Dublin Airport (Irish: Aerfort Bhaile Átha Cliath), is operated by the Dublin Airport Authority. Located in Collinstown, in the Fingal part of County Dublin, it is by far the busiest airport in Ireland - over 23.5 million passengers passed through the airport in 2008. Passenger traffic at Dublin Airport is predominantly international; only 900,000 of its 23.2 million passengers in 2007 were domestic. The airport is located 5.4 NM (10.0 km; 6.2 mi) north of Dublin City in a once rural area near Swords, and is served by buses and taxis. An underground railway line called 'Metro North' which will connect the airport to Swords and Dublin city centre has been approved and is in development. Dublin Airport is the headquarters of Ireland's flag carrier Aer Lingus, Europe's largest no-frills airline Ryanair & Ireland's domestic, regional airline Aer Arann.Ireland's third airline, CityJet, is based in the nearby town of Swords. The airport has an extensive short and medium haul network, served by an array of carriers. Domestic services are offered to most regional Irish airports.