Wednesday, September 1, 2004
A Deadly Sense of Euphoria
Understanding the signs of hypoxia may just get you out of trouble
The PA-28R-200 wasn’t equipped with a supplemental oxygen system and wasn’t pressurized, but the operator reported that the pilot didn’t take a portable supplemental oxygen unit with her; no supplemental oxygen equipment was found at the accident site. FAR Part 91, Section 211(a) prohibits any person from operating a civil aircraft at cabin pressure with altitudes above 12,500 feet MSL up to and including 14,000 feet MSL “unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that’s of more than 30 minutes duration.” The regulation provides data that for cabin-pressure altitudes that are above 14,000 feet MSL, the required minimum flight crew must be provided with and use supplemental oxygen during the entire flight time at those altitudes. It also requires that for cabin pressure altitudes above 15,000 feet MSL, each occupant of the aircraft must be provided with supplemental oxygen.
The airplane was equipped with left- and right-wing fuel tanks, each containing 25 gallons, giving a total of 48 usable gallons. The fuel selector can be set to “right,” “left” or “off.” The manufacturer recommends alternating tanks to keep the airplane in lateral trim. A representative of the airplane’s manufacturer told investigators that the manufacturer recommends flight-planning for an engine fuel burn rate of 12 gph, which accounts for fuel used during the climb. The representative said that a pilot flying a night and VFR flight, with the required 45-minute reserve and a 12-gph burn rate, could flight-plan for an approximate three hours and 15 minutes of maximum flight. The airplane’s Pilot Information Manual states that its service ceiling was 15,000 feet, and its absolute ceiling was 17,000 feet. Based on evidence that the engine had stopped running some time before impact and the extent of the fire, which broke out during the accident sequence, investigators determined that it was likely the airplane still had 10 or more gallons of fuel on board when it crashed, and the engine stopped when it became starved of fuel due to the pilot’s mismanagement of the fuel system.
At 8:53, the weather conditions at Canyonlands Field in Moab, Utah, about 36 nm from the accident site, showed the wind from 220 degrees at three knots, visibility at 10 miles, clear sky, temperature at 36 degrees F, dew point at 19 degrees F and an altimeter setting of 30.20. Winds-aloft data for the area around Grand Junction indicated that around the time of the accident, at 12,000 feet, the wind was coming from 285 degrees at 18 knots. At 14,000 feet, the wind was 290 degrees at 27 knots, and at 16,000 feet, it was 275 degrees at 33 knots. Radar data showed that after about an hour and 15 minutes of flying, the airplane’s groundspeed had diminished to between 95 and 100 knots. Investigators were unable to find evidence of problems with the engine or the airframe, which might have affected the plane’s performance.
The NTSB determined that the probable cause of this accident was the loss of total engine power due to fuel starvation, the pilot’s inability to follow fuel-management procedures and directives, and the pilot’s inadequate preflight planning and preparation for the flight. Contributing factors were the pilot’s inability to adequately equip the airplane with supplemental oxygen, her hypoxic physical impairment and her total lack of experience in the type of operation.
Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, NY 10602-0831.
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