What happened
During a ferry flight, the aircraft experienced an in-flight engine shutdown that necessitated a forced landing. The pilot had refueled the empty right tank and topped off the left tank with three gallons prior to departure. While airborne, the pilot operated on the left tank until it was nearly depleted before switching to the right tank. Shortly after this switch, the engine stopped. The pilot switched back to the left tank and temporarily regained power, but the engine quit again shortly thereafter. Attempts to restart using the hand primer while selecting the right tank were unsuccessful. Consequently, the pilot selected a dirt road for an emergency landing, during which the aircraft collided with a ditch and collapsed its landing gear.
The investigation
Post-accident examination uncovered several critical discrepancies within the fuel system that contributed to the failure. Investigators found that no filter screen was installed in the gascolator, leaving the system vulnerable to debris. Additionally, the mixture control was not properly attached, compromising engine management. The right fuel tank was found to be contaminated, and its drain sump could not be operated. Furthermore, the carburetor contained water and contamination at the bottom of the float chamber.
Findings
The sequence of events indicates that fuel contamination and mechanical irregularities in the fuel system were primary factors. The lack of a filter screen, improper attachment of the mixture control, and the presence of water and debris in the carburetor likely restricted fuel flow or caused erratic engine operation. The inability to drain the right tank suggests long-term maintenance issues that allowed contaminants to accumulate.