Overnight on January 22, 2021, NATS successfully changed over London City Airport's air traffic operation to a new digital tower at the Swanwick control centre.
Preparing to transition London City's digital control tower was a huge technical and engineering undertaking and a very human-centred one for NATS. From training the controllers on the new equipment, to supporting their relocation to the south coast of England the project was no mean feat. The technology is only ever part of the story for any transition and even more so in this case.
The journey began in 2017 when the airport started out on its wider redevelopment plan. A new taxiway and aircraft stands would have made visibility difficult from the airport's original 18m (60ft) high control tower, and with airside space at a premium, a digital alternative was the obvious answer and one that the airport embraced with enthusiasm.
From a technical perspective the move presented a new set of challenges for the NATS teams, with many interlinked parts. The crux of the project was to ensure all of the existing air traffic systems housed in the old tower – from radar and flight data to voice communications – could be accessible 115km (70 miles) away at Swanwick, with the addition of high-definition real-time images from a new 50m (165ft) high camera mast. The NATS engineering team had to ensure all of that data could be provided safely and securely and with a latency of less than a second, whilst ensuring safety requirements, resilience and contingency measures that would meet regulatory standards.
While the digital tower technology has been tried and tested at several airports with lower density traffic, it had never previously been deployed at an airport of the complexity of London City.
Configuring and assuring the new technology to be right for the airport and the controllers, while extending control of new and existing airport systems down to Swanwick was critical. We also had to give the controllers every chance available to become familiar and confident with the change. That's something that should never be underestimated with any operational transition. In this case, NATS developed a specific training package allowing the controllers to be introduced to the digital tower gradually, building on the information each time. This started with video tours and photographs, a Swanwick unit visit and distance learning, before moving onto practical training and final refresher training ahead of the transition.
A lot of planning went into the transition itself but delivering it during a worldwide pandemic threw up some specific challenges. The plans had to adapt to account for access restrictions and social distancing requirements, but in the end the changeover went extremely well.
The last departure from the old tower at London City was cleared for take-off on the Friday evening and the team opened up on Saturday morning from the Swanwick Centre. Multiple checks were carried out during the night, with several ‘go/no-go’ decision points should it be necessary to revert – but to anyone watching from the outside it was seamless.
What's next?
A lot was learned during the London City project, and the team and technology have all been working well since the transition at the start 2021. However, the industry is only just beginning to tap into the full potential of digital tower technology.
The idea that a digital tower is solely about replicating exactly what a controller can already see in a remote location is being increasingly challenged. With the right technology and specifically software, digital towers can be scalable and flexible in what they deliver for airport operations – from the smallest airfield to the world's biggest hubs.
The real transformative power lies in using the technology to augment and improve an existing operation to solve a specific problem or challenge, whether that's the need to cut costs, incorporate new ground-based infrastructure, or provide a contingency facility. As the solution is scalable, there is also flexibility in terms of adding to the capabilities as and when required. That's the mission NATS has been working towards, with its approach distilled into five operational models, which Searidge Technologies has successfully deployed at various airports around the world. All of the models are built on same proven software platform, with scalable hardware, redundancy, and applications.
Model one is currently in the process of being deployed at Miquelon and St Pierre airports with French ANSP the DSNA. It involves a tower-in-tower digital set up, whereby the smaller of the two airports is controlled from within the other airport's existing tower. The air traffic controller uses a personal video screen displaying live images from the secondary airfield to manage those movements, whilst they and their colleagues can still look out of the window to control as normal at their primary airport. It's a neat solution for very small airports with few movements. The model helps to ensure that they can still provide a full ATC service but without a controller being deployed to a physical tower location with otherwise little to do. There are any number of airports around the world where this model could be applied and where the use of digital tower technology, when used in this different way, can deliver clear efficiency gains.
Model two is the more traditional digital tower, with controllers in front of a single panoramic video wall managing movements on a single runway airport from a location outside of a traditional tower. Even with this well-established concept there is room for innovation.
The personal video screens used in all five Searidge Digital Tower models can here be used to provide specific additional views of the airfield for each controller. Blind spots are bought into sharp panoramic clarity. The ends of a remote apron or taxiway are suddenly under the controller's nose. Of course, this is only possible if you move away from the received wisdom that a digital tower can only ever involve a single mast with a predetermined number of cameras. Break that thinking and it can be whatever an airport needs to run better, more efficiently and even more safely.
Model three is being used by HungaroControl in Budapest. At the time of deployment, digital towers were beginning to be familiar in Scandinavia, but HungaroControl found the existing solutions unsuitable for an operation of their scale and complexity, with dual parallel runways and approximately 4km (2.5 miles) between furthest thresholds.
Searidge worked with them on a fully remote facility that used the concept of a combination of two panoramic video walls, one for each of the airport's runways, and personal screens for each of the controllers to provide auxiliary viewpoints via cameras distributed around the airfield. The system was then uniquely configured to local requirements in a floor to ceiling video display system.
Today, the facility serves as a dual contingency and operational environment, one that also saved Hungarocontrol approximately €5 million (US$6 million) in capital expenditure and twelve months in implementation effort.
Model four is a traditional tower environment, but this time with the controllers armed with a whole array of additional tools. Again, Searidge has worked with DSNA, implementing this hybrid model at Paris, Orly. Controllers still manage traffic by looking out of the window as they did previously, but now they each have their own personal viewing screens to zone-in on whatever part of the airfield they're working on. The air controller can bring the runway holding point directly to them, while the ground controller can get a better view of a particular stand while an aircraft pushes back. Of course, all this is only possible when the cameras are set free from being housed on top of a single mast.
The fifth and final model is a fully digital primary or contingency facility, suitable for multiple runway, multiple terminal high intensity runway airports and the world's biggest and busiest hubs. Multiple ultra-high definition panoramic video walls are needed to truly manage airports of this scale and size and support each runway and terminal, with personalized video screens for each controller. This model is ideal as the replacement of a physical control tower or as a fully digital contingency facility.
The fifth model is capable of the same or greater ATC service delivery than the extant physical control tower, meaning many controllers and airport operators may end up preferring it. That being the case, it may lead to either the physical tower needing a digital facelift and resulting in model four, hybridization or it itself becoming the actual contingency facility.
Digital transformation
These innovations in digital towers are a great step forward. In addition, there is amazing work being done based on artificial intelligence – building tools that will help controllers manage runway departure spacing, improve capacity in poor weather conditions and even monitor radio transmissions from pilots and highlighting any errors.
The experience NATS has of successfully introducing digital tower technology at London City Airport, combined with the varied deployments Searidge Technologies has delivered at airports of every size all around the world, means I've never been more certain that we are on the cusp of total airport ATC transformation. With the right technology, digital towers are a fully scalable and flexible concept that can help airports of all shapes and sizes, not just something that's limited to a few tiny remote airfields.
Digital towers can demonstrably be whatever an airport wants and needs them to be. They can be used at any size of airport, from the international hub through to the small, but vital remote island airfield. We are all missing a vital step forward in terms of ATC operations if we allow ourselves to think otherwise.