Airport Surface Detection Equipment, Model X, or ASDE-X, is a runway-safety tool that enables air traffic controllers to detect potential runway conflicts by providing detailed coverage of movement on runways and taxiways. By collecting data from a variety of sources, ASDE-X is able to track vehicles and aircraft on airport surfaces and obtain identification information from aircraft transponders.
Originally the FAA installed thirty-eight ASDE-3A radar systems at the United States' busiest airports. The cost-effective alternative to the ASDE-3/AMASS capability, referred to as ASDE-X, is one of the first new runway safety program technologies aimed at improving ATCS situational awareness by providing tools to supplement their tasks (McAnulty, Doros, & Poston, 2001). The data that ASDE-X uses comes from a surface movement radar located on the airport traffic control tower or remote tower, multilateration sensors, ADS-B (Automatic Dependent Surveillance-Broadcast) sensors, terminal radars, the terminal automation system, and from aircraft transponders. By fusing the data from these sources, ASDE-X is able to determine the position and identification of aircraft and vehicles on the airport surfaces, as well as of aircraft flying within 5 miles (8km) of the airport (selectively up to 60 nmi).
Controllers in the tower see this information presented as a color display of aircraft and vehicle positions overlaid on a map of the airport's runways/taxiways and approach corridors. The system essentially creates a continuously updated map of all airport-surface operations that controllers can use to spot potential collisions.
Consisting largely of commercial off-the-shelf products, ASDE-X was designed as a solution for the smaller of the top-tier airports, and is especially helpful to controllers at night or in bad weather when visibility is poor. The Federal Aviation Administration has also begun the process of deployment of visual and audio alarms, known as Safety Logic, that will assist ASDE-X by alerting controllers to possible collisions or runway incursions.
Pilots normally activate the aircraft transponder just prior to take off, then return it to standby or off after landing. When ASDE-X is available at an airport, that fact will be included in the recorded ATIS (Automatic Terminal Information Service) to indicate to the pilot that the transponder should be left on while maneuvering on the ground.
ASDE-X: Coming To An Airport Near You To Squawk Or Not To Squawk, That Is The Question from National Business Aviation Association March 28, 2004
McAnulty, D.M., Koros, A., & Poston, A. (2001). Airport surface detection equipment - Model X early user involvement event. (FAA Publication # ACT5302001-2a). Atlantic City International, NJ: Federal Aviation Administration.
Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airspace. The primary purpose of ATC worldwide is to prevent collisions, organize and expedite the flow of air traffic, and provide information and other support for pilots. In some countries, ATC plays a security or defensive role, or is operated by the military.
On the evening of February 1, 1991, USAir Flight 1493, a Boeing 737-300, collided with SkyWest Airlines Flight 5569, a Fairchild Swearingen Metroliner turboprop aircraft, upon landing at Los Angeles International Airport (LAX). Though air traffic was not heavy at LAX, as Flight 1493 was on final approach, the local controller was distracted by a series of abnormalities, including a misplaced flight progress strip and an aircraft that had inadvertently switched off the tower frequency. The SkyWest flight was told to taxi into takeoff position, while the USAir flight was landing on the same runway.
John Murtha Johnstown–Cambria County Airport is a civil-military airport three miles (5 km) northeast of Johnstown, in Cambria County, Pennsylvania. It is owned by Johnstown–Cambria County Airport Authority and is named after the late Congressman John Murtha. It sees one airline, subsidized by the Essential Air Service.
An airport surveillance radar (ASR) is a radar system used at airports to detect and display the presence and position of aircraft in the terminal area, the airspace around airports. It is the main air traffic control system for the airspace around airports. At large airports it typically controls traffic within a radius of 60 miles (96 km) of the airport below an elevation of 25,000 feet. The sophisticated systems at large airports consist of two different radar systems, the primary and secondary surveillance radar. The primary radar typically consists of a large rotating parabolic antenna dish that sweeps a vertical fan-shaped beam of microwaves around the airspace surrounding the airport. It detects the position and range of aircraft by microwaves reflected back to the antenna from the aircraft's surface. The secondary surveillance radar consists of a second rotating antenna, often mounted on the primary antenna, which interrogates the transponders of aircraft, which transmits a radio signal back containing the aircraft's identification, barometric altitude, and an emergency status code, which is displayed on the radar screen next to the return from the primary radar.
Runway Status Lights (RWSL) are a visual alerting system installed in some airport taxiways and runways for the purpose of collision-avoidance. When illuminated, red high-intensity LEDs indicate the presence of another vehicle either departing, occupying, or landing on an active runway. RWSL systems are fully-automated and intended to alert aircrews and ground vehicle operators of a potential runway incursion hazard. They operate as an additional layer of safety, independent of human-issued air traffic control clearances.
Gol Transportes Aéreos Flight 1907 was a scheduled flight of Gol Transportes Aéreos from Manaus, Brazil, to Brasília and Rio de Janeiro. On 29 September 2006, an Embraer Legacy 600 business jet over the Brazilian state of Mato Grosso collided in midair with the Boeing 737-8EH serving the flight. The upturned wingtip of the Embraer sliced off about half of the 737's left wing. The 737 broke up in midair and crashed into an area of dense jungle, killing all 154 passengers and crew. Despite sustaining serious damage to its left wing and tail, the Embraer Legacy jet landed with its seven occupants uninjured.
A transponder is an electronic device that produces a response when it receives a radio-frequency interrogation. Aircraft have transponders to assist in identifying them on air traffic control radar. Collision avoidance systems have been developed to use transponder transmissions as a means of detecting aircraft at risk of colliding with each other.
A runway incursion is an aviation incident involving improper positioning of vehicles or people on any airport runway or its protected area. When an incursion involves an active runway being used by arriving or departing aircraft, the potential for a collision hazard or Instrument Landing System (ILS) interference can exist. At present, various runway safety technologies and processes are commonly employed to reduce the risk and potential consequences of such an event.
The Airport Movement Area Safety System (AMASS) visually and aurally prompts tower controllers to respond to situations which potentially compromise safety. AMASS is an add-on enhancement to the host Airport Surface Detection Equipment Model 3 (ASDE-3) radar that provides automated aural alerts to potential runway incursions and other hazards. AMASS extends the capability of the ASDE-3 and enhances surface movement safety.
The 2007 San Francisco International Airport runway incursion occurred around 1:36 p.m. PDT on May 26, 2007 when SkyWest Airlines Flight 5741, an Embraer EMB 120 Brasilia turboprop aircraft, nearly collided with Republic Airways Flight 4912, an Embraer 170 Regional Jet, at the intersection of Runways 1L and 28R at San Francisco International Airport (SFO) in South San Francisco, California.
The Next Generation Air Transportation System (NextGen) is an ongoing modernization project of the United States National Airspace System (NAS). The U.S. Federal Aviation Administration (FAA) began work on NextGen improvements in 2007 and plans to have all major components in place by 2025.
Walker County Airport, also known as Bevill Field, is a public airport located five miles (8 km) northwest of the central business district of Jasper, a city in Walker County, Alabama, United States. It is owned by the Walker County Commission.
TWA Flight 427 was a regularly scheduled TWA passenger flight departing St. Louis Lambert International Airport (STL) in Bridgeton, Missouri on November 22, 1994, operated using a McDonnell Douglas MD-82. On the takeoff roll it struck a Cessna 441 Conquest II, killing both of its occupants. It was the second of two flights numbered 427 that were involved in an incident that year, the other being USAir Flight 427, which crashed in September near Pittsburgh, Pennsylvania killing all 132 on board.
Automatic Dependent Surveillance–Broadcast (ADS–B) is a surveillance technology in which an aircraft determines its position via satellite navigation or other sensors and periodically broadcasts it, enabling it to be tracked. The information can be received by air traffic control ground stations as a replacement for secondary surveillance radar, as no interrogation signal is needed from the ground. It can also be received by other aircraft to provide situational awareness and allow self-separation. ADS–B is "automatic" in that it requires no pilot or external input. It is "dependent" in that it depends on data from the aircraft's navigation system.
Surface movement radar (SMR) is used to detect aircraft and vehicles on the surface of an airport. It is used by air traffic controllers to supplement visual observations. It may also be used at night time and during low visibility to monitor the movement of aircraft and vehicles. Surface movement radar is the term accepted by ICAO, but it has historically been known by other names such a ground movement radar, airport surface detection equipment (ASDE) and airfield surface movement indicator.
Runway safety is concerned with reducing harm that could occur on an aircraft runway. Safety means avoiding incorrect presence (incursion) of aircraft, inappropriate exits (excursion) and use of the wrong runway due to confusion. The runway condition is a runway's current status due to meteorological conditions and air safety.
On December 20, 1972, North Central Airlines Flight 575 and Delta Air Lines Flight 954 collided on a runway at O'Hare International Airport in Chicago, Illinois, in the United States. Ten people died – all on the North Central aircraft – and 17 were injured in the accident. This was the second major airliner accident to happen in Chicago in December 1972; the other was United Airlines Flight 553, which crashed twelve days earlier on approach to Midway Airport.
On January 15, 1987, at 12:52 local time, SkyWest Airlines Flight 1834 a Swearingen SA-226TC, and a Mooney M20 were involved in a midair collision near Kearns, Utah. The two pilots and six passengers aboard the METRO II and the two pilots aboard the Mooney were killed. NTSB investigators primarily blamed the small plane pilots for wandering into restricted airspace, but a judge later assigned 51% responsibility to FAA air traffic controllers.
On July 7, 2017, an Airbus A320-211 operating as Air Canada Flight 759 was nearly involved in an accident at San Francisco International Airport in San Mateo County, California, United States. The flight, which originated at Toronto Pearson International Airport, had been cleared by air traffic control to land on San Francisco's runway 28R and was on final approach to land on that runway; however, instead of lining up with the runway, the aircraft had lined up with the parallel taxiway Charlie on which four fully loaded and fueled passenger airplanes were stopped awaiting takeoff clearance. The flight crew initiated a go-around prior to landing, after which it landed without further incident. The aircraft on the taxiway departed for their intended destinations without further incident. The subsequent investigation by the National Transportation Safety Board (NTSB) determined that the Air Canada airplane descended to 59 feet (18 m) above the ground before it began its climb, and that it missed colliding with one of the aircraft on the taxiway by 14 feet (4.3 m).
Airport Surface Surveillance Capability (ASSC) is a runway-safety tool that displays aircraft and ground vehicles on the airport surface, as well as aircraft on approach and departure paths within a few miles of the airport. The tool allows air traffic controllers and air crew in cockpits equipped with Automatic Dependent Surveillance-Broadcast (ADS-B) to detect potential runway conflicts by providing detailed coverage of movement on runways and taxiways. By collecting and fusing data from a variety of sources, ASSC is able to track vehicles and aircraft on airport surfaces and obtain identification information from aircraft ADS-B transponders.
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