LONDON (Reuters) - Both runways at London's Heathrow airport should be extended and divided to allow simultaneous take-offs and landings and solve the hub's capacity crunch, says a leading British think tank.
The airport is Europe's busiest and operates at around 98 percent capacity, so has little space to reschedule flights when there is even slight disruption to services. But discussions about extending it have caused controversy for years, with green campaigners and business groups at odds about how and where to provide the extra runways that London badly needs.
A report by the Centre of Policy Studies said on Monday that Heathrow's existing runways should be nearly doubled to 7,000 metres so that they each provide two, full-length, runways.
Those runways could be built north of Heathrow's terminal 5, connecting the airport with the M25 motorway, Crossrail, the Great Western rail line and an alternative high speed rail route via the airport, said the report, which was written by Jock Lowe, Concorde's longest serving pilot, and Mark Bostock, the former project manager of the Channel Tunnel Rail Link (HS1).
This idea has been explored by airport executives already, said a source with knowledge of Heathrow bosses' thinking, but they have concerns about its safety and possible impingement onto the busy M25 London ringroad, famous for its traffic jams.
Lowe and Bostock believe the runways at the west London hub, the shortest of which is 3,658 metres long and the longest 3,902 metres, should be extended at one or both ends and divided by an intermediate safety zone to comply with safety codes.
The M25 motorway should be diverted or bridged where crossed by runway and taxiway extensions, they said.
"The additional capacity would dramatically improve Heathrow's operational efficiency, both in normal operations by reducing the intensity of runway utilisation, and in periods of snow, low visibility or high winds," Lowe and Bostock said in the report, titled 'Double up on Heathrow'.
Under pressure from liberals and green groups, David Cameron's Conservative-led coalition government overturned a decision to build a third runway at capacity constrained Heathrow after it came to power in 2010. It also ruled out expanding London's smaller airports.
The government's commission on airport capacity, chaired by Howard Davies, is due to report in mid-2015. British aviation officials, including Heathrow executives, will submit their proposals to the commission later this month.
In 2012 70 million passengers arrived at and departed from Heathrow. The airport averages 191,200 passengers arriving and departing per day.
Editing by Sophie Walker