Controlling Sydney – Every movement matters, every second counts

The Australian Government’s 2009 National Aviation Policy White Paper, ‘Flight Path to the Future’, outlined Australian aviation’s contribution of more than half a million jobs and $6.3 billion to the national economy. But constraints at busy gateway airports such as Sydney, particularly during peak traffic periods, have the potential to adversely affect this community benefit and limit industry growth.

As the country’s air navigation service provider, Airservices Australia is working closely with the airport, airlines, operators and the community to achieve operational and environmental efficiencies using the existing infrastructure. We are also introducing new airborne and ground-based systems to handle rapid predicted future growth.

Considered as the gateway to Australia, Sydney Airport is the country’s busiest in terms of total passenger numbers and aircraft movements. Use of the three runways at Sydney Airport is restricted by a curfew between 11pm and 6am designed to provide noise amelioration to a population of four million in the greater Sydney area. Nestled on the shores of Botany Bay, approximately 10 kilometres south-east of the city’s central business district, the airport is closely scrutinised by the community it services. All bar two current flight paths track over heavily populated urban areas.

A typical Sydney day can involve around 900 aircraft movements. At times demand reaches the capacity of a capped (by Federal legislation) 80 movements per hour, particularly when poor weather sets in. The mix of traffic ranges from daily A380 operations to regional sized aircraft, helicopter joy flights, emergency medical retrieval operations, freight, business and VIP jet movements.

Airservices Australia has a number of new technologies, systems and management procedures in use or poised for introduction at Sydney to maximise movement efficiencies, while at the same time working to reduce the burden of aircraft noise on the community. Of notable interest is the precision runway monitor (PRM), wide area multilateration (WAM), advanced surface movement guidance and control system (A-SMGCS), ground based augmentation system (GBAS), collaborative decision making (CDM) programme and the Long Term Operating Plan (LTOP).

The airport’s two parallel north-south orientated runways (16L/34R and 16R/34L) handle the majority of movements annually. In use at Sydney since 1999, the precision runway monitor (PRM) for parallel runway operations, is a highly accurate surveillance system designed to offer a safe and practical way to maintain airport capacity when the weather conditions do not permit the use of independent visual approaches. Potentially cutting air traffic delays due to poor weather by as much as 80 per cent, PRM allows qualified pilots to accept reductions in lateral separation standards during ILS approaches to parallel runways separated by less than 1,525 metres.

At the heart of the system is a high resolution radar providing a very fast update rate for display to a specialist PRM controller monitoring each approach. A ‘No Transgression Zone’ (NTZ) with a width of 610 metres is established between the parallel approach paths to provide a suitable safety buffer between aircraft on adjacent ILS approaches.

Without PRM, air traffic control is required to apply a 2NM stagger separation between aircraft on adjacent ILS approaches. However, with PRM aircraft can be processed independently of any traffic on the adjacent approach track.

The recent introduction of wide area multilateration (WAM) at Sydney will ultimately replace PRM. WAM is an extension of the multilateration technology currently being introduced as part of the advanced surface movement guidance and control system (A-SMGCS). In addition to supporting independent parallel runway operations in IMC conditions, WAM will also provide a backup to secondary surveillance radar.

The introduction of A-SMGCS in May 2010 gives surface movement controllers at Sydney Airport the ability to see and identify every aircraft and vehicle across all runways and taxiways. The A-SMGCS programme improves situational awareness by providing an electronic picture of what is happening on the ground on a screen in front of the surface movement controller in the tower.

Through the collection of surveillance data from multiple sources, including surface movement radar, multilateration, ADS-B and terminal area radar, the system offers better conflict detection for controllers while improving the reliability and efficiency of airport operations during bad weather and at night, when distances from the control tower can make visual monitoring more challenging.

Airservices Australia is trialling the use of a satellite-based precision approach and landing system at Sydney Airport as a future replacement of current instrument landing systems (ILS). The ground based augmentation system (GBAS) is a critical component of Australia’s nextgeneration air traffic management infrastructure and will help better manage airport delays, aircraft fuel burn and noise.

In November 2006, Airservices Australia and Qantas launched the world’s first GLS (GNSS Landing System) approach using a prototype GBAS. Since then the airline has flown more than 2,000 GBAS-supported approaches and trained over 700 pilots on GBAS operations. Pilots have consistently reported that GBAS provides extremely smooth and stable guidance and in the coming years, over 50 per cent of Qantas’ aircraft fleet will have GBAS capabilities installed.

Earlier this year, the world’s first and only GBAS to receive FAA system design approval, the Honeywell SLS-3000 SmartPath precision landing system, was installed at Sydney. Acceptance testing of the new system is due to occur in August before a three month evaluation trial in September involving Qantas, Virgin Australia and Emirates. All going well, Airservices will then apply to Australia’s safety regulator, the Civil Aviation Safety Authority (CASA) to have GBAS Category I (CAT-I) operations approved for use in Sydney.

Airservices Australia is also developing tools to roll-out Collaborative Decision Making (CDM) at Sydney and at other capital airports. CDM has the potential to improve air traffic management through better sharing information and data between airlines, airport operators, ground handlers and air traffic control.

CDM can be applied to all air traffic management processes, from long-range schedule planning to tactical decisions related to ground delay programs. This exchange of information will allow all users to be aware of constraints, issues and the needs of other industry stakeholders. Overall, the goal is to create a more knowledgeable and participative aviation community. CDM partners can participate to a level that suits their operations and information requirements. However, in order to maximise the benefits, it is important that all affected users participate in the information sharing.

Airservices Australia has recently introduced a programme which aims to improve runway, taxiway and apron efficiency using existing infrastructure, particularly during peak periods. Leveraging off lessons learned from similar programmes already underway internationally, the initial focus of the programme will be runway usage and will involve improving the processes and practices of air traffic controllers, airport operators and airlines.

Critical to the efficient operation of the national airspace system and managing the impact of aviation on the environment, the steps taken to increase efficiency using these processes will be in harmony with current Australian standards and practices, while providing sufficient room for the development of local procedures. While every movement matters and every second counts, over many movements the seconds add up to create additional capacity that in turn can reduce delays and offer more capacity.

Airspace usage must take into account the effect of aircraft noise on the community. Sydney Airport has had a unique framework in place for noise sharing since 1996. The long term operating plan (LTOP) for the airport aims to ensure as many flights as possible operate over Botany Bay or non-residential areas. When this is not possible for weather or other operationrelated issues, LTOP is designed to share the noise burden of aircraft over residential areas as equitably as possible. Airservices Australia reports to the community on its compliance against the plan quarterly, with detailed reports published on our website.

Under the LTOP there are up to 16 different runway configurations, or modes, which are available to share noise around the community. LTOP targets include the majority of aircraft movements, some 55 per cent, operating to the south over water, with 17 per cent of movements to the north, 15 per cent to the west and 13 per cent to the east. Constricted by wind conditions, Airservices uses LTOP as part of its daily operating procedures. This can mean up to four mode or runways changes throughout a day’s operations.

While the architecturally iconic control tower at Sydney, commissioned in 1996, is currently Airservices Australia’s most modern in way of technology, four brand new control towers are currently being constructed at airports in Melbourne, Victoria, Adelaide, South Australia, Broome, Western Australia, Rockhampton, and Queensland. These will be fitted with a new suite of operator consoles fitted with the latest systems, hardware, networking and communications technology.

The technology will provide each tower controller station with up to four customisable touch screens capable of displaying electronic flight strips, operational information, weather, terminal area information and where available surface surveillance radar data.

It will be progressively rolled out to Airservices Australia’s remaining 23 towers, including Sydney, as they are refurbished or rebuilt under our extensive tower replacement and refurbishment programme.

With movement activity at Sydney Airport forecast to double over the next 20 years, the investigation into the location of a second Sydney airport continues. A federal government taskforce is considering a number of sites and is expected to report by the end of this year.

Overall, the future for aviation at Sydney is one of continuing growth and competition. With growth comes increasing complexity and congestion, greater community expectations, challenges of airspace use and the need for stronger environmental controls. Operationally, airlines will continue to demand greater levels of service efficiency.

Airservices Australia recognises the need for significantly greater co-operation among aviation industry players if the complex challenges of future growth are to be managed and met. Doing so successfully will ensure we can realise the benefits offered by a rapidly expanding industry to the community and national economic well-being. It’s a task we are well prepared for.

About the Author

Jason Harfield is the General Manager, Air Traffic Control Group for Airservices Australia. Jason is accountable for the management and operation of Airservices’ air traffic manage – ment and aeronautical data operations, which provide services to over four million flights across 11 per cent of the world airspace. Jason has over 22 years experience in the aviation and air traffic management industry, holding a number of operational management and senior executive positions as well as an operational air traffic controller and private pilot. Jason also has a MBA from Mt Eliza Business School and has completed the Advanced Management Programme at Harvard Business School.