Incident Overview
A pilot reported a complete loss of engine power at approximately 800 feet above ground level shortly after departing from Cook Field. The pilot noted that the windshield was covered with oil, necessitating the use of the side window for visibility. The pilot executed a landing in a grassy field, during which the nose wheel collapsed. The aircraft came to rest about midway along the 1,600-foot field. All passengers exited without injuries, according to the pilot.
Post-Landing Fire
A short time after the occupants cleared the accident site, the airplane became engulfed in flames. The fire eventually burned the fuselage and the inboard sections of both wings.
Examination Findings
Post-accident examination revealed that the number six cylinder had separated from the rest of the engine assembly. The crankshaft was fractured, and one propeller blade was fractured at the hub. The propeller hub was examined by McCaully Propeller Systems. The examination showed that the blade, serial number K95501YS, had failed in fatigue, with the fatigue origin located in the thread root. No anomaly or material/manufacturing defect was found. Additionally, internal components of the propeller contained a substantial amount of rust and rust residue.
Maintenance History
The specified time-between-overhaul (TBO) for the accident propeller was 1,200 hours or 60 calendar months, whichever occurred first. The propeller had never been overhauled and had been in service for 19 years since new. Furthermore, FAA Airworthiness Directive 91-15-04, which requires the propeller model to be modified to an oil-filled type for crack detection, had not been complied with.