-----
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