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.

The pilot responded with "Roger that. I appreciate it. I can't see a darn thing out here."

The radio communication between the pilot and ARTCC became increasingly difficult and erratic. Many other aircraft assisted in relaying information between the two.

The ARTCC radar data indicates that at about 8:30, the airplane departed at 14,800 feet. The rate of descent increased, and a maximum descent was calculated to be 1,077 fpm.

At 8:35, the pilot transmitted, "Denver radio, mayday, mayday. I've got myself in [unintelligible]."

At 8:37:42, the flight crew of a Federal Express airplane flying in the area radioed, "We just picked up a strong emergency locator transmitter [ELT] signal on 121.5. It's gone now."

The ELT signal wasn't received again. Two days later, the airplane's wreckage was discovered by a rancher.

The pilot had received her private-pilot certificate with a single-engine-land rating about two years before the accident. Her third-class medical certificate was current with no limitations. The pilot's flight logbook was not recovered. A couple of weeks before the accident, the pilot filled out an information sheet for a flying club, on which she reported having 128 hours of total flight time, 40 hours of which were in a high-performance, complex airplane.

The pilot flew with a flight instructor from the flying club three times, for a total of 3.7 hours. The flight instructor was an FAA Safety Counselor, and he commented that the pilot "always seemed to be in a hurry." He said that she would "run in the door, ready to go." All the flight time at the flying club was in a Cessna 172. The pilot had previously used the accident airplane for high-performance and complex airplane training. The instructor who flew with her said that he would not endorse her flight logbook for complex aircraft. He said that "she was a little behind the airplane in the traffic pattern." He told investigators that he never signed the flight center's rental agreement card for the pilot, authorizing her to operate the center's PA-28R-200. Five days after the accident, the flight instructor noted that the rental agreement card still had not been initialized by an instructor to fly the accident airplane. Several days after that, the NTSB's investigator-in-charge looked at the rental agreement card and observed an "okay" in the PA-28R-200 space. When the staff was queried about the sign-off, no one knew where it came from. The pilot had flown as a passenger with one of her friends on several trips in a Piper Navajo, a high-performance, twin-engine, complex airplane, but no documentation of her ever receiving a complex endorsement in her flight logbook could be found.

The NTSB noted that under Part 61 of the Federal Aviation Regulations (FARs), "no person may act as pilot in command of a complex airplane [an airplane that has a retractable landing gear, flaps and a controllable pitch propeller] unless that person has received a one-time endorsement in the pilot's logbook from an authorized instructor who certifies that the person is proficient to operate a complex airplane."

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.

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, visit www.ntsbreporter.us or write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, NY 10602-0831.

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