Australia this week will introduce the world’s largest-scale equipage mandate for automatic dependent surveillance-broadcast (ADS-B), although many airspace users will take advantage of a temporary exemption because they do not yet comply.

Airservices Australia is considered one of the pioneers of ADS-B. It has installed a nationwide network of more than 60 ground stations that provides seamless coverage of all of its domestic high-altitude airspace, and some offshore airspace. It is already using this network to provide ATM services for equipped aircraft, and by 2014 will have had a decade years of ADS-B operational experience under its belt.

On Dec. 12, Airservices will take another major step by introducing a nationwide mandate requiring aircraft to be equipped for ADS-B when flying above flight level 290. In this regard Australia is well ahead of the U.S., which is scheduled to introduce an ADS-B mandate in 2020.

With the mandate in place, Airservices controllers can maximize ADS-B’s operational benefits because more aircraft will be equipped. However, Australia’s Civil Aviation Safety Authority (CASA) has been forced to allow an exemption from the mandate, due to the failure of certain aircraft types to meet the deadline.

If operators apply for this exemption, non-equipped aircraft will be able to fly above FL290 as long as they remain in radar airspace. Radar coverage in Australia predominantly extends in a J-shaped zone down the east and south-east coasts, where most of the major cities are located.

Airlines have largely completed their retrofits. According to Airservices data, 95% of the airline fleet that operates above FL290 is ADS-B equipped. Qantas, for example, only has three older Boeing 737s that will not meet the deadline. These are scheduled to be retired soon and until then Qantas will operate them in radar airspace under the exemption.

The main problem is the business jet fleet, which has an equipage rate of about 40%. In most cases this is not the operators’ fault, as manufacturers have not yet made retrofit procedures available for some aircraft types.

For example, only 30% of Australia’s large fleet of Cessna business jets meets the ADS-B standard. The equipage rate is about half for Bombardier business jets, and none of the seven Bombardier aircraft are retrofitted yet.

The exemption lasts two years, to give manufacturers the chance to catch up. During this time the exemption will not cause too much disruption, as the non-equipped aircraft will be confined to airspace that already has radar coverage at high altitude. The business jets are far outnumbered by the airline fleet, and are operated less—so 94% of all operations above FL290 will comply with the mandate.

Airservices is now looking ahead to the next phases of its ADS-B program. From February 2014, all newly certified IFR aircraft must be ADS-B capable. By February 2016, all IFR operations within 500nm of Perth must be equipped, and the final mandate calls for all aircraft operating under IFR in any airspace to be equipped by February 2017.

The 2016-2017 deadlines will extend the ADS-B requirement to about 2,000 more aircraft, Airservices estimates. Another 15 ground stations are scheduled to be deployed over the next three years to improve coverage at lower levels.