Thursday, October 30, 2008

Area Control Center

From Wikipedia, the free encyclopedia

This temporary flight restriction map from the Federal Aviation Administration shows the boundaries of the regions controlled by the Area Control Centers within and adjoining the continental United States, as well as the FAA location identifier of each such Center operated by the United States.
This temporary flight restriction map from the Federal Aviation Administration shows the boundaries of the regions controlled by the Area Control Centers within and adjoining the continental United States, as well as the FAA location identifier of each such Center operated by the United States.

In air traffic control, an Area Control Center (ACC), also known as a Center, is a facility responsible for controlling instrument flight rules aircraft en route in a particular volume of airspace (a Flight Information Region) at high altitudes between airport approaches and departures. In the United States, 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 of another Center. Most Centers are operated by the national governments of the countries in which they are located. The general operations of Centers world-wide, and the boundaries of the airspace each Center controls, are governed by the ICAO.

In some cases, the function of an Area Control Center and a Terminal Control Center are combined in a single facility such as a CERAP.

FAA definition

The United States Federal Aviation Administration defines an ARTCC as

[a] facility established to provide air traffic control service to aircraft operating on IFR flight plans within controlled airspace, principally during the en route phase of flight. When equipment capabilities and controller workload permit, certain advisory/assistance services may be provided to VFR aircraft. An ARTCC is the U.S. equivalent of an Area Control Center (ACC).

Subdivision of airspace into sectors

The Flight Information Region controlled by a Center may be further administratively subdivided into sectors; each sector may use a distinct set of communications frequencies and personnel. An aircraft passing from one sector to another may be handed off and requested to change frequencies to contact the next sector controller. Sector boundaries are specified by an aeronautical chart.

Center operations

Controllers at work at the Washington Air Route Traffic Control Center.
Controllers at work at the Washington Air Route Traffic Control Center.

Air traffic controllers working within a Center communicate via radio with pilots of instrument flight rules aircraft passing through the Center's airspace. A Center's communication frequencies (typically in the very high frequency amplitude modulation aviation bands, 118 MHz to 137 MHz, for overland control) are published in aeronautical charts and manuals, and will also be announced to a pilot by the previous controller during a hand-off.

In addition to radios to communicate with aircraft, Center controllers have access to communication links with other Centers and TRACONs. In the United States, Centers are electronically linked through the National Airspace System, which allows nationwide coordination of traffic flow to manage congestion. Centers in the United States also have electronic access to nationwide radar data.

Controllers use radar to monitor the progress of flights and instruct aircraft to perform course adjustments as needed to maintain separation from other aircraft. Aircraft with which a Center has made radar contact can be readily distinguished by their transponders. Pilots may also request altitude adjustments or course changes to avoid turbulence or adverse weather conditions.

Controllers can assign routing relative to location fixes derived from latitude and longitude, or from radionavigation beacons such as VORs. See also Airway; VORs, Airways and the Enroute Structure.

Typically, Centers have advanced notice of a plane's arrival and intentions from its prefiled flight plan.

Oceanic air traffic control

Some Centers have ICAO-designated responsibility for airspace located over an ocean such as ZOA, the majority of which is international airspace. Because substantial volumes of oceanic airspace lie beyond the range of ground-based radars, oceanic airspace controllers have to estimate the position of an airplane from pilot reports and computer models (procedural control), rather than observing the position directly (radar control, also known as positive control). Pilots flying over an ocean can determine their own positions accurately using the Global Positioning System and can supply periodic updates to a Center. See also Air traffic control: Radar Coverage.

A Center's control service for an oceanic FIR may be operationally distinct from its service for a domestic overland FIR over land, employing different communications frequencies, controllers, and a different ICAO code.

Pilots typically use high frequency radio instead of very high frequency radio to communicate with a Center when flying over the ocean, because of HF's relatively greater propagation over long distances.

ACCs by continent (incomplete)

North America

United States

The continental United States has twenty centers, which are operated by the Federal Aviation Administration. The Centers are named after major cities, although most are physically located outside the cities for which they are named. Each Center is identified by a three-letter FAA identifier as well as a four-letter ICAO code, which is the same as the FAA code prefixed by the continental United States' region code "K".

The United States also operates Centers outside the contiguous United States:

Canada

Canada has seven Centers, which are operated by NAV CANADA. The ICAO code for each Canadian Center is the same as its three-letter code prefixed by the Canadian country code "C".

South America

Mexico

  • Mazatlan Center
  • Mexico Center
  • Monterrey Center
  • Merida Center

Europe

Africa

Asia

Japan

Oceania

Australia

Split from an arc 45nm North of Sydney to a line approximately to Port Hedland in Western Australia.

  • Brisbane Air Traffic Services Center - YBBB, has responsibility for the northern portion and the Tasman Sea. Located at Brisbane Airport.
  • Melbourne Air Traffic Services Center - YMMM, has responsibility for the southern portion including the Indian Ocean. Located at Melbourne Airport.

New Zealand

Two FIR's exist although they are both based in Christchurch.

  • Christchurch Control - NZZC, has responsibility for the air traffic over New Zealand itself out to approximately 200nm.
  • Auckland Radio - NZZO, has responsibility for the oceanic air traffic outside of the other FIR and includes half of the Tasman Sea stretching East to Samoa.

References

  1. ^ "INTRODUCTION TO PERFORMANCE BASED NAVIGATION SEMINAR," International Civil Aviation Organization
  2. ^ "REPORT OF THE TWENTY-SIXTH MEETING OF THE RVSM IMPLEMENTATION TASK FORCE (RVSM/TF/26)," International Civil Aviation Organization
  3. ^ "Third Meeting of the Cross Polar Trans-East Air Traffic Management Working Group (Cross Polar WG/3)," Federal Aviation Administration

No comments: