ATC operations

The primary objectives that all Air Traffic Controllers achieve are to:
• prevent collisions between aircraft;
• prevent collisions between aircraft on the manoeuvring area and obstructions on that area;
• expedite and maintain an orderly flow of air traffic;
• provide advice and information useful for the safe and efficient conduct of flights;
• notify appropriate organisations regarding aircraft in need of search and rescue aid, and assist such organisations as required.

Air Traffic Control is divided into two main types of operation: visual control operations provided at controlled aerodromes by Tower controllers, and instrument operations provided by Radar, Procedural and Oceanic controllers. Instrument operations are not necessarily based on or near aerodromes (e.g. all radar control over New Zealand is carried out from a single location, in Christchurch, except Oceanic which is based in Auckland).

Tower controls the landing, take-off and runway operations of aircraft, ensuring the safety of aircraft on the aerodrome, and in the surrounding control zone. Most activity in the tower is done visually, with assistance provided by such tools as: radar, VDF equipment and (in selected areas) MLAT

In some regions of New Zealand, approach control is also conducted from the control tower using procedural approach methods i.e. Gisborne, Napier, New Plymouth, Nelson, Queenstown, Dunedin and Invercargill. All of these areas lack reliable radar coverage at low altitudes, due to terrain and proximity from SSR (secondary surveillance radar) sites, so therefore responsibility for approach control is assigned to the Tower.

Radar controllers separate aircraft within controlled airspace, outside the towers’ designated areas of responsibility. In New Zealand, Radar controllers may either be Area Controllers or Approach Controllers.

Area Controllers: control aircraft within upper airspace, keeping them separated while en route to their destination.

Approach Controllers: use radar to separate aircraft arriving and departing primarily within the major terminal control areas (Auckland, Wellington and Christchurch).

Oceanic air traffic control is carried out utilising satellites (GPS, or Global Positioning Systems). Air traffic operations are similar to radar control except that Oceanic control vectors aircraft between international airspace boundaries. Oceanic controllers transfer control of aircraft to and from Radar controllers.

Video embedded from YouTube on 24 March 2010.

ATC around bad weather

Although it is not possible to ascertain whether the following video actually represents traffic management by air traffic control, it is a plausible scenario of how aircraft would be vectored around a thunderstorm. The simulation, apparently, is on FedEx flights arriving to Memphis (US).

Video embedded from YouTube on 17/Dec/2008.