Heathrow set for big increase in capacity

Exclusive: Potential for 120,000 extra flights a year at busiest airport

Heathrow's capacity problems could be solved without the need for a new runway, as strict rules on take-offs and landings are eased from next month.

Click HERE to see 'Heathrow mixed mode: How it works' graphic

The "silver bullet" solution to the airport's congestion crisis could unlock up to 25 per cent more slots with no extra building. Introducing so-called "mixed mode" flying – under which runways are used for both take-offs and landings at the same time – could allow 120,000 extra aircraft movements each year at Europe's busiest airport.

This would call into question the need for either a third runway or an entirely new airport in the Thames Estuary. New rules coming into force on 1 July will increase the number of circumstances in which simultaneous runway use is permitted. Heathrow says this will not for now lead to a net increase in slots, but it is under pressure from the airline industry to extend the scheme to allow more take-offs and landings. The fact that the Department for Transport has agreed to tinker with long-standing rules against "mixed mode" indicates they may be willing to overrule local residents' objections.

Steve Ridgway, the chief executive of Virgin Atlantic, told The Independent: "Mixed mode ... would allow a more efficient use of the existing, overstretched runways at Heathrow."

When working to full capacity – which it does much of the time – Heathrow can handle up to 44 departures and 43 arrivals every hour. Yet its nearest rival is even more productive: Gatwick is the world's busiest single-runway airport by a wide margin, with up to 54 movements an hour.

A study carried out by the air-traffic provider NATS concluded mixed mode could boost Heathrow's capacity by up to 15 per cent – adding 10 million passengers to today's annual total of 70 million. But a spokesperson for NATS said the operating changes needed to achieve that increase would require consultation, and, "it is not therefore an overnight capacity solution".

For Heathrow to achieve the same efficiency for each runway as Gatwick would require a radical re-drawing of airspace in south-east England. Were it achieved, movements could rise by 25 per cent and annual passenger numbers by 17 million.

Additional slots would quickly be snapped up by airlines eager to expand, and would allow more cities to be served non-stop from Heathrow. At present Gatwick and Manchester serve many more destinations than Heathrow.

Airline chiefs such as Willie Walsh, the chief executive of the holding company for British Airways and Iberia, have long complained that they cannot serve key cities in new markets because of slot restrictions at Heathrow. Regional airports in the UK such as Inverness, Leeds/Bradford and Newquay, which have all lost links from Heathrow, could see flights restored.

Looser rules on runway use at Heathrow take effect on 1 July as part of a trial designed to reduce stacking in the skies and delays on the ground. Measures include allowing more overnight flights from North America and Asia to land before 6am rather than "stacking" over South-east England. The world's biggest passenger plane, the Airbus A380, will be directed to land on the departures runway to accelerate arrivals of smaller jets that would otherwise be slowed to avoid the wake vortex from the "superjumbo".

After an experiment this year, Heathrow's owner, BAA, reported: "Few residents interviewed knew about the trial or noticed its impacts." But the tests do not allow any increase in aircraft movements.

A switch to mixed mode would lift capacity without breaching the night-time curfew, but residents of west London could expect noise from arriving aircraft all day long when the wind is from the west – which it is 70 per cent of the time. At present, the arrivals runway is switched halfway through the day's operations.

John Stewart, chair of the anti-expansion group HACAN ClearSkies, said: "The half-day period of peace and quiet would disappear and there would be a plane every 90 seconds all day long."

The Putney constituency of the Transport Secretary, Justine Greening, lies directly below the normal flight path for arrivals. Last month she said mixed mode would not be considered in the Government's review of airport capacity – and also ruled out a third runway at Heathrow.