A380 crews told to perform additional fuel-quantity check

Airbus A380 operators are being instructed to introduce an additional fuel-quantity check after a discrepancy observed during pre-departure preparations. The fuel quantity indicated by on-board instruments had differed from the expected figure, calculated by combining the initial fuel with the uplifted fuel. Investigations found that an incorrect signal from a refuel isolation valve was behind the discrepancy, says EASA. It states that this situation might have resulted from contamination of the isolation valve position sensor, because the valve had been indicated as closed during refuelling when it was actually open. EASA warns that undetected fuel-measurement errors could result in a loss of fuel supply to the aircraft’s engines. Airbus has temporarily revised the aircraft’s flight manual to include an additional tolerance check. <br/>