The fuel-leak incident was investigated by the UK Air Accidents Investigation Branch at the time, and the technical facts of what had happened were published in July 2004. But because there were found to be errors in Boeing's 777 maintenance manual and it was not clear why the mistakes had occurred, the chief investigator of accidents ordered a fuller study, the results of which have just been released.

It was found that, since the 2-10 May 2004 maintenance visit the aircraft had flown 53 sectors with the purge door missing, but the fault had not shown up because the maximum fuel loaded into the 80t-capacity tank on those sectors was 28t, so the fuel level was below the aperture. On departure for Harare the centre tank was charged with 43t, which made the fuel start to spill as soon as the aircraft began its acceleration for take-off.

Source: Flight International