O2 Mask On Pilot?

GeorgeB wrote:

What would have been the effect if the O2 bottle for the cockpit had
been inadvertently filled with breathing air rather than O2?

They would have tested the system before the flight and found it
working. They would have put on their mask in flight and thought it
worked, slowly fading away without recognizing it. You may or may not
recognize hypoxia when you suspect it and really watch your body, you
definitely don't recognize it when you're unwary.

Stefan

"Stefan" wrote in message
...
GeorgeB wrote:

What would have been the effect if the O2 bottle for the cockpit had
been inadvertently filled with breathing air rather than O2?

They would have tested the system before the flight and found it working.
They would have put on their mask in flight and thought it worked, slowly
fading away without recognizing it. You may or may not recognize hypoxia
when you suspect it and really watch your body, you definitely don't
recognize it when you're unwary.


The question was what happens when breathing air from the mask rather than
O2 and the answer is nothing at all at a cabin pressure of 10K feet.

fred wrote:

The question was what happens when breathing air from the mask rather than
O2 and the answer is nothing at all at a cabin pressure of 10K feet.

Got me :-). On the other hand, if the bottels were filled with say N2
instead of O2, they would still have faded away even at 10 kft. Further
speculations?

Stefan

"Stefan" wrote in message
...
fred wrote:

The question was what happens when breathing air from the mask rather
than O2 and the answer is nothing at all at a cabin pressure of 10K feet.

Got me :-). On the other hand, if the bottels were filled with say N2
instead of O2, they would still have faded away even at 10 kft. Further
speculations?

Yes and pure N2 is faster than air at 35,000.

On 2005-08-15, Dave S wrote:

I flew on an air ambulance Lear 25 for a while.. and I can say I NEVER
saw the cockpit crew remove the masks from the hangars and place them in
"the ready position" even though we routinely went to FL 450-490. I am

On our 25D the position of the hangers for the masks were considered in the
'ready' position, so you just made sure they were there. Believe it was a
5-sec operation (required time) to get them on your head, for the
quick-doning masks.

The old joke, before the quick-doning type masks, was that the Learjet
pilots always squeezed their noses before de-boarding to make it look like
they had been wearing their masks.

....Edwin
--
__________________________________________________ _____
"Once you have flown, you will walk the earth with your
eyes turned skyward, for there you have been, there you
long to return."-- da Vinci ... www.shreve.net/~elj

fred wrote:

The question was what happens when breathing air from the mask rather than
O2 and the answer is nothing at all at a cabin pressure of 10K feet.

But the question was asked about pilots that were at 35,000'. I believe that
George B. is correct that the partial pressure would be too low and the pilots
would pass out.

George Patterson
Give a person a fish and you feed him for a day; teach a person to
use the Internet and he won't bother you for weeks.

"GeorgeB" wrote in message
...

What would have been the effect if the O2 bottle for the cockpit had
been inadvertently filled with breathing air rather than O2?


From what would the oxygen system be serviced in your scenario? A
compressor?

On Thu, 18 Aug 2005 18:50:06 GMT, "Steven P. McNicoll"
wrote:


"GeorgeB" wrote in message
.. .

What would have been the effect if the O2 bottle for the cockpit had
been inadvertently filled with breathing air rather than O2?


From what would the oxygen system be serviced in your scenario? A
compressor?

I've far more experience with industrial compressed gasses than with
aircraft oxygen, and see much more "compressed breathing air" than
BREATHING compressed O2. (Oxygen for oxyacetelyne is to different
standards, but I think it is just as good; several college buddies
would spend some time breathing it after having too much to drink the
night before. Ah, the REAL hangover cure.

Firefighters and scuba divers use it in large quantiies. Bottles are
common with gas suppliers. What I don't know is how the fittings
compare.

Nor do I know how a plane's bottles are filled; via compressor from
low pressure sources, high pressure via cascade bottles, or ???

I do know that the fittings need to be clean of oxydizable materials;
storoes of a little oil on gauge threads, if true, keep one careful.

"GeorgeB" wrote in

I've far more experience with industrial compressed gasses than with
aircraft oxygen, and see much more "compressed breathing air" than
BREATHING compressed O2. (Oxygen for oxyacetelyne is to different
standards, but I think it is just as good;

Correct. It's just as good now.

moo

"GeorgeB" wrote in message
...

I've far more experience with industrial compressed gasses than with
aircraft oxygen, and see much more "compressed breathing air" than
BREATHING compressed O2. (Oxygen for oxyacetelyne is to different
standards, but I think it is just as good; several college buddies
would spend some time breathing it after having too much to drink the
night before. Ah, the REAL hangover cure.

Firefighters and scuba divers use it in large quantiies. Bottles are
common with gas suppliers. What I don't know is how the fittings
compare.

Nor do I know how a plane's bottles are filled; via compressor from
low pressure sources, high pressure via cascade bottles, or ???

I do know that the fittings need to be clean of oxydizable materials;
storoes of a little oil on gauge threads, if true, keep one careful.


In a previous life I was in aircraft maintenance. Aviator's breathing
oxygen systems were serviced from just two sources; compressed oxygen
bottles or liquid oxygen carts. The only other compressed gas bottle used
for servicing aircraft was nitrogen. I don't recall what measures were
taken to prevent servicing oxygen systems with nitrogen, other than colors
and markings on the bottles, but servicing oxygen systems with nitrogen
would be a very bad thing.