What happened
The aircraft had landed at the 5,600-foot level of Ruth Glacier for a 20-minute tourist stopover. During this time, another flight operated by a company senior pilot also landed on the glacier. The senior pilot observed that a fuel tank filler cap was hanging loose on the accident aircraft. Upon inspection, the two pilots measured the fuel levels in the tanks and discovered that one tank was empty.
The pilots decided to depart the glacier to verify the accuracy of the fuel gauges in a level flight attitude. They agreed that if the pilot had any doubt regarding the sufficiency of the fuel quantity, he would return to the glacier, at which point they would provide additional fuel.
Approximately three minutes after takeoff, the engine stopped functioning. The aircraft subsequently made a crash landing at an elevation of 2,800 feet. During the descent following the engine failure, the pilot instructed passengers to fasten their seatbelts. The passengers reported that they were not aware that an impact was imminent.
The investigation
Post-accident examination revealed that the right fuel tank was empty, while the left tank contained between 2 and 5 gallons of fuel. A passenger noted that during the initial flight from Talkeetna to the glacier, the right tank had been indicating an empty status.