Plane & Pilot
Tuesday, February 11, 2014

The Slippery Slope Of OSA

The FAA ignores obvious accident causes when it focuses on Obstructive Sleep Apnea

One of the accident pilots who actually did have sleep apnea reported the condition to the FAA and received a special-issuance medical certificate. According to the NTSB, his accident had nothing to do with sleep apnea. The pilot was on a VFR flight plan for a flight that went from sea-level terrain to mountains in Alaska. Although the weather briefing he received forecast isolated areas of low visibility, the mountain pass he had to traverse was forecast to be VFR in rain showers. The forecast turned out to be wrong; the Cessna T206H crashed into a mountain near Chickaloon, Alaska. The pilot and both passengers were killed. The NTSB determined that the probable cause of the accident was the pilot's continued VFR flight into instrument conditions and subsequent collision with mountainous terrain while maneuvering.

The FAA's fact sheet also claims that the NTSB's database contains 294 incidents involving some type of sleep disorder. My own "sleep" search returned 295 reports. These were quite consistent in having fatigue as the culprit, rather than a medical sleep disorder such as OSA, narcolepsy or insomnia, as might be inferred from the FAA's use of the term "sleep disorder."

One of the fatigue accidents involved a Cessna 172S that struck trees near Land O' Lakes, Fla., shortly before 2 a.m. The FAA-certificated private pilot was a Swiss citizen who worked as a captain of Airbus airplanes for a Swiss airline and had logged more than 13,000 hours. The VFR flight originated at Pensacola, Fla., and was destined for Tampa Executive Airport (VDF), Tampa, Fla.

At 1:49 a.m., Tampa Approach noticed that the airplane had descended below 1,000 feet, 15 miles from the airport. The pilot didn't respond to radio calls. The airplane continued in a gradual descent until radar contact was lost. The NTSB found that during the nine days before the accident, the pilot flew five days of international flights as captain, returning to Zurich three days before the accident. About four hours later, he began a trip as a passenger to Colorado. The day before the accident, the pilot began the three leg flight to Florida in the 172S. He had been awake for about 18 hours at the time of the accident, having stopped only for food and fuel.

The NTSB said that in the days before the accident, the pilot made three crossings of the Atlantic Ocean, each flight crossing six time zones. The NTSB said this disruption to his body's circadian rhy-thm would have hurt his ability to obtain restorative sleep. Add the pilot's extended time awake in the United States, and the result was fatigue. The NTSB didn't raise the subject of sleep apnea, concluding that the pilot's schedule resulted in fatigue that caused him to most likely fall asleep during the initial descent for landing.


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