Airport apron in the context of "Air traffic control"

An airport is an aerodrome with extended facilities, mostly for commercial air transport. They usually consist of a landing area, which comprises an aerially accessible open space including at least one operationally active surface such as a runway for a plane to take off and to land or a helipad, and often includes adjacent utility buildings such as control towers, hangars and terminals, to maintain and monitor aircraft. Larger airports may have airport aprons, taxiway bridges, air traffic control centres, passenger facilities such as restaurants and lounges, and emergency services. In some countries, the US in particular, airports also typically have one or more fixed-base operators, serving general aviation.

Airport operations are extremely complex, with a complicated system of aircraft support services, passenger services, and aircraft control services contained within the operation. Thus airports can be major employers, as well as important hubs for tourism and other kinds of transit. Because they are sites of operation for heavy machinery, a number of regulations and safety measures have been implemented in airports, in order to reduce hazards. Additionally, airports have major local environmental impacts, as both large sources of air pollution, noise pollution and other environmental impacts, making them sites that acutely experience the environmental effects of aviation. Airports are also vulnerable infrastructure to extreme weather, climate change caused sea level rise and other disasters.

In aviation, a runway is an elongated, rectangular surface designed for the landing and takeoff of an aircraft. Runways may be a human-made surface (often asphalt, concrete, or a mixture of both) or a natural surface (grass, dirt, gravel, ice, sand or salt). Runways, taxiways and ramps, are sometimes referred to as "tarmac", though very few runways are built using tarmac. Takeoff and landing areas defined on the surface of water for seaplanes are generally referred to as waterways. Runway lengths are now commonly given in meters worldwide, except in North America where feet are commonly used.

An international airport is an airport with customs and border control facilities, enabling passengers to travel between countries around the world. International airports are usually larger than domestic airports, and feature longer runways and have facilities to accommodate heavier aircraft such as the Boeing 747 and the Airbus A380 commonly used for international and intercontinental travel. International airports often host domestic flights, which helps feed both passengers and cargo into international ones (and vice versa).

Buildings, operations, and management have become increasingly sophisticated since the mid-20th century, when international airports began to provide infrastructure for international civilian flights. Detailed technical standards have been developed to ensure safety and common coding systems implemented to provide global consistency. The physical structures that serve millions of individual passengers and flights are among the most complex and interconnected in the world. By the second decade of the 21st century, over 1,200 international airports existed with around 3.8 billion international passengers as of January 2023 along with 50 million metric tonnes of cargo passing through them annually.

TWA Flight 847 was a regularly scheduled Trans World Airlines flight from Cairo to San Diego with en route stops in Athens, Rome, Boston, and Los Angeles. On the morning of June 14, 1985, Flight 847 was hijacked soon after take off from Athens. The hijackers demanded the release of a total of 784 Shia Muslims from Israeli custody and took the plane repeatedly to Beirut and Algiers. After the incident, Western analysts asserted that hijackers had been members of Hezbollah, however, Hezbollah refutes that claim to this day.

The hijacking and subsequent hostage situation played out over the course of 17 days, during which the aircraft crisscrossed the Mediterranean. Many passengers were tied up and beaten, and those with Jewish-sounding names were separated from the others. United States Navy diver Robert Stethem was murdered, and his body was thrown onto the Beirut airport apron. The ordeal finally ended after some of the hijackers' demands had been met and they agreed to release all remaining hostages. Many believed that due to the lawless nature of Lebanon at the time the captors would go unpunished.

A taxiway is a path for aircraft at an airport connecting runways with aprons, hangars, terminals and other facilities. They mostly have a hard surface such as asphalt or concrete, although smaller general aviation airports sometimes use gravel or grass.

Most airports do not have a specific speed limit for taxiing (though some do). There is a general rule on safe speed based on obstacles. Operators and aircraft manufacturers might have limits. Typical taxi speeds are 20–30 kn (37–56 km/h; 23–35 mph).

A gate is an area in an airport terminal that controls access to a passenger aircraft. While the exact specifications vary from airport to airport and country to country, most gates consist of a seated waiting area, a counter and a doorway leading to the aircraft. A gate adjacent to the stand where the aircraft is parked may be a contact gate, providing access by way of a jet bridge, or a ground-loaded gate, providing a path for passengers to leave the building to board via mobile stairs or airstairs built into the aircraft itself. A remote stand serves an aircraft stand further away, providing access to ground transportation to move passengers between the gate and the stand, where they board via stairs.

Each gate typically corresponds to one parking stand on the airport's apron. A gate that provides access to multiple stands/jet bridges may have separate, designated doorways – sometimes termed sub-gates – for each stand. Commercial airport stands have airside components to facilitate passenger boarding and aircraft ground handling.

The Dulles International Airport Main Terminal is located in Loudoun and Fairfax counties in Dulles, Virginia, United States. The original structure, 600 feet (180 m) long and 150 feet (46 m) wide, was designed by Eero Saarinen and completed in 1962 as the first terminal at Dulles International Airport. Annexes to the west and east were completed in 1996 as part of a renovation designed by Skidmore, Owings & Merrill (SOM), bringing its total length to 1,240 feet (380 m). The terminal is operated by the Metropolitan Washington Airports Authority, which operates Dulles Airport as a whole. The terminal's design is a suspended structure with roof panels of precast concrete suspended between cables which span the width of the building.

The Main Terminal's design includes parallel slanted colonnades on the terminal's north and south facades, interspersed with glass walls. The landside facade to the north is taller than the airside facade to the south; a concave roof supported by cables connects the two facades, descending toward the center. A concourse and control tower extend south toward the airport's apron. The interior was originally divided into two levels: an upper story for departing passengers and a lower story for arriving passengers. Saarinen's original design included mobile lounges that ferried passengers directly to planes, reducing the need for long walks or taxiing while increasing the airport's operational flexibility. The modern terminal includes four airline gates known as Z gates, where aircraft could unload passengers directly. In addition, two basements contain security screening facilities and an AeroTrain people-mover station.