What happened
On 15 March 2010, a Jabiru J 400, registration ZU-DFP, was conducting a training flight from George Aerodrome toward Oudtshoorn Aerodrome. The flight was operated by an instructor pilot accompanied by a student pilot and one passenger. During the initial climb to 5,500 feet, the instructor handed control of the aircraft to the student pilot to continue the training session.
Shortly after the handover, the engine ceased operation entirely. The instructor immediately regained control of the aircraft and attempted to follow emergency procedures, including troubleshooting and attempting an engine restart. Despite the propeller beginning to windmill, the engine failed to regain power. To avoid telephone poles located on the left side of a nearby gravel road, the instructor steered the aircraft toward the right, executing a forced landing on the unpended surface. While the occupants escaped no injuries, the impact caused the right main tyre to burst and a brake line to break.
The investigation
SACAA AIID investigators examined the aircraft's engine and components following the incident. The investigation included a teardown of the Jabiru 3300 engine to identify the source of the power loss. The inspection of the engine components revealed that the timing gear had developed a crack at the bolt hole. This mechanical failure disrupted the connection between the timing gear and the distributor drive shaft, which is essential for providing ignition to the combustion chamber.
Findings
- The primary cause of the engine failure was a cracked timing gear.
- The crack in the gear prevented the necessary ignition timing, leading to a complete loss of engine power.
- Meteorological conditions were clear with good visibility and no significant wind, and were not a factor in the incident.
- All personnel, including the instructor and student, held valid licenses and medical certificates.
- The aircraft maintained a valid Authority to Fly at the time of the occurrence.