Mythbusters Explosive Decompression Experiment

On Wed, 14 Jan 2004 06:24:34 -0700 "Tom Sixkiller" wrote:


"C J Campbell" wrote in message
...

"R.Hubbell" wrote in message |
|
| They did a reasonable job of recreating the environment but we all know
| how hostile things are at 35,000 and 600 mph and -35 degrees, where air
is
| less dense.
|
|
| So the question is would any of us be willing to head up to 35,000,
crank
her
| up to mach .76 and get out the Glock and let loose a few rounds??
|
| Also suppose the bullet hits some wiring or hydraulics or fuel line,
etc.

The air pressure in an airliner is less than one atmosphere, no matter
what.
At 35,000 feet you are talking half an atmosphere. Compare that to the
tires
in your car. The airliner produces all of 8 lbs psi, less than a third of
the inflation of an automobile tire. All of this other stuff, 600 mph or
slight variations of air pressure along the fuselage, etc., is minuscule.

Mythbusters gave the hyperventilating pants wetters a bit of a reality
check -- and all they can talk about are minor factors that will not
change
the results in any significant way. I don't care if you empty the entire
magazine into a window, you are not going to suck people out of the
airplane, the airplane is not going to go into some kind of dive, people
are
not going to fly all over the interior of the airplane, the seats are not
going to be ripped from the floor, or any other Hollywood bull**** like
that.

How much more clearly can things be explained...to a troll?

You know Sixkiler there's some really good research that shows how a
positive mental attitude can bolster the immune system. And also that
a negative one can have adverse effects. Try to lighten up and enjoy
life and concentrate on good things not bad. Yes I am serious.

Don't knock it until you try it.

R. Hubbell

On Tue, 13 Jan 2004 23:42:02 -0600 David Dyer-Bennet wrote:

"R.Hubbell" writes:

So the question is would any of us be willing to head up to 35,000, crank her
up to mach .76 and get out the Glock and let loose a few rounds??

Also suppose the bullet hits some wiring or hydraulics or fuel line, etc.


Not me.

I woudln't do it in a *car* either, though. It comes under the
heading of "negligible risk, *zero* gain" -- so why risk it?

I think you've missed the point. It was to say to Cambell "how
confident are you with mythbsuters conclusion?" "will you bet
your life on it?"


Shooting through the wall between windows pretty much guarantees I
won't hit hydraulics, fuel line, etc.

See my other post.



R. Hubbell

--
David Dyer-Bennet, , http://www.dd-b.net/dd-b/
RKBA: http://noguns-nomoney.com http://www.dd-b.net/carry/
Photos: dd-b.lighthunters.net Snapshots: www.dd-b.net/dd-b/SnapshotAlbum/
Dragaera/Steven Brust: http://dragaera.info/

On Wed, 14 Jan 2004 01:46:31 -0800 "C J Campbell" wrote:


"R.Hubbell" wrote in message |
|
| They did a reasonable job of recreating the environment but we all know
| how hostile things are at 35,000 and 600 mph and -35 degrees, where air is
| less dense.
|
|
| So the question is would any of us be willing to head up to 35,000, crank
her
| up to mach .76 and get out the Glock and let loose a few rounds??
|
| Also suppose the bullet hits some wiring or hydraulics or fuel line, etc.

The air pressure in an airliner is less than one atmosphere, no matter what.
At 35,000 feet you are talking half an atmosphere. Compare that to the tires
in your car. The airliner produces all of 8 lbs psi, less than a third of
the inflation of an automobile tire. All of this other stuff, 600 mph or
slight variations of air pressure along the fuselage, etc., is minuscule.

Mythbusters gave the hyperventilating pants wetters a bit of a reality
check -- and all they can talk about are minor factors that will not change
the results in any significant way. I don't care if you empty the entire
magazine into a window, you are not going to suck people out of the
airplane, the airplane is not going to go into some kind of dive, people are
not going to fly all over the interior of the airplane, the seats are not
going to be ripped from the floor, or any other Hollywood bull**** like
that.




You still didn't answer the question though. Will you take a plane up
to mach .76, get out your Glock and fire some rounds off through the cabin
floor, walls, ceiling or any other random place? If a skymarshal is wrestling
someone hell bent on getting his gun the bullets would firing at all angles
in all directions.


There are simply too many factors that mythbusters didn't replicate
to convince me that it's safe to fire 9mm rounds through a fuselage
of an aircraft traveling mach .76 at 35,000 ft. where it's -35 degrees.

There's something else that comes to mind as well. I was reading a report
on the HA (Hawai'i Airlines) accident and they talked about the concussive
force that caused the large hole to open up. What happens is similar to
water-hammer in water supply lines. The hole has air rushing out thru it
at some very high rate then some object from the aircraft plugs the hole.
Suddenly all the air destined for the hole backs up behind that object
and that generates an extreme and instantaneous amount of force on just
that spot. Guess what happens next? A bigger hole appears and if it's not
big enough it will get blocked again and we have a repeat of the previous
concussive event. Until the hole is bigger than all loose objects.

I can't find that site, someone posted it here a while back.



R. Hubbell

"R.Hubbell" wrote in message
...
|
|
| There are simply too many factors that mythbusters didn't replicate
| to convince me that it's safe to fire 9mm rounds through a fuselage
| of an aircraft traveling mach .76 at 35,000 ft. where it's -35 degrees.
|

No, it is much safer to pander to unreasoning fear of firearms and instead
allow terrorists to gain control of airplanes. I doubt that any test would
convince you otherwise.

| There's something else that comes to mind as well. I was reading a report
| on the HA (Hawai'i Airlines) accident and they talked about the concussive
| force that caused the large hole to open up.

So what? How many people on that flight died?

"C J Campbell" wrote:

Once they managed to induce an explosive decompression using the shaped
charge, the damage was incredible. The whole top of the fuselage was ripped
off and big chunks of the wall where the explosion was were missing. It
looked like those photos of the Hawaiian Airlines incident, only much worse.
I think it might have been possible to continue to fly the aircraft, but it
would have been very difficult, depending on how much damage the debris did
to wings, tail, engines and control surfaces.

Of course, to do that kind of damage a terrorist would have to somehow get a
shaped charge the size of a basketball onto the airplane, place it properly
up against the wall of the fuselage, and detonate it, all without being
noticed.

I don't think you can draw that wide a conclusion from the test that
they did. The Lockerbie bombing was a pretty effective demonstration
of damage that can be done from a small amount of explosive. I think
they worked out it was about 300 grams - what is that, 11 ounces?

"Andrew Rowley" wrote in message
...
"C J Campbell" wrote:

Once they managed to induce an explosive decompression using the shaped
charge, the damage was incredible. The whole top of the fuselage was
ripped
off and big chunks of the wall where the explosion was were missing. It
looked like those photos of the Hawaiian Airlines incident, only much
worse.
I think it might have been possible to continue to fly the aircraft, but
it
would have been very difficult, depending on how much damage the debris
did
to wings, tail, engines and control surfaces.

Of course, to do that kind of damage a terrorist would have to somehow
get a
shaped charge the size of a basketball onto the airplane, place it
properly
up against the wall of the fuselage, and detonate it, all without being
noticed.

I don't think you can draw that wide a conclusion from the test that
they did. The Lockerbie bombing was a pretty effective demonstration
of damage that can be done from a small amount of explosive. I think
they worked out it was about 300 grams - what is that, 11 ounces?

What type of explosive? A pound of C-4 will (IB) destroy an armored car or
do serious damage to a tank.

Remember, they were given the explosive by Libya (IIRC), so it was not some
mild store variety.

On Tue, 13 Jan 2004 at 07:25:32 in message
, C J Campbell
wrote:
I have seen static ports located just about everywhere on fuselages. It
probably does not matter much as long as it is on the side of the fuselage.
If there really was a big pressure difference due to the slipstream on the
fuselage then most static ports would be located toward the aft end, because
the biggest low pressure area would be towards the front, just like a wing.
It appears that the biggest factor in locating the static port is
convenience of plumbing the static lines.

Somebody check my sums but a rough calculation seems to show that the
full dynamic pressure at 300 knots and 35,000ft is about 0.30 lb/sq in

The 8 psi pressure difference is nearly 27 times greater than the full
pitot pressure. The pressure difference between the inside and outside
will be enough to create a shock wave in the hole and very high speed
flow. I cannot do the sum to estimate the velocity at present. Hence the
'explosive' decompression if the hole is of such a size that air can
escape initially at sonic or supersonic speed.

The possible pitot pressure is thus negligible at 35,000ft compared to
the cabin pressure.
--
David CL Francis

On Tue, 13 Jan 2004 at 09:37:56 in message
, Bill Denton
wrote:

I'm not an engineer so please forgive me if this next is in the "duuuhh"
category. Assuming a breach the size of a window in an aircraft in flight,
would not some type of "siphon" (or whatever) effect occur from the movement
of air across the fuselage, which would further remove air/people/etc from
inside the fuselage?

See my other post: the air going past creates a negligible pressure
compared to the cabin differential pressure at 35,000 ft..
--
David CL Francis

C.J.

You wrote with multi syllable words. You need to go back and rewrite
in all one syllable ones so those at the end of the food chain will
understand G

Big John
Pilot ROCAF


On Wed, 14 Jan 2004 01:46:31 -0800, "C J Campbell"
wrote:


"R.Hubbell" wrote in message |
|
| They did a reasonable job of recreating the environment but we all know
| how hostile things are at 35,000 and 600 mph and -35 degrees, where air is
| less dense.
|
|
| So the question is would any of us be willing to head up to 35,000, crank
her
| up to mach .76 and get out the Glock and let loose a few rounds??
|
| Also suppose the bullet hits some wiring or hydraulics or fuel line, etc.

The air pressure in an airliner is less than one atmosphere, no matter what.
At 35,000 feet you are talking half an atmosphere. Compare that to the tires
in your car. The airliner produces all of 8 lbs psi, less than a third of
the inflation of an automobile tire. All of this other stuff, 600 mph or
slight variations of air pressure along the fuselage, etc., is minuscule.

Mythbusters gave the hyperventilating pants wetters a bit of a reality
check -- and all they can talk about are minor factors that will not change
the results in any significant way. I don't care if you empty the entire
magazine into a window, you are not going to suck people out of the
airplane, the airplane is not going to go into some kind of dive, people are
not going to fly all over the interior of the airplane, the seats are not
going to be ripped from the floor, or any other Hollywood bull**** like
that.

"Andrew Rowley" wrote in message
...
| "C J Campbell" wrote:
|
| Once they managed to induce an explosive decompression using the shaped
| charge, the damage was incredible. The whole top of the fuselage was
ripped
| off and big chunks of the wall where the explosion was were missing. It
| looked like those photos of the Hawaiian Airlines incident, only much
worse.
| I think it might have been possible to continue to fly the aircraft, but
it
| would have been very difficult, depending on how much damage the debris
did
| to wings, tail, engines and control surfaces.
|
| Of course, to do that kind of damage a terrorist would have to somehow
get a
| shaped charge the size of a basketball onto the airplane, place it
properly
| up against the wall of the fuselage, and detonate it, all without being
| noticed.
|
| I don't think you can draw that wide a conclusion from the test that
| they did. The Lockerbie bombing was a pretty effective demonstration
| of damage that can be done from a small amount of explosive. I think
| they worked out it was about 300 grams - what is that, 11 ounces?

Actually, wasn't the Mythbusters' shaped charge only 120 grams? However, it
was spread out into a big cone the size of a basketball in order to obtain
maximum effect.