What happened
On the evening of 22 December 2013, a British Airways Boeing 747-400, registration G-BNLL, was preparing for a long-haul flight from OR Tambo International Airport (FAOR) to London Heathrow. Following standard procedures, the crew received instructions from Air Traffic Control to push back, start engines, and face south before taxiing via taxiway Bravo toward the holding point for Runway 01L.
During the taxi phase, the aircraft failed to follow the intended path. Instead of turning left to remain on taxiway Bravo, the crew continued straight ahead, crossing the intersection of taxiway Bravo and the aircraft stand taxilane Mike. While navigating taxilane Mike, the starboard wing of the aircraft struck a building belonging to Bid Air Services. The impact caused significant damage to the aircraft's wing, winglet, and various internal components, and resulted in a fuel leak. While no fatalities or injuries were reported among the 202 occupants, the collision caused substantial damage to both the aircraft and the structure.
The investigation
SACAA AIID investigators examined the cockpit voice recorder, aircraft maintenance records, and airfield lighting configurations. The investigation focused on the crew's navigation and their adherence to the taxi route. Investigators reviewed the pre-flight briefing, noting that while the crew had discussed potential threats and the expected route, there were discrepancies between their planned path and their actual movement.
Technical examination of the airfield lighting revealed that on the night of the accident, certain green centerline lights on taxiway Bravo were not illuminated in sequence. Furthermore, the edge lights for taxiway Mike were active due to the night-mode settings on the airfield's visual control panel. The investigation also looked into the crew's use of aerodrome charts and their awareness of the intersection between Bravo and Mike.