History of Flight
On 22 December 2013, a British Airways Boeing 747-400 (registration G-BNLL) operating flight BA034 was preparing for a scheduled passenger flight from OR Tambo International Airport (FAOR) in South Africa to Heathrow Airport in London. The aircraft had 202 occupants on board, including 3 pilots, 14 cabin crew, and 185 passengers. During the pre-flight briefing, the crew discussed the expected taxi route based on previous experience. At 20:34 UTC, the crew received pushback and engine start clearance from ATC. After starting all four engines, they requested taxi clearance. ATC instructed them to taxi via taxiway Bravo to the Category 2 holding point for Runway 03L.
The Accident
During the taxi, the crew mistakenly believed they were still on taxiway Bravo. Instead of turning left to follow Bravo, they continued straight on taxilane Mike. The aircraft crossed the intersection of Bravo and Mike and subsequently collided with a building on the right side of taxilane Mike. The accident occurred at 20:43 UTC. Four people on the ground were injured; there were no fatalities among the aircraft occupants or ground personnel.
Investigation Findings
The investigation determined that the crew lost situational awareness. They did not conduct a briefing to discuss the cleared route and did not refer to the correct taxiway information on chart 10-6. The ground movement visual aids, combined with the crew's confusion, contributed to the loss of situational awareness. The crew had expected a different taxi route involving taxiways Echo and Alfa, but ATC assigned taxiway Bravo. The cockpit voice recorder indicated that during the briefing, the crew had discussed threats and expectations but did not specifically review the assigned route after receiving clearance.
Probable Cause and Contributory Factors
The probable cause was the loss of situational awareness, leading the crew to taxi straight ahead on the wrong path. They crossed the intersection of Bravo and Mike instead of following Bravo where it turns right toward the holding point. Continuing on taxilane Mike, the aircraft impacted a building on the right side. Contributory factors included the absence of a crew briefing on the cleared route, failure to consult the correct chart, and inadequate ground visual aids that created confusion.