Incident Summary
Following departure, the pilot observed that the tachometer for the left propeller was not operating. The pilot decided to continue the flight after determining that he could keep the left and right propellers synchronized at both full and cruise power settings. The flight proceeded without further incident until the pilot began to reduce power in preparation for landing.
Approach Phase
When power was reduced, the propeller synchronization problem re-emerged. While on final approach, the pilot became preoccupied with managing this issue. His attention was absorbed by the synchronization difficulty, and the aircraft impacted trees. The collision occurred while the aircraft was on final approach.
Operational Context
The pilot had initially addressed the tachometer malfunction by relying on manual propeller synchronization. The problem was manageable at higher power settings but reappeared when power was reduced for landing. The pilot's focus on the synchronization problem coincided with the aircraft's impact with trees.