Accident Overview
The airplane collided with terrain following a loss of control during the takeoff/initial climb phase. It was the last of five aircraft traveling to another airport for a group's overnight trip.
Witness Observations
Witnesses reported hearing a loud bang when the airplane reached approximately 800 feet above ground level (agl). They observed the airplane roll once or twice as the nose pitched downward.
Wreckage and Fire
The airplane came to rest with its tail in an avocado tree and was largely consumed by fire.
Investigation Findings
Due to extensive mechanical and thermal damage, investigators could not establish control continuity. Examination of the fuel manifold valve revealed a thin coating of a viscous amber substance with a strong, foul odor on the screen, interior, and the line leading to the pressure gauge. Gas chromatography with mass spectrometry (GC/MS) identified major peaks for fatty acids and fatty nitriles with even numbers of carbon atoms, indicating the most likely source of the residue was biological contamination of the fuel. None of the additives or sealants approved by Teledyne Continental Motors were identified, and the compounds did not appear to be simple breakdown or combustion products of approved additives or sealants. The substance did not clog the valve or screen, and the fuel nozzles were open. No anomalies were found that would have prevented normal operation or production of rated power.