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 vary.

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 oxygen.

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 country.

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 CAMI instructor.

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) 954-4837.

You'll need a current medical certificate to get personal with hypoxia, an experience that could prove to be a lifesaver someday.

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 may have.