Cessna 206C Uncontained Engine Failure During Aerial Survey (ZS-EZK)

Incident Overview and Flight Details On 29 November 2019, a Cessna 206C aircraft, registration ZS-EZK, departed Port Elizabeth Aerodrome (FAPE) for an aerial survey flight over the Port Alfred area. The aircraft was operated under Part 137 of the South African Civil Aviation Regulations. The flight crew consisted of a pilot and a photographer. Pre-flight inspections, including a walk-around and fuel sample check, revealed no abnormalities. The aircraft took off without incident and conducted the survey at approximately 250 km/h and 20,000 feet above ground level. ## Engine Failure and Emergency Landing While en route back to FAPE, the pilot heard a loud bang from the engine compartment. The engine subsequently vibrated, produced abnormal sounds, and emitted white smoke. The pilot identified a low oil pressure indication but the engine continued to run. A MAYDAY call was broadcast to air traffic control, and the pilot requested to land on Runway 26. Approximately three minutes later, a second loud bang occurred, followed by oil leakage and a loss of engine power. The pilot maintained control of the aircraft and used the remaining engine power to execute a safe landing. No injuries were reported, and damage was limited to the engine. ## Post-Incident Investigation and Findings The aircraft was equipped with a Continental TSIO-520-C engine. Post-incident inspection revealed a hole on the top left side of the crankcase, caused by the No. 4 connecting rod. A subsequent teardown examination at an independent facility confirmed that the No. 4 connecting rod and piston had disconnected from the crankshaft journal, with the connecting rod shaft found fractured. Evidence of heat discoloration was noted on the No. 4 connecting rod journal area. The investigation determined that the failure resulted from excessive heat concentrated on the No. 4 camshaft journal area due to oil starvation. The engine oil filter element showed significant deposits of copper and bronze-colored material.