UK investigators have again criticised maintenance practices at British Airways (BA) after a lengthy investigation into a serious incident in which errors during work on a Boeing 757-200 led to roll-control problems during a diversionary approach to London Gatwick two years ago.
It marks the latest in a series of serious maintenance-related events at BA which have already prompted concern from inspectors.
In a scathing report into the 757 event, released today, the UK Air Accidents Investigation Branch (AAIB) reprimands the airline for ineffective supervision, poor standards of maintenance, and an inadequate safety culture. The AAIB adds that BA’s quality assurance programme was “not effective” in highlighting these “unsatisfactory” maintenance practices.
Shortly after the 757, registered G-CPER, departed London Heathrow for Paris on 7 September 2003, the crew opted to divert to Gatwick after detecting the smell of hot oil in the cockpit.
But during the approach the crew discovered that the twin-jet drifted to the right of the localiser after its flaps were deployed. Its pilot needed to use about 40° of left-hand control column input, applying some 75% of left aileron, to keep the wings level and prevent the 757 turning to the right. This situation remained all the way to touchdown although the aircraft landed safely at Gatwick with no injuries among the passengers and crew.
Investigators found that the 757 had been performing its first flight following a 26-day maintenance check, and determined that errors had led to personnel servicing engine oils incorrectly and failing to re-install two access panels on the aircraft’s right-hand outboard flap. Asymmetric aerodynamic effects caused by the missing panels led to the roll-control problems.
“The events were the result of a combination of [maintenance] errors on the part of the individuals involved and systemic issues that had greatly increased the probability of such errors being committed,” says the AAIB.
It says that the task of refitting the panels to the aircraft was “not performed to the required airworthiness standard” and adds: “Ineffective supervision of maintenance staff had allowed working practices to develop that had compromised the level of airworthiness control and had become accepted as the ‘norm’.
“There was a culture, both on the ramp and in the maintenance hangar, which was not effective in ensuring that maintenance staff operated within the scope of their company authorisation and in accordance with approved instructions.”
The 757 problem occurred just three months after another serious maintenance-related incident involving a BA Boeing 777 which lost a large access door in-flight. During the investigation into that event the AAIB highlighted three other serious events, across a ten-month interval, involving similar maintenance issues at the airline.
In a high-profile incident in June last year a fuel-tank door left open after maintenance on another BA Boeing 777 resulted in the aircraft having to return after trailing a stream of fuel vapour.
BA, which disputes some of the findings, has acted on seven AAIB safety recommendations directed at the carrier in response to the 757 investigation. It says that it has raised awareness of the problem of maintenance errors and discussed possible preventative action in open forums. Specific procedures for servicing the 757, it adds, have been reviewed and amended for clarity.
It has reviewed its quality management structure, as well as its internal maintenance error investigation process, and is implementing an enhanced supervisory structure to oversee maintenance standards.
“The supervisory function will provide team leadership and technical guidance to less-experienced maintenance staff, and will ensure that all activities are certified at the appropriate level by the staff involved in maintenance tasks,” says the airline.
“Formally recognising the supervisory level as part of the management of maintenance activity will also provide a defined line of communication between hangar management and staff performing tasks on the aircraft.”
BA says that quality issues are discussed regularly in forums to ensure that all maintenance areas have a good understanding of where working practice might be improved.
DAVID KAMINSKI-MORROW / LONDON
Kieran Daly suspects BA welcomes the UK's tough regulatory regime. Read and comment on his blog here.
Source: Flight International
