Excerpt from Air Warriors by Douglas C. Waller, plus links to reviews, author biography & more

The first week -- "Poopie Week" was its nickname -- fulfilled his worst nightmare. It began with officers just graduated from OCS and awaiting assignment who were supposed to indoctrinate the rookies into the regimentation of military life. The young ensigns did so with a vengeance -- payback for the hazing they had just endured. Never had McKinney been yelled at so much and for so long. When he wasn't at attention, he was pushing up the ground or running or swimming. The hazing from the ensigns, it turned out, was just the warm-up for Thursday morning at five o'clock, when Marine Corps sergeants barged into his barracks banging garbage can lids to wake up the recruits.

By then, however, McKinney realized he wouldn't die from the training. The Marine drill instructors were surly and intense, but fair. McKinney's sergeant had a rich heritage. His father and grandfather had been DIs and he considered the job a calling.

McKinney had always thought of himself as a disciplined fellow. Now he marveled at how slovenly he had been as a civilian. Beds had to be made square. Uniforms had to be immaculate. Marches and salutes crisp. The DIs were maniacal about detail and precision. There was a reason. A pilot had to be a nitpicker. Sloppiness in the cockpit could kill him. McKinney began to enjoy the grueling training. By the time he graduated from OCS, he couldn't wear civilian clothes without making sure there were no loose strings from his shirt. OCS had taught him true mental and physical discipline. It had taught him to think under pressure, to assimilate large amounts of information quickly, to keep his wits when surrounded by chaos.

The air inside the chamber smelled stale. Its walls were painted white and from its ceiling hung bright fluorescent bulbs and oxygen tubes for instructors who would monitor the students. There was something very antiseptic to it -- and quiet. Neither sound nor air could escape its hermetically sealed steel walls. McKinney felt no claustrophobia, as some students did when they walked into the chamber and the large door hatch sealed shut behind them. He liked small spaces. As a child he would always pick a corner of his bed to curl up as if in a cocoon.

Its full name was the hyperbaric chamber. Its purpose was to acquaint students with one of the most insidiously dangerous conditions a pilot faced at high altitudes: hypoxia, when not enough oxygen reached the tissues of the body. Hypoxia occurred for different reasons. When a pilot pulled Gs in a plane (gravitational pressure from sudden acceleration), the blood in his body sank to his bottom or legs instead of where it was needed in his brain, and he blacked out. A G suit the pilot wore on the lower half of his body inflated like a balloon, squeezing his hips and legs to force the blood back to his brain. Pilots also performed a "hook" maneuver, tightening their stomach muscles and quickly expelling air with a "hook" sound, like a weightlifter straining to pick up a heavy load. It also squeezed blood to their brains.

Another form of hypoxia occurred at high altitudes, where the atmospheric pressure was not great enough to keep the blood saturated with oxygen. A human could maintain a healthy blood-oxygen saturation level (of at least eighty-seven percent) up to about 10,000 feet. Any higher, and his cabin must be pressurized or he must have an oxygen mask strapped to his face. If not, less oxygen got to the blood, resulting in hypoxia.

Before becoming unconscious, a pilot might experience any one of a number of symptoms at the onset of hypoxia: a hunger for air, an apprehensive feeling, fatigue, nausea, headaches, dizziness, giddiness, hot and cold flashes, blurred vision, tunnel vision, numbness, tingling. He might hyperventilate, feel euphoric, become confused, uncoordinated, or belligerent. His lips and fingertips might turn blue.

The problem was that no two pilots experienced the same symptoms. What's more, hypoxia would quickly sneak up on a pilot. He could easily black out before he had a chance to treat himself for the condition. At 25,000 feet, for example, a pilot could lose consciousness in three to five minutes in the thin atmosphere.

Copyright © 1998 by Douglas C. Waller