What happened
On 18 February 2008, a Robinson R44 was conducting game-counting operations near Britstown in the Northern Cape. While flying at an altitude of approximately 100 feet above ground level, the pilot and a passenger experienced intense airframe vibrations immediately followed by a total loss of engine power. The pilot attempted to perform an autorotational landing on farm Smutskel, but the impact was forceful. The force of the landing caused the main rotor blades to strike the tail boom, severing it. There were 0 fatalities and 0 injuries resulting from the event.
The investigation
Investigators from the SACAA AIID examined the wreckage and noted significant oil spray throughout the engine nacelle. A detailed inspection revealed a large hole in the upper mid-section of the engine casing, confirming an uncontained engine failure. The Lycoming O-540-F1B5 engine was removed and disassembled at an approved facility under official supervision.
During the teardown, it was observed that the small end of the number two connecting rod was missing due to extensive damage to the crankcase. A maintenance engineer suggested that the failure likely originated from metal fatigue at the small end of the conrod, noting that this is a vulnerable area during the press-fitting of bushes. Despite an extensive search of the accident site, the missing portion of the connecting rod could not be recovered. Records indicated the engine had flown 905.5 hours since its last major 2,000-hour overhaul in 2003, and the aircraft was only 32.5 hours past its last mandatory periodic inspection.