What happened
On 20 February 2026, a Jabiru J430, registration ZU-ESS, was conducting a private flight from Witbank Aerodrome to Deneysville Airfield. While cruising at 6,400 feet, the pilot experienced a rapid succession of technical failures, beginning with the loss of the engine RPM indicator, followed by the failure of the GPS unit and the loss of radio connectivity.
As the pilot managed the emergency, engine vibrations became noticeable. Seeking to avoid a potential onboard fire, the pilot identified a grass airstrip on a private farm near Heidelberg for a precautionary landing. During the approach, the pilot executed a go-around before attempting a second landing with 30 degrees of flaps. The aircraft experienced a hard touchdown and a subsequent bounce. During the second touchdown and subsequent landing roll, the engine ceased operation. The pilot and passenger were uninjured, though the aircraft sustained minor damage to the propeller blades.
The investigation
SACAA AIID investigators examined the aircraft's Jabiru 3300 6-cylinder engine following its recovery to a maintenance organization. A teardown inspection of the engine revealed significant internal damage. Engineers discovered scoring marks on the journals and metal shavings within the crankcase.
Crucially, the inspection determined that the crankshaft had broken between the Number 2 main journal and the Number 1 big end journal. Measurements showed that the crankshaft journals were 0.010 inches undersized compared to the standards required by the engine overhaul manual. Furthermore, the main bearing shells were also 0.010 inches undersized, which created excessive crankshaft end float and caused damage to the front side faces of the connecting rods.