How to Experience Hypoxia Without
Leaving the Ground
by Paul Engstrom, Aviation Writer and IFA Member
Someone should shoot an action film and title it
"Hypoxia:This Time It's Personal."
One quirk of oxygen deprivation at altitude is the fact
that certain symptoms'which range widely among pilots, from fatigue
and nausea to air hunger and euphoria are unique to you and don't
In other words, if, due to hypoxia, you get a headache
and also become belligerent on a flight, those particular symptoms
will also appear the next time you fly too high without supplemental
The upshot: It's easier to recognize the mental and
physical danger signs of hypoxia and respond appropriately if you know
how this malady affects you personally.
Most general aviation pilots don't have a clue what
their symptoms are because hypoxia is a relatively rare phenomenon.
But you can find out safely, inexpensively, and with minimal effort by
spending time in an altitude chamber.
Only military pilots are required to train in these
simulators, in which aviators experience hypoxia at 25,000 feet under
daytime conditions and rapid decompression to 8,000 feet under
nighttime conditions without ever leaving the ground. The Federal
Aviation Administration recommends that all civilian pilots take at
least one such 'flight.'
To promote that, the FAA's Civil Aerospace Medical
Institute (CAMI) and the U.S. Air Force and Army together offer a
one-day course for civilian pilots at 16 Air Force Bases around the
Among other things, the $50 course features classroom
instruction on basic physiology, hypoxia, decompression sickness, gas
expansion, hyperventilation, and related topics; a demonstration of
spatial disorientation; and a closely supervised session in a steel
altitude chamber about the size of a family trailer.
"Our classroom feedback has been 100 percent positive
concerning physiological training and this ranges from student pilots
to pilots with over 25,000 flying hours," says Rogers V. Shaw II, a
The number of potential hypoxic symptoms goes well
beyond those cited above. Others are apprehension, hot or cold
flashes, blurred or tunnel vision, numbness, sweating, a tingling
sensation, lack of concentration, diminished coordination, giddiness,
an increased breathing rate, blue fingernails and/or lips, and a false
sense of security.
In the altitude chamber, participants fill out a
worksheet at 25,000 feet'it consists of simple math and word
exercises, questions, and a checklist of symptoms'to get a better
sense of how hypoxia disrupts their mental and physical functioning.
At 8,000 feet under nighttime conditions, reading and distinguishing
colors on a sectional chart prove to be quite difficult.
To learn more about the course and sign up, call (405)
You'll need a current medical certificate to get
personal with hypoxia, an experience that could prove to be a
When he isn't
flying, Paul Engstrom writes and edits in Sebastopol, Calif.
The information contained herein is meant for
informational purposes only. Neither IFA, nor Paul Engstrom assume any
responsibility or liability for events that occur due to actions you
or others on your behalf take based on the information given in this
article. You are proceeding at your own risk. It is strongly advised
that you seek the opinion and advice of a qualified aviation medical
examiner and appropriate medical physician for any medical needs you