On 30 June 1956, Trans World Airlines Flight 2 took off from Los Angeles International Airport, bound for Kansas City Downtown Airport. It would be involved in the worst air collision of its time – the first commercial airline incident to exceed 100 fatalities.

Shortly after take-off, the aircraft’s captain requested permission to climb to 21,000ft to avoid thunderheads that were forming near his flight path. Air traffic control (ATC) denied the request, as another aircraft was in the same airspace and the controller had no way to provide the horizontal separation required between two aircraft at the same altitude. The captain changed his request to ‘1,000 on top’ clearance, which would allow him to fly 1,000ft above the clouds, and was given the go-ahead by ATC. This allowed separation restrictions to be temporarily suspended, putting the responsibility for maintaining safe separation from other aircraft upon the captain and his crew.

As it crossed the Grand Canyon, Trans World Airlines Flight 2 collided mid-air with United Airlines Flight 718 – the other flight in the airspace – most likely due to cloud cover obstructing the pilots’ vision. All 128 people on board both flights perished.

The crash shattered the public’s illusion of a safe air travel system and drew attention to the antiquated state of the ATC of the time. In response, President Eisenhower increased funding to modernise ATC in the US and perform a complete overhaul of navigational rules. No other single event in history has caused such a drastic transformation to this element of the aviation industry.

Thankfully, ATC is in a much stronger position today and, while the Covid-19 pandemic remains a challenge unlike any other to all aspects of the industry, it is unlikely to reshape ATC in a similarly drastic fashion. That’s not to say, however, that there are no lessons to take away from the challenges air traffic controllers have had to overcome.

Planning for traffic

When Covid-19 first began to spread across the world, reactions from the world’s governments were initially slow – but when the lockdowns came, they came fast, leaving ATC operators scrambling to rework their industry around the new restrictions. It swiftly became clear that working from home wasn’t really an option for ATC teams, but operators were able to keep the numbers of people who had to be on-site to a minimum.

However, even with these measures in place, the concern over outbreaks in ATC centres remained. By the end of 2020, almost 300 ATC centres had been affected by the pandemic in the US alone, leading to flight delays while the facilities were temporarily closed for cleaning and a new team of controllers assembled. “We kept a lot of people at home on standby, on the basis that if we did have an outbreak, we had people […] we could bring in,” says Juliet Kennedy, operations director at NATS, which provides ATC across the UK. “We were trying to minimise the interactions people have as far as we possibly could and I think that really helped us.”

The UK managed to avoid much of the disruption the US was experiencing, aided in part to smaller domestic travel numbers and a more rapid drop in traffic. “It’s much easier for an [ATC] organisation to manage ten flights then it is to manage 100, so it’s easy to wind down,” Kennedy says. “The speed was the one thing that I think was a surprise to us. It did happen very quickly.”

In the US, the Federal Aviation Authority (FAA) also had to deal with how quickly traffic dropped. On 12 March 2020, the FAA was dealing with a seasonal high of 50,823 flights in one day. On 12 April, a month later, it was the low point for traffic handled by controllers, with only 10,757 flights – a 74% reduction.

The initial steep drop in traffic allowed the FAA to protect its staff by separating and rotating teams, so that if someone became ill, there would be other teams that were not exposed. “We always had unexposed crews to substitute for crews that might have come into contact with someone who had the virus,” says Teri L Bristol, COO of air traffic organization at the FAA. “We have occasionally had interruptions in the system due to the need to clean a facility, but we’ve adjusted our cleaning routines to make these disruptions much less frequent.”

Initially, when an FAA employee tested positive for Covid-19, the association emptied the facility in order to conduct a deep cleaning before allowing a new team to enter and operations to resume. By June 2021, the FAA had decided that it would be less disruptive to do a nightly deep clean instead, regardless of whether or not its employees tested positive for the virus.

The real challenge to the ATC industry – and indeed to the air travel industry as a whole – then, has been the lack of certainty over travel regulations by world governments, as countries enter and exit travel corridors seemingly at whim, one day on a nation’s green list, the next down to amber or red after news of a variant flare-up.

“The travel restrictions, particularly in the UK, have been really fluid,” says Kennedy. “What we don’t have is any certainty whatsoever over what the long-term forecast is – everybody’s got a different idea of when traffic is going to return. That makes it challenging for us to plan ahead, and the one thing that air traffic is based on is planning.”

Find the sweet spot

However, while the pandemic has been a difficult period for the industry, it also offers some valuable lessons. It has shone a light on ATC’s lack of flexibility – it takes a long time to train a controller and its operators to work within a relatively fixed shift pattern, making it difficult to quickly step operations up or down to match fluctuations in demand.

“We need to be able to more quickly match the supply of controllers to the demand from the traffic,” says Kennedy, who sees the length of time training takes up as the main issue. “[As] airlines are able to switch routes on and off [and] move routes really quickly, we find it more difficult to respond.”

The pandemic has also forced ATC operators to work more closely with airlines and airports, who are struggling with problems of their own as they prepare to slowly begin to wind operations back up again. In the UK, the Department of Transport is attempting to coordinate across the industry to make sure it is ready for when travel restrictions are finally lifted.


Flights handled by traffic controllers on 12 April 2020, a 74% reduction on the month earlier due to the onset of the pandemic.


“It’s much easier for an [ATC] organisation to manage ten flights then it is to manage 100, so it’s easy to wind down. The speed was the one thing that I think was a surprise to us.”

Juliet Kennedy

This spirit of cooperation has proved to be helpful when dealing with another of the main effects on the pandemic – a lack of income across the whole aviation industry. NATS focused on its short-term finances, looking to minimise their costs as much as possible by starting a voluntary redundancy programme and reducing the size of its non-operational workforce. As ATC makes up a big part of airport costs, working to minimise its costs have allowed both sides of this partnership to continue their operations.

“We’ve tried to work as closely as we can with them to make sure that we’re reducing costs for them as far as we can. We’ve focused very much on what can we do to build back better,” Kennedy says, co-opting one of the slogans of the current UK government. “If you’ve had a massive shock to the industry like this, then it’s a good opportunity to look at how you can do things differently and how you might want to build things back better in future.”

On the topic of rebuilding for the future, returning to prior traffic levels safely and efficiently also contains its own challenges, as many air traffic controllers have worked considerably fewer hours and managed fewer aircraft than they normally would have. Just like the reports of pilots struggling to shed their rust after missing out on a considerable amount of time in the cockpit, air traffic controllers will need some time to get back up to speed. “We are very focused on making sure that we give our controllers enough support so they’re ready for when the traffic comes back,” Kennedy says. In order to achieve that, NATS ran a simulation exercise from February to May 2021 for hundreds of its air traffic controllers. “It’s one compressed way to make sure that we can expose controllers to increased levels of traffic, so that when it does come back, they’re ready for it. Because above all else, what we’re here for is to deliver a safer air traffic service.”

The FAA have also made strides to address this issue, making some of its ATC training available in a digital platform, allowing it to study these newer techniques over time. It is then using this data to help determine the sweet spot for training between virtual and in-person training activities.

A digital solution

If controller training has been made more easily available on a digital platform, digitalisation could be the solution to some of the issues ATC operators have had during the pandemic. Fully digitalised and remote-control towers could manage more air traffic while requiring fewer controllers, reducing the risk that an operator could become short-staffed as traffic begins to return to normal levels.

“As vaccinations become available, we are seeing an increase in demand for air traffic services, and have adjusted our hours and staffing to be ready to meet the demand.”

Teri L Bristol

“[Digitalisation has] always been a subject of discussion,” says Kennedy, noting that while Covid- 19 has drawn attention to some of the benefits offered by digitalising ATC operations, it also disrupted the revenue streams that could have led to investment in this area. “Once we get out of the crisis period and we get back into a more normal business planning cycle, then yes, I think it’s heading in that direction.”

In the US, however, the FAA’s ATC System Command Center in Virginia is very much already operational, making strategic and tactical operational decisions that manage the daily flow of air traffic throughout the US and adjacent countries, balancing demands with an ever-changing system capacity. The ATC System Command Center also houses critical stakeholders, such as airline and military personnel who inform decisions in real time, along with input from traffic management specialists and air traffic controllers at facilities affected by Covid-19.

It is also the central hub for handling contingency situations, and ensuring continued safety and efficiency. On 11 March 2020, the Command Center activated a Joint Crisis Action Team (J-CAT), which worked around the clock to track and address Covid-19 cases at air traffic facilities. Centralising this activity in the ATC System Command Center’s J-CAT, which concluded at the end of May 2021, allowed affected facilities’ non-exposed employees to maintain their focus on the tactical operation.

Look to the future

So, what, then, does the future hold for airports and ATC operators? There is a general expectation that some recovery will be seen during the summer, but that will likely be hindered by ongoing Covid-19 checks and travel restrictions, particularly around those as yet unvaccinated against the virus. Traffic has already started moving in the right direction, however, allowing operators to begin scaling up their services once more.

“As vaccinations become available, we are seeing an increase in demand for air traffic services, and have adjusted our hours and staffing to be ready to meet the demand,” says Bristol, noting that the FAA’s ATC facilities resumed their normal schedules on 6 June 2021. “Traffic gradually increased over the [past few] months and we’ve recently seen more than 44,000 flights in one day.”

Kennedy is a little more cautious, but is also hopeful that ATC operators will see some form of recovery over the summer. “It’s not at all clear how [things are] going to play out for the second half of 2021,” she admits. “We are certainly hopeful that we will get some form of recovery over the summer, but we think it will be relatively limited.”

The scale of Covid-19 may be unprecedented, but ATC operators have come back from serious setbacks in the past and this time the rest of the aviation industry is all on the same page. While obstacles, risks and fears over the pandemic remain and threaten to hinder air travel for the foreseeable future, the industry has shown that it is ready and willing to overcome these challenges. And, with some luck, summer 2021 may just prove to be the light at the end of the tunnel.