What happened
On the morning of 8 June 2024, a Jabiru J160C aircraft, registration ZU-DWK, was performing a private flight from Stellenbosch Aerodrome to Caledon Airfield in the Western Cape. During the initial climb following takeoff from Runway 19, the pilot experienced a severe vibration and a significant drop in engine RPM, which fell from 2,960 to 1,390. As the stall warning activated, the pilot attempted to maintain airspeed by lowering the aircraft's nose to execute a forced landing. The aircraft subsequently crash-landed in a strawberry field approximately 500 meters from the runway threshold. The impact caused substantial damage to the aircraft's fuselage, wings, landing gear, and propeller. While the pilot sustained minor injuries, the passenger was uninjured. The incident also caused damage to local crops and protective sunshades.
The investigation
SACAA AIID investigators examined the aircraft's maintenance history and recent operational procedures. The investigation revealed that during a ground run-up on 28 May 2024, the engine had previously shut down due to carbon build-up on the spark plugs. Although the plugs were cleaned, they were not replaced. Furthermore, investigators looked into the engine ground run performed prior to the accident, noting that the duration of the run exceeded the five-minute limit specified in the manufacturer's manual, which likely increased the engine manifold temperature.
Findings
- The primary cause of the engine power loss was carbon build-up on the spark plugs, which were not replaced during the most recent 100-hour mandatory periodic inspection (MPI).
- The maintenance work pack had incorrectly marked the spark plug replacement task as not applicable (N/A).
- The engine ground run performed by the pilot exceeded the maximum time allowed by the maintenance manual, contributing to the loss of power.
- There was insufficient oversight of maintenance procedures by the approved person responsible for the aircraft's serviceability.
- Meteorological conditions were clear and were not a factor in the accident.