UK investigators have called for regulators to develop safeguards to prevent take-off performance miscalculations, following a serious incident in Jamaica involving a Thomas Cook Airlines Airbus A330-200.
The Air Accidents Investigation Branch (AAIB) recommendations were sparked by its investigation of the incident on 28 October last year at Montego Bay's Sangster International Airport.
Investigators found that the A330's commander had quickly selected take-off/go-around power when the aircraft failed to unstick at the calculated rotate speed.
The board says it could not determine the actual error that caused the take-off performance miscalculation, but the effect was as if a much lower weight than the actual take-off mass was entered, because the calculated decision and rotate speeds were too low.
The crew was also carrying out a 'flex' take-off, using a de-rated thrust level that was calculated, along with the take-off speeds, on a computer at Thomas Cook's base flight dispatch unit, using figures passed by the crew.
Runway 07 at Sangster, at 2,724m (8,930ft), was long enough for a safe take-off to be made, the AAIB says. Its report also cites several other examples of take-off performance miscalculation, including the October 2004 fatal MK Airlines Boeing 747 freighter crash at Halifax and several others that involved tailstrikes during take-off.
The AAIB adds that it found 26 "relevant events" in its own mandatory occurrence report database. It argues that such events happen too often and the potential consequences are serious.
It is recommending that the European Aviation Safety Agency provide specifications for a take-off performance monitoring system, capable of alerting crews to mismatched conditions, and require it to be fitted to airliners.