What happened
On 09 August 2011, an Atlas C4M Kudu, registration ZS-WYC, departed The Ranch private aerodrome for Rustenburg under visual flight rules. The flight, which included the pilot and two passengers, proceeded normally through Lowveld and Johannesburg airspaces. As the aircraft approached Rustenburg aerodrome, the pilot attempted to land on runway 3．4 but aborted the approach to perform a go-around due to traffic and obstacles near the Oliphant Nek dam.
During the go-around maneuver, at an altitude of approximately 1,200 feet, a fuel warning light illuminated in the cockpit. Shortly thereafter, the engine began to sputter and power dropped significantly. The pilot attempted to use the emergency fuel control unit override, but the engine failed to respond. Unable to maintain flight, the pilot identified an open field on a nearby farm and initiated an emergency landing. While the initial touchdown on the grass was successful, the aircraft entered a ploughed field, where it struck the nose and flipped over. All three occupants escaped the substantially damaged aircraft without injury.
The investigation
SACAA AIID investigators examined the wreckage and the aircraft's maintenance history. The investigation confirmed that the aircraft had been properly maintained, with the last annual inspection completed only 40.6 hours prior to the incident. Meteorological conditions were clear with good visibility, and the pilot held valid commercial and medical certifications.
Technical analysis of the fuel system revealed no mechanical blockages or leaks. However, investigators found evidence of vapor in the airframe fuel filter. Testing at a facility in Wonderboom demonstrated that the engine was capable of full power when supplied with sufficient fuel. The investigation also noted that while 152.2 liters of fuel had been added prior to departure, there was no formal record of the total fuel quantity on board, and the aircraft's consumption rate of approximately 220 liters per hour meant the remaining supply was critically low.
Findings
- The primary cause of the incident was an unsuccessful forced landing following fuel exhaustion during flight.
- The engine failure was exacerbated by fuel pump cavitation, occurring because the fuel level was too low to maintain a steady supply.
- The pilot performed an incorrect assessment of the available fuel quantity.
- There was a miscalculation regarding the total fuel required for the mission.
- The operator lacked formal records of fuel upliftments, and the flight folio was not maintained in an updated state.