What happened
On 1 October 2002, a Mooney M20F, registered ZS-FWD, departed Kimberley Aerodrome (FAKM) for a private flight destined for Lime Acres (FALC). Shortly after the aircraft became airborne, the engine suffered a sudden loss of power. In response to the failure, the pilot performed an emergency forced landing on the N12 national road, which connects to Cape Town.
During the descent and landing sequence, the aircraft struck a vehicle traveling on the highway. The impact caused the plane to veer left, exiting the roadway and crashing through a fence before coming to a stop in a nearby field. While the aircraft incurred substantial damage and the vehicle and fence sustained minor damage, there were no injuries to the pilot or the occupants of the vehicle.
The investigation
Investigators examined the aircraft's mechanical state and the fuel supply chain. The pilot was found to be fully qualified, holding a valid airline transport pilot license and a current medical certificate. Maintenance records indicated that the aircraft had been properly maintained according to regulations. Meteorological conditions at the time of the accident were reported as fine.
Regarding the fuel supply, inspections of the fuel filters at the Kimberley fuel depot revealed they were clean, and the fuel at the depot had passed contamination checks. However, a detailed examination of the aircraft's internal systems uncovered a critical issue within the fuel system itself.
Findings
- The primary cause of the engine power loss was severe dirt contamination within the aircraft's fuel system.
- The investigation identified that the fuel filter was contaminated with debris.
- It was determined that such contamination may not be detectable during standard fuel drain checks, as the dirt can become trapped within the filter itself, masking the presence of contaminants during routine inspections.