Depends on who you are, what you do and where you live. If you are an
athlete living in Frisco, CO (10,000"), 12,500 is trivial. Then there are
the people who get High Altitude Pulminary Edema on a bus from San Francisco
to Reno. You can choose to use O2 at sea level if you choose but lets not
make it apply to everybody.

We had an oximeter the last time I went climbing and the results were
interesting. Upon reaching each new altitude, O2 levels were in the mid 80s
but a day or two later they were in the low to mid 90s. This pattern
continued to over 17,000' where we stopped taking measurments. Looking
back, you could have predicted who would drop out several days before they
actually did. Those who had readings in the 70s upon arrival and low 80s a
day later dropped out 3,000' higher where their readings were in the 60s.

Mike
MU-2

"O. Sami Saydjari" wrote in message
...
Ross, Excellent articles. Thanks so much for pointing them out. I
particularly enjoyed the part about focused breathing yeilding a
significantly improved oxygen saturation.

I know it has been pointed out in several different places, but it seems
pretty clear that the FAA needs to reconsider its supplemental oxygen
requirements. Waiting until 12,500 seems like a bad idea.

-Sami

Ross Oliver wrote:
Every pilot should definitely read these two articles:

Review of Nonin Onyx Pulse Oximeter
(has good info that would probably apply to all brands of oximeters)
http://www.aeromedix.com/aeromedix/art/pulseox/

Respiration: What Pilots Need to Know (But Aren't Taught)
http://www.aeromedix.com/aeromedix/a.../respirat.html