Accident Overview
An aircraft experienced a loss of engine power while maneuvering in mountainous terrain under marginal weather conditions. The subsequent collision with trees and terrain resulted in substantial damage to the aircraft.
Preflight Conditions
Prior to the flight, the pilot received a weather briefing that detailed mountain obscuration and advised that visual flight rules (VFR) were not recommended. Despite this advisory, the flight proceeded.
Maintenance and Preceding Incident
During a flight before the accident, the aircraft had experienced a carburetor fire. A review of maintenance records indicated that proper procedures, as outlined in the manufacturer's maintenance manual, were not followed during subsequent maintenance actions.
Post-Accident Examination
Examination of the carburetor after the accident revealed that the accelerator pump plunger retainer washer was worn and had slipped off the plunger seat. Additionally, evidence of backfiring was found in the carburetor air box, air filter, and venturi. Records showed that the air box had been cleaned and the air filter reportedly replaced prior to the accident flight.