Accident Sequence
The aircraft was performing a swath run spraying crops when the engine suddenly lost power. The pilot had 200 yards of level field remaining to conduct an emergency landing. After touchdown, the pilot turned the aircraft to avoid a collision with trees. During the turn, the nose of the aircraft dug into the ground, causing the aircraft to nose over.
Engine Inspection
Inspection of the engine revealed that the magneto coupling was locked and would not rotate. Further inspection disclosed excessive play in the pawls and worn striker pins and shaft splines.
Maintenance Records
According to the aircraft logbooks, Airworthiness Directives (AD) 78-09-07 and AD 82-20-01 had been complied with 19 flight hours prior to the accident. However, the make, model, and serial number of the magnetos were not entered as required by the directives.