What happened
On 12 May 2016, a Jabiru SP, registration ZU-SES, departed Kitty Hawk Aerodrome for a private flight destined for Mooketsi. Shortly after becoming airborne, the pilot noted engine vibrations. During the initial climb, the aircraft suffered a partial loss of engine power. In an attempt to manage the emergency, the pilot executed a steep left turn to return to the runway, but the aircraft lost altitude rapidly. The aircraft impacted the ground at Plot 15, Boschkop, resulting in the death of the pilot and minor injuries to the passenger. The aircraft was destroyed upon impact.
The investigation
SACAA AIID investigators examined the wreckage and the engine components to determine the cause of the power loss. A teardown inspection of the engine revealed that a tappet adjuster for the number three cylinder's inlet valve had come loose and was found at the bottom of the rocker chamber. This failure rendered the valve inoperative, leaving the engine to operate on only three cylinders.
Furthermore, the investigation scrutinized the aircraft's weight and maintenance history. It was determined that the aircraft was operating significantly above its maximum certified take-off weight. The investigation also uncovered discrepancies in maintenance records, noting that the aircraft's Authority to Fly contained incorrect engine serial number information and that several mandatory service bulletins had not been implemented.