Washington Dulles International Airport and is on pace to exceed Ronald Reagan Washington National Airport's annual passenger numbers for 2018 after having fewer passengers ever since 2015. However, Dulles Airport still ranks behind Baltimore–Washington International Airport (BWI) in total annual passenger boardings, despite being a larger facility with more gates. Prior to World War II, Hoover Field was the main commercial airport serving Washington, on the site now occupied by The Pentagon and its parking lots. It was replaced by Washington National Airport in 1941, a short distance southeast. After the war, in 1948, the Civil Aeronautics Administration began to consider sites for a
London City Airport Authority. London City Airport has a single long runway, and a CAA Public Use Aerodrome Licence (Number P728) that allows flights for the public transport of passengers or for flight training (but only for training necessary for the operation of aircraft at the airport). Only multi-engine, fixed-wing aircraft with special aircraft and aircrew certification to fly 5.5° approaches are allowed to conduct operations at London City Airport. The largest aircraft which can be used at the airport is the Airbus A220-100. London City served over 4.5 million passengers in 2017. It is the fifth-busiest airport in passengers and aircraft movements