Primary finding
Probable cause
The loss of engine power due to a stuck carburetor needle valve; subsequent forced landing in unsuitable terrain, and impact with a tree.
Investigator assessment
Analysis narrative
After completing a 360 degree turn and returning to level flight the aircraft's engine lost power. The pilot elected to make a forced landing in a field. The airplane touched down in a field and struck a tree. Examination of the carburetor revealed that the needle valve was intermittently sticking on the seat. Further examination revealed that the spring wire clip on the needle valve was not strong enough to open up the valve when it got stuck.
Source record
Factual narrative
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