UK investigation into Virgin A340-600 incident reveals lack of formal requirements
Investigators in the UK are recommending that European and US regulators formally adopt a specific requirement for independent low-fuel warning systems on board large transport aircraft.
It comes as part of a continuing examination of a serious incident a year ago in which a Virgin Atlantic Airbus A340-600 suffered fuel exhaustion in two tanks without warning the crew. The UK investigation started after the incident in April last year.
In an update on the probe the Air Accidents Investigation Branch (AAIB) says that neither European Aviation Safety Agency (EASA) nor US Federal Aviation Administration certification specifications contain a low-fuel level warning requirement.
The AAIB points out that these specifications require installation of a fuel-quantity indicator and concedes that there is a generic requirement for “information concerning unsafe operating conditions” to be provided to the crew.
“It could be argued that the need to indicate fuel-system failures to the crew on complex aircraft is covered by [this generic rule],” says the AAIB.
“When the fuel-control system is operating normally on the A340-600 this is true, but this incident demonstrated a need for more specific requirements for certain warnings such as low fuel level in an engine feeder tank.”
While at least one member of the crew would normally be monitoring fuel status, the AAIB says that crew members have to monitor several systems and already depend on flags to identify potential problems. Given that fuel systems are also used for centre-of-gravity control, it adds, crew members could have difficulty in detecting abnormal behaviour within a complex fuel network.
Although most large transport aircraft certified by EASA and the FAA have independent fuel-warning systems fitted, UK investigators are putting forward a recommendation that both agencies’ certification requirements specifically cover installation of such equipment for each engine feed fuel tank.
Italian authorities last year submitted a proposal that EASA certification criteria be amended to ensure that low-fuel warning systems are independent of fuel-quantity indicators, following last August’s fatal fuel-exhaustion accident involving a Tunisian ATR off the Sicilian coast.
In its own recommendation to EASA and the FAA, the AAIB says that both agencies should review all certified large transport aircraft to ensure that these systems are independent.
DAVID KAMINSKI-MORROW / LONDON
External link:
Read the UK Air Accidents Investigation Branch report into The Virgin Atlantic Airbus A340-600 low fuel incident in April 2005
Source: Flight International
