Overcoming the Body’s Limitations

Overcoming the Body’s Limitations

In This Chapter

^ The body’s trouble with high altitude

V Hypoxia goes by many names

>" Airsickness: a common woe

>■ Flying phobias and their treatment

Although pilots sometimes pretend it’s not true, the fact is that man has about as much business flying through the sky as a goldfish has playing the harp. It’s obvious we’re out of our element.

In the air, nature holds plenty of cards she can play against us, from weather hazards like invisible and dangerous clear-air turbulence to the thin air at high altitude that can rob a pilot of her ability to think and make decisions.

The human body is a poor match for the extreme conditions we encounter in flight. Fortunately, we’ve been pretty clever in designing safe airplanes that shelter us from the worst of the elements. Still, it pays to be aware of our bodies’ limitations in flight and how we can live with these limitations.

How the Atmosphere Stacks Up

To understand how the atmosphere causes the body to function differently at different altitudes, we have to take a look at how the atmosphere is built.

Overcoming the Body’s Limitations

Each person’s body responds dif­ferently to the extreme condi­tions we encounter in flight, it’s not possible to generalize how each person will react to the rig­ors of high-altitude flight A small number of altitude cham­ber facilities around the country offer training in actual high – altitude conditions, which is the best way to gauge each person’s response.

Подпись: Turbulence

The air we breathe is about four-fifths nitrogen and one-fifth oxygen. About 1 percent of it is argon, an obscure little gas called “inert” because it won’t interact with any other element. There are a few other inert gases in our atmosphere, including neon, helium, and xenon. But after nitrogen, oxygen, and argon, the rest of the gases are so scarce they’re hardly there at all. Of course, water vapor is part of the mix as well, helping to drive weather. (For the skinny on weather and the importance of water vapor in creating it, see Chapter 17, “Talking About the Weather.”)

Air is heavier than you might think. The air in a room measuring 20 feet by 20 feet with an 8- foot high ceiling weighs about 237 pounds. The total weight of all the air in the earth’s atmosphere is about 5,600 trillion tons!

Air possesses weight because each molecule possesses mass. (Helium and other buoyant gases also possess mass, but their molecules are lighter than the nitrogen and oxygen mixture in the air. That’s why balloons filled with helium rise in our nitrogen-oxygen atmosphere.) We perceive air as weightless, however, because it presses on us from all sides. When we hold an arm out to our side, the air presses on it from above, but also from below, from the front, and from the back.