Accident Overview
An airline transport pilot, cleared for a localizer approach, impacted the ground 3.2 nautical miles from the runway threshold. The minimum descent altitude (MDA) for the approach was 560 feet mean sea level (msl), which is 263 feet above touchdown. Night, instrument meteorological conditions prevailed at the time.
Weather and Terrain
The surrounding terrain was flat, snow-covered, and featureless. Reported weather included 200 feet overcast ceiling, 1 1/2 miles visibility in snow, and winds from an unspecified direction at 12 knots gusting to 32 knots. The airport was equipped with high intensity runway lights, sequenced flashing lead-in lights, and visual approach slope indicator lights. All airport lights and navigation aids were functioning.
Pilot Testimony
The pilot reported that he was established on the final approach course, descending to the MDA, and then woke up in the snow. He stated he did not remember any problems with the airplane. No pre-accident mechanical anomalies were discovered with the airplane during the investigation.
Investigation Findings
The airplane was not equipped with an autopilot. Company policy allowed captains to request a copilot, but the captain's pay was reduced by a portion equal to one-half the copilot's pay. The pilot had returned from the previous night's trip at 0725. He had three rest periods—four hours, two hours, and five hours 15 minutes—since his previous night's flight. Each rest period was interrupted by contact with the company. The company indicated that it is the pilot's responsibility to inform the company if duty times are being exceeded. Title 14 CFR 135.267 requires that each assignment provide for at least 10 consecutive hours of rest during the 24 hours that precedes the planned completion of the assignment.
Probable Cause
The official probable cause was the pilot's descent below the minimum descent altitude on the instrument approach. Factors were pilot fatigue resulting from the pilot's rest period being interrupted by scheduling discussions and the night weather conditions of low ceilings and whiteout.