Aircraft

London Heathrow airport will be able to handle more Airbus A380s as a result of the wake separation reduction promulgated by the UK Civil Aviation Authority, says the airport's air traffic service provider, NATS. Heathrow operator BAA says the new criteria are already being used by controllers.

At present, NATS says, there are so few A380 movements at Heathrow that the new reduced separation criteria do not make any difference, and the existing movements by Singapore Airlines and Emirates do not take place during peak movement periods, so separation is not yet an issue.

However, by early in 2009 there will be three A380 evening arrivals daily, and the separation reductions create the option for about one additional aircraft movement per three A380 movements as the number of A380s in service increases. Heathrow is predicted to see more A380 movements than any other airport for many years.

The CAA, with approval from the International Civil Aviation Organisation, has reduced the precautionary separation originally proposed, while the A380's wake vortex behaviour was better understood following extensive testing using lidar visualisations of wake patterns and dispersal rates.

Light aircraft separation behind an A380 has been reduced from 10nm (18.5km) to 8nm, medium-weight aircraft separation has been reduced from 8nm to 7nm, and heavy aircraft separation remains the same at 6nm. Time separations for aircraft taking off after an A380 have also been reduced, the CAA document makes clear.

In the USA, the US Airline Pilots Association is still offering advice to its membership based on the original separation times and distances. The ICAO has not yet responded to requests for information about its rationale for reducing UK separations.