Operational pressures and "a lack of support infrastructure" contributed to inadequate fuel management on an Aer Arran flight which was involved in a "serious incident" two years ago, an official report has concluded.
The flight between Luton and Galway was forced to divert to Shannon airport where it landed on one engine after the right-hand engine stopped in mid-air about 64km (40 miles) west of Dublin.
In a report published yesterday, the Department of Transport's Air Accident Investigation Unit (AAIU) found the engine had cut out because the fuel tank feeding it was empty. This followed a manual refuelling in Luton that was done without a physical dip-stick check.
Such a check would have required the procurement of a set of steps, which the captain believed would have resulted in "considerable further delay". The flight was the last of four on August 8th, 2003, involving the same aircraft which was beset by bad weather and technical glitches.
On the first flight from Galway to Luton via Dublin, the fuel contents gauge of the left-hand fuel tank wound back to zero.
The crew on the first leg of the flight were conscious that the passengers "were already several hours behind schedule", and the crew "reasoned that if the defect were written up in the aircraft's technical log a further delay would ensue". As a result, the crew merely briefed their replacements on the defect, which could be carried for up to 10 days, according to the investigators.
The aircraft then completed its journey to Luton, and subsequently carried out a second flight to Waterford at which point it was running six hours behind schedule. As the aircraft was being refuelled in Waterford, the captain identified a separate problem with the input valve to the right-hand fuel tank.
This problem was confirmed during later refuelling in Luton.After that refuelling, the captain noted that there was no increase in the fuel contents shown by the right-hand fuel gauge, leading the captain to believe it was now unreliable.
In fact, the AAIU discovered, the captain had inadvertently diverted all the uplifted fuel into the left-hand tank during refuelling. This had not been detected, however, because the left-hand tank fuel gauge was inoperative.
The report said: "The practice, by several of the operator's flight crews, of carrying a faulty fuel gauge for an extended time always had the potential to cause a serious problem.
"Thus it was probably that sooner or later this problem, compounded by other problems and errors, would lead to the type of situation that finally did result in this serious incident.
"The crew was faced with considerable operational pressures and a lack of resources, including the simple non-availability of a set of steps to check the dip-stick indicators. These circumstances contributed to inadequate fuel management."
An Aer Arran spokeswoman said it was implementing all of the recommendations, adding that safety was its "top priority".
