Hi all,
I don't know if it was a rerun and has been thoroughly done over here,
but last nights episode of The Mythbusters 'busted' the explosive
decompression myth surrounding bullet holes in aircraft.
The guys sealed up a junked out cabin, pressurized it, then fired 9mm
bullets through first the skin and then a window. Nothing exciting happened.
Pretty interesting stuff.
They ended the episode by blowing a large hole in the fuselage. I was
out of the room when they set the charge so I don't know the size, shape,
etc. I did a bang up job of opening a hole.
My conviction of the miniscule damage to be caused by a sky marshall or
pilot popping off a few caps at a terrorists has been reinforced. The
diameter difference between a 9mm (.38") and a .44 Mag wouldn't make any
difference. Let's give the good guys the bigger cannon.

"Casey Wilson" > wrote in message
...
> Hi all,
> I don't know if it was a rerun and has been thoroughly done over
here,
> but last nights episode of The Mythbusters 'busted' the explosive
> decompression myth surrounding bullet holes in aircraft.

It was a re-run. And it sure does show how ridiculous the debate over arming
pilots and sky marshals can be.

On Wed, 07 Jul 2004 16:37:56 +0000, Casey Wilson wrote:
> The guys sealed up a junked out cabin, pressurized it, then fired 9mm
> bullets through first the skin and then a window. Nothing exciting
> happened. Pretty interesting stuff.

One factor that they neglected to account for is that many airliners fly
at speeds approaching Mach 0.85. I'd have to see a section of aluminum
skin with a bullet-hole in it staying intact in a transonic wind-tunnel
that was running about that speed before I put much stock in their
results.

-Luke

"Luke Scharf" > wrote in message
...
> On Wed, 07 Jul 2004 16:37:56 +0000, Casey Wilson wrote:
> > The guys sealed up a junked out cabin, pressurized it, then fired 9mm
> > bullets through first the skin and then a window. Nothing exciting
> > happened. Pretty interesting stuff.
>
> One factor that they neglected to account for is that many airliners fly
> at speeds approaching Mach 0.85. I'd have to see a section of aluminum
> skin with a bullet-hole in it staying intact in a transonic wind-tunnel
> that was running about that speed before I put much stock in their
> results.
>
Also, if the test was done on the ground then of course nothing would
happen. It needs to done in a wind tunnel that is depressurized to simulate
30K feet.

Earl G

Gee what do you think the indicated airspeed is at M.85 at FL350?

Mike
MU-2


"Luke Scharf" > wrote in message
...
> On Wed, 07 Jul 2004 16:37:56 +0000, Casey Wilson wrote:
> > The guys sealed up a junked out cabin, pressurized it, then fired 9mm
> > bullets through first the skin and then a window. Nothing exciting
> > happened. Pretty interesting stuff.
>
> One factor that they neglected to account for is that many airliners fly
> at speeds approaching Mach 0.85. I'd have to see a section of aluminum
> skin with a bullet-hole in it staying intact in a transonic wind-tunnel
> that was running about that speed before I put much stock in their
> results.
>
> -Luke

Earl Grieda wrote:

> Also, if the test was done on the ground then of course nothing would
> happen. It needs to done in a wind tunnel that is depressurized to simulate
> 30K feet.

"Of course", "Needs", and "Simulate" is it?

The only necessity arising out of your post is that it be ignored. Your
simulation of comprehension of the subject won't fly.

The subject has been done to death here on a regular basis. Those who
are convinced they are in great danger from the presence of fire arms in
their world will never admit that the threat to the integrity of the
aircraft from gunfire in an airline cabin is minuscule, especially when
compared to the aftermath of a successful hijacking.

Read the archives of this discussion and allow the rest of us to
consider more interesting topics.


Jack

What difference would that make?

Mike
MU-2


"Earl Grieda" > wrote in message
ink.net...
>
> "Luke Scharf" > wrote in message
> ...
> > On Wed, 07 Jul 2004 16:37:56 +0000, Casey Wilson wrote:
> > > The guys sealed up a junked out cabin, pressurized it, then fired 9mm
> > > bullets through first the skin and then a window. Nothing exciting
> > > happened. Pretty interesting stuff.
> >
> > One factor that they neglected to account for is that many airliners fly
> > at speeds approaching Mach 0.85. I'd have to see a section of aluminum
> > skin with a bullet-hole in it staying intact in a transonic wind-tunnel
> > that was running about that speed before I put much stock in their
> > results.
> >
> Also, if the test was done on the ground then of course nothing would
> happen. It needs to done in a wind tunnel that is depressurized to
simulate
> 30K feet.
>
> Earl G
>
>

On Wed, 07 Jul 2004 17:54:59 +0000, Mike Rapoport wrote:
> Gee what do you think the indicated airspeed is at M.85 at FL350?

It looks like the calibrated[0] airspeed is around 325mph:
https://ewhdbks.mugu.navy.mil/mach-as.htm

I seem to remember that Mach 0.85 is transonic, so air is actually flowing
at supersonic speeds over some parts of the airplane (nose, wings, tail?)
and subsonic over others. All kinds of stuff that I don't know how to
predict happens then. Maybe someone here is an aerodynamicist who has a
better feel for compressible flow?

But, *that* is why I am skeptical of the Mythbuster's conclusion -- it
seems to me that supersonic/transonic airflow anywhere would be a
significant consideration -- especially if the flow happens to
be over the bullet-hole.

-Luke

[0] IIRC, "indicated" airspeed isn't valid above Mach 0.3 because of
compressibility effects -- but it has been quite some time since I took
that class (and I wasn't proud of my grade) so I could be very wrong. I
have just enough education on the topic to appreciate the expertise of
people who actually know what they're talking about!

> My conviction of the miniscule damage to be caused by a sky
> marshall or pilot popping off a few caps at a terrorists has been
> reinforced.

Some years ago an airliner landed here in Richmond after having been shot by
someone on the ground. It was a completely coincidental thing where someone
shot into the sky and just happened to hit an airliner. The news report
showed the bullet hole; other than that the plane was fine.

If a bullet penetrated the skin of an aircraft, the plane could not have
been more than a couple of thousand feet high, and it would not be
pressurized.





"John Harlow" > wrote in message
...
> > My conviction of the miniscule damage to be caused by a sky
> > marshall or pilot popping off a few caps at a terrorists has been
> > reinforced.
>
> Some years ago an airliner landed here in Richmond after having been shot
by
> someone on the ground. It was a completely coincidental thing where
someone
> shot into the sky and just happened to hit an airliner. The news report
> showed the bullet hole; other than that the plane was fine.
>
>

> Also, if the test was done on the ground then of course nothing would
> happen. It needs to done in a wind tunnel that is depressurized to
simulate
> 30K feet.

Or, you can just do what they did, and pressurize it on the ground to get
the same pressure differential.

A small bullet hole will not cause much of a structural problem--you aren't
going to see an entire fuselage section ripping off because of aerodynamic
forces. What they did with the shaped charge might cause some problems, but
otherwise the slipstream wouldn't be much of an issue (structure-wise).

I forget the exact numbers but the dynamic preasure on the nose of an jet
aircraft at cruise is about 9psi above ambient. Anyway, anybody who has
ever seen pictures of shot-up military aircraft can see that the airflow
didn't cause the skins to tear.

Mike
MU-2


"Luke Scharf" > wrote in message
...
> On Wed, 07 Jul 2004 17:54:59 +0000, Mike Rapoport wrote:
> > Gee what do you think the indicated airspeed is at M.85 at FL350?
>
> It looks like the calibrated[0] airspeed is around 325mph:
> https://ewhdbks.mugu.navy.mil/mach-as.htm
>
> I seem to remember that Mach 0.85 is transonic, so air is actually flowing
> at supersonic speeds over some parts of the airplane (nose, wings, tail?)
> and subsonic over others. All kinds of stuff that I don't know how to
> predict happens then. Maybe someone here is an aerodynamicist who has a
> better feel for compressible flow?
>
> But, *that* is why I am skeptical of the Mythbuster's conclusion -- it
> seems to me that supersonic/transonic airflow anywhere would be a
> significant consideration -- especially if the flow happens to
> be over the bullet-hole.
>
> -Luke
>
> [0] IIRC, "indicated" airspeed isn't valid above Mach 0.3 because of
> compressibility effects -- but it has been quite some time since I took
> that class (and I wasn't proud of my grade) so I could be very wrong. I
> have just enough education on the topic to appreciate the expertise of
> people who actually know what they're talking about!

I wonder... did they just pressurize it with a low volume pressure
source or with a high volume pressure source. I remember being told that
some of the larger jetliners have enough bleed air capacity to maintain
cabin pressure with an entire window blown out. Not bad for the people
far away from the breach, but really sucks for those (literally) near
the breach.

IF this is true, then pressurizing the airliner on the ground with a low
volume source (only able to maintain the differential over the normal
leakage of the pressure vessel) then the airframe depressurizes. A high
volume source would be able to maintain cabin pressure despite the
breach of a bullet hole.

In any event, I will readily agree that the hollywood versions of
decompressions are exactly that.. hollywood.

So.. am I misinformed? or perhaps this might be pertinent/

Dave

Casey Wilson wrote:
> Hi all,
> I don't know if it was a rerun and has been thoroughly done over here,
> but last nights episode of The Mythbusters 'busted' the explosive
> decompression myth surrounding bullet holes in aircraft.
> The guys sealed up a junked out cabin, pressurized it, then fired 9mm
> bullets through first the skin and then a window. Nothing exciting happened.
> Pretty interesting stuff.
> They ended the episode by blowing a large hole in the fuselage. I was
> out of the room when they set the charge so I don't know the size, shape,
> etc. I did a bang up job of opening a hole.
> My conviction of the miniscule damage to be caused by a sky marshall or
> pilot popping off a few caps at a terrorists has been reinforced. The
> diameter difference between a 9mm (.38") and a .44 Mag wouldn't make any
> difference. Let's give the good guys the bigger cannon.
>
>
>
>
>

John Harlow wrote:
>> My conviction of the miniscule damage to be caused by a sky
>>marshall or pilot popping off a few caps at a terrorists has been
>>reinforced.
>
> Some years ago an airliner landed here in Richmond after having been shot by
> someone on the ground. It was a completely coincidental thing where someone
> shot into the sky and just happened to hit an airliner. The news report
> showed the bullet hole; other than that the plane was fine.

May or may not be relevant, depending on the following
two questions:

1. Did the bullet penetrate into any pressurized part
of the aircraft ?
2. What height (and speed) was it flying at when it was hit ?

CV

CV wrote:

> John Harlow wrote:
>
>>> My conviction of the miniscule damage to be caused by a sky
>>> marshall or pilot popping off a few caps at a terrorists has been
>>> reinforced.
>>
>>
>> Some years ago an airliner landed here in Richmond after having been
>> shot by
>> someone on the ground. It was a completely coincidental thing where
>> someone
>> shot into the sky and just happened to hit an airliner. The news report
>> showed the bullet hole; other than that the plane was fine.
>
>
> May or may not be relevant, depending on the following
> two questions:
>
> 1. Did the bullet penetrate into any pressurized part
> of the aircraft ?
> 2. What height (and speed) was it flying at when it was hit ?

hmmm, just thought of a third factor: The hole left by a bullet
entering the airframe may be aerodynamically very different
from one that went from the inside out.
CV

On Wed, 07 Jul 2004 20:21:51 +0000, Mike Rapoport wrote:
> I forget the exact numbers but the dynamic preasure on the nose of an jet
> aircraft at cruise is about 9psi above ambient.

~9psi doesn't sound too bad. I'd buy that that the skin would stay
together with that number.

I'm still curious to see if any sort of shockwave-like thing from a
the transonic flow over a bullethole would do any extra damage.

Also, someone recently was telling me that a supersonic wind-tunnel (up to
Mach 3, I believe) that they use works on 50psi -- but the system
maintains 50psi over a large area and pushes the air through a *much*
smaller throat...

> Anyway, anybody who has
> ever seen pictures of shot-up military aircraft can see that the airflow
> didn't cause the skins to tear.

Yes, but they're built with the expectation that they'll be shot at. I'd
probably put a thicker skin on an airplane that was designed for civilian
use. I've heard stories about midair collisions where the wing of a
jet fighter literally sliced the wing of another aircraft off (with
minimal damage to the wing).

But, at only 9psi above ambient pressure, I'd buy that the skin would stay
together. But I wouldn't want to actually try it without some rigorous
testing!

-Luke

uuuuhhhh,

What about that Hawaiian Air 737 that went "convertable" mid flight and
landed relatively intact?

What about the scores of military cargo aircraft that have been shot up and
still seem to stay together (not too structurally different, and made by the
lowest bidder!!!)

Hell, even the DHL A320 took a hit by a MANPAD and made it back...




"Luke Scharf" > wrote in message
...
> On Wed, 07 Jul 2004 16:37:56 +0000, Casey Wilson wrote:
> > The guys sealed up a junked out cabin, pressurized it, then fired 9mm
> > bullets through first the skin and then a window. Nothing exciting
> > happened. Pretty interesting stuff.
>
> One factor that they neglected to account for is that many airliners fly
> at speeds approaching Mach 0.85. I'd have to see a section of aluminum
> skin with a bullet-hole in it staying intact in a transonic wind-tunnel
> that was running about that speed before I put much stock in their
> results.
>
> -Luke

"Mark T. Mueller" > wrote in message
...
>
> What about the scores of military cargo aircraft that have been shot up
and
> still seem to stay together (not too structurally different, and made by
the
> lowest bidder!!!)
>

The military hasn't bought aircraft that way in a very long time.

>"Luke Scharf" wrote in message > I seem to remember that Mach 0.85 is
>transonic, so air is actually flowing
> at supersonic speeds over some parts of the airplane (nose, wings, tail?)
> and subsonic over others.

M.85 is called the transonic region, however, most airliners are designed to
cruise at a speed just below that speed where shock waves start to form.
Cruising with shock waves burns a whole lot of fuel. In the B-727, we
normally cruised at .77 unless it was the last leg of the week and we wanted
to catch a jumpseat home. Then we bumped it up to .88. At M.88, the
shockwaves coming off the square corners of the windscreen were so loud, we
couldn't converse with one another. We burned a bunch of extra fuel too. In
the MD-80, we normally cruise at M.76. We can bump it up, but at .81, the
rumble of shockwaves on the wings is disconcerting to the passengers. We
burn 6% more fuel just to go 10 or 12 knots faster. In contrast, the B-747
cruises at M.84 without forming shockwaves. It is designed that way.

> But, *that* is why I am skeptical of the Mythbuster's conclusion -- it
> seems to me that supersonic/transonic airflow anywhere would be a
> significant consideration -- especially if the flow happens to
> be over the bullet-hole.

Jetliners don't use thin .020" sheet aluminum for structural parts as you
would find in a Cherokee or Skyhawk. Shockwaves over a bullet hole are
insignificant. What is significant is when a force is strong enough to cause
some sheet metal to expand into the airstream and the airstream peels it
backwards. Then structural integrity is compromised, often catastrophically.

D.

>"Bill Denton" wrote in message > If a bullet penetrated the skin of an
>aircraft, the plane could not have been more than a couple of thousand feet
>high, and it would not be pressurized.

It would likely be pressurized, just not at maximum differential.

D.

Dave,

> I remember being told that
> some of the larger jetliners have enough bleed air capacity to maintain
> cabin pressure with an entire window blown out.
>

AFAIK, this is a certificatino requirement and the reason why the
Concorde's windows are so small. But I've been wrong before.

One aspect not mentioned yet: It kind of depends, too, what a bullet hits
on the way out. There are some cables and pressure lines that are better
left intact. But I agree that the depressuriation is a myth, mostly. No
fat bad guys are going to be sucked out of any window, James Bond
notwithstanding.

--
Thomas Borchert (EDDH)

"Luke Scharf" > wrote in message
...
cause the skins to tear.
>
> Yes, but they're built with the expectation that they'll be shot at. I'd
> probably put a thicker skin on an airplane that was designed for civilian
> use. I've heard stories about midair collisions where the wing of a
> jet fighter literally sliced the wing of another aircraft off (with
> minimal damage to the wing).
>

I suspect that the skin of a preasurized airliner is thicker than the skin
on the tail of a A-10.

Mike
MU-2

>Subject: Re: Mythbusters and explosive decompression
>From: Luke Scharf

>One factor that they neglected to account for is that many airliners fly
>at speeds approaching Mach 0.85. I'd have to see a section of aluminum

>skin with a bullet-hole in it staying intact in a transonic wind-tunnel
>that was running about that speed before I put much stock in their
>results.

Luke you must not of seen many combat acft return home with holes big enough to
park a V W in. Mac USAF retired

>From: "Earl Grieda"

>Also, if the test was done on the ground then of course nothing would
>happen. It needs to done in a wind tunnel that is depressurized to simulate
>30K feet.

Gads are we thinking here??? 8.5 PSID(or whatever) is the same at any
altitude----Mac

On Wed, 07 Jul 2004 16:37:56 GMT, "Casey Wilson" >
wrote:

> My conviction of the miniscule damage to be caused by a sky marshall or
>pilot popping off a few caps at a terrorists has been reinforced. The
>diameter difference between a 9mm (.38") and a .44 Mag wouldn't make any
>difference. Let's give the good guys the bigger cannon.

What's the point in having the bigger cannon? Do the advantages,
whatever they may be, outweigh the disadvantages of heavier weight,
larger size and less of an ammo load? In addition, if it's being used
because of superior penetrating power, in case of hijackers using body
armor, what if there's no body armor? How many bodies can a teflon
coated steel jacketed bullet pass through before it stops in the last
body?

I'd think that frangible bullets would be the better option to
minimize collateral damage and take the risk that the hijacker might
be wearing body armor. Or perhaps bring both loads? In which case
the 9mm automatic makes more sense as the clip can be quickly changed
to match the situation.

Corky Scott

PS, frangible bullets wouldn't penetrate the skin of the airliner
either.

wrote:

> ...the 9mm automatic makes more sense as the clip can be quickly changed
> to match the situation.

If I read you correctly, you feel that you are now prepared to counter
the decisions of law enforcement, weapons, and ballistics experts, as
well as aeronautical engineers? You may want to familiarize yourself
with the design and operation of the typical semi-automatic pistol
before you say any more.

There is nothing about the choice of calibers, whether 9mm, .40, or .45
that affects the ability to change magazines rapidly. The operation of
the pistol is virtually identical in what ever calibers it may be
offered. Cartridge size and the practical limits of grip size determine
the number of rounds which may be carried, but unless one is an advocate
of the "spray and pray" method, shot placement and terminal effects are
far more important than the number of rounds available.


Jack

>"Jack" wrote in message > If I read you correctly, you feel that you are
now >prepared to counter
> the decisions of law enforcement, weapons, and ballistics experts, as
> well as aeronautical engineers? You may want to familiarize yourself
> with the design and operation of the typical semi-automatic pistol
> before you say any more.

Perhaps you didn't read Corky's post as I read it. His thrust is that
caliber and barrel length do not need to be the largest available. He is
correct except for the frangible bullets unless he means hollow points.

D.

Capt.Doug wrote:

> Perhaps you didn't read Corky's post as I read it. His thrust is that
> caliber and barrel length do not need to be the largest available. He is
> correct except for the frangible bullets unless he means hollow points.

I'd agree that 's advocacy of the .44 Magnum is truly
phony nonsense, and is in fact one of the few alternatives to which the
9mm could be considered a superior choice.

It is my understanding that the "Air Marshals" do not use the 9mm. Do
you have other information?


Jack

>I'd think that frangible bullets would be the better option to
>minimize collateral damage and take the risk that the hijacker might
>be wearing body armor.

This was pretty thoroughly hashed over on the newsgroups some months
ago. As it happens, I just recently posted one of the better responses
on my website:

http://www.warbirdforum.com/airliner.htm

To me, it pretty much demolished the notion of "explosive
decompression." The author also goes into the subject of bullets used
by sky marshals.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

"Nomen Nescio" ]> wrote in message
...
> -----BEGIN PGP SIGNED MESSAGE-----
>
> From:
>
> >What's the point in having the bigger cannon?
>
> Shock. The point is to "shoot to stop", not "shoot to kill" (even though
the
> best way to "stop" someone is with a hollow point to the forehead). The
> energy - momentum debate has been going on as long as firearms have
> existed. I tend to be a proponent of the big, heavy, soft, slow, lump of
lead
> approach to defense. The idea is to "stop" someone from doing what they're
> doing, RIGHT NOW!! If someone is about to push a button and detonate a
> bomb, it's more important to interupt the action than to kill. Stab
someone in
> the heart and they will die, in 10 - 15 seconds. Hit them in the chest
with a
> baseball bat and they will stop what they are doing, immediately
>
Initially, I was being facetious when I said "...let them (marshals
and pilots) have the bigger cannon. In thinking about it, and reading
Nomen's comments above, the cannon makes a lot of sense. When I went through
classes for my concealed weapons permit, Shoot To Stop was the dictum. If in
the process of being stopped, the attacker died, oh well.
The 'big, heavy, soft, slow lump of lead' is the better choice over
high velocity. Any bullet that does not expend its entire energy within or
on) the target is a waste. I carry my .45 loaded with standard load jacketed
hollow-points for just that reason.
The bullet is expected to mushroom to almost 3/4 inches and dissipate
all of its energy within the body cavity. In the event the attacker is
wearing body armor, a hit in the sternum is expected to at least break one
or more ribs and perhaps even send the heart into fibrillation. My training
has been to get off two rounds to the 'center of mass' (meaning the chest)
in less than two seconds, then look for another target.
Some advocate two in the chest and one in the face. That's not how I was
trained and not what I've been taught in the several refresher courses. The
instructors have unanimously stated that even with body armor, an attacker
will not ignore two heavy lumps of lead in the chest.
Remember the Hollywood Shootout at the California bank a few years ago?
I've read more than one report saying that the reason the perpetrators there
were able to shrug off multiple hits on their armor was because the cops
were using 9mm.

On Thu, 08 Jul 2004 19:01:59 +0000, Mackfly wrote:
> Luke you must not of seen many combat acft return home with holes big
> enough to park a V W in. Mac USAF retired

How fast did they fly home? Also, how thick is the skin on a combat
aircraft compared to a civilian airliner?

I'll buy that the aircraft could stay together. The Mythbusters
simulation wasn't very comprehensive... But, then again, I know just
enough about high-speed aerodynamics to be afraid! :-)

-Luke

On Fri, 09 Jul 2004 00:55:34 -0500, Jack wrote:

> It is my understanding that the "Air Marshals" do not use the 9mm. Do
> you have other information?

You are correct, the Marshals are not using 9mm.

-Jack Davis
B737


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On Thu, 08 Jul 2004 19:03:35 +0000, Mackfly wrote:

> Gads are we thinking here??? 8.5 PSID(or whatever) is the same at any
> altitude----Mac

Thanks for the laugh, I needed that!

-Jack Davis
B737



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> saying that the reason the perpetrators there
>were able to shrug off multiple hits on their armor was because the cops
>were using 9mm.

For those who don't like conversions, 9 mm = 0.3543307 inches. That is
pretty small. I never realized how small!

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
The Piper Cub Forum www.pipercubforum.com
Viva Bush! weblog www.vivabush.org

The thing those guys missed was the effect of cold temps on the windows.
They did it in the desert, where it was likely above 80F.
At altitude, the windows would be over 100 degrees colder. Plastic windows
become much more fragile at those temperatures.

"MichaelR" > wrote in message
...
> The thing those guys missed was the effect of cold temps on the windows.
> They did it in the desert, where it was likely above 80F.
> At altitude, the windows would be over 100 degrees colder.

On one side.

> Plastic windows
> become much more fragile at those temperatures.

On one side.

Why do airliner cockpit windows have heaters?
The answer is to keep the windows warm enough and flexible enough so they
don't shatter if they hit a bird.
If Mythbusters had cooled that side window to -50C, it would have
disintegrated when the bullet hit it.

"MichaelR" > wrote in message
...
> Why do airliner cockpit windows have heaters?
> The answer is to keep the windows warm enough and flexible enough so they
> don't shatter if they hit a bird.

Why do they run them at altitudes that birds don't fly?

> If Mythbusters had cooled that side window to -50C, it would have
> disintegrated when the bullet hit it.

Tom Sixkiller wrote:

[re: heated airliner windscreens]

> Why do they run them at altitudes that birds don't fly?

I assume your question is rhetorical, but the range of altitudes at
which birds may be found is far greater than most people suspect. I have
seen them >14,000 msl over the lower 48, and that is no record.

Other reasons: ice & snow, FOD (balloons and their payloads, kites,
model aircraft, wind- and vertical current-borne objects and material),
and of course the ever-present possibility of mid air collision -- all
of which must be considered at all altitudes within the operating envelope.

But these considerations have little to do with the advisability of
preventing skyjacking by any means necessary, including the use of
firearms by Federal Sky Marshals. As a cockpit crew member, a blown out
window is something I can deal with -- a medium sized problem: a team of
terrorists controlling the cabin is going to be a much bigger problem,
and it will have ramifications well beyond anything we are likely to
include in our discussions here.


--
Jack

"Cave ab homine unius libri"

In article >, Jack >
wrote:

> I assume your question is rhetorical, but the range of altitudes at
> which birds may be found is far greater than most people suspect. I have
> seen them >14,000 msl over the lower 48, and that is no record.


As a side note on this, I'm pretty sure I once heard in a lecture or
presentation -- no!, it was in a wonderful quasi-documentary movie about
birds; was the title perhaps something like "Flight"? -- which described
one species of fairly small birds that migrate annually by taking off
from near or at sea level and flying over the Himalayas to a destination
far to the north, reaching altitudes higher than the top of Everest en
route -- and doing it nonstop.

Hope I don't have the details too far wrong here -- but if it stimulates
someone to dig out the movie itself, you may find it worth my possibly
erroneous memories.

They don't. They turn them on during descent because otherwise they would
still be cold enough to be fragile even after getting down into warmer air.


>
> Why do they run them at altitudes that birds don't fly?
>
> > If Mythbusters had cooled that side window to -50C, it would have
> > disintegrated when the bullet hit it.
>
>
>

>>
As a side note on this, I'm pretty sure I once heard in a lecture or
presentation -- no!, it was in a wonderful quasi-documentary movie about
birds; was the title perhaps something like "Flight"? --
<<

"Winged Migration". Excellent movie, every pilot should see it. Twice.

Jose

--
(for Email, make the obvious changes in my address)

On Sun, 11 Jul 2004 19:55:36 -0400, MichaelR wrote:

> They don't. They turn them on during descent because otherwise they would
> still be cold enough to be fragile even after getting down into warmer air.

My company's procedure for the 737 is to turn on the window heat a
minimum of ten minutes prior to takeoff and leave it on until parked at
the arrival gate. The window heat can be left all day long if desired.

-Jack Davis
B737


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>"Jack" wrote in message > Do you have other information?

Yes, but I am prohibited by TSA law from disclosing any more.

D.

Few notes -

Some years ago I hit a red-tail hawk on the left windscreen of a 707
at 16,000 ft climbing out of Houston. Made a mess - no damage. If we
lost windshield heat, our limitation was 250 kts below 14,0000 ft.
Guess that bird didn't know he shouldn't fly that high.

Also some years ago, I saw a Gulfstream that belonged to a Middle
East head of state at a US repair facility with a bullet hole that
entered in the belly and went out the top. They flew it normally all
the way to the States The Gulfstream carries a higher pressure
differential than any airliner I know of with an 8,000 ft cabin at
51,000 ft. and usually cruises about M .82 on long flights.

Aircraft pressurization is controlled by how much air gets let out by
the outflow valve/s. With a small hole or two, the outflow valve/s
would automatically close a bit and the aircraft would pressurize
normally anyway. If you do a ground pressure check on any aircraft,
they leak all over the place anyway. In flight it would just whistle
a bit louder and that's all.

Forget the pressure vessel as far as I'm concerned. What about those
rather large wire bundles being fed by a couple of 120 KvA generators?
Ask Swiss air. How about the primary control system, hydraulic
systems, or 20,000 gal of fuel? Fuel; ask TWA/ American. What would
happen if that 9 mm went through the fly-by-wire boxes on a B-777 or
Airbus? Don't know that one yet, but I hope we never find out.

Myself, I'd be just as happy if they'd leave the cockpit door locked
and used the crash axe if necessary. Besides, I know some of those
guys that fly those things and there are a few I wouldn't want to see
with a gun!!!

"Don Hammer" > wrote in message
...

> Myself, I'd be just as happy if they'd leave the cockpit door locked
> and used the crash axe if necessary. Besides, I know some of those
> guys that fly those things and there are a few I wouldn't want to see
> with a gun!!!
>
Would you fly with them?

"Don Hammer" > wrote in message

>... Besides, I know some of those
> guys that fly those things and there are a few I wouldn't want to see
> with a gun!!!

Amen to that, Don.

"John Gaquin" > wrote in message
...
>
> "Don Hammer" > wrote in message
>
> >... Besides, I know some of those
> > guys that fly those things and there are a few I wouldn't want to see
> > with a gun!!!
>
> Amen to that, Don.
>
And this proves...what?

"Tom Sixkiller" > wrote in message news:KOeJc.45
> > >... Besides, I know some of those
> > > guys that fly those things and there are a few I wouldn't want to see
> > > with a gun!!!
> >
> > Amen to that, Don.
> >
> And this proves...what?

It proves nothing, Tom. I was merely concurring in Don's opinion. If you
need any further clarification, just ask.

>I know some of those
> guys that fly those things and there are a few I wouldn't want to see
> with a gun!!!
>
Instead of an airpane?