What happened
Approximately fifteen minutes after takeoff, the aircraft experienced a loss of engine power while it was positioned on the downwind leg for an approach to a private airstrip. Unable to maintain altitude or complete the landing pattern, the aircraft descended and struck the tops of two trees. The impact caused the aircraft to crash and come to rest approximately 100 yards south of the runway.
The investigation
A thorough examination of the wreckage did not reveal any pre-impact mechanical failures that would account for the loss of power. The upper wing fuel tank was found to be empty, while the fuselage fuel tank had sustained damage during the impact sequence. Fuel from the damaged fuselage tank spilled onto the pilot's clothing and body.
Inspection of the fuel system controls showed that the wing fuel tank selector valve was in the off position, whereas the fuselage tank valve was in the on position. The engine was partially disassembled for analysis, but no pre-impact mechanical malfunction was noted within the powerplant itself. However, contaminants were identified in the fuel strainer. Additionally, yellowish-colored fuel containing additional contaminants was removed from the carburetor.
Findings
The investigation determined that fuel contamination was the critical factor in this accident. The presence of foreign material in both the fuel strainer and the carburetor likely restricted fuel flow or caused engine starvation, leading to the power loss. Although the wing tank selector was off, the fuselage tank valve was on, suggesting the contaminated fuel originated from that source rather than total fuel exhaustion.