What happened
The pilot was conducting a flight training exercise that involved making a power-off approach to simulate a forced landing. During this maneuver, the aircraft overshot the intended touchdown point on the runway. In an attempt to recover from the overshoot, the pilot added engine power; however, the engine ceased operating shortly thereafter.
Facing trees at the end of the runway, the pilot executed a 90-degree turn to land in a plowed field adjacent to the airfield. The aircraft struck the top of a fence before impacting the ground in a flat attitude. Following the impact, the aircraft nosed over. At the time of the incident, the surface temperature was recorded at 90 degrees Fahrenheit.
The investigation
Investigators examined the aircraft and the circumstances surrounding the engine failure. A thorough mechanical inspection revealed no evidence of pre-impact mechanical malfunction or failure that would account for the loss of power. The absence of mechanical defects pointed toward an operational cause related to fuel management.
Findings
The primary factor contributing to the accident was the use of automobile fuel in an aircraft engine designed for aviation gasoline. This misuse of fuel led to fuel exhaustion or contamination, causing the engine to stop during a critical phase of flight. The pilot's decision to add power after overshooting the runway triggered the failure, leaving insufficient altitude and distance to return to the airport safely.
Safety message
Pilots must ensure that only approved aviation fuel is used in aircraft engines. Using automobile fuel can lead to catastrophic engine failure due to differences in octane ratings, additives, and water content.