What happened
On 28 October 2008, an Airbus A330-243, registration G-OJMC, was preparing for a commercial passenger flight from Sangster International Airport in Montego Bay, Jamaica, to the United Kingdom. During the takeoff roll on Runway 07, the aircraft failed to rotate at the expected speed. The commander, sensing the aircraft did not feel correct, selected TOGA power. The aircraft subsequently became airborne and climbed away safely without any injuries to the 318 passengers or 13 crew members.
The investigation
The investigation established that the takeoff performance figures used were incorrect because the takeoff mass was recorded as 120,800 kg, whereas the actual takeoff mass was 210,183 kg. This discrepancy occurred because the flight crew requested performance data from a dispatch office in the UK via telephone. While the crew and dispatcher performed a cross-check of the figures, the primary source of the error was the input data used in the computerised performance tool.
Investigators found that the operator's performance manual was temporarily misplaced, forcing the crew to rely on remote calculations. Furthermore, the operator's FOVE system had been configured in a way that prevented a critical cross-check function—the Green Dot speed calculation—from being available to the crew. The investigation also noted that the dispatcher involved had recently returned to work following a period of sickness.
Findings
- The takeoff speeds (V1 and VR) were significantly lower than required for the actual aircraft weight.
- An incorrect aircraft weight was entered into the performance calculation system.
- The crew was unable to identify that the performance figures were outside the expected normal range.
- The operator's procedures for using the FOVE system lacked a requirement for the flight crew to record or verify specific emergency departure procedures.
- The Green Dot speed calculation, which could have served as a gross error check, was disabled on the operator's system.