What happened
On the afternoon of 11 March 2025, a Sling II aircraft, registration ZU-STA, departed Virginia Aerodrome in Durban for a scheduled training flight. The flight, conducted under visual meteorological conditions, was part of a flight instructor conversion course. The crew, consisting of a flight instructor and a pilot undergoing training, intended to fly a coastal route before returning to the aerodrome.
While flying near Tinley Manor Beach, approximately 49 kilometres northeast of the departure point, the crew experienced sudden engine vibrations. Although the instructor attempted to troubleshoot the issue by reducing power, the vibrations intensified. Shortly after, the engine lost all power while the aircraft was at an altitude of approximately 800 feet. The instructor immediately declared a Mayday to King Shaka International Airport control and executed a forced landing on Tinley Manor Beach. The landing was successful, and there were no injuries and no damage to the aircraft.
The investigation
Following the incident, engineers inspected the aircraft at the site and later at Virginia Aerodrome. The investigation included a thorough examination of the engine, fuel system, and propeller. Technicians confirmed that the propeller rotated normally and the engine's ignition and lubrication systems were functional. Fuel samples taken from both tanks were found to be the correct grade and free of contamination.
An engine ground run was conducted in the presence of an investigator. During this test, the engine started immediately, and the crew was unable to replicate the in-flight vibration. The engine performed normally across various power settings, and the auxiliary fuel pump functioned without affecting performance. Additionally, the carburetor bowls were inspected, and the floats were found to be within specified weight limits.