or airfield, place for landing and departure of aircraft, usually with facilities for housing and maintaining planes and for receiving and discharging passengers and cargo. There are about 16,000 airports in the United States, ranging from the Hartsfield-Jackson Atlanta International Airport, the world's busiest, which handles more than 94 million passengers on more than 900,000 flights a year, to remote airstrips that may handle only one plane a day. The essential requirements in airport construction are that the field be as level as possible; that the ground be firm and easily drained; that approaches to runways be free of trees, hills, buildings, and other obstructions; and that the site be as free as possible of smoke and weather that produces low-visibility conditions. The Federal Aviation Administration recommends that runways of large airports measure from 2,500 to 12,000 ft (762–3,658 m) in length and 200 to 500 ft (62–150 m) in width; Hartsfield-Jackson airport has four such runways. Narrower paved strips called taxiways that connect the runways to other parts of the airport are entered by aircraft as soon as possible after landing, thus freeing the runways for use by other traffic. A taxiway and a runway are usually connected at each end and at several intermediate points. Besides the hangars (buildings for housing and servicing aircraft), airports are usually provided with office and terminal buildings which house administrative, traffic control, communication, and weather observation personnel. The rapid development of aircraft, especially the jumbo jet and the newer superjumbo jet, has created problems for all major airports. Greater speed and weight of aircraft have made longer and more durable runways necessary. Greater numbers of passengers have necessitated more efficient methods of moving people and luggage from curb to plane. Despite efforts at curbing jet noise, many communities have rejected plans to build airports within their boundaries; the violent protests over the building of Japan's Narita Airport are the best-known example. Locating airports away from densely populated areas can alleviate noise problems, but this solution makes it difficult for passengers and others to reach the airport.
- See Major Airports of the World (1979), , Planning and Design of Airports (1983), and , Airport Planning and Management (1986). ,