Punctured pressure cabin.

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?

Mike
--
M.J.Powell

In article ,
"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?

Unnoticeable is almost all cases. A mild annoyance in the remainder, as
long as we're discussing smallarm-caliber rounds.

"M. J. Powell" wrote in message
...

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?


There won't be decompression via a bullet-sized hole. There are already a
variety of leaks in the pressure vessel. There are simply some things which
must penetrate the vessel. They're sealed reasonably well, but there's
still some unavoidable leakage. The pressure is maintained by controlling
the outflow of pressurized air. Another small hole will simply cause the
control valve to close a bit to compensate.

What do readers think is the result of decompression via a bullet hole?

Whose bullet? The American sky marshals (and presumably others) use
frangible bullets, which wouldn't make a hole.

The Brit argument is that the terrorist would use their guns in a
"shoot-out" caused (of course!) by the sky marshal's gun. Okay, we've
postulated that the terrorist has successfully smuggled a gun on
board. Why is that? So he can crash the plane into a target? Could be,
huh?

So are you worse off risking explosive decompression, or of crashing
into Times Square at midnight?

As to the possibility of explosive decompression, as I understand the
matter, it could happen if a bullet fractured a window (though not if
it went through the skin). That's a mere possibility, as opposed to
the certainty of a suicide dive, absent the sky marshal.

A normal bullet hole would be no problem. There's already a much
larger vent to the outside, which stabilizes cabin pressure against
the fresh & heated air being pumped in from the engines. People
smarter than I say that this hole is about three inches in diameter.


all the best -- Dan Ford
email:

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

"M. J. Powell" wrote in message
...

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?

Mike
--
M.J.Powell

Unless it hits electrical or hydraulic systems pretty much nothing. Score
it as a miss. A bullet hole will not decompress an airplane. A hatch leak
will probably leak more and can be easily overcome by the pressurization
system.

Tex

I think it depends on WHO the bullet passes through on its way to the
outside...

Jack

"M. J. Powell" wrote in message
...

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?

Mike
--
M.J.Powell

Cub Driver wrote in
:


What do readers think is the result of decompression via a bullet hole?

Whose bullet? The American sky marshals (and presumably others) use
frangible bullets, which wouldn't make a hole.

To the best of my knowledge,that's wrong;US Sky Marshals use .40 cal JHP
(jacketed hollowpoint) ammo(premium,the good stuff),as they might need to
penetrate some barrier that a hijacker hid behind.

Frangible ammo can be defeated by some forms of clothing,or a
shield.(briefcase?)

--
Jim Yanik
jyanik-at-kua.net

"Tex Houston" wrote in
:


"M. J. Powell" wrote in message
...

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?

Mike
--
M.J.Powell

Unless it hits electrical or hydraulic systems pretty much nothing.
Score it as a miss. A bullet hole will not decompress an airplane. A
hatch leak will probably leak more and can be easily overcome by the
pressurization system.

Tex




Even then,it's very hard for a bullet to get to the electrical or hydraulic
systems(besides actually hitting them),those being UNDER the passenger
deck.You'd have to shoot at a fairly steep angle,and the bullet would lose
energy pretty quickly.

--
Jim Yanik
jyanik-at-kua.net

From: Cub Driver

snip

As to the possibility of explosive decompression, as I understand the
matter, it could happen if a bullet fractured a window

It would still be only annoying. A few ear aches and a lot of noise along with
oxygen masks dropping. The person sitting next to the window might lose his
reading material or dinner.

This has been discussed here before and a Google search would turn up a lot of
information.

Dan, U. S. Air Force, retired

From: "Jack G"
Date: 12/31/2003 8:15 PM Central Standard Time
Message-id:

I think it depends on WHO the bullet passes through on its way to the
outside...

Jack

"M. J. Powell"

Which begs the question are terrorist more, less or equal in density to normal
people?

Another question is if the terrorist is female will she still get the 72
virgins when she is "martyred?"

Dan, U.S. Air Force, retired