What happened
On 18 June 2008, a Boeing 737-236A, registration ZS-OKD, was operating a scheduled commercial flight from OR Tambo International to Durban International Aerodrome. During the approach, the flight crew encountered heavy rain, which reduced visibility. While the aircraft was initially below the glide slope, an attempt to correct the deviation resulted in the aircraft becoming too high and too fast.
Upon touchdown, the aircraft experienced a long float, landing deep on the runway. As the aircraft decelerated, it began to veer to the right. Despite attempts by the crew to use braking, rudder input, and differential reverse thrust, the aircraft could not be stabilized. The plane subsequently ground-looped approximately 200 degrees to the right and skidded off the runway into soft mud, causing the left main gear to sink. There were no injuries among the 87 passengers or the 6 crew members on board.
The investigation
SACAA AIID investigators examined the flight data and cockpit voice recordings to determine the sequence of events. The investigation established that the aircraft's number one generator had failed shortly after capturing the localizer, causing the loss of the captain's flight director and autopilot.
Investigators also reviewed the runway conditions, noting that while a recent inspection had marked the runway as all in order, the friction level recorded in previous tests (0.43) was below the maintenance planning level (0.53). The investigation also noted that a nearby aircraft had reported windshear, but this information was not communicated to the crew of ZS-OKD by air traffic control.
Findings
- The primary cause of the incident was the incorrect landing technique used by the flight crew, which led to a deep touchdown and subsequent loss of directional control.
- The crew failed to recognize and manage various threats, including the high workload caused by heavy rain, the generator failure, and the glide slope deviation.
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