What happened
On the morning of 15 September 2025, a student pilot was conducting solo circuit training in a Jabiru J430, registration ZU-FSF, at Herminie Farm near Hartswater. The flight was being performed under visual meteorological conditions as part of a Part 141 training program. After completing several circuits with an instructor, the student pilot continued solo operations.
During the second solo circuit, the pilot initiated a go-around due to an unsatisfactory approach. While maintaining an altitude of approximately 1,000 feet, an unusual noise was heard from the engine, followed immediately by total engine failure. Despite attempts to restart the powerplant, the pilot was forced to execute a landing in a nearby farm field. The aircraft sustained minor damage to the left-wing tip and the left main gear strut, but the pilot escaped without injury.
The investigation
SACAA AIID investigators examined the Jabiru 3300A engine, which had accumulated 644.4 hours of operation. A teardown inspection performed by the manufacturer in George revealed significant internal destruction. The investigation focused on cylinder number 5, where the piston had been destroyed, scattering debris throughout the oil sump and filter. The inspection also identified a bent exhaust valve and a bent connecting rod.
Investigators noted that the circlip groove on the piston was rough and smaller than standard specifications. Evidence suggested that a circlip had dislodged from the gudgeon pin, leading to the catastrophic internal failure.