As Greek officials begin to unravel what caused the Sunday crash of a Helios Air Boeing 737, early reports seem to indicate that loss of cabin pressurization may be a factor. Greek Air Force pilots observed the 737 copilot wearing an oxygen mask but slumped over the controls. The passenger oxygen masks had deployed. And many of the bodies were reportedly found frozen, possibly indicating the jet's environmental control failed at altitude.
While the extremes at 30,000 feet are foreign to most general aviation aircraft, the issues are not as far removed from the typical single-engine pilot as you might think. Any time you fly above 10,000 feet (5,000 feet at night), you need to think about hypoxia - what effect diminished oxygen levels can have on you and your ability to fly the aircraft safely.
AOPA Online has a wealth of resources on the subject. For a quick review, see the Sporty's Safety Quiz on hypoxia in the AOPA Online Safety Center.
" By the Book: Hypoxia" is an in-depth explanation of the condition. Steve Ells describes how just changing his breathing patterns made him a safer pilot in " Airframe and Powerplant: Hypoxia Lowdown." And for even more information, see " High-Altitude Flying."
August 15, 2005