What happened
During a repositioning flight to a home base following several revenue operations, the pilot transitioned the engines from the main fuel tanks to the auxiliary tanks approximately 20 minutes after takeoff. After 30 minutes of flight on the auxiliary tanks, the pilot switched back to the main fuel supply. Shortly thereafter, the right engine experienced surging and eventually ceased operation, though it was briefly restarted using the fuel boost pump. Five minutes later, the right engine failed again and could not be restarted.
Following the loss of the right engine, the left engine began surging and lost significant power. The pilot attempted to divert to an alternate airport, but the aircraft was losing altitude and power. While attempting to maneuver for a landing, the pilot encountered power lines and determined that a landing in a nearby field was necessary due to the deteriorating flight conditions. During the landing roll, the aircraft type struck a ditch.
Findings
Investigations into the fuel system revealed that both the left and right main fuel filters were contaminated with polyacrylamide, a synthetic polymer used in agriculture to prevent soil erosion. The investigation of the fueling station identified several critical failures in fuel handling procedures. Employees at the facility lacked formal or on-the-job training, and there were no documented records of inspections or filter changes for the delivery system. Furthermore, maintenance of the fuel truck and storage equipment was performed inconsistently. The fuel truck was found to be improperly labeled, and the fuel nozzle was stored in a compartment containing dirt and gravel without any protective covers.