Air traffic control in the context of Radar

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.

The ICAO airport code or location indicator is a four-letter code designating aerodromes around the world. These codes, as defined by the International Civil Aviation Organization and published quarterly in ICAO Document 7910: Location Indicators, are used by air traffic control and airline operations such as flight planning.ICAO codes are also used to identify other aviation facilities such as weather stations, international flight service stations, or area control centers (and by extension their flight information regions), regardless of whether they are located at airports.

A dot matrix is a 2-dimensional patterned array, used to represent characters, symbols and images. Most types of modern technology use dot matrices for display of information, including mobile phones, televisions, and printers. The system is also used in textiles with sewing, knitting and weaving.

An alternate form of information display using lines and curves is known as a vector display, was used with early computing devices such as air traffic control radar displays and pen-based plotters but is no longer used. Electronic vector displays were typically monochrome only, and either leave the interiors of closed vector shapes unfilled, or perform slow, time-consuming and often non-uniform shape-filling, as on pen-based plotters.

King Khalid International Airport (Arabic: مطار الملك خالد الدولي, romanized: Maṭār al-Malik Khālid al-Duwaliyy; IATA: RUH, ICAO: OERK) is an international airport located about 35 kilometres (22 mi) north of Riyadh, Saudi Arabia. This airport consists of five passenger terminals with eight aero-bridges each, a mosque, and parking facilities for 11,600 vehicles. It includes a "Royal Terminal" designated for use by government officials, state guests, and the Saudi royal family. The airport has one of the world's tallest air traffic control towers, and two parallel runways, each 4,260 metres (13,980 ft) in length. It is one of the busiest airports in the Middle East. The airport is owned and operated by the state-owned Riyadh Airports Company.

The Royal Mosque was designed with a significant programme of integral art; the stained glass, by British architectural artist Brian Clarke, was a landmark work in the history of the medium, considered to be the largest and technically most advanced stained glass project of the modern period.

Airspace is the portion of the atmosphere controlled by a country above its territory and territorial waters that fall under the country's sovereignty and regulatory control.

Internationally, allocation and management of airspace is coordinated by the International Civil Aviation Organization (ICAO), which was established through the Chicago Convention in 1947 to unify air traffic. ICAO organizes airspace into Flight Information Regions (FIRs) and provides classification guidelines. National authorities, such as the FAA, CAA, or EASA implement rules and regulations for air traffic control, special-use airspace, and enforcement within their own FIRs.

In air traffic control, an area control center (ACC), also known as a center or en-route center, is a facility responsible for controlling aircraft flying in the airspace of a given flight information region (FIR) at high altitudes between airport approaches and departures. In the US, such a center is referred to as an air route traffic control center (ARTCC).

A center typically accepts traffic from—and ultimately passes traffic to—the control of a terminal control center or another center. Most centers are operated by the national governments of the countries in which they are located. The general operations of centers worldwide, and the boundaries of the airspace each center controls, are governed by the International Civil Aviation Organization (ICAO).

In aviation, an intersection is a virtual navigational fix that helps aircraft maintain their flight plan. It is usually defined as the intersection (in the geometrical sense) of two VOR (VHF Omnidirectional Range) radials. They are usually identified as major airway intersections where aircraft, operating under instrument flight rules, often change direction of flight while en route. According to the Federal Aviation Regulations, some intersections are designated as mandatory reporting points for pilots who are not in radar contact with air traffic control.

Intersections also play an important role in departure and approach procedures. All intersections have an alphabetical or alphanumeric designation. Near major airports, the intersection designation code typically consists of three letters followed by the runway number. Most other intersection designations consist of five-letter combinations that are either pronounceable or chosen for their mnemonic value, since either air traffic control or the flight plan may require the pilot to announce the designation. In the terminal procedure or approach plate example to the right, note that two of the intersections are called DONUT and KOFFE. Many intersections are named because of local points of interest. In the case of Carroll County Airport, there is a popular diner located on the field to which many pilots fly.

The airport apron, apron, flight line, or ramp is the area of an airport where aircraft are parked, unloaded or loaded, refueled, boarded, or maintained. Although the use of the apron is covered by regulations, such as lighting on vehicles, it is typically more accessible to users than the runway or taxiway. However, the apron is not usually open to the general public, and a permit may be required to gain access. An apron's designated areas for aircraft parking are called aircraft stands.

By extension, the term apron is also used to identify the air traffic control (ATC) position responsible for coordinating movement on this surface at busier airports. When the aerodrome control tower does not have control over the apron, the use of the apron may be controlled by an apron management service (also known as apron control or apron advisory) to provide coordination between the users. Apron control allocates aircraft parking stands (gates) and communicates this information to tower or ground control and to airline handling agents; it also authorises vehicle movements where they could conflict with taxiing aircraft such as outside of painted road markings. The authority responsible for the aprons is also responsible for relaying to ATC information about the apron conditions such as water, snow, construction or maintenance works on or adjacent to the apron, temporary hazards such as birds or parked vehicles, systems failure etc. Procedures should be established for a coordinated information provision between the aircraft, vehicle, apron control unit and ATC to facilitate the orderly transition of aircraft between the apron management unit and the aerodrome control tower.

Turkish Airports Authority or legally General Directorate of State Airports Authority (Turkish: Devlet Hava Meydanları İşletmesi Genel Müdürlüğü; DHMİ), is the Turkish government authority responsible for the functioning of airports in Turkey and the regulation and monitoring of air traffic control in Turkish airspace. It is associated with the Turkish Ministry of Transport and Infrastructure and is a member of ICAO, EUROCONTROL, and ACI Europe.

The authority operates most airports in Turkey, with the notable examples being Istanbul Airport, Antalya Airport, İzmir Adnan Menderes Airport, Milas–Bodrum Airport and Çukurova Airport.

A location identifier is a symbolic representation for the name and the location of an airport, navigation aid, or weather station, and is used for staffed air traffic control facilities in air traffic control, telecommunications, computer programming, weather reports, and related services.

Flight planning is the process of producing a flight plan to describe a proposed aircraft flight. It involves two safety-critical aspects: fuel calculation, to ensure that the aircraft can safely reach the destination, and compliance with air traffic control requirements, to minimise the risk of midair collision. In addition, flight planners normally wish to minimise flight cost through the appropriate choice of route, height, and speed, and by loading the minimum necessary fuel on board. Air Traffic Services (ATS) use the completed flight plan for separation of aircraft in air traffic management services, including tracking and finding lost aircraft, during search and rescue (SAR) missions. Flight planning typically includes route selection, fuel calculation, alternate aerodrome planning, weight and balance considerations, and an assessment of meteorological conditions.

Flight planning requires accurate weather forecasts so that fuel consumption calculations can account for the fuel consumption effects of head or tail winds and air temperature. Safety regulations require aircraft to carry fuel beyond the minimum needed to fly from origin to destination, allowing for unforeseen circumstances or for diversion to another airport if the planned destination becomes unavailable. Furthermore, under the supervision of air traffic control, aircraft flying in controlled airspace must follow predetermined routes known as airways (at least where they have been defined), even if such routes are not as economical as a more direct flight. Within these airways, aircraft must maintain flight levels, specified altitudes usually separated vertically by 1,000 or 2,000 ft (300 or 610 m), depending on the route being flown and the direction of travel. When aircraft with only two engines are flying long distances across oceans, deserts, or other areas with no airports, they have to satisfy additional ETOPS safety rules to ensure they can reach an emergency airport if one engine fails.

A flight service station (FSS) is an air traffic facility that provides information and services to aircraft pilots before, during, and after flights, but unlike air traffic control (ATC), is not responsible for giving instructions or clearances or providing separation. They do, however, relay clearances from ATC for departure or approaches. The people who communicate with pilots from an FSS are referred to as flight service specialists.

The precise services offered by stations vary by country, but typical FSS services may include providing preflight briefings including weather and notices to airmen (NOTAMs); filing, opening, and closing flight plans; monitoring navigational aids (NAVAIDs); collecting and disseminating pilot reports (PIREPs) and airport surface weather observations; offering traffic advisories to aircraft on the ground or in flight; relaying instructions or clearances from air traffic control; relaying information from or about airborne aircraft to their home bases, military bases or homeland security, providing weather advisories to aircraft inflight, initiating search and rescue on missing VFR aircraft, and providing assistance in an emergency. In many countries, flight service stations also operate at mandatory frequency airports to help co-ordinate traffic in the absence of air traffic controllers, and may take over a control tower frequency at a controlled airport when the tower is closed.

United Airlines Flight 93 was a domestic scheduled passenger flight that was hijacked by four al-Qaeda terrorists on the morning of Tuesday, September 11, 2001, as part of the September 11 attacks. The hijackers planned to crash the plane into a federal government building in the national capital of Washington, D.C. The mission failed when the passengers fought back, forcing the terrorists to crash the plane in Shanksville in Somerset County, Pennsylvania, preventing them from reaching al-Qaeda's intended target, but killing everyone aboard the flight. The airliner involved, a Boeing 757-200 with 44 passengers and crew, was flying United Airlines' daily scheduled morning flight from Newark International Airport in New Jersey to San Francisco International Airport in California, making it the only plane hijacked that day not to be a Los Angeles–bound flight.

Forty-six minutes into the flight, the hijackers killed one passenger, stormed the cockpit, and struggled with the pilots as controllers on the ground listened in. Ziad Jarrah, who had trained as a pilot, took control of the aircraft and diverted it back toward the East Coast, in the direction of D.C.

The Federal Aviation Administration (FAA) is a U.S. federal government agency within the U.S. Department of Transportation that regulates civil aviation in the United States and surrounding international waters. Its powers include air traffic control, certification of personnel and aircraft, setting standards for airports, and protection of U.S. assets during the launch or re-entry of commercial space vehicles. Powers over neighboring international waters were delegated to the FAA by authority of the International Civil Aviation Organization.

The FAA was created in August 1958 (1958-08) as the Federal Aviation Agency, replacing the Civil Aeronautics Administration (CAA). In 1967, the FAA became part of the newly formed U.S. Department of Transportation and was renamed the Federal Aviation Administration.

A ground stop is an air traffic control procedure that requires all aircraft that fit certain criteria to remain on the ground. This could be airport-specific or perhaps equipment- or airspace-specific, depending on the exact event that caused the ground stop to occur. Downstream effects can occur from a ground stop. It causes flights to be delayed or canceled and planes and flight crew to be unable to reach the location of their next scheduled flight.

Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF).

VHF radio waves propagate mainly by line-of-sight, so they are blocked by hills and mountains, although due to refraction they can travel somewhat beyond the visual horizon out to about 160 km (100 miles). Common uses for radio waves in the VHF band are Digital Audio Broadcasting (DAB) and FM radio broadcasting, television broadcasting, two-way land mobile radio systems (emergency, business, private use and military), long range data communication up to several tens of kilometers with radio modems, amateur radio, and marine communications. Air traffic control communications and air navigation systems (e.g. VOR and ILS) work at distances of 100 kilometres (62 miles) or more to aircraft at cruising altitude.

The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave band of the electromagnetic spectrum covering frequencies from 2 to 4 gigahertz (GHz). Thus it crosses the conventional boundary between the UHF and SHF bands at 3.0 GHz. The S band is used by airport surveillance radar for air traffic control, weather radar, surface ship radar, and some communications satellites, particularly satellites used by NASA to communicate with the Space Shuttle and the International Space Station. The 10 cm radar short-band ranges roughly from 1.55 to 5.2 GHz. India's regional satellite navigation network (IRNSS) broadcasts on 2.483778 to 2.500278 GHz.

The S band also contains the 2.4–2.483 GHz ISM band, widely used for low power unlicensed microwave devices such as cordless phones, wireless headphones (Bluetooth), garage door openers, keyless vehicle locks, baby monitors as well as for medical diathermy machines and microwave ovens (typically at 2.495 GHz). One of its largest uses is 2.4 GHz IEEE 802.11 Wi-Fi wireless networks, allowing smartphones, laptops, printers and TVs to connect to the internet without cables.