Incident Overview
A pilot reported that the airplane operated normally until arrival at the field designated for spraying. During the fourth swath run, the pilot noted that the airplane no longer felt as 'solid' as it had earlier in the flight. In response, the pilot chose to execute a precautionary landing in a nearby field.
Landing and Gear Collapse
During the landing roll, the main landing gear collapsed. The aircraft came to rest in the field after the gear failure.
Post-Incident Examination
An examination of the engine was conducted following the incident. Investigators found no mechanical problems with the engine. A subsequent test run demonstrated that the engine produced rated power, indicating normal performance.
Conclusion
The investigation did not identify a specific mechanical cause for the pilot's perception of diminished handling qualities or for the subsequent landing gear collapse. The engine was determined to be functioning properly.