What happened
On the night of 24 November 2007, a Robinson R44 Raven II helicopter, registration ZS-OXJ, was conducting a commercial vehicle tracking mission for Netstar. After completing an initial flight south of Grand Central Aerodrome, the crew returned to the base to refuel before being dispatched a second time toward the Northcliff area.
During this second mission, a second helicopter operating in the area observed low-lying clouds moving in and advised the pilot of ZS-OXJ to return to the aerodrome due to the deteriorating weather. The pilot of the first aircraft acknowledged the warning and began an approach to Grand Central Aeramente. While the second helicopter was shutting down its engines, the pilot suddenly found the aircraft surrounded by dense fog. During this period of obscured visibility, a loud impact was heard nearby.
Upon investigating the source of the noise, the crew of the second aircraft located the wreckage of ZS-OXJ approximately 5 meters to the right of Runway 17. Both occupants of the crashed helicopter survived the impact but sustained minor injuries, including shoulder and hand injuries.
The investigation
SACAA AIID investigators examined the wreckage and the environmental conditions at the time of the accident. The investigation established that the aircraft struck the ground with a substantial bank angle to the right, causing significant damage to the main rotor blades, the rotor shaft, and the gearbox assembly.
At the time of the accident, a power failure in the surrounding area had left the terrain to the west of the aerodrome in total darkness. While the runway lights remained operational, the investigation noted that the aircraft entered a layer of dense fog during its final approach. Satellite imagery and meteorological data confirmed the presence of patches of fog in the Johannesburg area shortly before the crash.
Findings
- The pilot encountered a layer of low-lying fog during a night approach for landing.
- The sudden loss of visual reference to the ground led to spatial disorientation.
- The combination of a dark, featureless landscape due to local power outages and the onset of dense fog contributed to the pilot's inability to maintain situational awareness.
- The aircraft impacted the terrain at a significant bank angle, indicating a loss of control during the approach phase.