Economy of London project is construction of 42 km (26 mi) of new tunnels connecting stations in central London including a branch to Canary Wharf in east London. It is Europe's biggest construction project with a £15 billion projected cost. An additional line, Crossrail 2, has been proposed. London is served by six international airports which are the world's busiest city airport system by passenger traffic. These are Heathrow, Gatwick, Stansted, Luton, London City, and Southend. There are a number of proposals for expanding airport capacity for London including expansion of London Heathrow Airport and expansion of Gatwick Airport. The principal argument in
London Biggin Hill Airport London Biggin Hill Airport London Biggin Hill Airport is an operational general aviation airport at Biggin Hill in the London Borough of Bromley, located south-southeast of Central London. The airport was formerly a Royal Air Force station RAF Biggin Hill, and a small enclave on the airport still retains that designation. Biggin Hill is best known for its role during the Battle of Britain in the Second World War, when it served as one of the principal fighter bases protecting London and South East England from attack by enemy bombers. Over the course of the war, fighters based at Biggin