hi alt oxygen

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.

Pensacola. Low pressure tank. 30,000 feet pressure. Instructor asks for
volunteer. (I tend to do dumb things) I said OK. "Please take this pencil
and write your name on this clipboard." "How many times?" "Don't worry. I'll
tell you when to stop."

Off comes mask. I write and I write and at the 4th perfect signature I stop --
wondering why am I doing this. "Hell, I can do this for the rest of my life."
(30,00 feet. Yeah) Instructor slams mask back on. My vision instantly
changed from looking down a soda straw to wide open, COLOR!, side vision. Wow!
Last signature was a straight line. (Hmmmm. Looked OK at the time.)

At 30K, one has about 4 seconds of useful consciousness -- unless one holds
one's breath. That may net one a couple of seconds more. No pain. No strain.
Quite pleasant. Been there. Done that. Fast and almost fun.

Humans need a constant supply of oxygen and we store almost none. Lack of
oxygen doesn't hurt. What hurts and gives the feeling of strangulation is an
overabundance of carbon dioxide. Want to know what too much CO2 feels like?
Hold your breath for 3-4 minutes.

Throw in a little exhaust gas and the ceiling easily drops to 20K or lower.

Quent

On 10 Mar 2004 21:12:59 -0800, (WaltBJ) wrote:

Rule of thumb - O2 over 10,000 feet.

It used to amuse me, in the days before the Eisenhower Tunnel, that
the highway over Loveland Pass in CO took the driver above the
altitude at which the USAF wanted pilots to use oxygen masks.

At Aspen of course we skied all winter at above 11,000 feet. (At
Loveland, the parking lot was higher than that.) Do you suppose that's
why ski bums are famously so unstable?


all the best -- Dan Ford
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see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

Cub Driver wrote:

On 10 Mar 2004 21:12:59 -0800, (WaltBJ) wrote:

Rule of thumb - O2 over 10,000 feet.

It used to amuse me, in the days before the Eisenhower Tunnel, that
the highway over Loveland Pass in CO took the driver above the
altitude at which the USAF wanted pilots to use oxygen masks.

At Aspen of course we skied all winter at above 11,000 feet. (At
Loveland, the parking lot was higher than that.) Do you suppose that's
why ski bums are famously so unstable?

The difference being the rate at which you ascend from lower altitudes,
although the military's 10,000 foot rule seems very conservativ. IIRR,
even the FAA allows pilots to fly between 12,500 and 14,000 ft. for 1/2 an
hour without O2, and pax can do it indefinitely. Pity the poor fighter
pilots in WW1, who used to climb up to 17-20,000 feet without O2 and
patrol there for an hour or so in open, unheated cockpits. And suffered
massive headaches as a result.

Guy

Cub Driver writes:

At Aspen of course we skied all winter at above 11,000 feet. (At
Loveland, the parking lot was higher than that.) Do you suppose that's
why ski bums are famously so unstable?

You can make up for some deficiency by doing more breathing.
Ed Gauss, an old AK bush pilot, told the story that he'd be
on O2 & his wife would keep awake without, by playing her
harmonica.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

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.

Same basic idea of the PPO2 is why SCUBA divers going down need to cut
the oxy levels of their breathing gas down to avoid PPO2 levels above
1.4 ATA... so you can find divers using as low as 5% oxy in a deep
dive Trimix (Oxy, Nitrogen, and Helium) bottom gas

More trivia on flight and oxygen:
1) the F102 always gave us 100%- there was no diluter function. Some
ground-pounding designer made the decision we'd always be wearing
pressure suits to go after those high-altitude bombers. As it turned
out it generally took a direct order to get a pilot airborne in the
old skin-tight MC-3&4 partial pressure suits, because they were very
unconfortable and visual lookout was definitely impaired because you
had to use your free hand to shove your head around to look to each
side. Well, one of our guys came down with his lower face singed -
claimed the oxygen had flamed his moustache wax. Good story but what
had reallyy happened was that he forgot to shut off his oxygen when he
lit a cigarette . . .speaking of p-suits I always had a good laugh
when I saw the Russky pics of their MiG21 pilots walking along in
p-suits that looked jusy like our partial pressure suits. Their flight
surgeons were a lot more involved in daily activities than ours -
thank God.
Next story - this crusty old WW2 pilot and I were off to Tyndall from
RG in a T33 - the wx down there was DS and we were at about 37000 to
save enough fuel for an alternate. He tried to light a cig but it
wouldn't take - the next hour he spent whining at me because I
wouldn't descend so he could grab a smoke.
Bends - we used to get bubbles under our skin in the older T33s
because the pressurization was so weak. Felt like little bugs crawling
under the skin (mobile chiggers?). So before a p-suit flight we
normally prebreathed 100% O2 for 30 minutes to flush out the N2 to
minimize the chance of getting bends. We were on another U2 intercept
mission when my squadron mate stopped the flightline trolley, opened
up his faceplate, threw up, wiped off his lips, closed the faceplate
and motioned to the young, now wide-eyed, airman driver to press on.
Hangovers and p-suits don't really go together. He still hacked the
mission, though.
Speaking of nicotine fits - I had a friend who used to chew tobacco in
a 104 - he kept a Prince Albert can in his Gsuit pocket to catch the
spit. Never was able to bounce him at just the right time, though.
Being a non-smoker I just don't understand guys like that.
As for the Rocky Mountains, when we get flatlanders up here for a
visit and take them for a drive up over Trail Ridge road - peak
altitude about 12,200, they usually doze off because they won't
breathe (pant) enough. Both the Pikes Peak and Mt. Evans roads will
let you drive up over 14,000.
Walt BJ

On 11 Mar 2004 19:31:57 -0800, (WaltBJ) wrote:

MC-3&4 partial pressure suits, because they were very
unconfortable and visual lookout was definitely impaired because you
had to use your free hand to shove your head around to look to each
side.

Good grief!

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

On 11 Mar 2004 19:31:57 -0800, (WaltBJ) wrote:

Trail Ridge road - peak
altitude about 12,200, they usually doze off because they won't
breathe (pant) enough.

When I was a ski-bum at Aspen, the conventional wisdom in the ski
patrol was that the turkeys (paying customers) breathed too much, or
too often, or too deeply. They claimed that the most important part of
their kit was a paper bag. You gave it to the immobilized turkey and
made him breath into it for a time, thus getting more carbon dioxide
into his lungs.

Of course skiers are exercising, so perhaps more like to over-breathe
than under-breathe.


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

In article , WaltBJ
writes
More trivia on flight and oxygen:

SNIP of fascinating trivia about high altitude breathing - more welcome
anytime!

breathe (pant) enough. Both the Pikes Peak and Mt. Evans roads will
let you drive up over 14,000.
Walt BJ

I went to Pike's Peak many years ago and was told that the engines of
the VW we were trucked in had special aspiration arrangements - no
surprise there.

But the people didn't have the same arrangements! Soon after we
arrived, some kids started running around and throwing snowballs fairly
indiscriminately. But one guy just smiled and said 'Don't worry, folks,
it won't last long'. And how true, within a minute the kids were
horizontal... :-)

Cheers,

Dave

--
Dave Eadsforth

WaltBJ wrote:

More trivia on flight and oxygen:

snip

As for the Rocky Mountains, when we get flatlanders up here for a
visit and take them for a drive up over Trail Ridge road - peak
altitude about 12,200, they usually doze off because they won't
breathe (pant) enough.

(Almost totally OT) Ah, Trail Ridge road. When my '88 Subaru GL Turbo 4WD
Wagon was almost brand new, I took four people and all our gear for a week
over Trail Ridge (we'd driven from California, but spent a night and half
day in Great Basin Nat. Park, including sleeping at 10,000 feet). The
Subaru only had 115 hp and had a curb weight of about 3,000 lb., and
virtually everyone had a better power/weight ratio and was faster than I
was -- at sea level. So there we were, climbing up the west side on a
hot, muggy summer day (it was in the high '80s or low '90s, I forget
which, when we passed through Granby @ 8,500 feet), and all of a sudden I
found I was just about the most powerful car on the road, as I passed what
were far more powerful cars (at sea level) while driving uphill at ca.
10,000 ft. I could drive as fast as I wanted to (max. 40-50 or so) uphill
on the fairly open two-lane road, with 1-2,000 foot dropoffs on the side
and usually no guardrails on the turns. Coming back over from east to west
was the same.

I never did find out what the critical altitude on the turbo was, but
judging by its performance on Trail Ridge that day it must have been well
over 14,000 feet (allowing for density altitude). Couldn't have a more
clear illustration of a turbo's thin air performance advantage than that.
I later took the car up to 13,200 feet in the White Mountains one
September with two people and gear, and I don't remember any altitude
problems there either, at least for the car (it was graded gravel and
dirt, so I wasn't driving very fast in any case). Both of _us_ had AMS
from ascending too fast from sea level, even though we'd slept at 9,000
feet the night before.

My Subaru Forester (some SOB stole my old Subie in its fifteenth year, or
I'd still be happily driving it) doesn't have a turbo (they only came out
with the XT turbo model in June or so of last year, and I had to buy a car
that January). It's got about 165 hp and more torque, so my old turbo
would come up short up to about 8,000 feet or so, but have more power
above that. Living in the SF Bay Area at sea level and driving up to the
Sierra it hasn't been a problem so far, but I have yet to carry that much
of a load that high, that hot. The highest paved road in California goes
over Tioga Pass (9,941 ft.) in Yosemite, and it handled that fine with two
people and backpacking gear last August, so I probably don't need a turbo
here, and I'm happy not to have to worry about the turbo blowing up or
suffering other expensive problems (not that I had any, but I changed my
oil every 3,000 miles and let it idle down properly after hard driving).
But if I was living in Colorado up against the Front Range and/or
commuting across it, I'd sure want one. I've read that Subaru developed
the Turbo Forester XT precisely because the normally-aspirated model was
left gasping for breath commuting through the Eisenhower tunnel (@11,000
feet). As Homer Simpson might say, "210 hp all the way up, M'mm."

Guy