On July 26, 1993, a Beech B19 (registration N1976W) operated by Mack C. Goodwin was involved in an aviation accident near Birmingham, MI. Investigators recorded the probable cause as: AN IMPROPER GRADE OF FUEL WAS LOADED INTO THE AIRPLANE BY THE OWNER/OPERATOR OF THE RENTAL AIRPLANE, IMPROPER PLANNING AND/OR DECISION BY THE PILOT, AND SUBSEQUENT VAPOR LOCK IN THE FUEL SYSTEM OF THE AIRPLANE (FUEL SYSTEM - OTHER), WHICH RESULTED IN FUEL… This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During takeoff, engine power loss led to a forced landing on a railroad bed, damaging the airplane. Investigators found the airplane was serviced with automotive fuel not certified for use, causing unreliable operation due to vapor lock.
Pilot Report
According to the pilot's report, during takeoff, as the airplane passed over the departure end of the runway, the engine began to lose power. The pilot subsequently performed a forced landing on a railroad bed located between two railroad tracks, resulting in damage to the airplane.
Investigation
An investigation into the incident found that the airplane had been serviced with automotive fuel. The fuel was identified as 87 octane and contained 10% ethanol. The airplane was not certified for the use of automotive fuel. Further testing demonstrated that engine operation was not reliable when using automotive fuel, due to vapor lock.
Additionally, an FAA/PMI representative reported that the pilot was aware of the use of automotive fuel in the airplane, although the pilot did not specifically identify the fuel as automotive during the preflight inspection.