Punctured pressure cabin.

"Emmanuel.Gustin" wrote...

In
extreme cases, rapid pressure loss (or perhaps
more accurately, an internal pressure differential) can
lead to major structural failures, especially around
bulkheads that are insufficiently vented -- the pressure
differential is enough to make these collapse -- or in
fuselages that are already 'tired'.

AFAIK, all current airliners have sufficient blow-out doors in interior
bulkheads to prevent that sort of structural failure.


There is also the risk of bullets bouncing around inside
the plane and doing damage to power lines, fuel systems,
etc. Historically, fire has been the major killer of
aircraft following projectile damage.

Since almost everything aft of the cockpit in an airliner is "soft" (aluminum,
fabric, plastic, fiberglass...), the likelihood of multiple ricochets is
extremely low. Also, the likelihood of hitting a pressurized fuel line in a
low-wing airliner is negligible. Even in a high-wing airplane like a BAE-146 or
ATR, it is also unlikely in any credible scenario I can think of. A single
inert bullet into a fuel tank would not likely cause a fire.


The worst problem is the prospect of a gun battle in a cabin
packed with people. Almost every stray bullet is going to
hit someone; even if the sky marshall hits the right man
(or woman) the bullet seems likely to hit others as well.

Considering the alternative of an uncontrolled crash into the ground, which do
you prefer?


I don't
think it is wise at all to give guns to pilots after
minimal training.

First, the training is NOT "minimal"! It is intense and specialized.

Second, the pilots' use of their weapon is restricted to the case where the
terrorist already has gained access to the cockpit (likely in an airplane where
there are NO Air Marshals). Again, there is only one credible alternative
today. Which do you prefer?

I don't
think it is wise at all to give guns to pilots after
minimal training.

First, the training is NOT "minimal"! It is intense and specialized.

Most American pilots now flying were trained in the military.
Furthermore, most American men have used firearms at one time or
another. The training (I think it is two weeks, for which the pilot
pays out of his pocket) is more of a refresher course for the pilots
who take it, and presumably a course in the wise use of airborne
firearms.

all the best -- Dan Ford
email:

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

On Thu, 01 Jan 2004 15:15:30 -0500, Cub Driver
wrote:


I don't
think it is wise at all to give guns to pilots after
minimal training.

First, the training is NOT "minimal"! It is intense and specialized.

Most American pilots now flying were trained in the military.

I think you're still safe if you say "many" or "over half", but not
"most". The demographics have changed markedly, with new hires being
about 70% civil only for the last decade or so.

Furthermore, most American men have used firearms at one time or
another.

Are you sure about this? And what about women pilots?

Mary

--
Mary Shafer Retired aerospace research engineer

Cub Driver wrote in
:


I don't
think it is wise at all to give guns to pilots after
minimal training.

First, the training is NOT "minimal"! It is intense and specialized.

Most American pilots now flying were trained in the military.
Furthermore, most American men have used firearms at one time or
another. The training (I think it is two weeks, for which the pilot
pays out of his pocket) is more of a refresher course for the pilots
who take it, and presumably a course in the wise use of airborne
firearms.

all the best -- Dan Ford
email:

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com


I would NOT say that "most American men have used firearms" at one time or
another.Firearms are not politically correct,and far too many people grow
up in urban environments where firearms are uncommon(legal usage),and most
don't join the military anymore.Many grade schools no longer have rifle/gun
clubs.
The military was my first encounter with a firearm.

--
Jim Yanik
jyanik-at-kua.net

In article ,
Jim Yanik wrote:

I would NOT say that "most American men have used firearms" at one time or
another.

Since about 45% of American homes have firearms in them, it would only
take a few more percent of people going shooting with their gun-owning
friends to put that into the "most" category.

Gun ownership has actually been going up for most of the last decade or
so.

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

(IIRC military aircraft were designed to maintain
lower cabin pressure than airliners, to limit the damage
amplification following a hit)

I was pondering this possibility also, but then I remembered that the
B-36 was supposed to be *depressurized* when the plane moved into a
combat situation.


all the best -- Dan Ford
email:

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

"Cub Driver" wrote...

(IIRC military aircraft were designed to maintain
lower cabin pressure than airliners, to limit the damage
amplification following a hit)

I was pondering this possibility also, but then I remembered that the
B-36 was supposed to be *depressurized* when the plane moved into a
combat situation.

For a couple data points, the A-4 and A-6 had cabin pressure differentials of
about 4 and 5 psi (8,000' cockpit at about 23,000'). There was no
depressurization procedure for combat. The 747-400 runs normally at 8.9 psi
(6,700' cabin at about 43,000').

The B-36 was an early pressurized aircraft, developed during war time. I
suspect engineers' knowledge of the aircraft reaction to combat damage and rapid
depressurization was a lot less than now...

"John R Weiss" wrote in message
news:NJ1Jb.24583$I07.64369@attbi_s53...
"Cub Driver" wrote...

(IIRC military aircraft were designed to maintain
lower cabin pressure than airliners, to limit the damage
amplification following a hit)

I was pondering this possibility also, but then I remembered that the
B-36 was supposed to be *depressurized* when the plane moved into a
combat situation.

For a couple data points, the A-4 and A-6 had cabin pressure differentials
of
about 4 and 5 psi (8,000' cockpit at about 23,000'). There was no
depressurization procedure for combat. The 747-400 runs normally at 8.9
psi
(6,700' cabin at about 43,000').

The B-36 was an early pressurized aircraft, developed during war time. I
suspect engineers' knowledge of the aircraft reaction to combat damage and
rapid
depressurization was a lot less than now...

I wonder where this depressurization before entering combat thing came from?
IIRC my father never mentioned any routine depressurization during the
combat missions he pulled during WWII on the even earlier designed B-29.

Brooks

He or she also has to distinguish between a
conventional hijack best dealt with by negotiation (are
sky marshalls trained to conduct hostage-release
negotiations?) which are the vast majority of cases,
and a rare attempt to use an airliner as a suicide bomb.

I think that the sky marshal would choose to err on the side of
caution--i.e., to kill or wound the hijacker rather than worry about
his motives. No American jury would fault him for that.

You have touched on a sore spot: the training. Whenever I look at
police officers, I see a heart attack waiting to happen. They are
mostly overweight; they mostly spend their days sitting down (the sky
marshal would be required to sit down!); their diet is mostly awful;
and if they have to go into action, it is likely to be sudden and
stressful.

Bam!

How well trained are these sky-marhsal guys (and girls, of course:
likely the hiring ratio was 50/50 by fiat)? What kind of shape are
they in after a year or two on the job?

I seem to remember an incident where a passenger kept returning to a
suitcase in the overhead bin, and the sky marshal put everyone in a
state of terror by waving his pistol around and requiring the
passengers to freeze in their seats. Not very reassuring.


all the best -- Dan Ford
email:

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

Emmanuel.Gustin wrote:
M. J. Powell wrote:

: There has been a bit of a furore over here concerning the new US
: requirement to airlines to supply air marshals when requested. The
: concern is mainly over the possible puncture of a pressure cabin.
: What do readers think is the result of decompression via a bullet hole?

A bullet hole would not in itself cause for much concern.
The loss of a cabin window would be more serious, not
because the pressurisation system would be unable to cope,
but because the strong air current could move (in the worst
case, blow out through the window) or wound passengers. In
extreme cases, rapid pressure loss (or perhaps
more accurately, an internal pressure differential) can
lead to major structural failures, especially around
bulkheads that are insufficiently vented -- the pressure
differential is enough to make these collapse -- or in
fuselages that are already 'tired'. Apart from the Comet
disasters, I know of no loss of aircraft caused by the
loss of windows (although some passengers have been lost)
but a number of aircraft have been lost when doors failed.

There is also the risk of bullets bouncing around inside
the plane and doing damage to power lines, fuel systems,
etc. Historically, fire has been the major killer of
aircraft following projectile damage.

Seems to me that although loss of cabin pressure is serious
concern (IIRC military aircraft were designed to maintain
lower cabin pressure than airliners, to limit the damage
amplification following a hit) but not the most serious one.
The worst problem is the prospect of a gun battle in a cabin
packed with people. Almost every stray bullet is going to
hit someone; even if the sky marshall hits the right man
(or woman) the bullet seems likely to hit others as well.

This is going to require very fine judgment by the sky
marshall. He or she also has to distinguish between a
conventional hijack best dealt with by negotiation (are
sky marshalls trained to conduct hostage-release
negotiations?) which are the vast majority of cases,
and a rare attempt to use an airliner as a suicide bomb.
This seems to be a job requiring very extensive training,
a very cool head, and fine judgment. I am not convinced
that the large number of sky marshalls rapidly trained
and deployed now have the right capabilities, and I don't
think it is wise at all to give guns to pilots after
minimal training.

You have touched a sore spot here on this last point. You seem
to be under the impression that there might be "conventional"
highjackings. These are a thing of the past. The minute that
passengers and cabin crew subdued Richard Reid, it was clear that
"conventional" highjackings, were no longer. There is no negotiation
skill required. Kill anyone that is attempting to commandeer an
aircraft. Time has to be divided into pre 9/11 and post 9/11. Your
statement applies to pre 9/11 highjackings only. The judgement required
of the sky marshal--- Is this person an unruly/drunk passenger, or is he
intent on mischief. If he is a drunk, or unruly passenger, subdue, and
restrain him. If he (or she) is intent on mischief, deadly force is
mandatory.
KenG