Finnish investigation board critical after A330 diverts to Helsinki and arrives with less than final reserve remaining
Scandinavian Airlines (SAS) and one of its Airbus A330-300 crews have been criticised in a Finland Accident Investigation Board (FAIB) report for flight-planning shortcomings resulting in an arrival at Helsinki Vantaa airport with 500kg less than the minimum permissable reserve fuel at touchdown. Flight SK946 took off from Chicago, USA bound for Stockholm Arlanda airport, Sweden and was due to arrive at 05:35 GMT on 3 October 2003, but had to divert because of fog.
The airline is criticised for the programming of its RODOS operational flight-planning tool and for failing to advise crews to carry extra fuel, when records showed two-thirds of its recent flights on that service used more fuel than calculated.
Projections indicate that three previous services had probably landed with less fuel than the planned minima. The RODOS distance and fuel-use assumptions for the Arlanda runway 01L standard arrival procedure via waypoint ELTOK were also lower than the reality - particularly in the incident, when low visibility air traffic control (ATC) procedures lengthened the process. SAS says it is reviewing the incident.
The crew were criticised for not allowing extra fuel for potential delay when the destination weather forecast gave a high probability of marginal visibility, and the instrument landing system approach capability was Category 2, not Cat 3B "blind landing". The report remarked on the pilots' lack of reaction when it was evident within 45min of take-off that fuel consumption was higher than planned, so the entire 1,300kg contingency fuel allowance had been used by latitude 10°W.
It noted their failure to warn Stockholm ATC on approach that they had changed their flight-planned alternate airport from Gothenburg to Helsinki because it would require less fuel. Apart from asking Arlanda for a low-fuel priority vectored approach, the crew's decision to change alternates was their first executive reaction to the fuel state. When the crew carried out a missed approach at Arlanda because the runway was not in sight at decision height, ATC could not immediately provide an optimum clearance to Helsinki.
The crew could have used the A330's flight-management guidance system (FMGS) for flight profile optimisation but did not, the report says, and on changing the alternate to Helsinki, they did not enter this into the FMGS.
On a requested emergency radar vectored approach to runway 15 at Vantaa, where the weather was clear, the crew advised ATC that in the event of a go-around they would fly a visual circuit to land. The aircraft landed safely, but the fuel remaining was only 1.8t.
DAVID LEARMOUNT / LONDON
Source: Flight International
