Air Tractor AT 602 N50634 accident near Walls, Mississippi

Probable cause

The improper fuel servicing of the airplane, which resulted in water contamination of the airplane's fuel supply and a subsequent loss of engine power.

NTSB analysis

The pilot reported that he had been conducting an aerial application flight for a few hours and returned to the airport to reload. While one loader was loading, another loader used a forklift to tilt the fuel tank so that fuel would flow toward the suction hose on the tank. The airplane was fueled with about 100 gallons of fuel. Once loading was complete, the pilot departed. He reported that the takeoff was normal until about 1/4 mile past the end of the airstrip; the airplane then lost engine power, which resulted a forced landing and substantial damage to the fuselage and right wing. He reported that the airplane had been functioning normally up until that time.

A postaccident examination of the airplane revealed a large quantity of water contamination in the fuel system components. No other preimpact anomalies were detected.

Based on the available evidence, it is likely that ground personnel’s use of the forklift to tilt the fuel tank allowed water that had settled in the bottom of the tank to be drawn into the suction hose, thereby contaminating the fuel being delivered to the airplane. The resulting contamination of the airplane's fuel supply was significant enough to result in the loss of engine power.

Text from the NTSB. Open the NTSB docket for CEN19LA244 for the full record.