On January 18, 1993, a Cessna 310 (registration N1776G) operated by Olson Air Service, Inc was involved in an aviation accident near Teller, AK. Investigators recorded the probable cause as: THE PILOT-IN-COMMAND'S FAILURE TO MAINTAIN AN ADEQUATE TERRAIN AVOIDANCE ALTITUDE. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WERE THE DARK NIGHT AND FEATURELESS SNOW COVERED TERRAIN, BOTH WHICH CREATED A 'FEATURELESS TERRAIN ILLUSION' WHICH PROBABLY LED THE… This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An airplane collided with level, snow-covered terrain about 3 miles southeast of the destination airport during dark night conditions. The featureless terrain and lack of ground references preceded the accident.
Accident Overview
An airplane collided with nearly level terrain approximately 3 miles southeast of the destination airport. The terrain was covered with snow, featureless, and unilluminated, while the night sky was described as very dark. The accident occurred prior to the onset of civil twilight.
Navigation and Visibility Conditions
The destination airport is not served by any navigation aids; navigation in the area is conducted by pilotage. Witness reports indicated that visibility of ground reference objects was not possible due to total darkness and a lack of contrast with the complete snow-covered terrain.
Pilot Experience and Warnings
No record of pre-dawn company flights by the pilot during the past 90 days were found. The Cessna Aircraft Company provides a warning about the "featureless terrain illusion," noting that an absence of ground features—such as when landing over water, darkened areas, or terrain made featureless by snow—can create the illusion that the airplane is at a higher altitude than it actually is. The warning states that a pilot who does not recognize this illusion will tend to fly a lower approach.