What happened
During a scheduled spray run, the pilot of the aircraft experienced a partial loss of engine power. In an attempt to recover, the pilot applied carburetor heat, pumped the throttle, and leaned the mixture. Despite these efforts, the pilot could not restore enough power to maintain altitude. The pilot subsequently performed an emergency landing in a soft, fallow field, which resulted in the aircraft nosing over.
The investigation
The engine was removed from the airframe for further examination. During the removal process and the subsequent preparation of the engine for a test run in a different aircraft, several mechanical issues were identified:
- Water was discovered in the fuel gascolator.
- Oil was found within the left magneto.
- A broken high tension lead was identified and replaced.
- A different carburetor air box was installed on the engine.
Following these interventions, the engine started and operated normally, though a slight roughness was noted when running at full rated power.