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 City Airport May 1987, with the first commercial services operating from 26 October 1987. Queen Elizabeth II officially opened London City Airport in November of the same year. In 1988, the first full year of operation, the airport handled 133,000 passengers. The earliest scheduled flights were operated to and from Plymouth, Paris, Amsterdam and Rotterdam. With a runway of only in length, and a slope of the glidepath of 7.5° (for noise abatement reasons), the airport could only be used by a very limited number of aircraft types, principally the Dash 7 and the smaller Dornier Do 228. In 1989 the airport