On March 16, 1993, a Beech F33A (registration N5592A) operated by Niehus, William B. was involved in an aviation accident near Park, KS. Investigators recorded the probable cause as: The cause of the accident was the physical incapacitation of the pilot, though the specific source of carbon monoxide fumes entering the cabin could not be determined. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A seventy-three-year-old pilot became incapacitated during a solo cross-country flight, leading to an airplane impact with terrain during the cruise phase.
What happened
A 73-year-old private pilot was conducting a solo cross-country flight when he became physically incapacitated for unknown reasons. During the cruise phase of the flight, the aircraft began to descend until it impacted the terrain. Following the impact, the airplane skipped and slid for 1,450 feet before coming to a complete stop.
The investigation
Medical evaluation at a hospital following the accident revealed that the pilot had 9% carbon monoxide in his blood. Investigators performed a post-accident examination of the aircraft and the cockpit heat muffler; however, this inspection failed to identify a specific source for exhaust fumes entering the cabin. The pilot, who was a non-smoker, noted that his most recent medical certificate had been issued in 1988.
Probable cause
The cause of the accident was the physical incapacitation of the pilot, though the specific source of carbon monoxide fumes entering the cabin could not be determined.