The incorrect entry of take-off weight data that resulted in the tail strike and runway overrun of an Emirates Airbus A340 aircraft was not a unique event. Similar events continue to occur throughout the world, according to the Australian Transport Safety Bureau (ATSB).
"These sorts of errors have potentially serious safety consequences," said ATSB Chief Commissioner, Mr Martin Dolan. "It is encouraging to see the significant safety action that is occurring as a result of the ATSB's investigation."
Mr Dolan was speaking on publication of the ATSB's final report of its investigation into a 20 March 2009 accident, when flight EK407, with 18 crew and 257 passengers, sustained a tail strike and overran the runway end on departure from Melbourne Airport, Victoria.
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 (or 'electronic flight bag') to calculate the aircraft's take-off settings. The error passed through several subsequent checks without detection.
The ATSB's investigation examined a number of systemic safety issues surrounding the accident. The investigation was supported by an ATSB research report titled Take off performance calculation and entry errors: A global perspective.
"We now understand what caused the error and why it wasn't picked up," Mr Dolan said. "We also know there have been a number of other accidents and incidents that involved similar errors in a range of different aircraft operated by different airlines around the world."
"All of those events had two basic elements in common: the error in entering the weight was not detected before take-off, and the degraded take-off performance was not detected until well into the take-off run, if at all."
Mr Dolan noted that, currently, the only checks in place to prevent these types of accidents are procedural and vulnerable to human error. "But a lot of work is being done to minimise the risk of similar events in future," he said.
"This includes developing technological aids to assist flight crew in recognising both when take-off parameters are inappropriate and when take-off performance is degraded below a safe level" noted Mr Dolan. "The aviation industry as a whole realises the seriousness of these issues and is working towards a solution."
To stress that further action is still needed with technological aids, the ATSB has issued a safety recommendation to the United States Federal Aviation Administration. It has also issued safety advisory notices to a number of international aviation organisations. These notices highlight the importance in the meantime of managing the problem pilots face in deciding whether the parameters calculated for a particular take-off are appropriate.
A full copy of the investigation report AO-2009-012 is available on the ATSB website.