19 May 2006

Plane Wars 2

Picture Airbus: Singapore Airlines Airbus 380

All major airports in Europe are battling to increase their runway throughput to meet the ever-increasing passenger demand. The situation can be improved by use of larger aircraft types such as Boeing 747 and especially a new 550-seat Airbus A380.

Currently air traffic controllers are using distance separation (depends on aircraft weight category, must be minimum 2.5-3 NM over the runway threshold) between consecutive landings that must be increased significantly behind heavier aircraft due to wake vortex. Separating aircraft precisely on final approach without losing landing slots is notoriously difficult task for flights with different final approach speeds because the approaching aircraft have to follow the same final path established typically at least for the last 10-15 NM before landing.

Airport ATC system planners (see also the WakeNet2-Europe site) want to improve airport throughput e.g. by changing a distance-based separation to a time-based separation that would take into account different and gradually decreasing final approach speeds used by aircraft on final approach. This would require automated systems to assist controllers, and those are not currently available although there are some such systems in development phase.

The problem caused by wake vortex was highlighted by Airbus A300 crash on take-off from New York’s Kennedy airport in autumn 2001 soon after 9/11 killing everybody on board. The aircraft suffered major structural damage one minute into the flight and the investigation concluded that turbulance caused by wake vortex was a contributing factor in the accident.

On Thursday this week, Airbus’s new giant jet, A380, landed first time at London Heathrow, the world’s busiest international airport. The UK Civil Aviation Authority, following an International Civil Aviation Organisation (ICAO) recommended practise, has ordered that an 11 NM separation must be maintained behind a landing A380, maximum weight 540 tonnes, this is almost twice as much as separation behind a landing Boeing 747 (max weight 360 tonnes). If this is carried through to line operations of A380, the airlines – and airport operators – fear that the advantage offered by a 550-seater A380 would be lost by missing scarce landing slots.

Head of flight testing at Airbus, Fernando Alonso, has said that the Airbus's own flight tests have shown slightly more severe vortex behind an A380 than a 747, but that would not require almost doubling of landing separation minimum compared to 747. Airbus is trying to convince ICAO that a separation same or very similar to 747 would be safe behind an A380.

According to the London’s The Times –newspaper the president of the Emirates (of Dubai, orders for 49 A380s) Maurice Flanagan has speculated that ICAO’s decision on an excessive separation was influenced by the US, keen to protect Boeing’s share of the jumbo market.

Picture: Changi airport at the time when flights took days to finis and passangers stayed in the Raffles Hotel as part of their flight experience. Airbus A380 will be able to fly directly from London to Sydney, so even a Singapore stop-over will be just a part of nostalgic history. So soon even a quick drink of Singapore sling on the terrace in the Raffles will be impossible

Airbus has so far 159 firm orders for the A380. The first A380 with paying passengers will be operated by Singapore Airlines in December 2006 between Singapore Changi International and Sydney airports.

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