London's Heathrow is the fourth busiest airport on the planet, and it's not nearly big enough to handle the doubling in traffic the UK's Department for Transport predicts will hit by 2030.
Some want to construct a third runway, but that would likely require the demolition of entire villages, as Heathrow is in a dense area outside London.
There is a more outlandish idea that takes advantage of unused space... Build a new airport on the estuary of the Thames River.
One group pushing for this option, the Thames Estuary Research and Development Company (Testrad) has released new plans for its "innovative and spectacular" London Britannia Airport.
The new six-runway hub airport on the Thames estuary to the east of London could be built within seven years at a cost of US$76 billion ($91.2 billion), said a consortium formed by London Mayor Boris Johnson to address the capital's air capacity crunch.
The British government and business groups want to expand flights to fast-growing economies to ensure the UK can tap into billions of pounds of trade opportunities.
With Heathrow, London's biggest airport, operating at 99 per cent capacity, more runways are needed.
The proposed new airport would sit on a purpose-built island off the Isle of Sheppey in Kent, some 50 miles east of central London, and would be known as London Britannia Airport, said the Thames Estuary Research and Development (Testrad) consortium formed by Johnson to study options for estuary airports.
The plan, to be launched at the House of Lords, the upper house of parliament, comes two years after architect Norman Foster unveiled proposals for a four-runway hub in the Thames Estuary, backed by Johnson and dubbed "Boris Island".
Testrad said the new hub would have six runways and could be built within seven years at a cost of 47.3 billion pounds, without having to demolish houses or industrial infrastructure.
"This project avoids flying over densely populated areas of London and the south east, removing completely the noise contours and impact which have bedevilled millions of people throughout and around London over the past 40 years," a Testrad spokeswoman said, adding that Heathrow airport would likely have to close to accommodate its plans.
Britain's Conservative-led government last year set up the UK Airports Commission, chaired by Howard Davies, to look into airport capacity in southern England. It is due to publish a list of potential schemes by the end of this year with the final report due after the 2015 general election.
Earlier this year bosses at Heathrow, Gatwick and Stansted airports urged the government to let them build additional runways to solve the capacity shortage, plans vigorously opposed by Johnson.
Johnson previously proposed a new four-runway hub should be built either east of central London on the Isle of Grain or further out in the Thames Estuary on an artificial island.
- Business Insider/Reuters