Australia’s unique geography and reliance on aviation to bridge distances within the country and to the rest of the world, means that the national air navigation service provider, Airservices Australia, has been an early adopter of technology to overcome this challenge.
In March 2010, Airservices signed a memorandum of understanding with defence and security company Saab and Swedish ANSP and airport operator, Luftfartsverket (LFV) to explore the use of remote tower technology in Australia. Airways NZ has since joined the project.
Since then, Airservices had been studying the potential technical, engineering, human factors and regulatory aspects of the introduction of the technology.
Trials are ongoing to test the technology at Alice Springs in Central Australia, with the control centre in Adelaide in South Australia – more than 1,500km away.
Airservices General Manager Air Traffic Control, Jason Harfield, explains that the drivers for the adoption of remote tower technology are different in Australia to that of Europe.
“At Airservices, we are not required to provide control tower services for all regular public transport operations aircraft as are some European air navigation service providers,” says Harfield.
“At Alice Springs, where we will trial the technology, aircraft movements are 65 per day on average over a year – a light traffic regional tower for Australia.”
Due to the cost of data communications in Australia, Harfield estimates the initial operating costs of a remote tower centre to be roughly the same as a traditional tower to start with. The savings will be reflected through the construction costs of new towers and in future years, the benefits of scale by providing services to multiple airports from a single location.
“Given the growth of regional air traffic in Australia, there are several airports where we may be required to construct control towers in the next five years,” says Harfield. “And in Australia, the air navigation service provider builds the towers, not the airport owner.”
However, the opportunity to use remote tower technology also comes with some significant challenges.
“Any trial of the technology in the Australian environment will provide a good test of its viability in truly remote and harsh conditions, ” says Harfield.
“The environment in Australia is remarkably different to that in Europe. In comparison to the snow, fog and low temperature issues that LFV will face with their remote tower at Sundsvall, we will have to deal with heat, dust and very occasionally, heavy rain at our site in Alice Springs,” Harfield explains. “We may not have to melt the snow off the camera housing, but we probably will have to blow the dust off the camera windows!”
Australia also tends to have a lot of weather suitable for visual meteorological conditions, and regional towers tend to have a roughly equal mix of instrument flight rules and visual flight rules aircraft.
This mix of traffic means that Airservices air traffic controllers are reliant on visual separation within the circuit area when conditions are suitable, thereby reducing the delays for all aircraft.
“Our remote tower technology solution must provide enough fidelity to ensure our controllers are comfortable to use visual separation, as well as meet any regulatory requirement,” says Harfield.
“It is important that controllers feel confident in their equipment as well as in their own abilities. Gaining that confidence will require us to answer the questions of the controllers and prove to them that the equipment is capable, as well as answer the questions of the regulator.”
“savings will be reflected through the construction costs of new towers and in future years, the benefits of scale by providing services to multiple airports from a single location“
Locations for remote located towers also provide a challenge to the organisation, especially with regards to living conditions. In Karratha, a mining tower on the remote north west coast of Western Australia, average daily temperatures are more than 36 degrees Celsius for six months of the year.
Accommodation rental costs are extraordinary in the town because of the current mining boom, and a large part of the workforce in the area operates under a fly-in/fly-out labour contract.
Harfield said that getting air traffic controllers to work in such arduous conditions over a long period will become more challenging as time goes on and the remote tower technology will offer a staffing benefit in such adverse remote areas because of the ability to locate the remote tower centre in areas which provide a greater lifestyle benefit.
In hard-to-get-to locations, another consideration is the high cost of construction.
“Any construction activity in the remote areas of Western Australia commands at least a 40 per cent premium on costs when compared to construction in major cities,” says Harfield.
“As one of the driving forces in the Australian economy at the moment is mining activity, some of these remote and expensive locations are where air traffic is increasing the most, therefore requiring new control tower services to be provided.”
“Any increases in the cost of service provision may see a reduction in low cost carrier movements at a particular aerodrome, therefore negating the necessity for air traffic control services.”
This can result in a ‘stranded’ asset, an air traffic control tower not in use, but which, in Australia, the industry pays for. It is here that remote tower technology can play an important role in providing for that adaptability if services are required to re-locate, but also being more cost effective than a ‘traditional’ tower.
Notwithstanding geographical and meteorological challenges, there are also a number of technical challenges that Airservices needs to overcome in Australia.
The distance between the remote tower centre in Adelaide and the airport at Alice Springs is around 1,500km, slightly more than the distance between Amsterdam and Budapest.
“This is a lot of fibre optic cable for some farmer or cattle station owner to cut when digging a hole with a tractor,” quips Harfield.
“remote tower technology will offer a staffing benefit in such adverse remote areas because of the ability to locate the remote tower centre in areas which provide a greater lifestyle benefit“
There are two routes out of Alice Springs via fibre optic cable – south to Adelaide and north via Darwin.“Using the northern route for path diversity will involve a transmission distance of around 7,000km, which is greater then the distance between Amsterdam and New Delhi,” says Harfield.
“If this diverse path proves to be too challenging, an alternative diverse path could be provided using satellite links. However, given the bandwidth required, satellite links would be a very expensive alternative path unless the bandwidth is somehow reduced.”
Airservices intends to explore the option of using a reduced data load (by reducing frame rates and picture resolution) via satellite for contingency services only, if the terrestrial path fails. However, a lack of multiple communication systems in Australia’s sparsely populated interior means providing appropriate back-up paths for critical data in the event of an outage is also a formidable task.
Harfield also emphasised that data latency is another issue with the scale of distance. Each computer that processes the data and each router the data passes though increases the total time for an event to occur and then be displayed in the remote tower centre.
“We cannot afford the latency to be too great,” says Harfield. “Therefore we are targeting a maximum value of one second.”
Australia does not have the communications backbone that exists in much of Europe or the United States and so this scenario is one that Airservices will face in many remote locations. According to Organisation for Economic Co-operation and Development (OECD) data from 2009, Australian broadband communications costs are among the highest – nearly double the rate of the United Kingdom and Sweden, although not as high as those of Norway.
“Naturally, this adds to the costs of operating a remote tower centre and so affects the business case. Fortunately, data communications costs have been reducing over time and we expect them to continue to do so,” adds Harfield.
Another technical consideration is that the locations where Airservices are likely to use remote tower technology do not have surveillance coverage at this stage. This issue, along with the use of visual separation, requires Airservices to carefully evaluate the visual component of the available technology above all others.
While the communications problems are technical issues that may be solved by increased funds, the human factors effects of display quality, situational awareness and ease of use are critical to the success of the technology.
The final challenge faced in Australia is not unique – it is that of regulatory approval of the technology. “As glad as we are to have Saab, LFV and Airways New Zealand to work with on this project, we will be working very closely with our regulator, the Civil Aviation Safety Authority (CASA) to ensure that they both understand the technology and Airservices’ approach to its use in Australia,” says Harfield.
“Such new technology will take a considerable amount of thought and discussion before gaining regulatory approval for its use and we look forward to working closely with our partners and regulators to place the technology in to the air traffic control toolbox for all to use in the future.”
“Airservices has a proud history of adopting emerging technology for the benefit of the Australian aviation industry. The trial of this technology will allow us to see whether the system has the potential to assist us meet demand for services in remote areas.”
Read More: Remote towers near European certification, Virtual Worlds and Remote Possibilities
This technology feature appeared in Issue 2, 2011. Subscribe to Air Traffic Management today. Details can be found at: Key Shop