airports An airport solely serving helicopters is called a heliport. An airport for use by seaplanes and amphibious aircraft is called a seaplane base. Such a base typically includes a stretch of open water for takeoffs and landings, and seaplane docks for tying-up. An international airport has additional facilities for customs and passport control as well as incorporating all the aforementioned elements. Such airports rank among the most complex and largest of all built typologies, with 15 of the top 50 buildings by floor area being airport terminals. Management Smaller or less-developed airfields, which represent the vast majority, often have a single runway shorter than . Larger airports for airline flights generally have paved runways of or longer. Skyline Airport in Inkom, Idaho has a runway that is only long. In the United States, the minimum dimensions for dry, hard landing fields are defined by the FAR Landing And Takeoff Field Lengths. These include considerations for safety margins during landing and takeoff. The longest public-use runway in the world is at Qamdo Bamda Airport in China. It has a length of . The world's widest paved runway is at Ulyanovsk Vostochny Airport in Russia and is wide. , the CIA stated that there were approximately 44,000 "airports or airfields recognizable from the air" around the world, including 15,095 in the US, the US having the most in the world. Airport ownership and operation Most of the world's large airports are owned by local, regional, or national government bodies who then lease the airport to private corporations who oversee the airport's operation. For example, in the UK the state-owned British Airports Authority originally operated eight of the nation's major commercial airports – it was subsequently privatized in the late 1980s, and following its takeover by the Spanish Ferrovial consortium in 2006, has been further divested and downsized to operating just Heathrow. Germany's Frankfurt Airport is managed by the quasi-private firm Fraport. While in India GMR Group operates, through joint ventures, Indira Gandhi International Airport and Rajiv Gandhi International Airport. Bengaluru International Airport is controlled by Fairfax .Chhatrapati Shivaji International Airport, Chaudhary Charan Singh International Airport, Mangalore International Airport, Thiruvananthapuram International Airport, Lokpriya Gopinath Bordoloi International Airport, Jaipur International Airport, Sardar Vallabhbhai Patel International Airport are operated by Adani Group through a Public Private Partnership wherein Adani Group, the operator pays Airports Authority of India, the owner of the airports, a predetermined