More intercontinental flying makes globally harmonised air navigation system performance increasingly important

Last week in Montreal, Canada the International Civil Aviation Organisation mounted the world's first attempt to win global acknowledgement of the need for universal standards in air traffic services. At the same time ICAO is launching a campaign to define ATS provision by performance specification rather than by prescribing the technical means like navigation aids and on-board equipment.

Part of the reason for this change in approach is the fact that the tools for communications, navigation and surveillance/air traffic management - like global navigation satellite systems available now, compared with 20 years ago, enable much greater navigational accuracy at lower cost, making the present standards and metrics for judging what constitutes good ATS provision obsolete. Area navigation, rather than beacon-to-beacon routeing, is now widespread and can be achieved using a number of different technologies, proving ICAO's point that ATS and aircraft navigation performance, rather than the means by which it is achieved, is the essence.

Pilots in cockpit 
© Max Kingsley Jones / Flight International   
ICAO wants aircraft to be operated to harmonised ATS standards

Although ICAO Annex 11 prescribes standards and recommended practices for the rules of the air and ATS, in reality wide divergencies exist between air navigation provision in different states and regions. When it organised last week's worldwide symposium on performance of the air navigation system, ICAO did not know what response to expect. In the event more than 400 delegates from nearly 100 of ICAO's 189 member states attended to find out what performance-based navigation would mean to them. In April there is to be a familiarisation seminar in New Delhi, India, at which China is to be well represented.

Eurocontrol and the Single European Sky project embody regionally what the president of the ICAO Council Roberto Kobeh Gonzales says he would like to see other regions do all over the world. In a scene-setting presentation Eurocontrol director general Victor Aguado recalled that, in 1997, the independent Performance Review Commission was set up to monitor the effectiveness of ANS provision in the individual European states and the region as a whole. "All regions gradually need to reach the same level in performance management," said Aguado, even if the agreed performance level can be varied locally according to traffic intensity, airspace sector complexity and local topography.

Kobeh Gonzales pointed out that the concept of PBN is less prescriptive than traditional technology-based systems, and although adherence to internationally agreed perfomance metrics is essential, regions can choose accuracy levels according to local needs. An ICAO task force has produced a guidance document called the performance-based navigation manual, now available to anyone involved in managing ATS. Kobeh Gonzales says at present it is advisory, but if validated it will probably be incorporated into Annex 11.

Aguado pointed out that to achieve global ATS performance homogenisation - and to maintain it once achieved - will require monitoring by ICAO. Kobeh Gonzales said this will be achieved by inspecting states' aviation systems, including the ATS provider, under the Universal Safety Oversight Audit Programme which, he said, is already beginning to have a favourable effect on ATM standardisation even if there is a long way still to go. He said he believes high-quality PBN, where it does not yet exist, is best achieved regionally rather than nationally, and that ICAO regional offices will provide assistance. Kobeh Gonzales added that ICAO is switching its priorities away from developing new standards and towards ensuring the implementation of existing ones.

Finally, ANS performance is not to be measured only in CNS/ATM quality terms, says ICAO, but also in cost/efficiency. That is a specification in Annex 11. But as Kobeh Gonzales said: "This far, individual countries have developed [their ANS provider] independently, not necessarily with efficiency or interoperability in mind."

"All regions gradually need to reach the same level in performance management"

Roberto Kobeh Gonzales, ICAO

Source: Flight International