AOPA Pilot Magazine - July 2023 - 24

PROFICIENT PILOT
Chicken soup
Bringing along an oxygen supply can't hurt
BY BARRY SCHIFF / AOPA Foundation Legacy Society chairman
IT WAS A RARE DAY IN ANCHORAGE. I could see 120 mile distant
Denali (formerly Mount McKinley) from my hotel room. Highest
peak in North America, the 20,310 foot sentinel stood beckoning
against the northern horizon. My friend Bob Cleaves and I rushed
to the airport and departed northbound in our rented Piper Archer.
Denali, like Kilimanjaro in Tanzania, is shy and elusive,
frequently hiding behind a shroud of cloud, but not this day. The
majestic mountain grew larger in the windshield and posed for the
photographs we had hoped to take. The Archer struggled toward
the summit. Finally, when it could climb no more, Cleaves suggested
that I hop into the backseat and take a wide angle shot that would
include him in the foreground and the peak in the background.
It wasn't easy, but I finally made it-and then promptly
collapsed for what seemed like an eternity but was for only a
few seconds. I hurriedly framed Cleaves and the mountain in the
viewfinder, snapped the picture, and yelled for him to descend.
At 18,500 feet, my chest was pounding, and I was having difficulty
recovering from the exertion.
Cleaves quickly lowered the nose and noticed that he too was
having trouble breathing. Moments later, we returned to that very
thin layer of the atmosphere where pilots can function normally
without the aid of supplemental oxygen.
I used to think that this was my first experience with hypoxia
(a shortage of oxygen), but I was wrong. I have since learned that
pilots can suffer from low grade hypoxia as soon as they leave the
ground. In this sense, a pilot is like a normally aspirated engine
that loses performance as it climbs.
It is interesting that we readily accept the concept of an
engine losing power with altitude but are less willing to
acknowledge a personal loss of performance. This is because
the effects of hypoxia develop so insidiously. The most common
symptoms include visual disturbances, loss of muscular
coordination, judgment impairment,
lightheadedness,
dizziness, apprehension, and a bluish discoloration of
extremities. Although it might seem that pilots would recognize
these symptoms, they often cannot because of what might be
hypoxia's most dangerous effect: euphoria, a strong sense of
wellbeing that camouflages other symptoms. This should lay to
rest any notion that a pilot can wait to recognize the symptoms
of hypoxia before taking corrective action.
24
AOPA PILOT / July 2023
Although most pilots would never risk flying under the
influence of drugs and alcohol, many of them expose themselves to
similar dysfunctions by unwittingly operating under the influence
of hypoxia. Most of what I read about hypoxia usually involves a
discussion of hemoglobin, erythrocytes, alveoli, red corpuscles,
permeable membranes, and other terms that only remind me of
how I struggled through Physiology 101.
There are only two things a pilot needs to understand about
hypoxia. The first is that he usually cannot recognize its disabling
effects-particularly during periods of stress. The second is that
there is only one instrument that can warn of hypoxia: the altimeter.
Although the use of supplementary oxygen is not required until
above 12,500 feet for more than 30 minutes and whenever above
14,000 feet for any period, these rules seem too liberal. Military
instructors teach that oxygen should be used whenever above 5,000
feet at night and above 10,000 feet during the day. One pilot-who
also is a flight surgeon-is so conscientious about avoiding hypoxia
that he has printed in bold red the word " OXYGEN " on his high
altitude power charts as a reminder to begin using oxygen at the
appropriate altitude. He regards his supplemental oxygen system
as a " turbocharger " that allows him to recapture the personal
performance lost during climb (see " Into Thin Air, " p. 89).
Over the years, I have purchased a number of safety related
items to take on appropriate flights. These include a first aid kit,
a survival kit, a fire extinguisher, and-most recently-a portable
oxygen system that goes along on all night cross-country flights
and those daylight flights that could wind up above 10,000 feet. (I
would love to have had a bottle available during my flight into La
Paz, Bolivia. The elevation of the airport there is 13,300 feet msl,
and I needed oxygen just to perform a walkaround inspection.)
There have been many accidents that can be at least partially
attributed to hypoxia. Perhaps this is why many airline pilots don
a mask and breathe oxygen prior to a night approach or when
tired. Does this do any good when flying an aircraft pressurized to
several thousand feet above sea
level? I believe that it does. On
the other hand, oxygen is a little
like chicken soup. According to
my mother, it can't hurt.
BarrySchiff.com
BARRY SCHIFF'S articles
have appeared in 116
different military and
civil aviation publications
throughout the world.
http://www.BarrySchiff.com
AOPA Pilot Magazine - July 2023

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