What happened
During a familiarization flight, a pilot was executing the landing pattern at an airport when the engine suffered a complete loss of power. The pilot reported that the power loss occurred shortly after activating the carburetor heat and switching the fuel selector to the right tank. Following multiple failed attempts to restart the engine, the pilot determined that the runway was unreachable and initiated an emergency landing in a nearby small field.
During the descent toward the field, the aircraft type struck a power line. The impact caused the plane to nose over and come to rest in an inverted position. The accident resulted in substantial damage to the fuselage and the wings.
Findings
An investigation of the fuel system following the accident revealed approximately 16 ounces of water within the components. This moisture was identified in the lower gascolator, the fine fuel filter, and the fuel line leading to the carburetor inlet. Additionally, corrosion, rust, and water were found on the brass screen at the carburetor inlet and within two carburetor fuel bowl thumb screens.
Maintenance records indicated that the fine fuel filter was not easily accessible for drainage during standard preflight checks. While the aircraft inspection checklist required the cleaning or replacement of the fine fuel filter every 100 hours, the most recent maintenance performed by the mechanic did not include draining or inspecting this specific filter. The last documented cleaning of the fuel filters occurred approximately four years prior to the incident, suggesting water contamination in the fuel system was the primary factor in the engine failure.