Airport is a place where airplanes and other aircraft take off and land. Planes also load and unload passengers and cargo at airports. Air travel has become the chief means of long-distance transportation, and modern aircraft provide the safest means of travel. Every day, the world’s airports handle millions of passengers flying on thousands of commercial airplanes for business and leisure travel.
Airports are exciting places to see commercial airliners, general aviation aircraft, and sometimes even military aircraft. Overhead, planes approach or depart. On the ground, one plane after another takes off or lands. Automobiles, buses, taxis, and trains carry travelers to and from the passenger terminal. Thousands of people fill the terminal area. Most of them are passengers. Others are employees of the airport, airlines, or commercial establishments operating in the airport.
The largest airports resemble small cities. Many have hotels, restaurants, banks, post offices, and shops. Many airports also have their own police force, fire departments, medical facilities, and utility plants and facilities. These services and facilities are important and useful for passengers and employees at an airport. In addition, some of them help produce the income necessary for the airport to operate successfully. During lengthy flight delays or emergencies, these services can become vital.
Airports differ from other transportation terminals, such as bus or train stations, in two important ways: (1) airports require more land, and (2) most airports are far from the centers of the cities they serve. An airport needs much more land to accommodate the same number of passengers as a bus or train station. A medium-sized city airport needs from 700 to 3,000 acres (280 to 1,200 hectares). The largest airport in the world in area is King Fahd International Airport near Ad Dammam, Saudi Arabia. It covers about 192,000 acres (78,000 hectares). The largest airport in the United States is Denver International Airport. It has an area of about 34,000 acres (14,000 hectares).
National governments, state-sponsored bodies, local governments, and corporations own most of the world’s large airports. Many small airports are privately owned.
In most countries, one or more federal agencies oversee airport certification and air safety. In the United States, for example, those agencies are the Transportation Security Administration (TSA) and the Federal Aviation Administration (FAA). In Australia, the agency is the Civil Aviation Safety Authority. In Canada, it is Transport Canada. In India, that agency is the Ministry of Civil Aviation; and in the United Kingdom, the Civil Aviation Authority. Nearly all countries, including Australia, Canada, India, South Africa, the United Kingdom, and the United States, belong to the International Civil Aviation Organization (ICAO) of the United Nations. The ICAO establishes standards for its members in such areas as airport safety, operations, and air traffic control.
The FAA is an agency of the U.S. Department of Transportation. The FAA licenses U.S. aircraft and pilots and certifies airports and airlines. It also regulates safety and sets design and operations standards for airports. The FAA also operates air navigational aids and controls air traffic. The TSA, an agency of the U.S. Department of Homeland Security, is responsible for airport and airline security in the United States.
Kinds of airports
Airports are classified in different ways in different countries. The FAA classifies most U.S. civilian airports as either commercial service airports or general aviation airports. Military airfields make up a third classification.
Commercial service airports,
also called air carrier airports, serve planes of commercial airlines. They may also serve such small aircraft as business, charter, or private planes. Nearly all major civilian airports are commercial service airports.
A commercial service airport may serve regional, national, or major airlines—or a combination of these types. Regional airlines generally fly short routes using smaller aircraft. These airlines connect small communities with one or two large airports. However, some regional jets fly routes of up to 1,000 miles (1,600 kilometers). National airlines fly from large airports as well as smaller ones. They use both large and small jet aircraft. Major airlines are large air carriers that generate annual revenues of more than $1 billion in U.S. dollars. They generally provide both national and international flights.
Most airports that handle international flights have the word international in their names. International airports serve airlines of both their own country and other countries.
General aviation airports
serve all types of aircraft except scheduled airliners—planes that operate over specified routes on a timetable. general aviation airports serve business, charter, and private aircraft. They also serve scheduled air taxis, which carry passengers between towns and to and from commercial service airports. In addition, general aviation airports handle small aircraft used for aerial surveys, crop-dusting, and flight instruction. Airports that handle only specialized aircraft, such as helicopters or seaplanes, also fall into this category.
There are thousands of general aviation airports ranging from small grass or gravel strips to large, busy airports that handle huge corporate jets. The FAA classifies all general aviation airports—except those that serve only specialized aircraft—into four groups. The classifications are based on the size of the planes the airports can handle. Basic utility airports serve single-engine and some small twin-engine, propeller-driven planes. General utility airports can handle slightly heavier propeller aircraft. Basic transport airports can accommodate small jet airplanes. General transport airports handle all types of aircraft.
Special classifications of general aviation airports include heliports and seaplane bases. Heliports are areas where helicopters land and take off. A heliport may be on the ground, the roof of a building, or the deck of a ship. Seaplane bases are used by seaplanes and amphibians, aircraft that can land and take off on water or land. Seaplane bases may be on bays, lakes, or rivers. Most seaplane bases have onshore facilities to service the aircraft. The world’s busiest seaplane base is in Anchorage, Alaska.
Military airfields
are airports operated by the armed forces. Some military units, such as the U.S. Air National Guard, share facilities at commercial airports. Military airfields range in size from small fields for light planes to huge airports for heavy jet bombers.
Airport facilities
An airport’s facilities depend on the size of the community it serves, the area of land it covers, and the type of air service it provides. This section deals chiefly with the numerous facilities provided by most large commercial service airports. The subsection Planning and building an airport later in this article discusses different types of designs for airport passenger terminals.
The passenger terminal.
Passengers begin and end their flights at the passenger terminal. Airports may have one or more terminal buildings. At airline ticket counters, departing passengers purchase tickets, have their tickets checked, and receive boarding passes. They also can leave their baggage to be loaded into the airplane’s cargo hold. Loudspeakers, flight monitors, and electronic message boards announce flight arrivals and departures. Boarding lounges provide seats for waiting travelers and airline crews.
Passengers board and leave aircraft from openings called gates. At most large airports, an enclosed walkway connects the terminal gate with the aircraft during boarding. A common trade name for such a walkway is a Jetway. Arriving passengers pick up their luggage at a baggage claim area in the passenger terminal.
Many of the activities in the passenger terminal take place behind the walls or under the floor. These activities include the transport of baggage and cargo from the ticket counter to the aircraft. Airlines also maintain offices in these areas.
Each airline has a briefing room, where pilots receive flight information. The briefing room includes a dispatch office. The dispatch office handles communications with the airline’s operations center and with its airplanes, both on the ground and in flight. The airport manager and the management staff, who oversee the operation of the airport, also have offices at the airport.
Hangars
are buildings in which aircraft are stored and repaired. Most airlines have their own hangars. Some hangars can hold several large jets at one time. Most airports locate hangars far enough from the terminal building to avoid interference with aircraft traffic on the ground.
The control tower
is the air traffic nerve center. In the tower, air traffic controllers may use Automatic Dependent Surveillance-Broadcast (ADS-B), radar, signal lights, and other equipment. ADS-B, which replaces or supplements radar-based surveillance, is surveillance technology that uses signals from Global Positioning System (GPS) satellites to direct air traffic near the airport as well as aircraft on the ground. Control towers at the busiest airports may handle more than 200 landings and take-offs an hour. Large, tinted windows enable controllers to see all the aircraft at the airport. Some control towers are over 400 feet (120 meters) tall.
Runways
must be long enough and wide enough to handle the largest planes using the airport. They must be as level as possible. However, runways slope slightly from the center toward each side to provide good drainage. A government body usually sets minimum runway lengths for different types of aircraft. Many small airports use only strips of mowed grass called landing strips. Some of these strips are only 2,000 to 2,500 feet (610 to 760 meters) long. The runways of large airports are paved with concrete or asphalt. These runways may be as long as 13,000 to 14,000 feet (4,000 to 4,300 meters) to handle the biggest planes. Runways must have a clear zone at each end to give aircraft additional space to take off or land without endangering people or property on the ground.
Lines down the center and sides and across the ends of runways guide pilots in the air and on the ground. Numbers on each end of a runway tell pilots the compass direction in which the runway is laid out. For example, the numbers 18 and 36 indicate a north-south runway. The number 18 (an abbreviation for 180°) is painted on the north end of the runway. The number 36 (360°) appears on the south end. Most airports design runways in at least two directions so planes can take off and land as nearly as possible into the wind.
At night and other periods of low visibility, white lights outline each runway. Green lights mark the beginning of a runway. Red and white approach lights shine just in front of the area where a plane should touch down.
Loading aprons and taxiways.
The aircraft parking area at the gates of the passenger terminal is called a loading apron or tarmac. The word tarmac originally referred to a paving material made of crushed rock and tar. Today, however, the apron is made of concrete or asphalt because these materials better resist damage from heat and fuel leaks. While an airplane is on the apron, workers refuel it. They also load baggage, cargo, and meals for the passengers. The crew and passengers board airplanes on the loading apron. A small airport may service only 1 or 2 aircraft on the apron at one time. Large airports may accommodate more than 100 planes at once.
Aircraft use lanes called taxiways to taxi from the apron to the runways and from the runways to the hangars. Many large airports have double taxiways so aircraft can move to and from the runways and hangars at the same time. At night, blue lights mark the taxiways. Red lights mark barriers or other dangers.
Ground transportation and parking.
Large airports provide roadways alongside the terminal buildings. Airport buses, hotel vans, private automobiles, limousines, and taxis pick up and drop off passengers on these roadways. Some airports are connected to the city center by light rail systems or subways.
All airports maintain parking lots. Most large airports have multistory parking garages. Garages take less land than parking lots do to hold the same number of cars. Parking is a major source of revenue for many airports.
Airport operations
The airport manager and the management staff direct the operation of the entire airport. In some regions, they may be responsible for several airports, including one or two air carrier airports and several general aviation airports. The management staff at large airports is divided into several departments. The departments include administration, finance, operations, maintenance, engineering, safety, security, and public affairs. The airport staff works to ensure that the airport operates safely and efficiently.
An airport must operate like a business. Airports rent space to the airlines for offices, check-in counters, and baggage areas. Airports also give leases to restaurants, gift shops, hotels, and car rental agencies. The leases provide revenue for the airport. In addition, the airport receives income from parking lots, telephones and advertisements in the terminal, and landing fees paid by the airlines. Most commercial service airports also get income from a passenger facility charge, a fee added to each passenger’s ticket.
Airline passenger services.
Airline workers provide many services for passengers at commercial airports. Ticket counter employees sell tickets, check in passengers who already have tickets, and provide information about the times and gates for flight arrivals and departures. A passenger’s ticket may be a printed ticket or an e-ticket, a ticket purchased over the telephone or the Internet and recorded electronically with the airline. Ticket counter agents use airline computer systems to quickly print boarding passes and baggage tags. Ticket kiosks at some airports enable passengers to check themselves in without the aid of a ticket agent.
Ticket counter workers also check in passengers’ baggage. Baggage handlers and ramp agents (workers that service aircraft between flights) see that baggage is loaded on the flight. After a plane reaches its destination, handlers unload bags and transport them to the baggage claim area.
Other airline workers include an airline station manager, who oversees passenger services. Reservations agents keep records of flight reservations. The dispatch staff maintains contact with planes in the air and with other airports that the airline serves.
Cargo handling.
Most airports use the term cargo for mail and all other freight carried by aircraft except baggage. Much air cargo includes items that spoil rapidly, such as flowers, fruits, vegetables, seafood, and medical supplies, including organs for transplant. Other typical air cargo includes such products as electronic goods and machinery parts. Both cargo aircraft and passenger aircraft carry cargo.
Large airports have several separate terminals for cargo processing. Cargo brought in from the surrounding area is often sorted at the airport for various flights. Postal workers sort any mail. Carts, towed by small vehicles called tugs, then carry the cargo to the apron, where workers load it into aircraft.
Small aircraft services.
Commercial service airports must provide many services for small planes that are not operated by commercial airlines. In the United States, these small planes account for about 10 percent of the traffic at most large commercial service airports. They make up approximately 65 percent of the flights at small commercial service airports. A service center called a fixed base operator provides these small aircraft with such services as fuel, hangars, mechanical maintenance, ground transportation, and food.
Air traffic control.
In the control tower, the air traffic controllers guide aircraft as they land, take off, and taxi. The controllers make sure that the traffic moves smoothly, rapidly, and safely. They must have good eyesight, speak clearly over the radio, and think quickly. The controllers must also remain calm during periods of heavy air traffic. Their job becomes especially difficult when fog or other weather conditions reduce visibility. In such situations, the controllers must rely entirely on ADS-B technology, radar, or GPS satellite signals to locate and guide aircraft in flight.
Planes approach or depart on assigned routes called traffic patterns. Instruments in aircraft cockpits electronically display an airport’s traffic patterns for pilots to follow. When necessary, a pilot can safely fly without instruments if the weather is clear enough to see other aircraft and the airport.
The control tower has several types of all-weather landing equipment to help bring planes down safely. Most commercial airports have an electronic aid called an Instrument Landing System (ILS). The ILS sends radio signals to receivers on an airplane. The airplane receivers show the pilot whether the plane is left, right, above, below, or directly on the correct approach path to the airport.
Other navigation aids include Airport Surveillance Radar (ASR) and the Global Positioning System. ASR gives traffic controllers a view of all aircraft activity within about 60 miles (100 kilometers) of the airport. This information helps controllers prevent midair collisions by choosing the safest route for pilots to follow.
The GPS uses a network of navigation satellites to enable pilots anywhere on Earth to determine their location. These satellites send out radio signals that are picked up by receivers on the aircraft. GPS equipment can compute an aircraft’s position and speed every second. The system bases the calculations on the distances between the satellites and the receiver. Many airports use a wide-area augmentation system (WAAS) that enhances GPS data to provide more accurate positioning information for approaches and landings.
Airport security.
Commercial service airports worldwide maintain security to prevent such dangerous activity as terrorist hijackings and bombings. TSA personnel search airplanes for hidden weapons and explosives. They also inspect passengers’ baggage before it goes onto the plane. Passengers must pass through electronic scanners that detect guns, knives, and other metal objects.
The federal government has established security regulations for all air carrier airports in the United States. The regulations include rules on inspection of planes, baggage, and passengers. The airports are required to have law enforcement personnel on the premises as part of their security programs. Federal legislation passed after terrorist attacks in the United States in September 2001 increased security measures at airports. These measures include screening all checked baggage for explosives. The new law also transferred responsibility for passenger and baggage screening from private security firms to the TSA.
Other operations.
In the hangars, trained mechanics repair planes. Other employees keep records of spare parts needed for repairs. Many airline employees work in the apron area. Some direct aircraft into parking spaces. Mechanics check the engines and other equipment. Some employees clean the interior of airplanes between flights. After all the work has been completed, the captain of an aircraft notifies the dispatch office that the flight is ready to leave.
Airlines contract with commercial flight kitchens to prepare food for passengers on some flights. Dietitians plan the menus, and chefs do the cooking. Food handlers transport the meals to waiting aircraft.
At most U.S. airports, FAA employees operate the control tower. They also maintain electronic equipment in the tower. The workers who do passenger and baggage inspection in U.S. airports are also federal employees. Other federal workers at airports include postal workers, customs and immigration officials, and security personnel.
Many large commercial service airports have a station for their national weather service. Airports and airlines typically use private weather services to check conditions in specific areas of interest. Such services provide airlines, pilots, and airport operators with world and national weather information.
Airport development
Planning and building an airport
takes a long time. Many environmental and economic issues must be considered. When a governmental body wishes to build an airport, it may take several years and many studies before construction can begin. The first step is to hire an airport planning firm to select the best site for the new airport. The planners evaluate each potential site for many factors. These factors include environmental impact and distance to the city. The planners also consider the homes and businesses that must be moved, and the difficulty of building on the terrain. The governmental body then holds public hearings where elected officials and the public can express their opinions about the chosen site.
Following approval by the community and the federal government, funding must be arranged. Voters may be asked to approve a bond issue to help pay for the new airport. The governmental body then contracts with an architectural firm to design the airport. It employs an engineering firm, contractors and suppliers, and perhaps a project management firm to build the airport. The actual construction of a major airport usually takes three to five years.
Few cities build new airports. Instead, most cities expand or renovate their existing airports. Planners prepare a document called an airport master plan. The plan shows the airport’s present facilities and describes how the airport should be developed to meet future needs. These plans generally show the location of new runways and terminal buildings so these areas can be protected for future development. The nation’s government often funds such plans. As homes and businesses are built near an airport, they decrease the ability of the airport to grow in the future.
Terminal designs.
Designs for airport passenger terminals use one of three types of plans. These plans are (1) linear, (2) pier, and (3) satellite.
In a linear plan, arriving and departing passengers enter and exit the terminal along the building’s curb. Aircraft also park along the length of the building. This arrangement results in short walking distances for passengers. Linear plans work best for passengers beginning or ending their trips. Such plans are less efficient, however, for passengers or baggage transferring between flights.
A pier plan has a central terminal building with a pier or passageway called a concourse. The concourse extends onto the apron where the airplanes park. Although this type of plan may create longer walking distances, it allows more aircraft to park near the building. It also centralizes such functions as baggage handling, ticketing, and check-in. Many modern pier terminals have moving sidewalks to help passengers walk long distances.
In a satellite plan, passengers board aircraft from terminals called satellite terminals. Passengers travel from the main terminal to a satellite terminal by riding a shuttle or a driverless electric rail car called a people mover. Shuttles and people movers run at ground level, overhead, or underground from the main terminal. The satellite plan enables a greater number of aircraft to park at a terminal and shortens walking distances.
Airport noise.
When airports were built years ago, they lay far from cities and people’s homes. However, as cities have grown, more people have come to live near airports. As a result, aircraft noise has become an increasing problem. In the United States, federal noise laws have resulted in airlines phasing out old, noisy aircraft and purchasing quieter new planes. In addition, airports sometimes obtain federal funds to buy homes affected by noise. They may pay for the soundproofing of schools, libraries, and homes. At many airports, pilots must follow specific approach and departure patterns to reduce the impact of noise on populated areas.
