I had a pair of Mountain High EDS units which use about 1/4 as much O2 as
the Cannulas. Worked great! See
http://www.mhoxygen.com/

Mike
MU-2

"O. Sami Saydjari" wrote in message
...
I flew the plane I just bought back from Reno on 1/12/04. I flew back
at 17,000.

Just to get a baseline, I monitored my O2 level on the commercial flight
on the way to Reno to see what cabin pressure commercial jets do. My
normal saturation on the ground is 97%. At altitude (I thikn around
35,000) on a commercial jet with cabin pressure, it dropped to 92 (+/- 2).

Flying the Turbo Arrow III, I noticed O2 levels falling below 90 at
around 12,000. So, I went onto 02 at that point. Low flow rates were
quite adequate for the next few thousand feet. At 17,000, a flow of 2
liters per minute seemed very comfortable. With focused deep breathing,
we could easily get away with about 1/2 liter per minute...but it was
too difficult to maintain that sort of breathing for long...too
distracting. My co-pilot went off oxygen for 5 minutes as an
experiment. His 02 dropped to about 80. He definitely felt affected.

One thing I noticed is that two people breathing 2 lpm can consume quite
a lot of oxygen. A 40 Cu ft. bottle was 2/3 empty after 4 hours. We
used 02 masks. After that, I decided to get a conserving nasal canula.
They are supposed to use one fourth as much 02. Given the cost of
refills, that will be a big cost saver.

-Sami (Piper T-Arrow III N2057M)


Mark Astley wrote:
As with many regs, this one probably didn't even exist until someone
bent
metal because they were careless. Adhering to the regs makes you legal
but
not necessarily wise. If you think you need to use oxygen at a lower
altitude, then by all means do so. But making it a reg may not actually
change anything, an example...

Every time I take a checkride, the DE spends about 5 minutes talking
about
what it takes to be legal versus what makes you a safe pilot. On my
last
checkride, she related that when she started flying, there was no
minimum
fuel requirement (e.g. 45 minutes IFR reserves, etc) because the FAA
assumed
pilots were smart enough to bring enough fuel and monitor the flow. The
requirement for reserves was added AFTER too many pilots ran out of fuel
and
wrecked planes. Note, however, that even with the "new" regs pilots are
still running out of fuel at an embarrasing rate.

I think education is the key here, not more regs.

blue skies,
mark

"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