Aircraft: Beech Bonanza. Injuries: 1 Fatal. Location: Taos, N.M. Aircraft damage: Destroyed.
What reportedly happened: The 79-year-old private pilot, who held an instrument rating and had logged 1,643 hours, obtained two abbreviated weather briefings prior to departure.
He initially planned to fly a familiar route over mountainous terrain, but then changed his proposed route of flight to one that would take him further north over the mountains on an unfamiliar path.
He did not obtain any additional weather briefings. Had he obtained a weather briefing for his revised flight path, he would have received an AIRMET for mountain obscuration along his route of flight.
A review of GPS track data revealed that the flight was uneventful until the pilot began to cross over the mountains on a northwesterly heading at 12,500 feet. The airplane entered IFR conditions, which witnesses described as a fast, west-to-east moving front that involved mountain obscuration, turbulence, snow, and icing conditions.
During the last 4 1/2 minutes of the flight, the pilot began a series of climbing and descending turns that involved variations in airspeeds consistent with a loss of situational awareness or disorientation. The last recorded data by an onboard GPS indicated the airplane was at an altitude of 11,279 feet on a heading of 084° at a groundspeed of 81 knots. The airplane crashed in mountainous terrain at an elevation of about 10,700 feet.
A post-accident examination revealed no mechanical deficiencies with the airplane or the engine. Results of postmortem toxicology testing were consistent with the relatively recent use of an impairing antihistamine, which is often used to treat allergies. It is possible that the pilot was impaired by his recent use of the antihistamine, although the role of any such impairment in the accident sequence could not be established.
Probable cause: The pilot’s continued visual flight into instrument meteorological conditions, which resulted in loss of situational awareness, and a possible encounter with icing conditions.
NTSB Identification: CEN11FA347
This May 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.