Why do ram air canopies malfunction less often than rounds? Intuitively you'd
expect the opposite since a round is a simple canopy and a square is far more
complex.

From:	Lucas, Peter
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	13 Jan 2005 11:17:41 GMT

boeing377@aol.com (BOEING377) who is a closet loony wrote in
news:20050113031112.05186.00000082@mb-m01.aol.com:

> Why do ram air canopies malfunction less often than rounds?
> Intuitively you'd expect the opposite since a round is a simple canopy
> and a square is far more complex.
>

It 'rams' the air into it more quicker?

:-P

--
Peter Lucas
Brisbane
Australia

Qui desiderat pacem, bellum praeparat; nemo provocare ne offendere audet
quem intelliget superiorem esse pugnaturem

Flavius Vegetius Renatus, "De re militari" 390 B.C.E.

From:	ynotssor
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	Thu, 13 Jan 2005 10:29:00 -0800

"BOEING377" wrote in message
news:20050113031112.05186.00000082@mb-m01.aol.com

> Why do ram air canopies malfunction less often than rounds?

Would you please provide some information to support the contention.

--
use hotmail for email replies

From:	Tom B
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	Fri, 14 Jan 2005 00:02:54 GMT

"BOEING377" wrote in message
news:20050113031112.05186.00000082@mb-m01.aol.com...
> Why do ram air canopies malfunction less often than rounds? Intuitively
> you'd
> expect the opposite since a round is a simple canopy and a square is far
> more
> complex.

Like Tony said, I am not sure that they do. Collecting them into simple
groups of round and square puts a lot of very different canopies in each
pile. The military rounds with anti-inversion nets have a very good record.
Line Over seemed more common. on other rounds. A Paracommander has a lot of
vents/holes in the canopy that can permit things to go through and entrap
and wrap things during deployment. Not clearing the apex or stabilizers can
be fun too.

But still, I go with Tony, what makes you believe they are more likely to
have bad deployments.

Tom B

From:	KeithV7712
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	14 Jan 2005 06:06:27 GMT

I thought this might be a trolling
expedition from the start ..

KV

From:	Tom B
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	Fri, 14 Jan 2005 12:35:18 GMT

"KeithV7712" wrote in message
news:20050114010627.12074.00000121@mb-m15.aol.com...
>I thought this might be a trolling expedition from the start ..

Probably. But at least it was about skydiving and raised a reasonable point
to ponder. Besides it is a question that lets old skydivers like Jimbo and
Mike remember jumping their 7TU. :)

Tom B

From:	Mike Spurgeon
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	Fri, 14 Jan 2005 19:18:31 GMT

Tom B wrote:

> Probably. But at least it was about skydiving and raised a reasonable point
> to ponder. Besides it is a question that lets old skydivers like Jimbo and
> Mike remember jumping their 7TU. :)

I distinctly remember it being said that squares have no
'inherent malfunction mode'.

Not exactly sure what that means, but it was being said to
explain fewer malfunctions on squares (when they were first being
touted as reserves).

From:	Joseph Walther
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	Fri, 14 Jan 2005 17:35:31 -0500

Mike Spurgeon wrote:
> Tom B wrote:
>
>> Probably. But at least it was about skydiving and raised a reasonable
>> point to ponder. Besides it is a question that lets old skydivers like
>> Jimbo and Mike remember jumping their 7TU. :)
>
>
> I distinctly remember it being said that squares have no 'inherent
> malfunction mode'.
>
> Not exactly sure what that means, but it was being said to explain fewer
> malfunctions on squares (when they were first being touted as reserves).

Walther responds...

Please note this disclaimer...

I am not one to render technical advice (relative to skydiving) on this
forum. I have enough problems keeping myself alive.

This thread screams for a reply, however. This is not aimed at Mike
Spurgeon or Tom Birdwell. Neither of them made the "inherent" statement.
I am sure that Mike does know the meaning but there are probably many
others who do not.

It means that there are no "built in" malfunction opportunities. This is
pure bullshit, of course.

Only a criminal would produce a system and intentionally include
malfunction opportunities. And, only an idiot would purchase one, unless
the purchase was motivated by a death wish or unless the purchaser was
clueless.

On the other hand, as long as human judgment is involved in system
production, malfunction is part of the equation. Good quality assurance
programs can minimize malfunctions.

Finally, there is no amount of quality assurance that will prevent a
malfunction if the product user is a moron!

Regards

Joe Walther

From:	Tom B
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	Sat, 15 Jan 2005 04:22:29 GMT

"Joseph Walther" wrote in message
news:_fSdnViVXomx1HXcRVn-gA@comcast.com...
> Mike Spurgeon wrote:
>> Not exactly sure what that means, but it was being said to explain fewer
>> malfunctions on squares (when they were first being touted as reserves).
>
> Walther responds...
>
> Please note this disclaimer...
> I am not one to render technical advice (relative to skydiving) on this
> forum. I have enough problems keeping myself alive.
>
> This thread screams for a reply, however. This is not aimed at Mike
> Spurgeon or Tom Birdwell. Neither of them made the "inherent" statement. I
> am sure that Mike does know the meaning but there are probably many others
> who do not.
>
> It means that there are no "built in" malfunction opportunities. This is
> pure bullshit, of course.
>
> Only a criminal would produce a system and intentionally include
> malfunction opportunities. And, only an idiot would purchase one, unless
> the purchase was motivated by a death wish or unless the purchaser was
> clueless.

I guess that depends on one's view of intentionally including "defects".
Products the world over are knowingly produced with malfunction properties.
Usually this happens due to ultimate conflicts in performance, weight, or
life vs constraints including cost, materials, manufacturability, etc. One
example is the properties of tires sold with new cars. Selection of a better
tire in low cost cars would reduce hydroplanning, blowouts, etc. Another is
the integrity of vehicle fuel tanks. They can absolutely be made safer, but
at an increased cost. A compromise is reached based on some level of
acceptence of fires and death and lawsuits. Closer to home in skydiving is
the trade off between high performance and safety. Safe things are generally
not as fun. The early elipitical canopies were certinly an example of this
including the nicknamed Spineto. High performance suspension lines with
shorter lives are another example. All of these examples can, have, or will
be pointed to by attorneys and described as "built in" defects.

> On the other hand, as long as human judgment is involved in system
> production, malfunction is part of the equation. Good quality assurance
> programs can minimize malfunctions.

True, but the greatest gains can be made in the design process, for example,
designing products that simply can't be misassembled, instead of using a
quality program to find the defective units. .

> Finally, there is no amount of quality assurance that will prevent a
> malfunction if the product user is a moron!

True. And until significant tort reform happens, there is little that will
stop a lawyer from attempting to enrich the moron and himself by putting
the responsibility on someone else in the product chain.

> Regards
> Joe Walther

Tom B

From:	Winsor Naugler III
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	Fri, 14 Jan 2005 17:59:33 GMT

"BOEING377" wrote in message
news:20050113031112.05186.00000082@mb-m01.aol.com...
> Why do ram air canopies malfunction less often than rounds? Intuitively
you'd
> expect the opposite since a round is a simple canopy and a square is far
more
> complex.

It relates, in part, to the difference between what constitutes a
malfunction in a round or a ramair. Also the statistics for rounds include
those from unmodified C-9 bailout rigs, mesh skirted modified parabolics
(which function in a near-flawless manner), inverted apex types.and other
sport canopies, with reefing mechanisms ranging from none through hydraulic,
sleeves, diapers, sliders, confluence wraps and bags.

Be advised that many circumstances that constitute a "malfunction" under a
round merely require a good PLF to walk away with nothing more than another
war story. With ramairs, most of the common malfunctions result in dire
consequences if emergency procedures are not executed in a timely manner.

Thus, we are talking apples and oranges to the extent that relating the
"failure rate" of one to the other is generally meaningless.

Rounds are fun as a novelty, but I'll stick with ramairs - regardless of any
perceived difference in reliability.

Blue skies,

Winsor

From:	Nicko
Subject:	Re: why do ram airs malfunction less often than rounds?
Date:	Tue, 18 Jan 2005 19:46:42 -0600