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Air traffic management

Communications, navigation, surveillance/air traffic management

Airspace capacity is determined by the combined capabilities of the communications, navigation, surveillance and air traffic management systems (CNS/ATM) in place. These include ground and aircraft-based systems. Advanced technologies enabled by immediate and accurate satellite signals are improving safety and efficiency in air traffic management and harmonising Australian operations with global standards. 


The communications element of CNS/ATM is evolving with technology. Work is underway to establish a common regional virtual private network (CRV) in the Asia/Pacific region for improved ground to ground communications. This internet protocol based network will provide a more cost effective, flexible and advanced solution to overcome limitations with the current system of multiple point-to-point connections for the air traffic service message handling system (AMHS).

Other emerging communications technology is enabling greater use of datalink communications in lieu of the legacy VHF and HF voice communication systems. However, for most operations the primary means of communications will continue to be VHF and HF voice.

This section contains information relevant to aircraft communications.


Air navigation in continental airspace has transitioned from conventional ground-based radio navigation aids to performance-based navigation (PBN). The shift to PBN enables more direct routes along a flight path and more efficient take-offs and landings. Overall, this means a reduction in fuel burn, aircraft emissions and airport and airspace congestion.

Where available, ATS routes, terminal procedures and instrument approach procedures should be flown to the following standard PBN navigation specifications:

  • Routes in oceanic control area (OCA) – RNP 4 where capable, otherwise RNAV 10 (RNP 10)
  • Continental routes (routes other than those in OCA) – RNP 2
  • Terminal procedures (SIDs and STARs) – RNP 1
  • RNAV non-precision instrument approach procedures (NPA) and approach procedure with vertical guidance (APV) – RNP APCH (still titled 'RNAV GNSS' on Australian approach charts), with LNAV or LNAV/VNAV landing minima.

For aircraft fitted with navigation systems certified for Baro-VNAV approach operations, PBN has also enabled the addition of actual (as opposed to advisory) vertical guidance derived from barometric sources, permitting the use of LNAV/VNAV landing minima.

The roll-out of Baro-VNAV in Australia is in line with ICAO recommendations to establish safer approaches to landing.

This section provides information on aircraft navigation.


The aircraft equipment requirements to support CNS/ATM and instructions for performance-based navigation are set out in CAO 20.91. Instructions and directions for performance-based navigation and CAO 20.18 Aircraft equipment – basic operational requirements. These CAOs affect all IFR pilots and aircraft operating in Australia.

This section provides links to the regulations, ACs and other related guidance material.

Useful links


For CNS/ATM queries email: cns.atm@casa.gov.au, or phone 131 757 and request to speak to the CNS team.

Last modified: 10 March 2018