Effect on aeroplane of sudden depressurisation

[Guy Lux]

Often in films, when a plane flying at high altitude has its window
shot out, it seems to experience major turbulence and/or seem to dive
before it is stabilised.

I can't understand why a load of air rushing out of the pressurised
cabin would do this in *real* situations, does it actually happen?

Any explanations?

Guy

[Orval Fairbairn]

In article >,
(Guy Lux) wrote:

> Often in films, when a plane flying at high altitude has its window
> shot out, it seems to experience major turbulence and/or seem to dive
> before it is stabilised.
>
> I can't understand why a load of air rushing out of the pressurised
> cabin would do this in *real* situations, does it actually happen?
>
> Any explanations?
>
> Guy

Explanation: Hollywood drama.

The inside might fog up, due to the sudden cooling of the air, but it
should not affect the flight characteristics of the plane.

[Gene Seibel]

The pilot will dive to bring the plane down to an altitude where
passengers can breathe without oxygen. But in a real situation there
should be no loss of control or severe turbulence.
--
Gene Seibel
Hangar 131 - http://pad39a.com/gene/plane.html
Because I fly, I envy no one.




(Guy Lux) wrote in message >...
> Often in films, when a plane flying at high altitude has its window
> shot out, it seems to experience major turbulence and/or seem to dive
> before it is stabilised.
>
> I can't understand why a load of air rushing out of the pressurised
> cabin would do this in *real* situations, does it actually happen?
>
> Any explanations?
>
> Guy

[Dick Cheney]

Orval Fairbairn wrote:
> In article >,
> (Guy Lux) wrote:
>
>
>>Often in films, when a plane flying at high altitude has its window
>>shot out, it seems to experience major turbulence and/or seem to dive
>>before it is stabilised.
>>
>>I can't understand why a load of air rushing out of the pressurised
>>cabin would do this in *real* situations, does it actually happen?
>>
>>Any explanations?
>>
>>Guy
>
>
> Explanation: Hollywood drama.
>
> The inside might fog up, due to the sudden cooling of the air, but it
> should not affect the flight characteristics of the plane.

True, although the pilot *should* dive the plane deliberately as fast as
is safe in order to get down to a more breathable altitude. But you're
right: whenever something goes drastically wrong in a Hollywood plane
(such as the pilot taking his hands off the controls) the plane *must*
go into a death dive and (regardless of type) make that Stuka noise.

[Troy Towner]

In real life, the pressure in will stay constant, the pressure out will stay
very close to constant. There are valves called the outflow valve which is
basically a flute like on a Chimney. There are usually 2 on large transport
category aircraft. The Out flow valve open when there is too much pressure
in the fuselage, and closes to allow the air pressure to build up. So like a
gun shot through the thin skin... wont do anything....a few guns shot? ehh
maybe a noticeable difference, but there is always the airmasks. As long as
the roof don't rip off like the Aloha airlines B737-297.... you'll probably
be ok

anyway hope it helps

Troy


"Guy Lux" > wrote in message
om...
> Often in films, when a plane flying at high altitude has its window
> shot out, it seems to experience major turbulence and/or seem to dive
> before it is stabilised.
>
> I can't understand why a load of air rushing out of the pressurised
> cabin would do this in *real* situations, does it actually happen?
>
> Any explanations?
>
> Guy

[Guy Lux]

Orval Fairbairn > wrote in message >...
> In article >,
> (Guy Lux) wrote:
>
> > Often in films, when a plane flying at high altitude has its window
> > shot out, it seems to experience major turbulence and/or seem to dive
> > before it is stabilised.
> >
> > I can't understand why a load of air rushing out of the pressurised
> > cabin would do this in *real* situations, does it actually happen?
> >
> > Any explanations?
> >
> > Guy
>
> Explanation: Hollywood drama.
>
> The inside might fog up, due to the sudden cooling of the air, but it
> should not affect the flight characteristics of the plane.

Perfect Orval, all I needed to know. Thanks

Guy

[R.Hubbell]

On 5 Feb 2004 06:39:32 -0800 (Guy Lux) wrote:

> Often in films, when a plane flying at high altitude has its window
> shot out, it seems to experience major turbulence and/or seem to dive
> before it is stabilised.
>
> I can't understand why a load of air rushing out of the pressurised
> cabin would do this in *real* situations, does it actually happen?
>
> Any explanations?


It's Hollywood! I heard that mythbusters tried to recreate a similar scenario.
But from all accounts they fell way short in setting up the experiment to mimic
real conditions at FL350.

R. Hubbell
>
> Guy

[Steven Polczynski]

Hi People

I am an A&P student and read what was posted on the de-pressurization
question. You guys did well in answering Guy's question.

Orval: said that it might fog up. Well, If your talking about a slow
decompression no it won't but if it is a sudden decompression it will fog up
and there will be an immediate drop in temperature. And it if the plane is
high enough it can kill instantly. Auto pilot will not necessarily do
anything. ex. last year a Learjet crashed after it ran out of fuel. the
pressure release valve failed suddenly and the windows fooged over and the
crew died. the auto pilot kept the plane on course until it ran out of fuel
and crashed. No big chunks of fuselage suddenly ripped from the plane.

tony: I single gunshot can cause major damage or not depending on where it
penetrated the fuselage. If it goes through a window (depending on caliber)
it can make a small hole and eventually get worse or it can blow out the
whole windoe and cause major damage. unless there is major structural
damage that maintenance doesn't know about it still would not cause a gaping
7 foot hole. It might create a hole that would get worse at 700 MPH and it
would also decompress the cabin and fog up. the passengers next to the hole
would most likely die instantly. the masks would release but not everyone
would be alive to use them.

Obviously since I am not a Professional but merely a student in AMT school I
would not take my word as gospel. But I have gone through some classes that
covered such subjects. The learjet mentioned earlier was talked about in
class.

thanks

hope I didn't offend anyone
"Guy Lux" > wrote in message
om...
> Often in films, when a plane flying at high altitude has its window
> shot out, it seems to experience major turbulence and/or seem to dive
> before it is stabilised.
>
> I can't understand why a load of air rushing out of the pressurised
> cabin would do this in *real* situations, does it actually happen?
>
> Any explanations?
>
> Guy

[Michael Houghton]

Howdy!

In article <fXTUb.39070$L_4.14247@okepread01>,
Steven Polczynski > wrote:
>Hi People
>
>I am an A&P student and read what was posted on the de-pressurization
>question. You guys did well in answering Guy's question.
>
>Orval: said that it might fog up. Well, If your talking about a slow
>decompression no it won't but if it is a sudden decompression it will fog up
>and there will be an immediate drop in temperature. And it if the plane is
>high enough it can kill instantly. Auto pilot will not necessarily do
>anything. ex. last year a Learjet crashed after it ran out of fuel. the
>pressure release valve failed suddenly and the windows fooged over and the
>crew died. the auto pilot kept the plane on course until it ran out of fuel
>and crashed. No big chunks of fuselage suddenly ripped from the plane.
>
Ummm...not quite.

In fact, not close.

Instant death won't happen. Rapid incapacitation followed by death can
occur, but it takes some time. In the Payne Stewart incident (that you
probably allude to), the NTSB was unable to determine why the aircraft
lost cabin pressurization. Neither were they able to explain why the
crew were incapacitated by that loss of pressurization. The apparent
icing on the cockpit windows suggests a loss of bleed air (input) as
opposed to a "big leak". No evidence could be found to support any
specific conclusion about why the cabin lost pressure, nor any to permit
any inference about the rate of depressurization.

I recommend http://www.ntsb.gov/Publictn/2000/AAB0001.pdf highly.

yours,
Michael


--
Michael and MJ Houghton | Herveus d'Ormonde and Megan O'Donnelly
| White Wolf and the Phoenix
Bowie, MD, USA | Tablet and Inkle bands, and other stuff
| http://www.radix.net/~herveus/

[Tarver Engineering]

"Michael Houghton" > wrote in message
...
> Howdy!
>
> In article <fXTUb.39070$L_4.14247@okepread01>,
> Steven Polczynski > wrote:
> >Hi People
> >
> >I am an A&P student and read what was posted on the de-pressurization
> >question. You guys did well in answering Guy's question.
> >
> >Orval: said that it might fog up. Well, If your talking about a slow
> >decompression no it won't but if it is a sudden decompression it will fog
up
> >and there will be an immediate drop in temperature. And it if the plane
is
> >high enough it can kill instantly. Auto pilot will not necessarily do
> >anything. ex. last year a Learjet crashed after it ran out of fuel.
the
> >pressure release valve failed suddenly and the windows fooged over and
the
> >crew died. the auto pilot kept the plane on course until it ran out of
fuel
> >and crashed. No big chunks of fuselage suddenly ripped from the plane.
> >
> Ummm...not quite.
>
> In fact, not close.
>
> Instant death won't happen. Rapid incapacitation followed by death can
> occur, but it takes some time. In the Payne Stewart incident (that you
> probably allude to), the NTSB was unable to determine why the aircraft
> lost cabin pressurization. Neither were they able to explain why the
> crew were incapacitated by that loss of pressurization. The apparent
> icing on the cockpit windows suggests a loss of bleed air (input) as
> opposed to a "big leak". No evidence could be found to support any
> specific conclusion about why the cabin lost pressure, nor any to permit
> any inference about the rate of depressurization.

That conclusion is silly, considering the maintenance on the Lear done
before the flight.


> I recommend http://www.ntsb.gov/Publictn/2000/AAB0001.pdf highly.