What happened
Following a refueling stop, the pilot departed at night and reached a cruising altitude of flight level 200. Approximately 30 minutes into the flight, the right engine fuel filter bypass warning light illuminated. Two minutes later, the left engine's fuel filter bypass warning light also activated. Shortly after these warnings, the right engine lost power, followed by the loss of power to the left engine.
The pilot performed a forced landing on a moving ice pack located in the Bering Sea. The impact resulted in substantial damage to the aircraft; there were no fatalities or injuries reported.
The investigation
Post-accident examination revealed that ice was present within the engine and the main fuel screens. Investigators found significant amounts of water and/or ice inside three fuel tanks that had been refueled prior to takeoff. Additionally, a fuel sample taken from the nozzle of the refueling tanker contained a higher than normal amount of water.
Findings
Investigation determined that the fuel at the refueling stop was not premixed with an approved ice inhibitor. While the flight manual requires an approved ice inhibitor (such as PRIST) to be added to non-premixed fuel, the pilot did not have any icing inhibitor on board for this flight. Furthermore, the pilot did not drain the fuel from the tanks during the preflight inspection because extreme cold temperatures created a fear that the fuel drains might freeze in the open position.