Bad Week for Airbus

On Nov 26, 12:54 pm, Stefan wrote:
george schrieb:

Okay.
The aircraft has an explosive decompression event at 35,000 feet.
The crew immediately initiate a high speed descent to 12.000 feet
And all in about 3 minutes.

That 23,000 feet pressure difference is less than sea level to the 30
feet underwater level.
A diver can spent 30 minutes at 30 feet with no decompression
required.

Yo have no idea. You better inform yourself before bashing others.

Okay.
Point out to me where I am wrong...
and where I 'have no idea'
FYI the barometric pressure at 30,000 is somewhere about 300 mb and at
10,000 around 600mb.
Thats a pressure differentiation of 300mb which isn't going to do
anything but pop your ears!

Mxsmanic wrote in
:

Phil writes:

Actually the flight attendant says it in every pre-flight emergency
briefing. You are right that it is a simple concept, and I don't know
anyone who is too stupid to understand it.

Then why do flight attendants point it out on every flight?

Perhaps the airlines have considered the possibility that not every
passenger on every flight has researched this as much as you have. I
believe it reasonable to presume that not all passengers on all flights fly
frequently enough to remember this minute detail of aircraft emergency
procedures, and as such require a reminder during the emergency briefing.
This holds especially true for those people who have never flown before. I
further believe that unlike some of the pre-flight announcements, this
announcement is made in an effort to be thorough, prudent, and even
intentionally repetitve for the sake of parents who might otherwise
instinctively react differently what this instruction suggests.

A lack of knowledge or recall is not the same as a lack of intelligence or
aptitude. For example, the fact that you don't know or understand the
instinctive reaction that might cause a mother or father to attempt to put
his child's life before his own does not make you stupid.

It certainly makes you ignorant.

Andrew Gideon wrote in news:fid82v$rr9$1
@taco.int.tagonline.com:

On Sun, 25 Nov 2007 02:58:09 +0000, Judah wrote:

Now SEATBELTS they explain because they think people are stupid...

No. They explain seatbelts after the plane's already started to
move...which means that everyone is already belted.

It's not the passengers' stupidity that's at issue, I fear.

- Andrew

I'm still trying to find the exact definition of a "Water Landing". I have
yet to be on an airliner with floats...

Judah wrote:
Mxsmanic wrote in
:

Phil writes:

Actually the flight attendant says it in every pre-flight emergency
briefing. You are right that it is a simple concept, and I don't know
anyone who is too stupid to understand it.

Then why do flight attendants point it out on every flight?

Perhaps the airlines have considered the possibility that not every
passenger on every flight has researched this as much as you have. I
believe it reasonable to presume that not all passengers on all flights fly
frequently enough to remember this minute detail of aircraft emergency
procedures, and as such require a reminder during the emergency briefing.
This holds especially true for those people who have never flown before. I
further believe that unlike some of the pre-flight announcements, this
announcement is made in an effort to be thorough, prudent, and even
intentionally repetitve for the sake of parents who might otherwise
instinctively react differently what this instruction suggests.

Or perhaps they do it because it is required by the FAR's.


--
Jim Pennino

Remove .spam.sux to reply.

george wrote:
You're wrong. It can happen in any decompression situation, if the
decompression is severe enough. Like e.g. in a pressurized airplane
at very high altitude which instantly looses its pressurisation.

Okay.
The aircraft has an explosive decompression event at 35,000 feet.
The crew immediately initiate a high speed descent to 12.000 feet
And all in about 3 minutes.

That 23,000 feet pressure difference is less than sea level to the 30
feet underwater level.
A diver can spent 30 minutes at 30 feet with no decompression
required.
In other words he can return from 28-30 psi to 14.7 psi (or 1
atmosphere) without harm in around 2 minutes

I would expect that it is not the addititve difference but the
multiplicative quotient in pressure, that dictates whether nitrogen might
resolve from the blood (resp. potential bubbles). Although I'm not a medical
expert, I do remember that diving in lakes at higher altitudes requires much
more adjustment of allowable ground times than a difference of e.g. 200mbar
at 6000ft would warrant.

Going from a cabin pressure of 800mbar/12psi to an ambient pressure at
36000ft of 250mbar/4psi represents a reduction in pressure of factor 3, more
like a return from 60ft underwater to the surface, which certainly can
create harm, if too much time was spent at depth. Mind you, the people
aboard a plane have spent much more than 30 Minutes at the higher pressure,
probably all of their life so far.

regards,
Friedrich

Morgans wrote:
"Stefan" wrote

And again you're wrong. You may or may not like him, but sometimes
even he is correct.

Even a stopped clock (12 hour type) is right twice a day. That
doesn't make him any more useful.

true. But why deny that it actually IS 12 o'clock (if it is), just because
this stopped clock happens to be stopped at 12 o'clock?

regards,
Friedrich

wrote in :

Judah wrote:
Mxsmanic wrote in
:

Phil writes:

Actually the flight attendant says it in every pre-flight emergency
briefing. You are right that it is a simple concept, and I don't
know anyone who is too stupid to understand it.

Then why do flight attendants point it out on every flight?

Perhaps the airlines have considered the possibility that not every
passenger on every flight has researched this as much as you have. I
believe it reasonable to presume that not all passengers on all flights
fly frequently enough to remember this minute detail of aircraft
emergency procedures, and as such require a reminder during the
emergency briefing. This holds especially true for those people who
have never flown before. I further believe that unlike some of the
pre-flight announcements, this announcement is made in an effort to be
thorough, prudent, and even intentionally repetitve for the sake of
parents who might otherwise instinctively react differently what this
instruction suggests.

Or perhaps they do it because it is required by the FAR's.

Technically, that's true. But what is the basis for putting it in the FARs?

If you've ever flown JetBlue or Song, where they generally mock the
seatbelt briefing, and even the "water landing" part, they generally don't
leave out this important tidbit or even joke about of it...

Perhaps this is one of those few portion of the FARs that people actually
think makes sense...

Judah wrote in
:

If you've ever flown JetBlue or Song, where they generally mock the
seatbelt briefing, and even the "water landing" part, they generally
don't leave out this important tidbit or even joke about of it...

Perhaps this is one of those few portion of the FARs that people
actually think makes sense...


Did you ever fly People's Express? They mocked everything in the
announcements. People actually listened to them if for no other reason
than to hear the jokes. They probably had a higher percentage of
passengers, even frequent flyers, listen to the entire announcement than
anyone else did.

--
Marty Shapiro
Silicon Rallye Inc.

(remove SPAMNOT to email me)

george schrieb:

Point out to me where I am wrong...

Your mistake is, that the quantity of gas which can be solved in water
is proportional to pressure. So you mustn't think in absolute
quantities, but in relative.

Example: At flightlevel 360 (give or take a few) the atmospheric
pressure has dropped to roughly a quarter. So, solutionwise, climbing
from sea level to FL360 has roughly the same effect as a diver which
climbs from a water depth of 100ft to the surface (at sea level). Now if
you're saturated at 100ft (and we are saturated!), and then suddenly go
up to the surface, you *will* encounter serious decompression disease. I
would expect the same in a sudden pressure loss at FL360.

Of course the two situations are not exactly the same, because in
aviation there is a much smaller quantity of gas involved. (Besides that
the cabin pressure is usually not equal to sea level but to something
like 7000ft.) I would expect some air forces to have seriously studied
this, and plenty of literature to be available, because the climb rate
of fighter jets allow for such critical pressure changes. But frankly, I
don't know anything about it, except that your reasoning was wrong. But
then, at the climb rate my glider gives me, I guess that I needn't to
worry anyway, even in strong wave.

If you think of the preflight briefing as a checklist, the reasons for
including even obvious points becomes more clear. Pilots use
checklists all of the time, to help assure themselves that, for
example, the wheels are down when they should be. Does that use of
checklists make them stupid, or careful? Why mock their use when they
are used to remind people what to do in circumstances that occur less
frequently than the need to extend the gear, or retract it?


On Nov 25, 11:22 pm, Judah wrote:
Mxsmanic wrote :

Phil writes:

Actually the flight attendant says it in every pre-flight emergency
briefing. You are right that it is a simple concept, and I don't know
anyone who is too stupid to understand it.

Then why do flight attendants point it out on every flight?

Perhaps the airlines have considered the possibility that not every
passenger on every flight has researched this as much as you have. I
believe it reasonable to presume that not all passengers on all flights fly
frequently enough to remember this minute detail of aircraft emergency
procedures, and as such require a reminder during the emergency briefing.
This holds especially true for those people who have never flown before. I
further believe that unlike some of the pre-flight announcements, this
announcement is made in an effort to be thorough, prudent, and even
intentionally repetitve for the sake of parents who might otherwise
instinctively react differently what this instruction suggests.

A lack of knowledge or recall is not the same as a lack of intelligence or
aptitude. For example, the fact that you don't know or understand the
instinctive reaction that might cause a mother or father to attempt to put
his child's life before his own does not make you stupid.

It certainly makes you ignorant.