Primary finding
Probable cause
The failure of the throttle valve actuating arm which resulted in partial opening of the throttle valve. A factor related to the accident was the unsuitable terrain available for landing.
Investigator assessment
Analysis narrative
While at cruise, the airplane's engine lost partial power. The pilot reported that he applied carburetor heat and checked the oil temperature and pressure. The engine did not regain power. The pilot attempted to make a forced landing in a yard below the airplane's flight path but during the approach to landing, the airplane collided with trees. The airplane fell to the ground and came to rest inverted. Post accident examination of the airplane did not reveal any airframe anomalies. The engine was dismantled and examined. Examination of the carburetor revealed that the throttle valve actuating arm, which was fastened to the throttle shaft, was loose and therefore would not open the throttle valve fully.
Source record
Factual narrative
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