Accident Summary
Shortly after takeoff, at an altitude of about 25 feet above ground level, the pilot reported hearing a loud bang. The aircraft subsequently settled back onto the runway, after which power was regained. However, the aircraft then veered off the left side of the runway and nosed over.
Investigation Findings
Post-accident inspection revealed that maintenance personnel had overhauled the fuel selector valve to remedy a leak but had reassembled the unit incorrectly. Additionally, the owner and pilot did not insist that the valve problem be remedied.
Conclusion
The accident occurred as a result of the incorrect reassembly of the fuel selector valve by maintenance personnel, combined with the failure of the owner and pilot to insist on the valve problem being remedied.