Mythbusters Explosive Decompression Experiment

[C J Campbell]

Now, that was cool!

Mythbusters pressurized an old DC-9 and fired a bullet through the wall to
see if it would cause an explosive decompression. It didn't. Then they fired
a bullet through the window to see if the window would shatter and cause an
explosive decompression. The bullet only made a small hole in the window
because the windows are made of shatter-proof plastic. No explosive
decompression.

Then Mythbusters put explosive all around the window to blow it out and
deliberately cause an explosive decompression. The crash test dummy,
"Buster," was damaged but was not sucked out the window. If he had been a
real person he would have been injured but probably lived. His arm was badly
damaged enough that a human arm might have been lost. So Mythbusters patched
everything up and used a shaped charge to blow out the whole wall. The
explosive decompression ripped the entire top off the fuselage and much of
the wall out, but the seats and the crash test dummy remained in the
airplane. I would guess that if the "Buster" had been a live human he would
have been seriously injured and possibly killed.

Mythbusters then talked about how strong these airplanes really are and
closed with photos of the Hawaiian Airlines plane that suffered an explosive
decompression similar to the one that the show created with a shaped charge.
The only person killed was a flight attendant who was pulled from the plane
by the airstream, but the passengers all survived.

I thought the show was fascinating. It really demonstrated the engineering
that goes into an airliner. Besides, I like watching things blow up. It must
appeal to my inner 12 year old.

--
Christopher J. Campbell
World Famous Flight Instructor
Port Orchard, WA


If you go around beating the Bush, don't complain if you rile the animals.

[David Brooks]

"C J Campbell" > wrote in message
...

> Mythbusters then talked about how strong these airplanes really are and
> closed with photos of the Hawaiian Airlines plane that suffered an
explosive
> decompression similar to the one that the show created with a shaped
charge.
> The only person killed was a flight attendant who was pulled from the
plane
> by the airstream, but the passengers all survived.

However, at one of the passengers soon after gave birth to a little girl who
died a day later. There was no particular pathology. Milagro they called
her. She was my sister-in-law's niece.

I'm not blaming anyone - if anything I just wanted to honor her memory.

-- David Brooks

[Jay Honeck]

> Now, that was cool!

Agreed. The ten minutes I caught at the end were very well done, and should
go a long way toward dispelling the myth.

Now if only they had a more significant viewership...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Dennis O'Connor]

Neonates do die, fortunately not with great frequency... As a working doc I
immediately wondered about Caisson Disease from the rapid decompression,
when I read your posting... The fetus is normally well protected and
buffered by the body of the mother for trauma like that... And, the total
psi/bar drop in that form of decompression is minor compared to divers, et.
al., however the rate of change of the decompression is far more
instantaneous than for caisson workers and divers, so if it was Caisson
Disease the rate of change had to be the key..

Denny
"David Brooks" >
> However, at one of the passengers soon after gave birth to a little girl
who
> died a day later. There was no particular pathology. Milagro they called
> her. She was my sister-in-law's niece.

[Dennis O'Connor]

There is no problem so vexing as cannot be solved by application of
sufficient explosives...

"C J Campbell" > wrote in message
...
> Now, that was cool!

[Mark]

"C J Campbell" > wrote in message >...
> Now, that was cool!
>
> Mythbusters pressurized an old DC-9 and fired a bullet through the wall to
> see if it would cause an explosive decompression. It didn't. Then they fired
> a bullet through the window to see if the window would shatter and cause an
> explosive decompression. The bullet only made a small hole in the window
> because the windows are made of shatter-proof plastic. No explosive
> decompression.
>
> Then Mythbusters put explosive all around the window to blow it out and
> deliberately cause an explosive decompression. The crash test dummy,
> "Buster," was damaged but was not sucked out the window. If he had been a
> real person he would have been injured but probably lived. His arm was badly
> damaged enough that a human arm might have been lost. So Mythbusters patched
> everything up and used a shaped charge to blow out the whole wall. The
> explosive decompression ripped the entire top off the fuselage and much of
> the wall out, but the seats and the crash test dummy remained in the
> airplane. I would guess that if the "Buster" had been a live human he would
> have been seriously injured and possibly killed.
>
> Mythbusters then talked about how strong these airplanes really are and
> closed with photos of the Hawaiian Airlines plane that suffered an explosive
> decompression similar to the one that the show created with a shaped charge.
> The only person killed was a flight attendant who was pulled from the plane
> by the airstream, but the passengers all survived.
>
> I thought the show was fascinating. It really demonstrated the engineering
> that goes into an airliner. Besides, I like watching things blow up. It must
> appeal to my inner 12 year old.

I also watched the show and one factor they did not take into account
was the speed of an airliner at altitude. Also, what would happen to
the forces on the damnaged airframe during the descent/emergancy
landing? As in most tests, this was a controlled experiment. I'm sure
if they placed the shaped charge closer to the wing root, more
damnaged would occure.

Still a good show, I especially like the part where they used a 22
bullet for a fuse replacement.

[John Harper]

Shame I missed it, maybe I'll see it on the 394th rerun.

But anyway I DID see Goldfinger the other night so I know
this is all wrong. If you shoot a bullet through the window of
an airplane, first the whole window explodes. Then everything
is sucked through the window, including people who are
considerably larger than the window aperture (except James
Bond of course). This continues indefinitely. Also the plane
goes into an uncontrollable dive and ends up spiralling into
the ground, despite the combined efforts of two people on
the flight deck.

I think I prefer the James Bond version.

John

( :-), for the irony challenged)

"C J Campbell" > wrote in message
...
> Now, that was cool!
>
> Mythbusters pressurized an old DC-9 and fired a bullet through the wall to
> see if it would cause an explosive decompression. It didn't. Then they
fired
> a bullet through the window to see if the window would shatter and cause
an
> explosive decompression. The bullet only made a small hole in the window
> because the windows are made of shatter-proof plastic. No explosive
> decompression.
>
> Then Mythbusters put explosive all around the window to blow it out and
> deliberately cause an explosive decompression. The crash test dummy,
> "Buster," was damaged but was not sucked out the window. If he had been a
> real person he would have been injured but probably lived. His arm was
badly
> damaged enough that a human arm might have been lost. So Mythbusters
patched
> everything up and used a shaped charge to blow out the whole wall. The
> explosive decompression ripped the entire top off the fuselage and much of
> the wall out, but the seats and the crash test dummy remained in the
> airplane. I would guess that if the "Buster" had been a live human he
would
> have been seriously injured and possibly killed.
>
> Mythbusters then talked about how strong these airplanes really are and
> closed with photos of the Hawaiian Airlines plane that suffered an
explosive
> decompression similar to the one that the show created with a shaped
charge.
> The only person killed was a flight attendant who was pulled from the
plane
> by the airstream, but the passengers all survived.
>
> I thought the show was fascinating. It really demonstrated the engineering
> that goes into an airliner. Besides, I like watching things blow up. It
must
> appeal to my inner 12 year old.
>
> --
> Christopher J. Campbell
> World Famous Flight Instructor
> Port Orchard, WA
>
>
> If you go around beating the Bush, don't complain if you rile the animals.
>
>
>

[C J Campbell]

"John Harper" > wrote in message
news:1073933174.414447@sj-nntpcache-5...
| Shame I missed it, maybe I'll see it on the 394th rerun.
|
| But anyway I DID see Goldfinger the other night so I know
| this is all wrong. If you shoot a bullet through the window of
| an airplane, first the whole window explodes. Then everything
| is sucked through the window, including people who are
| considerably larger than the window aperture (except James
| Bond of course). This continues indefinitely. Also the plane
| goes into an uncontrollable dive and ends up spiralling into
| the ground, despite the combined efforts of two people on
| the flight deck.
|
| I think I prefer the James Bond version.
|
| John
|
| ( :-), for the irony challenged)

Mythbusters seemed to prefer the "U.S. Marshals" version, complete with
shackled prisoners and guards being sucked out the airplane. The James Bond
"Die Another Day" version is just not as good as the "Goldfinger" scene.

I think I know the origin of all of this -- it is none other than Dr.
Wernher von Braun and Walt Disney. Disney made a film about the Dyna Soar
space project ("Man and Space" -1957) that was narrated by Braun. That film
shows a cartoon of the occupants being sucked out of the spacecraft after a
meteor pierces a tiny hole in the structure.

[Bob Gardner]

The speed of the airplane at altitude has nothing to do with it. The
pressure differential between the cabin and the great outdoors is the only
factor...airspeed does not exert any pressure on the sides of the fuselage.

Bob Gardner

"Mark" > wrote in message
om...
> "C J Campbell" > wrote in message
>...
> > Now, that was cool!
> >
> > Mythbusters pressurized an old DC-9 and fired a bullet through the wall
to
> > see if it would cause an explosive decompression. It didn't. Then they
fired
> > a bullet through the window to see if the window would shatter and cause
an
> > explosive decompression. The bullet only made a small hole in the window
> > because the windows are made of shatter-proof plastic. No explosive
> > decompression.
> >
> > Then Mythbusters put explosive all around the window to blow it out and
> > deliberately cause an explosive decompression. The crash test dummy,
> > "Buster," was damaged but was not sucked out the window. If he had been
a
> > real person he would have been injured but probably lived. His arm was
badly
> > damaged enough that a human arm might have been lost. So Mythbusters
patched
> > everything up and used a shaped charge to blow out the whole wall. The
> > explosive decompression ripped the entire top off the fuselage and much
of
> > the wall out, but the seats and the crash test dummy remained in the
> > airplane. I would guess that if the "Buster" had been a live human he
would
> > have been seriously injured and possibly killed.
> >
> > Mythbusters then talked about how strong these airplanes really are and
> > closed with photos of the Hawaiian Airlines plane that suffered an
explosive
> > decompression similar to the one that the show created with a shaped
charge.
> > The only person killed was a flight attendant who was pulled from the
plane
> > by the airstream, but the passengers all survived.
> >
> > I thought the show was fascinating. It really demonstrated the
engineering
> > that goes into an airliner. Besides, I like watching things blow up. It
must
> > appeal to my inner 12 year old.
>
> I also watched the show and one factor they did not take into account
> was the speed of an airliner at altitude. Also, what would happen to
> the forces on the damnaged airframe during the descent/emergancy
> landing? As in most tests, this was a controlled experiment. I'm sure
> if they placed the shaped charge closer to the wing root, more
> damnaged would occure.
>
> Still a good show, I especially like the part where they used a 22
> bullet for a fuse replacement.

[David Dyer-Bennet]

"Bob Gardner" > writes:

> The speed of the airplane at altitude has nothing to do with it. The
> pressure differential between the cabin and the great outdoors is the only
> factor...airspeed does not exert any pressure on the sides of the fuselage.

In the case of a bullet hole, it's probably not significant (although
I'd think the exit hole would would be somewhat ragged, and would
stick out into the airstream, so even that might). In the more
extreme cases, where they used shaped charges to blow out many square
feet of fuselage, I'd have thought the airstream would be a *very*
important factor in what happened next.
--
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/>

[Icebound]

Bob Gardner wrote:
> The speed of the airplane at altitude has nothing to do with it. The
> pressure differential between the cabin and the great outdoors is the only
> factor...airspeed does not exert any pressure on the sides of the fuselage.
>
> Bob Gardner
>


Well, yes and no.

It depends on the shape of the hole and its placement relative to the
geometry of the fuselage (that is: relative to the apparent air flow).
With speed, the hole may assist adding pressure (as does a
forward-pointing pitot tube) or it may assist depressuring, due to
Bernoulli effect, (as demonstrated by a household-plumbing vent-stack in
a strong wind).

[R.Hubbell]

On Sun, 11 Jan 2004 21:13:28 -0800 "C J Campbell" > wrote:

> Now, that was cool!
>
> Mythbusters pressurized an old DC-9 and fired a bullet through the wall to
> see if it would cause an explosive decompression. It didn't. Then they fired
> a bullet through the window to see if the window would shatter and cause an
> explosive decompression. The bullet only made a small hole in the window
> because the windows are made of shatter-proof plastic. No explosive
> decompression.

I don't watch much TV but I admit I would have liked to have seen this.

Can you provide more detail on how they setup the test?

What was the cabin pressure? What was the pressure external to the
DC-9? Did they have a huge pressure chamber?

What about the temperature differentials? There's also a pressure
differential from the flow of air over the fuselage. Correct?
How did they simulate that?


R. Hubbell

>
> Then Mythbusters put explosive all around the window to blow it out and
> deliberately cause an explosive decompression. The crash test dummy,
> "Buster," was damaged but was not sucked out the window. If he had been a
> real person he would have been injured but probably lived. His arm was badly
> damaged enough that a human arm might have been lost. So Mythbusters patched
> everything up and used a shaped charge to blow out the whole wall. The
> explosive decompression ripped the entire top off the fuselage and much of
> the wall out, but the seats and the crash test dummy remained in the
> airplane. I would guess that if the "Buster" had been a live human he would
> have been seriously injured and possibly killed.
>
> Mythbusters then talked about how strong these airplanes really are and
> closed with photos of the Hawaiian Airlines plane that suffered an explosive
> decompression similar to the one that the show created with a shaped charge.
> The only person killed was a flight attendant who was pulled from the plane
> by the airstream, but the passengers all survived.
>
> I thought the show was fascinating. It really demonstrated the engineering
> that goes into an airliner. Besides, I like watching things blow up. It must
> appeal to my inner 12 year old.
>
> --
> Christopher J. Campbell
> World Famous Flight Instructor
> Port Orchard, WA
>
>
> If you go around beating the Bush, don't complain if you rile the animals.
>
>
>

[R.Hubbell]

On Mon, 12 Jan 2004 08:26:04 -0500 "Dennis O'Connor" > wrote:

> Neonates do die, fortunately not with great frequency... As a working doc I
> immediately wondered about Caisson Disease from the rapid decompression,
> when I read your posting... The fetus is normally well protected and
> buffered by the body of the mother for trauma like that... And, the total
> psi/bar drop in that form of decompression is minor compared to divers, et.
> al., however the rate of change of the decompression is far more
> instantaneous than for caisson workers and divers, so if it was Caisson
> Disease the rate of change had to be the key..


If that were true others on board would also have suffered from "the bends".
If the mother was severly traumatized (and who wouldn't have been) then
that could easily have caused complications. Sever emotional trauma sets
off a chain reaction of chemical events in the body. They are designed
to protect but it could have been too stressful for the baby.


R. Hubbell

>
> Denny
> "David Brooks" >
> > However, at one of the passengers soon after gave birth to a little girl
> who
> > died a day later. There was no particular pathology. Milagro they called
> > her. She was my sister-in-law's niece.
>
>

[C J Campbell]

"R.Hubbell" > wrote in message
...
| On Sun, 11 Jan 2004 21:13:28 -0800 "C J Campbell"
> wrote:
|
| > Now, that was cool!
| >
| > Mythbusters pressurized an old DC-9 and fired a bullet through the wall
to
| > see if it would cause an explosive decompression. It didn't. Then they
fired
| > a bullet through the window to see if the window would shatter and cause
an
| > explosive decompression. The bullet only made a small hole in the window
| > because the windows are made of shatter-proof plastic. No explosive
| > decompression.
|
| I don't watch much TV but I admit I would have liked to have seen this.
|
| Can you provide more detail on how they setup the test?

They took a derelict DC-9 at an aircraft graveyard and plugged up the holes.
They had real trouble with the cockpit because the windows had been removed.
They tried to replace the windows with plywood cemented in with foam, but
the plywood proved to not be strong enough to allow pressurization of the
aircraft. It kept blowing out, sometimes spectacularly.

The pistol was mounted on a stand in the cabin and fired by remote control
using a servor cannibalized from a vending machine, of all things. The
handgun was a 9 mm automatic; it looked like a Glock.

The aircraft was pressurized using one of those giant ground starter units
designed for 747s, a huffer. They dumped huge sacks full of packing peanuts,
scattering them around the cabin to so that the airflow inside the cabin
would be visible. The bullet holes disturbed the airflow so little that even
the packing peanuts stayed where they were.

|
| What was the cabin pressure? What was the pressure external to the
| DC-9? Did they have a huge pressure chamber?

They calculated the pressure differential at 35,000 feet to be 8 lbs psi, so
they pressurized the interior to 8 lbs psi. As mentioned, they had trouble
doing this. The plywood in the cockpit could only stand about 6 lbs psi. At
one point the plywood blew out and ejected a cushion from the pilot seat
more than 125 yards. They finally ended up reinforcing it enough to
withstand the 8 lbs psi differential. I guess the lesson there is that if
you ever lose a cockpit window you can forget about restoring cabin pressure
by plugging it up with plywood.

|
| What about the temperature differentials? There's also a pressure
| differential from the flow of air over the fuselage. Correct?
| How did they simulate that?

The 8 lbs psi differential comes pretty close to the pressure differential
for an aircraft pressurized to 6,500 feet flying at 35,000 feet. After all,
the total weight of the entire atmosphere is only 15 lbs psi. If anything,
they erred on the side of increased pressure differential. A pound of air
psi is a pound of air psi, no matter what the source.

One thing I found interesting which they did not talk about was watching the
skin of the airplane inflate and become taught as the airplane was
pressurized.

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. In any event, a bullet will not do that kind of damage, unless the
bullet is some kind of anti-tank artillery round. It was obvious that any
handgun bullet is too small by several orders of magnitude to do any
significant damage. You could have pressurized that plane for space flight
and the result would have been the same. Well, no it wouldn't. That much
pressure would have started popping windows or something long before they
would have had a chance to fire their gun or set off their explosives. But a
bullet hole would not have made a measurable difference even then.

[Ben Jackson]

In article <qmHMb.35613$nt4.69560@attbi_s51>,
Bob Gardner > wrote:
>The speed of the airplane at altitude has nothing to do with it.

I don't know, have you ever used an aspriator? It uses the Bernoulli
principle to create suction by passing a jet of water by a hole. Used
to use them all the time in chemistry class. I would think the slipstream
by a hole in an airplane would be the same as being in a much lower
static pressure environment.

--
Ben Jackson
>
http://www.ben.com/

[Mark]

"Bob Gardner" > wrote in message news:<qmHMb.35613$nt4.69560@attbi_s51>...
> The speed of the airplane at altitude has nothing to do with it. The
> pressure differential between the cabin and the great outdoors is the only
> factor...airspeed does not exert any pressure on the sides of the fuselage.
>
> Bob Gardner

My point was that the explosion *could* cause other damage which
*could* bring the airliner down (the Souix City Iowa crash of a United
DC-10 for example). In the case of the MB episode, they wanted to see
IF a decompression could bring down an airliner. Well, the last
explosion was large enough to cause a very rapid decompression,
however with the plane sitting on the ground that's ALL that occured.
If the aircraft was in flight you might have ruptured hydraulic lines,
fuel lines, airframe damage and the large hole in the fuselage that is
causing a lot of drag. All these factors would increase the origional
damage in a more serious emergancy.

So, if the MB'ers were ONLY trying to prove they could cause a rapid
decompression then the speed of the airliner in flight is not a
factor. However if the goal was to see if a rapid decompression could
cause an airliner to crash, then you have a lot more factors to
consider than the initial incident.

I really like MB as a show however it's chewing gum for the mind. I
feel their attempts at trying to prove or disaprive a myth is far from
the final word. I'm sure everyone in the scientific community likes to
tune in each week and laugh at their methods.

[Kyler Laird]

"Bob Gardner" > writes:

>The speed of the airplane at altitude has nothing to do with it. The
>pressure differential between the cabin and the great outdoors is the only
>factor...airspeed does not exert any pressure on the sides of the fuselage.

So...it doesn't matter where one places the static port?

--kyler

[C J Campbell]

"Kyler Laird" > wrote in message
...
| "Bob Gardner" > writes:
|
| >The speed of the airplane at altitude has nothing to do with it. The
| >pressure differential between the cabin and the great outdoors is the
only
| >factor...airspeed does not exert any pressure on the sides of the
fuselage.
|
| So...it doesn't matter where one places the static port?

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.

[Bill Denton]

A couple of notes/questions...

Given that it is fairly rare for someone to only fire a single shot under
these circumstances, shouldn't the effect of the typical three shots have
been considered? While a single shot to the window only created a single
hole, would it not be possible for three shots into that same window to
compromise the window structure resulting in the entire window failing and
coming out of the aircraft?

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?

Those were just a couple of things I thought of while watching the
demonstration...



"Nomen Nescio" ]> wrote in message
...
> -----BEGIN PGP SIGNED MESSAGE-----
>
> From: "R.Hubbell" >
>
> >What about the temperature differentials? There's also a pressure
> >differential from the flow of air over the fuselage. Correct?
> >How did they simulate that?
> >
> >
> >R. Hubbell
>
> I wouldn't think that the airflow would make a significant difference. But
the temp. difference?
> You hit on an area that I was wondering about myself. It was done at
ambient(maybe 60 -
> 80 deg.F). The properties of materials certainly can change at -60 deg F.
>
>
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[Tim K]

(Ben Jackson) wrote in message news:<DYQMb.41817$5V2.62520@attbi_s53>...
> In article <qmHMb.35613$nt4.69560@attbi_s51>,
> Bob Gardner > wrote:
> >The speed of the airplane at altitude has nothing to do with it.
>
> I don't know, have you ever used an aspriator? It uses the Bernoulli
> principle to create suction by passing a jet of water by a hole. Used
> to use them all the time in chemistry class. I would think the slipstream
> by a hole in an airplane would be the same as being in a much lower
> static pressure environment.

I don't think that would make a great deal of difference, assuming the
hole isn't forward facing as Icebound points out.

The moving air over the hole would certainly create a pressure
differential between the inside of the tube and the outside air, as
you say, but I would expect the additional increase in pressure
differential created as a result to be negligible compared with the
huge delta caused by a pressurised cabin.

There must be math for calculating the pressure drop across a hole
(it's just a venturi isn't it?) in a surface in a moving stream of air
at a given velocity. The size of the hole is definitely a factor;
smaller the better if I remember correctly, and no real effect above a
certain size.

What may be more relevant to causing general chaos in the cabin is the
high-velocity air entering the cabin through the hole once the
pressure is equalized.

Regards,

Tim Kemp

[C J Campbell]

The myth that Mythbusters was interested in was whether a single shot from a
handgun can cause an explosive decompression. The answer is no.

Deliberately firing three rounds into the shatter-proof plastic of an
airliner window probably would not cause an explosive decompression, either.
It would just make three holes in the window. Eventually you could probably
put enough holes in the window to cause it to break, but that might take so
long that it still would not cause an explosive decompression.

Nevertheless, Mythbusters tried on the show to simulate the effect of an
entire window blowing out using high explosives. While the air rapidly left
the fuselage, there was no "siphon" effect that would carry people or
objects of any size out of the fuselage.

An explosive decompression is almost instantaneous. There can be no "siphon"
effect. If the air is just running out of the airplane, there is a "siphon"
effect, but no explosive decompression.

Anyone who has been in an altitude chamber knows that when you create an
explosive decompression the occupants just sit there. They don't even feel a
breeze. There is a brief moment of fog as water vapor suddenly condenses out
of the air. During a slow decompression the occupants do not feel a breeze,
either, unless they are sitting right next to the valve.

A good vacuum cleaner should be able to generate 8 lbs psi if you block the
hose opening. When you take your hand off the opening (and, you will note,
you *can* take your hand off the opening unless you are some kind of
weakling) the vacuum cleaner does not cartoon-like suck up everything in the
room. Things more than a few inches away from the nozzle do not feel the
effect of the vacuum cleaner. Really, when you make a hole in the fuselage,
all you are doing is creating a little vacuum cleaner. Make the hole small
enough and it will whistle.

I think the people who worry about getting sucked out of an airplane by
decompression are the same sort of people who had childhood fears about
being sucked down by the bathtub drain or getting sucked up by the vacuum
cleaner. Such fears are irrational, Hollywood plays up to them, but they are
there nonetheless.

[Bill Denton]

While I would agree that three shots would probably result in three holes,
you cannot discount the possibility of three random shots causing enough
damage to the window to result in total failure. Consider the demolition of
buildings, a small amount of explosive is placed at some structurally
significant points and down it comes!

As far as the siphon effect goes, it definitely exists, even though I may be
using incorrect terminology. Try this experiment: Drive down the road in
your car at highway speed, with all of the windows closed except the
driver's. Then take an ordinary tissue and release it about a foot away from
the window. Voila, it will be "sucked" out of the window. Obviously a tissue
is not a human being, but the effect of both decompression and this "siphon"
effect could combine to create enough force to pop a human out.

And on a lighter note...I have seen several vacuum cleaners that would suck
up a human. They're typically in places like plywood factories and such.


"C J Campbell" > wrote in message
...
> The myth that Mythbusters was interested in was whether a single shot from
a
> handgun can cause an explosive decompression. The answer is no.
>
> Deliberately firing three rounds into the shatter-proof plastic of an
> airliner window probably would not cause an explosive decompression,
either.
> It would just make three holes in the window. Eventually you could
probably
> put enough holes in the window to cause it to break, but that might take
so
> long that it still would not cause an explosive decompression.
>
> Nevertheless, Mythbusters tried on the show to simulate the effect of an
> entire window blowing out using high explosives. While the air rapidly
left
> the fuselage, there was no "siphon" effect that would carry people or
> objects of any size out of the fuselage.
>
> An explosive decompression is almost instantaneous. There can be no
"siphon"
> effect. If the air is just running out of the airplane, there is a
"siphon"
> effect, but no explosive decompression.
>
> Anyone who has been in an altitude chamber knows that when you create an
> explosive decompression the occupants just sit there. They don't even feel
a
> breeze. There is a brief moment of fog as water vapor suddenly condenses
out
> of the air. During a slow decompression the occupants do not feel a
breeze,
> either, unless they are sitting right next to the valve.
>
> A good vacuum cleaner should be able to generate 8 lbs psi if you block
the
> hose opening. When you take your hand off the opening (and, you will note,
> you *can* take your hand off the opening unless you are some kind of
> weakling) the vacuum cleaner does not cartoon-like suck up everything in
the
> room. Things more than a few inches away from the nozzle do not feel the
> effect of the vacuum cleaner. Really, when you make a hole in the
fuselage,
> all you are doing is creating a little vacuum cleaner. Make the hole small
> enough and it will whistle.
>
> I think the people who worry about getting sucked out of an airplane by
> decompression are the same sort of people who had childhood fears about
> being sucked down by the bathtub drain or getting sucked up by the vacuum
> cleaner. Such fears are irrational, Hollywood plays up to them, but they
are
> there nonetheless.
>
>

[Martin X. Moleski, SJ]

On Tue, 13 Jan 2004 09:37:56 -0600, "Bill Denton"
> wrote:

>Given that it is fairly rare for someone to only fire a single shot under
>these circumstances, shouldn't the effect of the typical three shots have
>been considered? While a single shot to the window only created a single
>hole, would it not be possible for three shots into that same window to
>compromise the window structure resulting in the entire window failing and
>coming out of the aircraft?

Their test sequence was this:

1. One bullet hole in the glass. No big deal.

2. One bullet hole through the side of the plane. No big deal.

3. They blew out the whole window with a small shaped charge.
Buster the dummy got sucked out the hole. I don't
know whether he had his seatbelt fastened. He
might have lost his arm and died if the plane had
been in flight. They glossed over the differences
between their static test and a real-life situation.

4. They blew a hole in the side of the fuselage with a shaped
charge. I forget the power of the load. The resulting
explosion created a hole in the fuselage reminiscent
of the fuselage that failed due to metal fatigue on
a trans-Pacific flight. They showed pictures of
the airliner after the incident. A stewardess lost
her life, but the passengers and the plane survived.

>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?

They speculated only the passenger next to the window would be
affected. Once decompression is over, the flow of air would be
a great deal less, I imagine.

Marty
not an engineer, either

[Martin X. Moleski, SJ]

On Tue, 13 Jan 2004 10:22:03 -0600, "Bill Denton"
> wrote:

>As far as the siphon effect goes, it definitely exists, even though I may be
>using incorrect terminology. ...

The first two blowouts of the plywood shield over the
cockpit windows demonstrated this pretty effectively.
In the first case, a plastic bag got sucked through
a relatively small opening. In the second, a whole
seat got blown out the window and was found
about 175 yards away from the plane. This was
at about 6 pounds per square inch of pressure.
They seemed pretty impressed.

I don't know whether the seat was bolted down
at the time.

Marty

[C J Campbell]

"Martin X. Moleski, SJ" > wrote in message
...
| On Tue, 13 Jan 2004 10:22:03 -0600, "Bill Denton"
| > wrote:
|
| >As far as the siphon effect goes, it definitely exists, even though I may
be
| >using incorrect terminology. ...
|
| The first two blowouts of the plywood shield over the
| cockpit windows demonstrated this pretty effectively.
| In the first case, a plastic bag got sucked through
| a relatively small opening. In the second, a whole
| seat got blown out the window and was found
| about 175 yards away from the plane. This was
| at about 6 pounds per square inch of pressure.
| They seemed pretty impressed.
|
| I don't know whether the seat was bolted down
| at the time.

It was just the seat cushion, even though they said it was the seat. The
frame of the seat is bolted down, but cushions are often not attached to
anything at all. They also tend to be light weight.

[C J Campbell]

"Martin X. Moleski, SJ" > wrote in message
...
| On Tue, 13 Jan 2004 09:37:56 -0600, "Bill Denton"
| > wrote:
|
| >Given that it is fairly rare for someone to only fire a single shot under
| >these circumstances, shouldn't the effect of the typical three shots have
| >been considered? While a single shot to the window only created a single
| >hole, would it not be possible for three shots into that same window to
| >compromise the window structure resulting in the entire window failing
and
| >coming out of the aircraft?
|
| Their test sequence was this:
|
| 1. One bullet hole in the glass. No big deal.
|
| 2. One bullet hole through the side of the plane. No big deal.
|
| 3. They blew out the whole window with a small shaped charge.
| Buster the dummy got sucked out the hole.

No he was not. Buster the dummy remained in his seat for all the tests,
although he was crushed by the seat in front of him on the fourth test. The
tray table also hit him in the throat. His arm was pulled out the window on
the third test, but it remained attached to the rest of him. But Buster was
never sucked out any of the holes. The shaped charge was used for the fourth
test. The window was blown out using explosive putty around the edges. The
shaped charge was used to destroy the whole wall. Given that Buster
represented a terrorist using a shaped charge on the fourth test, he
probably richly deserved getting blown up, crushed and burned. :-)

Buster wore his seat belt for all tests.

[Judah]

And sometimes they even float.


"C J Campbell" > wrote in
:

>
> "Martin X. Moleski, SJ" > wrote in message
> ...
>| On Tue, 13 Jan 2004 10:22:03 -0600, "Bill Denton"
>| > wrote:
>|
>| >As far as the siphon effect goes, it definitely exists, even though I
>| >may be using incorrect terminology. ...
>|
>| The first two blowouts of the plywood shield over the
>| cockpit windows demonstrated this pretty effectively.
>| In the first case, a plastic bag got sucked through
>| a relatively small opening. In the second, a whole
>| seat got blown out the window and was found
>| about 175 yards away from the plane. This was
>| at about 6 pounds per square inch of pressure.
>| They seemed pretty impressed.
>|
>| I don't know whether the seat was bolted down at the time.
>
> It was just the seat cushion, even though they said it was the seat.
> The frame of the seat is bolted down, but cushions are often not
> attached to anything at all. They also tend to be light weight.
>
>
>

[Bob Gardner]

OK...that point was not clear in your original post. My answer was based on
the fact that fuselage-mounted static ports (as opposed to under-the-wing
a'la Piper) are located on the sides of the fuselage precisely because there
is neither positive nor negative pressure acting on the skin of the airplane
in flight.

The shaped charge demonstration hardly belongs in this discussion, because
the odds are that it would kill the airplane...Mythbuster's original
argument was whether or not a bullet would cause that kind of destruction,
as visualized by a lot of folks who do not understand pressurization.

Bob Gardner

"Mark" > wrote in message
om...
> "Bob Gardner" > wrote in message
news:<qmHMb.35613$nt4.69560@attbi_s51>...
> > The speed of the airplane at altitude has nothing to do with it. The
> > pressure differential between the cabin and the great outdoors is the
only
> > factor...airspeed does not exert any pressure on the sides of the
fuselage.
> >
> > Bob Gardner
>
> My point was that the explosion *could* cause other damage which
> *could* bring the airliner down (the Souix City Iowa crash of a United
> DC-10 for example). In the case of the MB episode, they wanted to see
> IF a decompression could bring down an airliner. Well, the last
> explosion was large enough to cause a very rapid decompression,
> however with the plane sitting on the ground that's ALL that occured.
> If the aircraft was in flight you might have ruptured hydraulic lines,
> fuel lines, airframe damage and the large hole in the fuselage that is
> causing a lot of drag. All these factors would increase the origional
> damage in a more serious emergancy.
>
> So, if the MB'ers were ONLY trying to prove they could cause a rapid
> decompression then the speed of the airliner in flight is not a
> factor. However if the goal was to see if a rapid decompression could
> cause an airliner to crash, then you have a lot more factors to
> consider than the initial incident.
>
> I really like MB as a show however it's chewing gum for the mind. I
> feel their attempts at trying to prove or disaprive a myth is far from
> the final word. I'm sure everyone in the scientific community likes to
> tune in each week and laugh at their methods.

[Bob Gardner]

Exactly my point...if there is neither positive nor negative pressure
measured at the location of the static port on the fuselage skin, then
motion through the air, in and of itself, plays no part in the bullet hole
scenario.

Bob Gardner

"C J Campbell" > wrote in message
...
>
> "Kyler Laird" > wrote in message
> ...
> | "Bob Gardner" > writes:
> |
> | >The speed of the airplane at altitude has nothing to do with it. The
> | >pressure differential between the cabin and the great outdoors is the
> only
> | >factor...airspeed does not exert any pressure on the sides of the
> fuselage.
> |
> | So...it doesn't matter where one places the static port?
>
> 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.
>
>

[Ben Jackson]

In article <LP_Mb.45273$nt4.79391@attbi_s51>,
Bob Gardner > wrote:
>the fact that fuselage-mounted static ports (as opposed to under-the-wing
>a'la Piper) are located on the sides of the fuselage precisely because there
>is neither positive nor negative pressure acting on the skin of the airplane
>in flight.

Are you sure the instruments aren't just calibrated for the error?


--
Ben Jackson
>
http://www.ben.com/

[Eric Miller]

"C J Campbell" > wrote in message
...
> I think the people who worry about getting sucked out of an airplane by
> decompression are the same sort of people who had childhood fears about
> being sucked down by the bathtub drain or getting sucked up by the vacuum
> cleaner. Such fears are irrational, Hollywood plays up to them, but they
are
> there nonetheless.

Hey, not so fast!

MB only proved that a bullet through an aircraft fuselage, aircraft window,
or even losing an entire window wouldn't cause explosive decompression. They
didn't cover getting sucked down a bathtub drain or sucked up by a vacuum
cleaner yet. Maybe next episode =D

Eric

[R.Hubbell]

On Mon, 12 Jan 2004 23:37:03 -0800 "C J Campbell" > wrote:

>
> "R.Hubbell" > wrote in message
> ...
> | On Sun, 11 Jan 2004 21:13:28 -0800 "C J Campbell"
> > wrote:
> |
> | > Now, that was cool!
> | >
> | > Mythbusters pressurized an old DC-9 and fired a bullet through the wall
> to
> | > see if it would cause an explosive decompression. It didn't. Then they
> fired
> | > a bullet through the window to see if the window would shatter and cause
> an
> | > explosive decompression. The bullet only made a small hole in the window
> | > because the windows are made of shatter-proof plastic. No explosive
> | > decompression.
> |
> | I don't watch much TV but I admit I would have liked to have seen this.
> |
> | Can you provide more detail on how they setup the test?
>
> They took a derelict DC-9 at an aircraft graveyard and plugged up the holes.
> They had real trouble with the cockpit because the windows had been removed.
> They tried to replace the windows with plywood cemented in with foam, but
> the plywood proved to not be strong enough to allow pressurization of the
> aircraft. It kept blowing out, sometimes spectacularly.
>
> The pistol was mounted on a stand in the cabin and fired by remote control
> using a servor cannibalized from a vending machine, of all things. The
> handgun was a 9 mm automatic; it looked like a Glock.
>
> The aircraft was pressurized using one of those giant ground starter units
> designed for 747s, a huffer. They dumped huge sacks full of packing peanuts,
> scattering them around the cabin to so that the airflow inside the cabin
> would be visible. The bullet holes disturbed the airflow so little that even
> the packing peanuts stayed where they were.
>
> |
> | What was the cabin pressure? What was the pressure external to the
> | DC-9? Did they have a huge pressure chamber?
>
> They calculated the pressure differential at 35,000 feet to be 8 lbs psi, so
> they pressurized the interior to 8 lbs psi. As mentioned, they had trouble
> doing this. The plywood in the cockpit could only stand about 6 lbs psi. At
> one point the plywood blew out and ejected a cushion from the pilot seat
> more than 125 yards. They finally ended up reinforcing it enough to
> withstand the 8 lbs psi differential. I guess the lesson there is that if
> you ever lose a cockpit window you can forget about restoring cabin pressure
> by plugging it up with plywood.
>
> |
> | What about the temperature differentials? There's also a pressure
> | differential from the flow of air over the fuselage. Correct?
> | How did they simulate that?
>
> The 8 lbs psi differential comes pretty close to the pressure differential
> for an aircraft pressurized to 6,500 feet flying at 35,000 feet. After all,
> the total weight of the entire atmosphere is only 15 lbs psi. If anything,
> they erred on the side of increased pressure differential. A pound of air
> psi is a pound of air psi, no matter what the source.
>
> One thing I found interesting which they did not talk about was watching the
> skin of the airplane inflate and become taught as the airplane was
> pressurized.



That brings up another question (don't have to answer, just food for thought)
How many pressurization cycles did the DC-9 experience over its lifespan?



>
> 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. In any event, a bullet will not do that kind of damage, unless the
> bullet is some kind of anti-tank artillery round. It was obvious that any
> handgun bullet is too small by several orders of magnitude to do any
> significant damage. You could have pressurized that plane for space flight
> and the result would have been the same. Well, no it wouldn't. That much
> pressure would have started popping windows or something long before they
> would have had a chance to fire their gun or set off their explosives. But a
> bullet hole would not have made a measurable difference even then.
>
>


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.


Not me. :)


R. Hubbell

[David Dyer-Bennet]

"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?

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

[David Dyer-Bennet]

"Bill Denton" > writes:

> A couple of notes/questions...
>
> Given that it is fairly rare for someone to only fire a single shot under
> these circumstances, shouldn't the effect of the typical three shots have
> been considered? While a single shot to the window only created a single
> hole, would it not be possible for three shots into that same window to
> compromise the window structure resulting in the entire window failing and
> coming out of the aircraft?

Could well be an issue of their mechanism holding the pistol too
firmly -- so further shots would have hit the same place. And they
didn't want to go to the next level of complexity. I do agree that
multiple shots to the same window is a case worth investigating.
--
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/>

[Morgans]

"Ben Jackson" > wrote
>
> Are you sure the instruments aren't just calibrated for the error?
>
>
> --
> Ben Jackson

Ahhh, yea!?!!!!!

Haven't been around much, have you?
--
Jim in NC

[Morgans]

"Bill Denton" > wrote

.. Try this experiment: Drive down the road in
> your car at highway speed, with all of the windows closed except the
> driver's. Then take an ordinary tissue and release it about a foot away
from
> the window. Voila, it will be "sucked" out of the window.


Different than an airliner fuselage. There is slightly higher pressure in
font of the windshield, and low pressure slightly behind the windshield,
where the window is. A cylindrical fuselage has few changes such as that,
has few pressure changes along its length.
--
Jim in NC

[C J Campbell]

"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.

[Bill Denton]

I used the automobile as a simple example; you would also observe the same
phenomena at the middle or rear of a school bus. And most of us have heard
of situations where a sectional was "sucked" out the window of a J3 Cub or
similar aircraft with larger, operable windows.

Again, I am not an engineer and I don't know the correct terms for all of
this.

Obviously you will see position-dependent variances, but if you take a large
aircraft, remove one of the windows, and fly the aircraft unpressurized, the
movement of air along the fuselage will "draw" air from inside the cabin out
through the window opening.

And until a PE tells me otherwise, that's my story and I'm sticking to it!
GBG


"Morgans" > wrote in message
...
>
> "Bill Denton" > wrote
>
> . Try this experiment: Drive down the road in
> > your car at highway speed, with all of the windows closed except the
> > driver's. Then take an ordinary tissue and release it about a foot away
> from
> > the window. Voila, it will be "sucked" out of the window.
>
>
> Different than an airliner fuselage. There is slightly higher pressure in
> font of the windshield, and low pressure slightly behind the windshield,
> where the window is. A cylindrical fuselage has few changes such as that,
> has few pressure changes along its length.
> --
> Jim in NC
>
>

[Tom Sixkiller]

"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.
>
Yes, but evidently Hubbel is stuck on his Hollyweird delusions.

[Tom Sixkiller]

"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?

[R.Hubbell]

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

>
>
>
>

[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/>

[R.Hubbell]

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

[C J Campbell]

"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?

[Andrew Rowley]

"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?

[Tom Sixkiller]

"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.

[David CL Francis]

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

[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

[Big John]

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.
>

[C J Campbell]

"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.