What happened
On the afternoon of 8 May 2024, an Orion Cub aircraft, registration ZU-COB, was conducting a private flight departing from Krugersdorp Aerodrome (FAKR) in Gauteng. After taking off from Runway 26 and circling the general flying area, the pilot attempted to return to the aerodrome for landing. During the final approach, the engine unexpectedly ceased operation.
Unable to reach the runway, the pilot executed a forced landing on a private farm located approximately 2 kilometres north of the aerodrome. The impact of the landing was heavy, causing the main landing gear struts to sustain substantial damage and resulting in the propeller blades striking the ground. The pilot escaped the incident without any injuries.
The investigation
An investigation by the SACAA AIID examined the circumstances leading to the engine failure and the subsequent impact. Technical examinations of the engine following the accident showed no mechanical abnormalities, as the engine performed reliably during post-accident ground testing.
Investigators reviewed the meteorological data, noting that while visibility was good, the ambient temperature and dew point were at levels that promoted ice formation within the carburettor. The investigation also confirmed that the aircraft, which had only 3.6 airframe hours since its recent construction and certification, was in good operational condition and all regulatory documentation for both the pilot and the aircraft was valid.
Findings
- The primary cause of the engine stoppage was carburettor icing.
- The icing occurred because the pilot failed to utilize the carburettor heat setting while flying in atmospheric conditions highly conducive to ice formation.
- The environmental conditions at the time of the flight supported moderate icing at cruise power and more severe icing during the descent phase.
- The heavy impact during the forced landing was a result of the engine failure preventing a controlled approach to the runway.