Accident Sequence
After takeoff, the flight proceeded to another airport where one touch-and-go landing was performed. The flight then proceeded to Venice Municipal Airport. A witness reported hearing an airplane for a total time of between 30 seconds and 1 minute. During the entire time she heard the airplane, the engine sputtered. She observed an airplane flying southbound, then observed the airplane bank to the right and descend nose low before the sound of the crash. The witness also reported it was a dark night.
Post-Accident Examination
The post-accident examination of the airplane revealed the fuel vent line was internally obstructed with an insect nest. Both fuel tank caps were of the vented type, and the air passages were clear. The crossover vent line from the right to left tank was crushed but free of obstructions.
Preflight Inspection Guidance
The Pilot's Operating Handbook indicates that during the preflight inspection, the fuel tank vent opening is to be checked for stoppage; though the handbook does not indicate to check that the vent line assembly into the fuel tank is free of obstructions.
Prior Reports and Action
The investigation revealed the left-seat occupant had noted on the day of the accident that the vent line was blocked and informed the owner of the airplane. The owner checked but it did not appear to him that the line was blocked. No subsequent maintenance was performed on the line. The airplane was then operated about 1 hour 13 minutes on two separate flights. The owner was aboard the airplane during one of the flights, which lasted about 20 minutes. The owner did not report any discrepancies during his 20-minute flight.
Service Manual Requirement
The airplane "Service Manual" indicates that, "Any fuel vent found plugged or restricted must be corrected prior to returning aircraft to service."
Probable Cause
Not explicitly stated in the source.