What happened
While performing a cross-country flight, the pilot reported to air traffic control that the left engine of the aircraft had lost power, making it impossible to maintain the current altitude. Although air traffic control suggested a closer airfield, the pilot opted to divert to a more distant airport featuring a 9,003-foot runway. During the approach, the pilot descended while circling the runway end twice. The aircraft approached the runway on a glide path significantly higher than standard.
Witnesses noted that the aircraft failed to touch the runway, and tracking data indicated an increase in ground speed as the plane passed over the runway. Surveillance footage captured the aircraft pitching up and to the left at the far end of the runway. The plane entered a descending left turn and struck the ground approximately one-quarter mile west of the runway departure end. The impact and subsequent fire destroyed the wreckage. There were 0 fatalities and 0 injuries reported in the provided text.
Findings
Investigators determined that the pilot likely attempted a single-engine go-around after failing to establish an appropriate airspeed and altitude. During the maneuvers required for this climb, the pilot lost control, leading to the uncontrolled descent.
Technical analysis of the engines revealed that the left engine's propeller was feathered and not rotating under power at the time of impact, while the right engine showed signs of powered rotation. A post-accident inspection of the left engine identified severe detonation damage in the No. 4 cylinder piston.
Contamination of the fuel servos was identified as a critical factor. Both the left and right engine fuel servos contained significant amounts of sand-like debris, identified as polyethylene terephthalate (PET). This substance, a common thermoplastic polymer, was found in the inlet filters of both engines. Additionally, the right engine showed evidence of a lean fuel-to-air ratio. It is believed that this contamination caused unpredictable fuel-to-air ratios, leading to the engine power loss and the detonation in the left engine. The exact source and timing of the PET introduction into the fuel system could not be determined due to fire damage.