What happened
On 19 December 2012, a Boeing 737-244 cargo flight, registration ZS-SID, was operating from OR Tambo International Airport to Port Elizabeth International Aerodrome. During the initial stages of the flight, the crew noted intermittent malfunctions with the anti-skid system, specifically involving the landing gear lever jumping to the OFF position and the illumination of anti-skid inoperative lights. Despite these indications, the crew elected to proceed with the flight, having calculated that sufficient landing distance was available at Port Elizabeth.
Upon touchdown on Runway 08, the aircraft experienced two audible tyre bursts. This was immediately followed by the simultaneous bursting of the remaining two main tyres. The resulting friction and mechanical failure led to wheel fires on both the left and right main landing gear. Aerodrome rescue and fire-fighting personnel responded to the emergency, successfully extinguishing the flames and assisting the three crew members to evacuate the aircraft safely. The incident resulted in no injuries, though the aircraft sustained substantial damage to its landing gear and wheels, and the runway surface suffered minor damage.
The investigation
SACAA AIID investigators examined the aircraft's maintenance history and flight data. The investigation revealed that the anti-skid system had been displaying intermittent faults throughout the flight. While the flight data recorder did not capture specific brake pressure or wheel speed parameters due to the age of the system, the investigation focused on the mechanical and maintenance aspects of the landing gear.
Investigators also reviewed the cargo manifest, noting a discrepancy between the documented weight and the actual weight of the cargo, though the aircraft remained within safe weight and balance limits. Furthermore, the investigation looked into the recovery efforts, noting that a non-approved, substandardly welded jack was used to lift the aircraft for repairs.