hi alt oxygen

Im just wondering why pure oxygen is used for high altitude flying
instead of regular air. I thought prolonged exposures to breathing
pure oxygen can be harmfull as you can become oxygen dependant.

"Arquebus257WeaMag" wrote in message
m...
Im just wondering why pure oxygen is used for high altitude flying
instead of regular air. I thought prolonged exposures to breathing
pure oxygen can be harmfull as you can become oxygen dependant.

http://www.batnet.com/mfwright/hypoxia.html
Hypoxia

Hypoxia is a state of oxygen deficiency in the body which is sufficient to
cause an impairment of function. Hypoxia is caused by the reduction in
partial pressure of oxygen, inadequate oxygen transport, or the inability of
the tissues to use oxygen.

In brief, being drunk is kind of the same as being exposed to high altitude.
In both cases, oxygen to your brain and muscles is reduced.

Tarver Engineering wrote:

In brief, being drunk is kind of the same as being exposed to high altitude.
In both cases, oxygen to your brain and muscles is reduced.

Even briefer, being Tarver illustrates the results of chronic hypoxia.

Rick

"Rick" wrote in message
hlink.net...
Tarver Engineering wrote:

In brief, being drunk is kind of the same as being exposed to high
altitude.
In both cases, oxygen to your brain and muscles is reduced.

Even briefer, being Tarver illustrates the results of chronic hypoxia.

"Rick" wrote in message
link.net...

Ah, memories come back ... in my old freight dog days I used to fly with
an older guy who hated to waste fuel on pressurization while crossing
the Rockies in Montana. His only complaint was that he had a hard time
keeping his cigarettes lit when the MEA's were in the flight levels.

chronic hypoxia

Bwahahahahahahahaha

Subject: hi alt oxygen
From: "Tarver Engineering"
Date: 3/11/04 8:32 AM Pacific Standard Time
Message-id:


"Rick" wrote in message
thlink.net...
Tarver Engineering wrote:

In brief, being drunk is kind of the same as being exposed to high
altitude.
In both cases, oxygen to your brain and muscles is reduced.

Even briefer, being Tarver illustrates the results of chronic hypoxia.

"Rick" wrote in message
hlink.net...

Ah, memories come back ... in my old freight dog days I used to fly with
an older guy who hated to waste fuel on pressurization while crossing
the Rockies in Montana. His only complaint was that he had a hard time
keeping his cigarettes lit when the MEA's were in the flight levels.

chronic hypoxia

Bwahahahahahahahaha


Actually you are right. Oxygen drunks were not uncommon (hic)



Arthur Kramer
344th BG 494th BS
England, France, Belgium, Holland, Germany
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer

"ArtKramr" wrote in message
...
Subject: hi alt oxygen
From: "Tarver Engineering"
Date: 3/11/04 8:32 AM Pacific Standard Time
Message-id:


"Rick" wrote in message
thlink.net...
Tarver Engineering wrote:

In brief, being drunk is kind of the same as being exposed to high
altitude.
In both cases, oxygen to your brain and muscles is reduced.

Even briefer, being Tarver illustrates the results of chronic hypoxia.

"Rick" wrote in message
hlink.net...

Ah, memories come back ... in my old freight dog days I used to fly
with
an older guy who hated to waste fuel on pressurization while crossing
the Rockies in Montana. His only complaint was that he had a hard time
keeping his cigarettes lit when the MEA's were in the flight levels.

chronic hypoxia

Bwahahahahahahahaha


Actually you are right. Oxygen drunks were not uncommon (hic)

I knew a few of those.

You live off off something called the "partial pressure of oxygen" in the
medium you are breathing. As altitude increases, the partial pressure of
oxygen in air decreases. Therefore, you must "enrich" the breathing medium
with more oxygen in order to achieve the *same* partial pressure of oxygen
that exists at lower altitudes.

Two solutions: 1) increase the relative percentage of oxygen inht e
medium, or 2) pressurize hte medium. 1) is much less expensive than 2).

Steve Swartz

(The partial pressure of oxygen is what gets the O2 across your lung tissue
into your bloodstream. As total pressure decreases, the partial pressure of
oxygen decreases. Eventually, as ambient pressure goes down, you would need
to breathe pure *pressurized* [3.2 psi IIRC] oxygen in order to make up the
deficit.)

"Arquebus257WeaMag" wrote in message
m...
Im just wondering why pure oxygen is used for high altitude flying
instead of regular air. I thought prolonged exposures to breathing
pure oxygen can be harmfull as you can become oxygen dependant.

Thank you for the information. Very interesting!

On Wed, 10 Mar 2004 11:46:52 -0500, "Leslie Swartz"
wrote:

You live off off something called the "partial pressure of oxygen" in the
medium you are breathing. As altitude increases, the partial pressure of
oxygen in air decreases. Therefore, you must "enrich" the breathing medium
with more oxygen in order to achieve the *same* partial pressure of oxygen
that exists at lower altitudes.

Two solutions: 1) increase the relative percentage of oxygen inht e
medium, or 2) pressurize hte medium. 1) is much less expensive than 2).

Steve Swartz

(The partial pressure of oxygen is what gets the O2 across your lung tissue
into your bloodstream. As total pressure decreases, the partial pressure of
oxygen decreases. Eventually, as ambient pressure goes down, you would need
to breathe pure *pressurized* [3.2 psi IIRC] oxygen in order to make up the
deficit.)

"Arquebus257WeaMag" wrote in message
om...
Im just wondering why pure oxygen is used for high altitude flying
instead of regular air. I thought prolonged exposures to breathing
pure oxygen can be harmfull as you can become oxygen dependant.


all the best -- Dan Ford
email: (requires authentication)

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

Here's some quick and dirty info on oxygen - normally about 1/5 of
'air'. So the 'partial pressure' is 1/5 of 29.92 inches/760 mm Hg
equalling 152mm O2. The ambient air pressure drops by 1/2 every 18,000
feet (roughly). So at sea level you get 1/5 of 760mm; at 18,000 you
get 1/5 of 380mm. At about 34000 you get the equivalent of sea level
oxygen partial pressure breathing 100% oxygen. If you keep going on up
pretty soon you reach a dangerously low level of partial pressure -
that's at about 41,000. So modern diluter-demand O2 regulators start
feeding you oxygen under pressure. Easy to inhale - you have to work
to exhale. This gets worse as you keep going up. At 50,000 cabin
pressure it is physically demanding to exhale and the mask has to be
very tightly strapped on your face. Not to mention painful. Note that
so far we don't have any 'cabin pressure' - air bled from the
engine(s) to remedy the situation. Also as you keep climbing into
areas of lesser pressure water boils at progrssively lower
temperatures. At 63,000 ambient pressure water boils at 98.6F/37C -
body temp. That means your lungs are now filled with water vapor and
you can no longer absorb oxygen. Hence pressure cabins and pressure
suits over 50,000 feet. Breathing pure oxygen for extended periods of
time is a hassle. First, there is no water in Aviator's oxygen - can't
take the chance of water freezing in the lines. Therefore every breath
you're becoming more and more dehydrated. Second, oxygen can flood the
inner ears (through the eustachian tubes) and late at night in bed
that oxygen gets absorbed by the blood and you wake up with giant
earaches. Third, if you're breathing pure O2 and pulling lots of G -
the lower airsacs in your lungs tend to stick together because with
pure O2 you're not breathing as deeply. Back on the ground when you
take a deep breath it feels as if someone just knifed you. This is
termed 'atelactasis'.
Now, oxygen is used to keep pilots crew and passengers functioning at
more or less an efficient level. Rule of thumb - O2 over 10,000 feet.
There is a 'cheat' where one can got to 12 for 30 minutes. But the
brain needs O2 to function properly. With hard training one can
function adequately at higher altitudes. But even the best can screw
up - read 'Into Thin Air'. FWIW I used to teach this stuff.
Walt BJ

Subject: hi alt oxygen
From: (WaltBJ)
Date: 3/10/04 9:12 PM Pacific Standard Time
Message-id:

Here's some quick and dirty info on oxygen - normally about 1/5 of
'air'. So the 'partial pressure' is 1/5 of 29.92 inches/760 mm Hg
equalling 152mm O2. The ambient air pressure drops by 1/2 every 18,000
feet (roughly). So at sea level you get 1/5 of 760mm; at 18,000 you
get 1/5 of 380mm. At about 34000 you get the equivalent of sea level
oxygen partial pressure breathing 100% oxygen. If you keep going on up
pretty soon you reach a dangerously low level of partial pressure -
that's at about 41,000. So modern diluter-demand O2 regulators start
feeding you oxygen under pressure. Easy to inhale - you have to work
to exhale. This gets worse as you keep going up. At 50,000 cabin
pressure it is physically demanding to exhale and the mask has to be
very tightly strapped on your face. Not to mention painful. Note that
so far we don't have any 'cabin pressure' - air bled from the
engine(s) to remedy the situation. Also as you keep climbing into
areas of lesser pressure water boils at progrssively lower
temperatures. At 63,000 ambient pressure water boils at 98.6F/37C -
body temp. That means your lungs are now filled with water vapor and
you can no longer absorb oxygen. Hence pressure cabins and pressure
suits over 50,000 feet. Breathing pure oxygen for extended periods of
time is a hassle. First, there is no water in Aviator's oxygen - can't
take the chance of water freezing in the lines. Therefore every breath
you're becoming more and more dehydrated. Second, oxygen can flood the
inner ears (through the eustachian tubes) and late at night in bed
that oxygen gets absorbed by the blood and you wake up with giant
earaches. Third, if you're breathing pure O2 and pulling lots of G -
the lower airsacs in your lungs tend to stick together because with
pure O2 you're not breathing as deeply. Back on the ground when you
take a deep breath it feels as if someone just knifed you. This is
termed 'atelactasis'.
Now, oxygen is used to keep pilots crew and passengers functioning at
more or less an efficient level. Rule of thumb - O2 over 10,000 feet.
There is a 'cheat' where one can got to 12 for 30 minutes. But the
brain needs O2 to function properly. With hard training one can
function adequately at higher altitudes. But even the best can screw
up - read 'Into Thin Air'. FWIW I used to teach this stuff.
Walt BJ


I was just glad to get rid of the high pressure system with the spitbag to the
low pressure demand mask. It doesn't take much to make me happy.


Arthur Kramer
344th BG 494th BS
England, France, Belgium, Holland, Germany
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer