Heathrow ‘tower in cloud’ project

Deploying digital towers at international hub airports


The world’s busiest hub airports, with multiple terminals, runways and taxiways demand a bespoke digital tower solution.

With cameras distributed around the airfield, multiple ultra-high-definition panoramic video walls and personalised video screens for each controller, it’s possible to create a total digital replacement for a physical control tower or equally, a fully digital contingency facility.

And when you then equip the controllers with the latest digital and Artificial Intelligence enabled tools, you also begin to unlock the next level of HIRO airport performance.

That’s what NATS has been testing in its Digital Tower Laboratory at Heathrow Airport.


Heathrow’s 87-metre-tall control tower is the highest in the UK and provides commanding views of the airport and surrounding landscape, but its height can also mean it disappears into low cloud, even when the runways below are clear.

In those conditions, where the controllers have to rely on radar to know if an arriving aircraft has left the runway, extra time is needed between each landing to make sure they’re safely clear. The result is a 20% loss of landing capacity, which at an airport as busy as Heathrow, very quickly creates delays for passengers and knock-on disruption for the rest of the operation.

NATS and Searidge Technologies set out on a pioneering project to understand whether the innovative deployment of ultra-high-definition cameras and industry leading AI could help solve the problem.


Non-operational trials set out to prove that when a tower like Heathrow’s disappeared into low cloud – known as ‘VIS 2 conditions’ – Aimee could help recoup the lost landing capacity in those conditions.

NATS deployed 20 ultra high-definition cameras at the airfield – 18 on the physical tower and two strategically placed at one of the exit points to the airport’s northern runway. The views from each camera were then fed into a Searidge Technologies’ air traffic management AI platform, Aimee.

Aimee was able to learn to interpret the images, track the aircraft and then inform the controllers in NATS’ Digital Tower Laboratory when each arrival had successfully cleared the runway. Aimee spent months monitoring arrivals to ensure correct identification of each, regardless of its livery or type and in a range of weather conditions.


Once trained, Aimee continually monitored arrivals on Runway 27R/09L, identifying over 40,000 arrivals in all. Data analysis proved hugely exciting, showing Aimee performed extremely well, including being able to identify aircraft in poor weather conditions and in near darkness, when the 4K cameras were shown to perform better than the human eye.

So successful were the initial trials, NATS expects to extend the trial to include more varied weather conditions, giving further opportunities to refine the model and test whether the solution would works in full CAT II/III low visibility conditions. If Aimee performs as well as expected, it will prove an enormous benefit given the impact Low Visibility Procedures (LVPs) have on operations at airports around the world.

What Next?

This is a radically different kind of application of digital tower technology. Combining the 4K camera needed for large airports, with industry leading AI expertise to deliver solutions to real operational challenges.

And that’s just the start. The natural extension of this work can lead to the creation of a total digital replacement for a physical control tower or equally, a fully digital contingency facility, allowing the world’s hub airports to go beyond the limits of human performance.