sure I'd
remember it all a few years later, anyway. My final analysis that each
had some advantages for my situation, leading it to be a wash overall,
so I went with price and known comfort to pick the mini-Softie.

And, while all this is interesting discussion, my guess is getting
everyone to switch to ram-airs would not increase "emergency bail-out
safety" near as much as getting everyone to install a Roeger hook. But
that's another thread...

--
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

But from the manufacturor's website:
http://www.rigginginnovations.com/products/aviator.htm

"The 246 and 280 sq ft canopies have a unique modulated control
system, which allows for their use by aircrew personnel with minimal
additional training required over and above what they receive on
current round parachute systems."

That doesn't sound like a big barrier to use.

The only real barrier (IMHO) is the price difference.

Todd Smith
3S

but this note (and also from reading the manual, as I remember),
put me
off the idea:

"Because of the advanced characteristics of these canopy designs, the
Sport Aviator model may only be used by individuals who either have
ram-air jumping experience such as skydiving, or have received special
training in the use and performance of these canopies."

While they do recommend that for the Sport Aviator Model, that is not
the case for them all. They have two different control systems for
their 6 canopy options for the P-124. Four of them require jumping
experience but Two do they just say "minimum additional training"
Calling Rigging Innovations would answer exactly what that means.
http://www.rigginginnovations.com/products/aviator.htm

FWIW, I'm waiting for my new Softie to show up, with a good ole'
roundie under the hood. I would however like to do some jumps in the
future (not in my Softie!), at least enough to competently jump solo
since a broken airplane makes a terrible classroom...no matter how old
your chute is, how fast it opens, or whether it is square or round.
Training seems to be the answer to most of aviation's other ills...

-Paul

This has been an interesting discussion, but it is easy to become confused
by the fact that a high speed chute is designed to delay opening, and a
low speed chute is designed to open quickly, if I understand correctly.
Apparently the word speed refers to aircraft speed at egress and has
nothing to do with rapidity of deployment. Did I get that right?


At 03:47 11 December 2008, toad wrote:
But from the manufacturor's website:
http://www.rigginginnovations.com/products/aviator.htm

"The 246 and 280 sq ft canopies have a unique modulated control
system, which allows for their use by aircrew personnel with minimal
additional training required over and above what they receive on
current round parachute systems."

That doesn't sound like a big barrier to use.

The only real barrier (IMHO) is the price difference.

Todd Smith
3S

I come to the conclusion that the jumpers choose the "square" chute
because of its' controllability.

Wayne,

You make a good point, but they don't "choose" the square any more
than we "choose" to use a calculator instead of an abacus. The square
is an overwhelming winner in both controllability and speed-of-
opening. For BASE jumpers there is no "choice" to be made.

There are many BASE jump locations that could only be done safely with
a square (more arguments for the square!), but for the ones safe for a
round (e.g. downwind from most antennae), BASE jumpers would still
choose a square parachute, packed with the slider down.

But in this discussion, the speed of opening is only relevant if you
anticipate leaving a mal-assembled glider during a winch launch. For
most glider pilots, it falls solidly into the "doesn't matter"
category; deployments below the standard deviation of pull altitudes
still average above a safe altitude. (At least the ones I've read
about.)

In the context of glider pilots choosing round vs square parachutes,
to me the deciding factor is probably *where* the pilot does most of
his flying. East or midwest, over largely flat terrain? Again,
probably "don't care" territory (for the average pilot, not me, I
would still choose square). But in the southwest, where terrain can be
very unfriendly and help remote, it's a no-brainer.

Not that I have any opinion on the matter ... I still can't get fuses
straight.

2NO

Tuno wrote:

In the context of glider pilots choosing round vs square parachutes,
to me the deciding factor is probably *where* the pilot does most of
his flying. East or midwest, over largely flat terrain? Again,
probably "don't care" territory (for the average pilot, not me, I
would still choose square). But in the southwest, where terrain can be
very unfriendly and help remote, it's a no-brainer.

That does remind me of something one of the people I talked to said,
along the lines of "landing in trees is easier and safer with a round
than a square, unless you are experienced with the square".

Not that trees are an issue for Tuno, I suppose!

--
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

Nyal -- not quite. "High speed" refers to the maximum velocity when
opening for which the parachute was designed, not for how fast they
open (i.e., strength, not speed). There are high speed mains, high
speed reserves; high speed rounds, well, you get the picture. The
military T-10 is an example of a round, non-high-speed canopy.

Sport reserves are high-speed, but designed for fast opening at any
velocity, the anticipation being that a skydiver might have anything
between a terminal velocity and a low speed deployment, which may
happen after a canopy collision (or for canopy formation skydivers,
the dreaded wrap).

I don't know of any parachutes made today that are not "high speed"
rated. And the square ones, yes, they open FAST.

Your right about high and low speed bail outs. I did not get any
crotch burns during my bail out with a canopy in a bag.

I was addressing the comments about round canopy inversion which I
never saw with the round chutes in a bag.

Big John
************************************************** *****

On Wed, 10 Dec 2008 17:35:33 -0500, "Tim Mara"
wrote:

there are high speed parachutes and low speed parachutes.....we use low
speed parachutes for emergency parachutes in gliders....and everyone thinks
at first...."hey, I'm pretty fast I want a high speed parachute"
.....wrong....
low speed parachutes (150MPH or less) mean they open quickly..High speed
parachutes (with delayed opening (150MPH or higher) so they don't explode or
rip themselves off your back along with appendages...when you suddenly bail
out of your F18....
tim

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

Tech Support wrote in message
.. .
Will use this post to add some data.

In 1968, when I had to use a military chute, they packed the chute by
folding the canopy and then pulling it into a long slim bag. Pilot
chute was attached to top end of bag. When rip cord was pulled, pilot
chute came out and pulled the bag, with the canopy in it, full
extended and then the shroud lines extended. When lines full out the
weight and air resistance of pilot let the pilot chute pull the bag
off the canopy which then deployed.

I had access to Air Force accident reports and never saw where a
canopy did not deploy properly. We were never told this packing system
delayed the full deployment of chute and reduced the altitude at which
it could be deployed safely.

Any idea why the round glider chutes are not packed this way?

Big John
************************************************** **************

On Wed, 10 Dec 2008 04:06:44 GMT, Eric Greenwell
wrote:

Gregg Ballou wrote:

At 23:58 09 December 2008, Eric Greenwell wrote:

Are there published tests for opening times?

http://books.google.com/books?id=2Po...sult#PPA235,M1
Hope the link works. Read pages 234 and 235. There is info on
deployment
speed and reliability. I rest my case.

Now I'm confused. I don't have notes from my March 2008 calls, but
before I made my purchase, I talked to two major parachute
manufacturers, one of which makes a ram reserve, and also a well known
rigger. What I recall is they all encouraged me to stick with the round
parachute for my glider. One reason I recall was the round emergency was
more tolerant of body position during opening. These same people also
made similar comments to the ones made here about the advantages of the
round emergency for the untrained "jumper" (like me - I'm just a pilot).

Another issue I think recall correctly, was I could find only one
company supplying a ram air parachute that they claimed was suitable for
the "lightly" trained pilot looking for an emergency parachute. I wasn't
persuaded by what they said on their website that it's advantages were
small and might not actually exceed the disadvantages.

There was puzzling statement on page 235 of Poynters book:

"Round canopies blow up more often, possibly 30% in normal use."

This sounds incredible for certified emergency parachutes, and it makes
me wonder if he is even talking about the same thing I am, where "normal
use" is 20 years as a seat cushion, and very rarely, only one jump in
it's entire service life. My perception is round emergency parachutes
function properly with failure rates far less than 30%.

Big John,

The long slim bag you're referring to is called a "sleeve". Iirc their
primary purpose was to prevent inversions, which have long plagued
round parachutes. (The military also uses nets around the skirts of
their parachutes to prevent this type of malfunction.)

I believe Dan Poynter's book has a better explanation.

2NO