What happened
On 12 December 2010, a Cessna 206G, registration ZS-OYV, departed from Hoedspruit Civil Aerodrome (FAHT) for a private flight destined for Kruger Mpumalanga International Aerodrome (FAKN). While the aircraft was traversing the Bushbuckridge area, the engine suddenly ceased operation. The pilot attempted to restart the engine, but the failure persisted.
Recognizing the situation, the pilot identified an open, grass-covered area for an emergency descent. During the forced landing, the aircraft sustained damage to the propeller, the nose landing gear, and the cargo pod attached to the lower fuselage. The pilot, who was the only person on board, escaped the incident without any injuries.
The investigation
Following the accident, the engine was removed and sent to a maintenance facility for a detailed teardown inspection. Investigators examined the mechanical state of the Continental IO-520-F engine to determine the origin of the power loss.
Technical analysis of the engine components revealed significant mechanical issues. Specifically, the inspection uncovered that the crankshaft had failed. Furthermore, evidence of mechanical fretting was found on the number three main bearing, and observations indicated that the bearing had shifted forward and backward within its casing. The engine manufacturer provided expert insight, noting that such patterns—including bearing movement and fretting—are often associated with under-torqued crankcase through bolts.