Accident Overview
An aircraft was on final approach to land when the engine lost power. The pilot reported that after the power loss, he switched fuel tanks, activated the electric fuel boost pump, and operated the related wobble pump as rapidly as possible, but was unable to restore engine power. The aircraft subsequently crashed into a building and cartwheeled into a parking lot.
Fuel System Examination
Examination of the wreckage revealed that the left fuel tank was empty. Approximately 10 gallons of fuel remained in the right tank, and an undetermined amount of fuel was present in the auxiliary tank.
Investigation of the wobble pump/fuel selector assembly disclosed that the tank selector valve (part number 35-924068) had been modified but was not installed in accordance with the manufacturer's specification. The selector's detent ball (part number 35-921166) was missing, and the assembly's spring was riding on the valve. Additionally, the assembly's housing (part number 35-921185) was damaged. In this condition, the pilot could not determine the exact position of the selector valve.
Final Moments
Examination of the aircraft revealed that it had crashed in a steep nose-down, left-wing-low attitude.