Incident Overview
During departure from an airport, the pilot and a pilot-rated passenger experienced a loss of engine power at an altitude between 300 and 600 feet above ground level. The aircraft subsequently turned to the right, entered a steep descent, and crashed.
Investigation Findings
Post-accident examination found no preimpact part failure or malfunction of the aircraft or engine. However, the investigation revealed that the aircraft had been serviced with auto fuel. Approximately 24 hours after the accident, a fuel sample showed a Reid vapor pressure (RVP) of 11.8. The fuel supplier stated that the auto fuel consisted of 17.5% winter-grade fuel and 82.5% summer-grade fuel. By comparison, aviation fuel typically has an RVP between 5.5 and 7, making it less susceptible to vapor lock.
Aircraft Modifications
The aircraft log indicated that the aircraft had been modified under Supplemental Type Certificates SA2010CE and SE1931CE for auto fuel usage. However, required identification clamps and placards were not installed. The carburetor float was made of composite material.
Weather and Carburetor Icing Conditions
At the time of the accident, the temperature was 80°F and the dew point was 50°F. According to carburetor icing charts, serious carburetor icing could have occurred at glide power, and visible icing was possible at rated power.