Bad Week for Airbus

On Nov 26, 11:31 pm, Stefan wrote:
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.

Going from a short exposure of low pressure to a longer period of
exposure to a higher presure will have no effect on soluble gases in
the bloos stream.
The only time that becomes a factor is if the subject has been SCUBA
diving and using decompression time.


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.

The pressure at 100 feet (to use your figures) is approx 4 atmospheres
= 56 psi
The barometric pressure at sea level is 14.7 psi.
A change of pressure of 44 psi. or about 4048 mb

Decompression at altitude is covered in the Regs that specify the
longest permitted time before descent has to be initiated.

The pressure difference between Fl30 and Fl10 is about 30 mb.

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.

The Diamond height is yet to come eh :-)