Incident Summary
An experimental RV-8 kit-plane, built by the pilot, experienced engine roughness approximately 100 feet above ground level while on approach. The pilot made a left 90-degree turn to return to the runway, during which all engine power was lost. Subsequently, the pilot turned back right and executed a hard landing, resulting in the collapse of the landing gear.
Investigation Findings
Post-crash examination of the aircraft's fuel system revealed that the fuel pick-up tube inside the right fuel tank had been mispositioned. The tube had twisted approximately 180 degrees, placing its pick-up end at the mid-level of the 21-gallon tank. This caused fuel starvation, as the tube could not draw fuel from the lower portion of the tank. Fueling records indicated that, according to the pilot's estimate, approximately 10 gallons of fuel were present in the right tank at the time of the incident.
Maintenance History
The pilot had performed maintenance on the right fuel tank several weeks before the incident. The work included tightening a hex nut that retained the 90-degree elbow fitting holding the pick-up tube in place. The design of the aircraft and its construction predated the dissemination of revised design plans that included an anti-rotation bracket. The manufacturer had not issued any notice regarding the bracket specifications to the pilot-builder. Consequently, the pilot-builder, unaware of these specifications, had not installed the anti-rotation bracket in the right fuel tank. Without this bracket, tightening the hex nut could inadvertently rotate the pick-up tube into a mispositioned orientation.