Air traffic control has looked much the same since the Second World War. High towers, various technical systems and binoculars have been important elements of an activity which, for natural reasons, has been characterised by stringent safety requirements and regulatory control. At the same time the need for cost-efficiency is growing, and many small airports in sparsely populated areas are threatened with closure. In a small airport air traffic control can account for 30-40 per cent of the operating costs. This was the reason why Saab and LFV started to collaborate in 2006 in the search for a more efficient way of handling air traffic control in Sweden. It would take ten years of intensive development work to realise the vision of a remote tower system and take the technology overseas with successful test installations in several countries.
“Today even large airports may need to invest in a remote tower system and other digital services linked to air traffic management, but when we started the venture it was because small airports were disproportionately expensive to operate,” says Niclas Gustavsson, Director of Business Development and International Relations at LFV.
First operations in northern Sweden
Since April 2015 the air traffic control tower at Örnsköldsvik airport in northern Sweden has been empty with the curtains drawn. There are cameras and sensors located at the airport to record what is happening instead. A data network is used to digitally transfer images and data to a new facility in Sundsvall, where the air traffic controllers manage Örnsköldvik airport at a distance.
There is a row of large 55-inch screens hanging on the walls with images and a window-like 360-degree view over the airport 150 kilometres away. “We know that the technology works after numerous tests and validations. The challenge was to find an operational environment which corresponds to the one we have in the tower today, or is even better,” Gustavsson says.
The camera technology in the new remote-controlled tower makes it possible to cope with difficult light conditions much better than before. The system adjusts the images automatically when there is direct sunlight or there are snow reflections so that it is possible to follow an aircraft that is climbing skywards without being dazzled. The technology also allows you to zoom in and enhance the image in order to pick out details. Different types of data can be integrated into the same view on the screen, such as weather and wind force data, which provides a better overview.
Broad acceptance after testing
The journey towards an operational remote tower system has been marked by several instructive test projects. In 2008 a first demonstration facility was built at Malmö in southern Sweden to monitor the airport in Ängelholm a hundred kilometres to the north. “We undertook careful testing of the entire system and were able to demonstrate in practice that it worked and was safe. There was broad acceptance of the technology which resulted in us being able to build a fully operational facility in Sundsvall,” says Per Ahl, Sales Director of Saab Digital Air Traffic Solutions. Operational approval from the Swedish Transport Agency was, however, required first. This was formally obtained in early 2015. “The authority has been monitoring our work since 2011 and it was the first authority in the world to deal with a permit for a remote air traffic control service. The Swedish model with well-functioning cooperation between industry, operator and licensing authority has been crucial in driving the project forward to its objective,” Ahl says. He points out that the new system is tested and approved in line with the existing rules and regulations, thus ensuring that the remote air traffic control centre uses exactly the same procedures as a traditional tower. “This shows that we are complying with all the applicable safety requirements,” he says.
Four ways to enhance safety
The remote air traffic control system complies with existing rules and regulations. But the technology allows one to further enhance safety. Per Ahl, Sales Director of Saab Digital Air Traffic Solutions, provides a few examples:
- Cameras can provide better night vision.
- Advanced image processing can detect dangers or obstacles such as tools left on the runway.
- Target tracking technology – tracking via radar and camera – can automatically detect and highlight incoming aircraft so that it is easier for the air traffic controller to monitor them on the screen.
- Information overlaid on the screen can display everything from the weather and visibility conditions to the identity of aircraft and ground vehicles.
This is how Remote Tower works
Cameras and sensors are located at the airports. Everything they record is sent digitally to an air traffic control centre and is projected onto a 360-degree view. The data traffic can take several routes to ensure that the data arrives even if an interruption occurs.
Image monitoring is combined with other systems which the air traffic controllers use to manage the traffic, such as radar display, navigation aids and information about flight plans and weather conditions.