What happened
The aircraft experienced an in-flight engine failure during the initial climb phase of a crop-dusting operation. At approximately 100 feet above ground level, the engine quit while the pilot was carrying a load of 125 gallons of fungicide intended for spraying trees. In response to the power loss, the pilot dumped the chemical load and maneuvered the aircraft to the right in an attempt to land in an open field.
During the forced landing approach, the aircraft struck a tree located on the boundary of the field. The impact caused the airframe to rotate approximately 45 degrees to the right before it settled on the ground. The aircraft bounced upon contact and eventually came to rest heading north in an upright position.
The investigation
A post-accident examination of the engine revealed that it would only operate with the electric fuel boost pump engaged. The mechanical failure was traced to the engine-driven fuel pump, specifically part number 638154-1. Examination showed that the drive shaft had sheared and the seizure occurred at the shaft seal, identified as part number 13507.
Findings
The primary contributing factor was the failure of the engine-driven fuel pump. The seizure of the pump's drive shaft resulted in a complete loss of engine power during a critical phase of flight. The pilot's decision to dump the load and attempt a field landing was consistent with emergency procedures, but the proximity of trees limited available options.
The accident highlights the risks associated with mechanical failures in agricultural operations where low-altitude maneuvering is required. The loss of engine power due to fuel system failure left the pilot with insufficient altitude to clear obstacles during the forced landing.