Catastrophic Decompression; Small Place Solo

"khobar" wrote in message
news:_7iJb.16944$7D3.30@fed1read02...
C J Campbell wrote in message
...
|
| What bullets, if any, possess sufficient energy to penetrate an
airliner
| window and would that airliner window spider or would said bullet
simply
| leave a small hole? We already know that an adult PAX will,
apparently,
fit
| through a typical airliner window.
|

We do not really know any such thing. If the passenger is bigger than
the
window he simply cannot be pulled through it any more than he can sucked
up
through a vacuum cleaner hose.

http://aviation-safety.net/database/1973/731103-0.htm

"As a result, the cabin depressurized and one cabin window, which was
struck
by a fragment of the fan assembly, separated from the fuselage. The
passenger who was sitting next to that window was forced through the
opening
and ejected from the aircraft."



http://www.super70s.com/Super70s/Tech/Aviation/Disasters/73-11-03(National).
asp

"According to a witness, the occupant of the seat was partially forced
through the window opening and was temporarily retained in this position
by
his seatbelt. Efforts to pull the passenger back into the airplane by
another passenger were unsuccessful, and the occupant of seat 17H was
subsequently forced entirely through the cabin window."

Paul Nixon

No doubt the pax in ? departed through the hole left by the "window".

"Windows for AC" are essentially like those used in houses, in that they are
"Prefab Units" of a specified size installed/secured in the structure of the
house or A/C.

Just as with a window in a house, there is a vast difference in the size
hole remaining between the glass being broken out, compared to the entire
Prefab Unit being forced from the structure.

The "Prefab Window" departing the A/C structure surely weakened the A/C
structure surrounding the "Departed Window".

In 1 of the above references, it is stated, the pax that lost was sitting in
seat 14L. #'s 1 & 2 engines were damaged by FOD from the #3 engine, plus
assorted damage to wings & their components.

It would be interesting to know if the engine fragment that caused the
"Window Failure" struck the window/window frame structure from inside or
outside.

Most uncontained engine failures result in damage to the A/C in patterns
at/near 90 degrees to the engine components "plane of rotation" for the
failed components.

Anyone know the angle between the "plane of rotation" for the "fan assembly"
of the #3 engine & engines #'s 1 & 2.
Ralph Nesbitt
Professional FD/CFR/ARFF Type

On Wed, 31 Dec 2003 20:48:28 GMT,
(Aviation) wrote:


Someone also pointed out my goof about "holding" your breath
upon going from cabin (8000 ft pressure) to ambient (25-35,000
ft pressure). In estimating how much time the average civilian
passenger could go without TAKING a breath of good air (14,000
ft or below), I used the HOLD your breath estimate. Assuming
there is 3-5 minutes of mask-oxygen and one minute of "holding"
the last breath, they've got 3-6 minutes to get down to breathable
(14,000 ft?) air and then below. For the movie Executive Decision,
they were cruising at 39,000 ft. so they'd have to dive 25,000 ft
to 14,000 ft in 5 minutes, 5,000 ft/minute, average. Doable?

No, the length of time you can hold your breath on the ground doesn't
help. You will outgas O2 from your blood into your lungs and then
exhale it as part of your response to the RD, because the pressure
will be so greatly reduced. You will begin using the O2 mask with a
serious deficit and you'll continue to blow off O2, even with the
mask, until you get down to the altitude where the partial pressure is
large enough. Many people can't hold their breath for a minute,
either.

Airline pilots have quick-don masks that supply O2 at a higher rate
than do the cabin masks. The cockpit O2 is a separate supply from the
cabin O2, with more O2 at higher pressure. To be blunt, it's much
more important to keep the pilots conscious, of course.

Langeweische wrote, in his article about the ValuJet accident, that no
passenger had ever been saved by cabin O2. I don't know where he got
that information, but he's pretty good about checking statements like
that.

Mary

--
Mary Shafer Retired aerospace research engineer

Ralph Nesbitt wrote in message
m...
I have no experience with "A/C Window Bullet Impact". Have seen "Spidering
due Debris" from "uncontained engine failures. Have seen, dealt with the
aftermath of encounters between fighter type A/C & large birds such as
"Buzzards, Eagles, or other large carrion Feeders.

I have seen some of those. They make quite a mess.

The "Windshields of Southern 232", a DC-9, were broken out along with
"Catastrophic Engine Damage" by hail at altitude resulting in a
catastrophic
incident. Many "Hail Stones of ~3" Diameter were in the cockpit when we
arrived on scene within ~ 7 minuets of the incident. There were
substantial
"Dents/Dings" in the rear cockpit bulkhead from the "Hail Stones".

You've probably seen the Easyjet pics:
http://www.zap16.com/Easyjet%20out%20of%20hail.htm

Paul Nixon

"Mary Shafer" wrote in message
|
| Langeweische wrote, in his article about the ValuJet accident, that no
| passenger had ever been saved by cabin O2. I don't know where he got
| that information, but he's pretty good about checking statements like
| that.

He is probably right. At the altitudes airliners fly the partial pressure of
oxygen is too low to be absorbed by the bloodstream. You could fill the
entire cabin with pure oxygen and everybody would still suffocate. Those
little masks are not pressurized. Even if they were, the little elastic
thingies that hold the mask on would not maintain the required pressure. The
crew, of course, have pressurized masks.

On the other hand, it would take some time for people to start dying or
suffering permanent brain damage from lack of oxygen. The frail would be
most vulnerable, but a healthy passenger would at worst just pass out until
the airliner descended into breathable air.

"C J Campbell" wrote;

....... At the altitudes airliners fly the partial pressure of
oxygen is too low to be absorbed by the bloodstream. You could fill
the
entire cabin with pure oxygen and everybody would still suffocate.
Those
little masks are not pressurized.

If that were true, why would mountain climbers take little bottles of O2
with them when climbing Everest (and other 20K ft. and up mountains)?

--
Marc J. Zeitlin
http://marc.zeitlin.home.comcast.net/
http://www.cozybuilders.org/

"Marc J. Zeitlin" wrote in message
news_lJb.261887$_M.1216641@attbi_s54...
| "C J Campbell" wrote;
|
| ....... At the altitudes airliners fly the partial pressure of
| oxygen is too low to be absorbed by the bloodstream. You could fill
| the
| entire cabin with pure oxygen and everybody would still suffocate.
| Those
| little masks are not pressurized.
|
| If that were true, why would mountain climbers take little bottles of O2
| with them when climbing Everest (and other 20K ft. and up mountains)?
|

Airliners fly a lot higher than 20,000 feet. Those bottles are pressurized
and regulated as well. Climbers who use the oxygen usually only take a
breath or two when they need it. Although the masks are not very good, they
are better than the passenger masks on airliners. A lot of the oxygen is
still wasted, though. There are climbers who manage to make it up Everest
without any supplemental oxygen at all. Granted, they have had time to
acclimatize themselves, but even so it supports the idea that passengers are
not going to instantly die if the airplane depressurizes.

"Bob Gardner" wrote in message
news:QODIb.85072$VB2.187788@attbi_s51...
No way. You start off at sea level, of course, and they pump the chamber
pressure down to 25000 feet with masks on...then they do some experiments
with a few of the pilots taking their masks off, just to show how severely
their abilities are affected. Then comes the explosive decompression,
which
takes the chamber from 25K back down to sea level in a second or two.

SIlly question but ...

Why would "they" pressurize the aircraft to sea level? Why not some
compromise "pressure" like that equivalent to, say, 6,000 or 8,000 feet?


EMWTK

"khobar" wrote in message
news:LvlJb.16967$7D3.16664@fed1read02...
Ralph Nesbitt wrote in message
m...
I have no experience with "A/C Window Bullet Impact". Have seen
"Spidering
due Debris" from "uncontained engine failures. Have seen, dealt with the
aftermath of encounters between fighter type A/C & large birds such as
"Buzzards, Eagles, or other large carrion Feeders.

I have seen some of those. They make quite a mess.

The "Windshields of Southern 232", a DC-9, were broken out along with
"Catastrophic Engine Damage" by hail at altitude resulting in a
catastrophic
incident. Many "Hail Stones of ~3" Diameter were in the cockpit when we
arrived on scene within ~ 7 minuets of the incident. There were
substantial
"Dents/Dings" in the rear cockpit bulkhead from the "Hail Stones".

You've probably seen the Easyjet pics:
http://www.zap16.com/Easyjet%20out%20of%20hail.htm

Paul Nixon

Have seen the Easy et Pic's.

Was FD/CFR/ARFF Officer in Charge/On Scene Commander at the Southern 232
incident.
Ralph Nesbitt
Professional FD/CFR/ARFF Type

"Mike Rapoport" wrote in message
hlink.net...

"Ralph Nesbitt" wrote in message
gy.com...

"Mike Rapoport" wrote in message
hlink.net...

"Ralph Nesbitt" wrote in message
m...
Hopefully all realize when referring to "Air Pressure" at altitude
this
is
an "absolute" pressure value inside the fuselage irrespective of
ambient.
When referring to air pressures at ground level the pressure reading
is
above unadjusted ambient barometric pressure.

This is incorrect, pressurization is the differential between ambient
and
cabin preasure.

Mike
MU-2

Please reconsider your statement above as it applies to pressurization
of
A/C cabins at altitude.

At altitude A/C cabins are like a pressure vessel. A/C cabins are
pressurized to maintain ~ 12 PSI Gauge, ~ the same as normal atmospheric
pressure @ 11,000' ASL, in the cabin irrespective of altitude above
11,000'
ASL.
Ralph Nesbitt
Professional FD/CFR/ARFF Type

No, the cabin is not at a constant preasure above 11,000' (and the number
that you are looking for is 8,000') unless the rate controller is set to a
rate greater than the climb rate of the aircraft (which is never done).
If
what you say were true then the cabin altitude would not climb with the
airplane above 11,000' (8,000') which it clearly does. If you doubt this,
go buy an altimeter watch and see for yourself. Or you could buy a
pressurized airplane.

OK, I'll bite.

Just how does the psia in the cabin track the psia "ambient."

John Gilmer wrote:



SIlly question but ...

Why would "they" pressurize the aircraft to sea level? Why not some
compromise "pressure" like that equivalent to, say, 6,000 or 8,000 feet?


Typically, they start at whatever the local pressure altitude
happens to be (which of course may or may not be sea level, depending
on where you happen to have the chamber). Also, I've never
experienced in any altitude chamber ride a rapid REcompression
down to sea level- it strikes me as a good way to have sinus
or ear problems.

Mike