What happened
The aircraft was operating under normal conditions when the engine began to exhibit irregular performance. The pilot reported a surging condition and specifically described the engine sound as sputtering, indicating a rough running state. In response to this mechanical anomaly, the pilot initiated an off-airport precautionary landing.
During the landing maneuver, the aircraft lost control or failed to clear obstacles, resulting in a collision with a tree. The impact occurred while the aircraft was attempting to land outside of a designated airport environment.
The investigation
Following the incident, investigators examined the aircraft's fuel system to determine the cause of the engine's rough operation. A total of approximately 1.5 gallons of 100LL aviation gasoline were drained from each wing tank. The presence of fuel in both tanks suggests that fuel exhaustion was not the primary cause, pointing instead toward a mechanical failure or contamination within the engine itself.
Findings
The primary factor leading to the accident was the engine's rough running condition, characterized by surging and sputtering sounds. This loss of power or irregular operation necessitated an emergency landing in an unprepared area, which directly led to the collision with a tree.