Wednesday, September 1, 2004
A Deadly Sense of Euphoria
Understanding the signs of hypoxia may just get you out of trouble
One of the subjects that is frequently emphasized in the materials that are published by the Federal Aviation Administration’s (FAA) Aeromedical Education Division is hypoxia, which is more commonly referred to as “oxygen starvation.” The FAA points out that hypoxia is insidious in its onset. It sneaks up on you, and you lose the ability to sense that something is going wrong. Altitude-chamber tests have shown that as oxygen deprivation increases, some victims experience a sense of increasing well-being, even euphoria, while they’re losing the ability to function in a thoughtful, coordinated manner. The FAA points out that even though it’s not required by regulation, it’s prudent to use supplemental oxygen at night when flying above 6,000 feet MSL because vision is particularly sensitive to diminished oxygen.
According to the National Transportation Safety Board’s (NTSB) report, on January 23, 2003, at 8:37 p.m., mountain standard time, a Piper PA-28R-200 was destroyed when it crashed and burned in a night forced landing attempt near La Sal, Utah. The private pilot, who wasn’t instrument-rated, and her three passengers were fatally injured. Visual meteorological conditions prevailed for the personal flight, which began in Longmont, Colo., and was expected to finish in Las Vegas.
At 4:24 p.m., the pilot called the Denver Automated Flight Service Station (AFSS) to file a flight plan and get a weather briefing. She changed her original flight plan from going direct to Grand Junction, Colo., then to Las Vegas, to another flight plan going to Pueblo and Durango, Colo., to St. George, Utah, to Las Vegas. The pilot requested an altitude of 15,500 feet, estimated a cruising airspeed of 140 knots—a time en route of four hours—and told the briefer that she’d have eight hours of fuel onboard, which was about twice what the airplane actually carried.
Witnesses reported that the airplane began to taxi for takeoff between 4:45 and 4:50. The first radar return was recorded at 4:58. At 5:02, the pilot contacted Denver radio to open her VFR flight plan. Denver Air Route Traffic Control Center (ARTCC) radar data indicates that the Piper PA-28R-200 flew south to Walsenburg, Colo., and at approximately 6:10, turned west toward Alamosa, Colo. Radar data indicates that the pilot flew above 12,500 feet for two hours and 17 minutes. One hour and 49 minutes of that time were spent above 14,000 feet, and about 45 minutes were spent above 16,000 feet.
While flying above 14,000 feet, from 6:42 to 8:31, the pilot received numerous heading corrections from ARTCC, some of them by as much as 70 degrees. On one occasion, the pilot reported that she was over Montrose, Colo., and the ARTCC informed her that she actually was over Telluride, Colo.
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