The incorrect entry of take-off weight data that resulted in the tailstrike and runway overrun of an Emirates Airbus A340 aircraft in 2009 was not a unique event. Similar events continue to occur throughout the world, according to the Australian Transport Safety Bureau (ATSB).
The ATSB published the final report of its investigation into a 20 March 2009 accident, when flight EK407, with 18 crew and 257 passengers, sustained a tailstrike and overran the runway end on departure from Melbourne Airport. The aircraft became airborne in the grass clearway but struck a light and several antennae, which damaged and disabled the instrument landing system for the airport.
The flight crew climbed the aircraft to 7,000 ft and circled over Port Phillip Bay, Victoria, while jettisoning fuel to reduce the aircraft’s weight. The flight crew then returned the aircraft to Melbourne for an uneventful landing on runway 34.
The ATSB found that the accident resulted from the use by the crew of incorrect take-off performance parameters. The initial error was likely due to mistyping, when a weight of 262.9 tonnes, instead of the intended 362.9 tonnes, was entered into a laptop computer to calculate the aircraft’s take-off settings. The error passed through several subsequent checks without detection.
Although a number of contributing factors were identified, the ATSB determined that there were two primary factors in the development of the accident as follows:
- the flight crew did not detect the erroneous take-off weight that was used for the take-off performance calculations, and
- the flight crew did not detect the degraded take-off performance until very late in the take-off roll.
- ATSB Investigation Report
- ATSB Study: Take-off performance calculation and entry errors: A global perspective
ATSB animation of the occurrence.