Heathrow weather delays slashed by mixed mode, says BA

Weather delays at Heathrow could be cut by up to two thirds by more flexible use of the two existing runways, according to British Airways. An analysis by the airline examined the effects of Heathrow's method of runway operation, where arrivals are confined to one runway at a time, on flight delays in conditions of high winds.

It found that strong headwinds frequently led to reductions in the arrival rate set by air traffic controllers.

In contrast at Gatwick, where landings and take-offs are sequenced on the same runway in 'mixed mode' operation, arrivals can be maintained at a consistent rate in windy conditions because separation is greater to allow for intervening departures.

The outcome is to generate more take-offs and landings per runway per hour: typically 48 at Gatwick and 42 at Heathrow. This results in fewer delays, particularly for incoming flights.

Though weather conditions are similar at both airports, aggregate delays for arrivals are many times worse at Heathrow than at Gatwick.

In 2006, the last full year for which data is available, Heathrow was subject to air traffic control restrictions on arrivals on 276 days with a total shorthaul delay of 280,000 minutes.

Gatwick was subject to arrivals restrictions on only 52 days with a total shorthaul delay of 21,000 minutes. Heathrow's shorthaul operation is less than twice the size of Gatwick's, yet its aggregate delays were 13 times worse.

The figures are part of British Airways' response to the Government's consultation on increasing Heathrow's runway capacity, which includes proposals for the phased introduction of mixed mode. The full response will be sent to the Department of Transport by Wednesday.

Paul Ellis, British Airways' infrastructure manager, said: “Years of practical experience of runway operation at Heathrow and Gatwick has shown conclusively that mixed mode operation provides much better protection against delays when weather conditions are difficult.

“The introduction of mixed mode at Heathrow would be a real bonus for passengers. We estimate that it would cut weather delays by up to two thirds from Day One and provide much greater reliability throughout the timetable.”