Chapter 6 CPL LAW

• Air Traffic Services (ATS)


  Provided to New Zealand aviation in the domestic FIR by The Airways Corporation of New Zealand Limited (Airways), which is a State Owned Enterprise
• Air Traffic Services provided

  • Air Traffic Control Service to IFR flights in controlled airspace
  • Air Traffic Control Service to VFR flights in Class C airspace
  • Air Traffic Control Service to aerodrome traffic at controlled aerodromes
  • Area Flight Information Service (FIS) to give advice and information for the efficient conduct of any flight
  • Aerodrome Flight Information Service (AFIS) to aircraft operating in the vicinity of an aerodrome at which a Flight Service Station (FSS) is in operation
  • Alerting Service to all flights that have filed a flight plan and, as far as practicable, to all flights known to ATS
• Air Traffic Control service


  The provision of control in order to prevent collisions and the maintenance of an orderly flow of traffic
• Air Traffic Control services

  • Area Control Service
  • Approach Control Service
  • Aerodrome Control Service
• Area Control Service


  • Primarily deals with IFR flights enroute, provided by radar controllers at an Area Control Centre (ACC) or by a controller located in an Aerodrome Control Tower using non-radar control methods
• Approach Control Service


  • Primarily deals with IFR and controlled VFR flights arriving and departing from controlled aerodromes, provided by radar controllers located at an ACC or by a controller located in an Aerodrome Control Tower using non-radar control methods
• Aerodrome Control Service


  • Deals with aircraft operating on and around controlled aerodromes, provided by a controller in the control tower at the aerodrome
• There are two Area Control Centres in New Zealand: the larger is in Christchurch and the second is at Auckland
• Aerodrome Control Service


  Provided to aerodromes by controllers in the control tower, who provide clearances, instructions and information to aircraft operating in the vicinity of the aerodrome to prevent collisions and to achieve runway and traffic flow
• Aerodrome controllers primarily use visual means to provide an Aerodrome Control service, but may have a radar screen in the tower to assist them
• Aerodrome Flight Information Service (AFIS)


  The provision of information and advice useful for the safe and efficient conduct of flights within the vicinity of aerodromes that have a Flight Service Station (FSS) in attendance, but AFIS personnel cannot exercise control over aircraft
• AFIS is currently provided at Milford Sound and Paraparaumu aerodromes in New Zealand, and may be established temporarily at any uncontrolled aerodrome for a special event
• Area Flight Information Service (FIS)


  The provision of information and advice useful for the safe and efficient conduct of flights, dealing with advising pilots about weather information, NOTAM and traffic information
• The national Flight Information Centre (FIC) at Christchurch provides a Flight Information Service to aircraft operating in Class G airspace, as well as to other aircraft requiring information
• Alerting Service


  An air traffic service provided to notify appropriate organisations regarding aircraft in need of search and rescue aid, and to assist such organisations as required
• ATS Surveillance Systems


  • Primary Surveillance Radar (PSR)
  • Secondary Surveillance Radar (SSR)
  • Automatic Dependent Surveillance-Broadcast (ADS-B)
  • Multilateration (MLAT)
• Primary Surveillance Radar (PSR)


  • Works by sending out a signal from the radar aerial and receiving a 'reflection' back from the aircraft, but can be affected by hills, clouds, rain and other interference
• Secondary Surveillance Radar (SSR)

  • Works by sending out a signal that causes the aircraft's transponder to send a signal back, which is less affected by environmental factors and can provide additional information like aircraft code and altitude
• PSR and SSR coverage in New Zealand is generally good, with most of the North Island and the top two-thirds of the South Island covered by radar
• Automatic Dependent Surveillance-Broadcast (ADS-B)


  The aircraft's transponder automatically and continuously broadcasts a package of digital data that is received by ADS-B ground stations and other ADS-B equipped aircraft, allowing for ATC surveillance and cockpit traffic displays
• The use of an ADS-B system in all controlled airspace is now mandated throughout New Zealand
• Multilateration (MLAT)


  A modern version of triangulation where the location of a transponder is determined by calculating its range from several different ground receiver stations, used for both Local Area Multilateration (LAM) and Wide Area Multilateration (WAM)
• Multilateration surveillance is independent of GNSS and only requires the aircraft to be fitted with a transponder
• Multilateration


  A technique that uses several small radio receivers spread around an airport to continuously monitor transponder transmissions from aircraft, transponder equipped vehicles or other objects
• Local Area Multilateration (LAM)

  • Uses several small radio receivers spread around an airport to continuously monitor transponder transmissions
  • The ranges, and therefore the position of the transponder, is established by calculating the response time at each of the receivers
  • The calculated position can then be presented to ground controllers on a display which is very similar to a radar display
• Wide Area Multilateration (WAM)

  • Uses several small radio receivers spread over a wide area to continuously monitor transponder transmissions
• One advantage of multilateration surveillance is its independence from GNSS and the use of existing aircraft equipment
• The only operational consideration for multilateration is that the aircraft must be fitted with a transponder, either Mode A, C or S, and that the flight crew must have selected their transponder ON (XPNDR/XPDR position) whenever they are moving on the ground
• While ADS-B is not required for multilateration, it is compatible
• Recent improvements in timing, synchronisation and computer processing are yielding aircraft positions using LAM equal to, and often better than GNSS (3-7 metres), and significantly better than airport surveillance radar
• Waypoints are not covered in this study material
• A transponder can be installed in an aircraft so that the aircraft can be identified by the secondary radars (SSR)
• Transponder modes


  • Mode A - sends a four-digit code
  • Mode C - sends altitude information
• Transponder functions


  • OFF - transponder is off
  • SBY - transponder is on but will not reply to interrogations
  • ON - transponder is on and will reply to interrogations but will send Mode A information only
  • ALT - transponder is on and will reply to interrogations, sending both Mode A and Mode C altitude information
• The transponder IDENT button highlights the aircraft's radar symbol on the screen to flash so that the controller can positively identify the target aircraft
• A serviceable transponder (with Mode A and Mode C) is required for flight in all controlled airspace in New Zealand
• Transponder mandatory airspace is identified by the symbol TM on maps and charts
• If an aircraft does not have an operable transponder, permission to enter transponder-mandatory airspace must be requested at least 30 minutes before the start of the flight
• Transponder testing should be conducted in specific controlled conditions to avoid interfering with radar scales or plots of ACAS equipped aircraft
• The ATC radar system in New Zealand is a national system with primary and secondary radars, a computer, operating consoles and ATS staff