"David Megginson" wrote:

I'm interested in the same questions, but further to #1, I was
wondering if anyone can post a complete-idiot's guide to using
portable oxygen in an airplane: everyone who writes about using
oxygen, either online or in aviation books and magazines, seems to
assume that the whole process is simple and obvious.

It mostly is trivially simple. If you've never put on a cannula before it
might take you a couple tries to get it on right. The trick is to get it
around your neck then back over your ears and have it facing the right
direction under your nose. That and getting it to fit with the bows of your
sunglasses, your hat, and your headset. It can be quite a production.

Which leads to tip #2. If you think you're going to want O2, put your
cannula on during your preflight preparations. It's just easier to do it on
the ground. This also solves the problem my wife had the first time, which
is that you'll never figure out how to put on the cannula once you're
hypoxic.

Turn on the gas at the tank. My cannula also has a needle valve to meter
the precise amount of oxygen for the altitude. It's got a little ball that
floats along a scale which is calibrated in thousands of feet. If I'm
flying at 13000, I adjust the needle valve so the ball floats between the 12
and the 14.

Cannulas are not effective for delivery above 18,000. I've flown a couple
times at 17,500, and I had to open up the needle valve wide open in order to
stay alert. It was damn cold up there too. Note: never open a soda at that
altitude, or you'll be wearing most of it.


I know that people who fly in the mountains learn this stuff from day
one, but as a flatland pilot, I've never even talked with a pilot who
uses portable oxygen, much less used it myself (I've never flown over
9,000 ft MSL). I'm not even sure how to get started. I've heard of
canulas, and I know that some people use welder's oxygen, but that's
pretty-much it.

For the same reason that helium gives you the voice of a cartoon squirrel,
oxygen gives you a nice deep airline captain's voice on the radio. A nice
deep nasally congested airline captain, anyway.

Oxygen is basically free. Whatever you pay for a refill is a service
charge, so it varies radically depending on how badly people want to fill
your tank for you. Every once in a while I get a free refill, but when I
pay it's usually in the ballpark of $25. I only fill up once or twice a
year.

I usually use O2 for flights at 9500 and up, especially if I'm going to be
up there for a couple of hours. Recently I had a three-hour flight at
11,000 and I did not use O2, and I could feel myself starting to get punchy.
I use it at night when 5000 or above.

You can get a really nice portable O2 system for significantly less than the
cost of a handheld GPS. If you fly an airplane that can get you above
10,000 easily, it really makes sense to have one. Out here on the west
coast, MEAs go up to 10-12K just to fly back and forth between the largest
cities (Portland-San Francisco, San Francisco-Los Angeles). I spend a lot
of time up there.