O2 and Cypriot airliner crash

George Patterson wrote:
No. 12,500' if you exceed it for 30 minutes or 14,000' if you go over
that at all. At 15,000', passengers also have to be on oxygen. Section
91.211.

actually the passengers must be *provided* with oxygen; notice
the different wording between 91.211(a)(2) and 91.211(a)(3);
i.e., your passengers do not have to be *on* oxygen (makes
for much quieter passengers, and saves on o2 refills :-)))

--Sylvain

Happy Dog wrote:
"Jack" wrote in message

Partially crap. Learn how lungs work.

Your post is complete crapp. Why don't you spend five seconds and tell us
all you know in the subject?


Adorable. In five seconds. Below a minimal partial pressure of O2, (40mm
Hg is the typical partial pressure in tissue / 100mm is pO2 in the lungs) an
exchange won't occur in the lungs. Period. Exhaling to the best of one's
ability, as the previous poster suggested, isn't analogous. Lungs work just
fine in reverse.

For more, Google +oxygen +"partial pressure" +respiration 39,500 hits.

moo

T o d d P a t t i s t wrote:
Wrong. the partial pressure has everything to do with it.

Wrong, the partial pressure has nothing to do with it.

The lungs (or more accurately the blood in the lungs) need
O2 pressure to pick up O2. That O2 pressure is referred to
as the partial pressure of O2. You can be at altitude on
100% O2 and have the same partial pressure as at sea level
on partial O2

The lungs (not the blood) need pressure to allow gas exchange
(respiration) in the alveoli. The pressure (or lack thereof)
determines the effectiveness of respiration. Reduced effectiveness can
be compensated for with supplemental oxygen.

Sounds like you don't understand the process.

I think we're talking about different parts of the process. It sounds
like you don't know what I mean by respiration.

You may be referring to the breathing reflex
that requires sufficient CO2 to trigger breathing ...

I did not refer to that.

The original question was why you lose consciousness faster
at altitude than if you hold your breath at sea level.

The original question is why you lose consciousness at altitude with
supplemental oxygen when the partial pressure of oxygen appears to be
the same as at sea level. It had nothing to do with holding one's
breath.

True - because the PP drops too low for consciousness or
life. It's all about PP of O2.

True because the lungs become unable to respirate effectively at
reduced atmospheric pressure, which leads to hypoxia.

In article GqcMe.161$zb.155@trndny04,
George Patterson wrote:

Bruce Hoult wrote:

My recollection of my O2 training is that the rule is 30 minutes over
10,000 ft, or if you go over 12,500 ft at *all*.

No. 12,500' if you exceed it for 30 minutes or 14,000' if you go over that at
all. At 15,000', passengers also have to be on oxygen. Section 91.211.

I don't see a section 91.211 in the New Zealand regulations.

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

There are other, important, limiting factors. The alveoli need to exchange
two gases--CO2 and O2 and pressure gradients are needed for this. The fly in
the ointment is that water vapor pressure in the alveoli remains near
constant at 47mm Hg (Torr). The CO2 comes from diffusion across the
capillary-alveolar barrier, from the blood, and therefore remains somewhat
high and at 30,000 ft is about 30 mm Hg. So the O2 must ovecome this
pressure and about 30 mm more to get into the blood effectively. So unless
the O2 is above about 107 mm Hg you don't get enough in your blood to do you
any good.

--
Hartley Falbaum,


"Brien K. Meehan" wrote in message
oups.com...
T o d d P a t t i s t wrote:
Wrong. the partial pressure has everything to do with it.

Wrong, the partial pressure has nothing to do with it.

The lungs (or more accurately the blood in the lungs) need
O2 pressure to pick up O2. That O2 pressure is referred to
as the partial pressure of O2. You can be at altitude on
100% O2 and have the same partial pressure as at sea level
on partial O2

The lungs (not the blood) need pressure to allow gas exchange
(respiration) in the alveoli. The pressure (or lack thereof)
determines the effectiveness of respiration. Reduced effectiveness can
be compensated for with supplemental oxygen.

Sounds like you don't understand the process.

I think we're talking about different parts of the process. It sounds
like you don't know what I mean by respiration.

You may be referring to the breathing reflex
that requires sufficient CO2 to trigger breathing ...

I did not refer to that.

The original question was why you lose consciousness faster
at altitude than if you hold your breath at sea level.

The original question is why you lose consciousness at altitude with
supplemental oxygen when the partial pressure of oxygen appears to be
the same as at sea level. It had nothing to do with holding one's
breath.

True - because the PP drops too low for consciousness or
life. It's all about PP of O2.

True because the lungs become unable to respirate effectively at
reduced atmospheric pressure, which leads to hypoxia.

Happy Dog wrote:
"Jack" wrote in message
Partially crap. Learn how lungs work.

Your post is complete crapp. Why don't you spend five seconds and tell us
all you know in the subject?

Adorable. In five seconds. Below a minimal partial pressure of O2, (40mm
Hg is the typical partial pressure in tissue / 100mm is pO2 in the lungs) an
exchange won't occur in the lungs. Period. Exhaling to the best of one's
ability, as the previous poster suggested, isn't analogous. Lungs work just
fine in reverse.

For more, Google +oxygen +"partial pressure" +respiration 39,500 hits.
Wow! Dude your so cool! This is the second time within a day or so you
explain others how to google. You seem to have mastered this uneasy
task and can't help showing off! Now the next task is to try not to be
an asshole.

For more, Google +asshole 2,522,000 hits.



moo

Bucky wrote:
wrote:
40,000 15 seconds
35.000 20 seconds
30,000 30 seconds

I don't get it. Can't a person stay conscious for longer than 30
seconds without breathing? Most people can hold their breath for over
a minute.

If you try to hold your breath your lungs will explode when the outside
pressure drops. That's why in altitude chambers they never tell you when
they're going to give the explosive decompression. When it happens the air
in your lungs automatically expels from your body since it is at a much
higher pressure than the ambient air. Pressure breathing through an oxygen
mask is difficult since your must manually forcibly exhale and just relax to
inhale.

--

Darrell R. Schmidt
B-58 Hustler History: http://members.cox.net/dschmidt1/
-

wrote in message
"Jack" wrote in message
Partially crap. Learn how lungs work.

Your post is complete crapp. Why don't you spend five seconds and tell
us
all you know in the subject?

Adorable. In five seconds. Below a minimal partial pressure of O2,
(40mm
Hg is the typical partial pressure in tissue / 100mm is pO2 in the lungs)
an
exchange won't occur in the lungs. Period. Exhaling to the best of
one's
ability, as the previous poster suggested, isn't analogous. Lungs work
just
fine in reverse.

For more, Google +oxygen +"partial pressure" +respiration 39,500 hits.

Wow! Dude your so cool! This is the second time within a day or so you
explain others how to google. You seem to have mastered this uneasy
task and can't help showing off! Now the next task is to try not to be
an asshole.

My post was an appropriate response to the previous one. Why people ask
questions before even attempting to find the answers, usually in less time
than it takes to post is a mystery to me.

Anonymous twit.

moo

Shawn wrote:

You should check Bruce's Lat/Long in his sig before you start quoting
him US FARs.

My original post stated that "the FAA requires that a pilot use oxygen if they
spend over 30 minutes above 12,500'." He said that was wrong. Doesn't matter
where he happens to live, the FAA *still* requires that a pilot use oxygen if
they spend over 30 minutes above 12,500'.

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.

Bruce Hoult wrote:

I don't see a section 91.211 in the New Zealand regulations.

I didn't say there was. *You* said the FAA didn't have this requirement.

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.