----- Original Message -----
Sent: Friday, August 05, 2005 11:35
AM
Subject: [FlyRotary] Re: Back from Osh/
Dave & Buly repair notes
On 8/5/05, Ernest
Christley <echristley@nc.rr.com> wrote:
John
Slade wrote:
> I will want one suitable for two users.
My back seater won't go over
> 10,500 without it.
>
>
Tracy.
> Glad you survived that one. We'd miss you for all sorts of
reasons :)
> Take a look at http://www.aeromedix.com
> I got
their 2 place system for around $400 complete with a full 640 ox
>
bottle. It's gone up a bit since. Haven't had a chance to use it
yet,
> but the quality and service seem good.
> Regards,
>
John
>
I've bookmarked this page. Very interesting
stuff. I'm basically
healthy, and don't plan on much FL
flying. But I think one of their
miniature, $289 systems would
be useful for the type of situation Tracy
found himself in. If
I had that and the Nonin Flightstat, it would
minimize the weight I carry
around but still maximize safety. $600 for
a complete oxygen
system isn't all that bad.
David, this is probably a good question
for you. Would it be necessary
to carry one of the oxygen
monitors all the time, or would it be enough
for someone to wear one for
a few flights to characterize how their body
reacts and then just use
oxygen in those conditions? In other words,
can a person
expect to react the same everytime, or is it unpredictable?
Difficult question. In general over the short term you will react
pretty much the same as long as nothing else changes. Also, it is not so
much your O2 saturation that matters as your ability to tolerate lower
saturations. For example, some mountain climbers can function in
strenuous environments with SpO2 in the low 30's!!! Others will begin to
notice significant effects in the low 90's. Some people live in the low
80's at sea level.
With age, in general, tolerance declines while the amount your
saturation drops increases. Many things affect your tolerance such as
smoking or other carbon monoxide exposure, lung disease, dehydration, anemia,
cerebral vascular disease, heart disease, change in activity level or
even a hang over.
So really, the SpO2 monitor tells you very little. It will drop
more or less predictably with altitude, but there is no way to say what
number is a safe decline.
As expected, the FAA regulations are set for a reasonable lowest common
denominator. That means that a few people will experience
significant effects even while following the letter of the law, while most can
tolerate significantly higher altitudes.
A few years ago I spent about 10 min at 27,000' in an altitude
chamber. I was somewhat dizzy, but could communicate and do math.
My O2 sat was in the low 70's and dropping. Longer exposure might
change things somewhat. Probably couldn't do that now. I notice
very little effects at 23k (in a chamber) except for loss of color vision and
slight uncoordination - I certainly would have the where-with-all to fly
en-route stuff for short periods.
What is hard for me to remember is that I am getting older, as I am in
denial. Either way, the important thing is to be able to recognize
the subtle effects and say "that's enough," above 14.5k or
not.
If you get the opportunity, a chamber ride is an excellent
experience. A few people, even those young and in great shape, do react
very strangely - and it can vary day to day.
Also, having O2 readily available even if not continuously used would be
an excellent and cost effective safety measure for those fly at altitudes
where there is the possibility of an issue.
--
Dave Leonard