Incident Overview
Following takeoff and after initiating a left turn to return to the field being sprayed, the pilot—who had accumulated 19,000 flight hours—reduced the propeller RPM. Subsequently, the two-bladed propeller "went to the full coarse setting and lost drive."
Forced Landing and Impact
During the ensuing forced landing, the airplane struck a power line and then impacted terrain. The sequence of events directly resulted from the loss of propeller drive.
Examination Findings
A post-incident examination of the propeller governor by a repair facility revealed that the "propeller governor pilot valve had failed, causing an internal oil leak, which resulted in the failure of the propeller governor." No other causal factors were identified in the available information.