O2 and Cypriot airliner crash

Brien K. Meehan opined

The "partial pressure of O2" has nothing to do with it.

Your premise is wrong. Loss of cabin pressure IS what incapacitates
pilots. The lungs need atmospheric pressure to exchange gasses with
hemoglobin in the alveoli. It doesn't matter what gas it is - without
the pressure, respiration stops happening. As altitude increases and
pressure decreases, respiration becomes less effective. Below a
certain pressure, you can suffocate on 100% oxygen.

Seems to me that astronauts use 3psi of pure O2 during EVAs.


-ash
Cthulhu in 2005!
Why wait for nature?

Ash Wyllie wrote:

Seems to me that astronauts use 3psi of pure O2 during EVAs.


-ash
Cthulhu in 2005!
Why wait for nature?


Correct and 3psi of pure O2 is about the same as the ppO2 in Air at Sea
Level.
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Scott F. Migaldi
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N8116B

PADI MI-150972
Join the PADI Instructor Yahoo Group
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In article .com,
wrote:

In accounts of the crash of the Cypriot airliner in Greece, all I've
read say that loss of cabin pressure could not, by itself, incapacitate
the pilot. Yet, I was once told by an ATP that at 40k feet (admittedly
this plane was at 35k) O2 supply by itself will not suffice to keep you
conscious and that the drop down masks only give a false sense of
security. He said that the ambient pressure is so low that even 100% O2
does not provide enough to keep you conscious without a pressure
breathing mask.

I personally know glider pilots here in New Zealand who have flown to
betweeen 35,000 and 37,000 ft with only an ordinary oxygen mask, not a
pressure system.

The glider world record of 49,000 ft used a pressure system.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

"Bruce Hoult" wrote in message news:bruce-566936.
wrote:

In accounts of the crash of the Cypriot airliner in Greece, all I've
read say that loss of cabin pressure could not, by itself, incapacitate
the pilot. Yet, I was once told by an ATP that at 40k feet (admittedly
this plane was at 35k) O2 supply by itself will not suffice to keep you
conscious and that the drop down masks only give a false sense of
security. He said that the ambient pressure is so low that even 100% O2
does not provide enough to keep you conscious without a pressure
breathing mask.

I personally know glider pilots here in New Zealand who have flown to
betweeen 35,000 and 37,000 ft with only an ordinary oxygen mask, not a
pressure system.

It's OK at 34,000 ft and above 38,000 ft. And all other altitudes,
partialy. You were asleep or missed this class, right?

moo

Tlme of useful
consciousness
Altitude (ft) without oxygen

40,000 15 seconds
35.000 20 seconds
30,000 30 seconds
28,000 1 minute


How, then, can someone like Ed Viesturs repeatedly climb the tallest
mountain peaks in the world without supplemental oxygen? Is it because of
the slower ascent and the time spent acclimating to the higher altitudes?

John K.

John Kirksey wrote:

How, then, can someone like Ed Viesturs repeatedly climb the tallest
mountain peaks in the world without supplemental oxygen? Is it because of
the slower ascent and the time spent acclimating to the higher altitudes?

First, acclimatisation.

Second, walking (and climbing) is different from flying. You don't need
much brain to walk. When piloting, however, everything is about
thinking. And it's the brain which needs the most oxygen.

And maybe a third reason: There are exceptional people who are just
better suited for such things than you and me.

Stefan

Partially because he is acclimated and partly because he is Ed Visteurs.

Mike
MU-2


"John Kirksey" wrote in message
news:cZ0Me.4596$H_4.4209@trnddc07...
Tlme of useful
consciousness
Altitude (ft) without oxygen

40,000 15 seconds
35.000 20 seconds
30,000 30 seconds
28,000 1 minute


How, then, can someone like Ed Viesturs repeatedly climb the tallest
mountain peaks in the world without supplemental oxygen? Is it because of
the slower ascent and the time spent acclimating to the higher altitudes?

John K.

"John Kirksey" wrote in message
news:cZ0Me.4596$H_4.4209@trnddc07...
Tlme of useful
consciousness
Altitude (ft) without oxygen

40,000 15 seconds
35.000 20 seconds
30,000 30 seconds
28,000 1 minute


How, then, can someone like Ed Viesturs repeatedly climb the tallest
mountain peaks in the world without supplemental oxygen? Is it because of
the slower ascent and the time spent acclimating to the higher altitudes?

That and by breathing like he's running a marathon. Sleep and you die.

mo

Happy Dog wrote:

That and by breathing like he's running a marathon. Sleep and you die.

This is just plain bull****. It's all about partial pressure.

Stefan

"Stefan" wrote in message
...
Happy Dog wrote:

That and by breathing like he's running a marathon. Sleep and you die.

This is just plain bull****. It's all about partial pressure.

Breathing technique is crucial to high altitude activity. The technique is
very similar to that used by joggers.

moo