Airports of London Heathrow, more than Paris and Frankfurt combined, and Heathrow is the European terminus for 11 of the 25 busiest north Atlantic routes. The busiest long-haul route in the world is between London (Heathrow and Gatwick) and New York (JFK and Newark), with a total of 3,898,460 passengers travelling between the two cities in 2011. Airports of London The metropolitan area of London, England, United Kingdom is served by six international airports and several smaller airports. Together, they make the busiest airport system in the world by passenger numbers and the second-busiest by aircraft movements. In 2016, the six airports handled
London Underground departmental stock London Underground departmental stock Departmental locomotives on the London Underground consist of vehicles of a number of types which are used for engineering purposes. These include battery locomotives, diesel locomotives, electric locomotives, sleet locomotives, pilot motor cars and ballast motor cars. Details of the first four types are covered elsewhere. Pilot motor cars and ballast motor cars are generally vehicles which have been withdrawn from passenger service, but continue to be used by the engineering department. Pilot motor cars are used to move other vehicles around the system, while ballast motor cars are used to haul ballast trains and engineering