Accident Sequence
The pilot had refueled the auxiliary tanks of the airplane at a different airport one month prior to the accident and had not used those tanks since. While repositioning the aircraft to home base after a series of revenue flights, approximately 20 minutes after takeoff, the pilot switched the left and right engines to their respective auxiliary fuel tanks. Thirty minutes later, the pilot returned the engines to the main tanks. Shortly thereafter, the right engine began to surge and subsequently stopped running. Activating the fuel boost pump restarted the engine, but five minutes later the engine quit again. After unsuccessful restart attempts, the pilot secured the right engine.
Then the left engine began to surge and was developing only partial power. The pilot diverted to an alternate airport with decaying altitude and power in the remaining engine. Upon crossing the airport, the pilot realized he was too high to land with a tailwind, so he circled to land into the wind. On the base leg, due to power lines in his path, rapidly decaying altitude, and power, he decided to land straight ahead in a field. During the landing roll, the airplane collided with a ditch.
Fuel Contamination
Examination of the left and right main fuel filters revealed a foreign substance, which laboratory analysis identified as polyacrylamide. This is a manmade synthetic polymer used as an agricultural soil amendment to reduce soil erosion. The distribution of this polymer is typically not performed by aircraft.
Fueling Facility Issues
Inspection of the fueling facility where the auxiliary tanks were filled showed that employees responsible for refueling had received no formal or on-the-job training. There was no record that the delivery system filters had been examined or changed. Maintenance of the truck, delivery system, and storage facility was performed by employees on an as-needed, time-permitted basis. The fuel truck was improperly labeled, and the fuel nozzle was lying in a compartment amid dirt, gravel, and other contaminants with no caps or covers for protection.