Thousands of people suffered flight delays and cancellations after the UK’s automated air traffic control system failed yesterday. Though the problem in the National Air Traffic Services (NATS) network has now been resolved, services will continue to be impacted today.

Thousands of passengers are facing flight delays after the UK air traffic control system failed. (Photo by MiniStocker/Shutterstock)

The fault was discovered by NATS, which manages all UK airspace, yesterday morning, and led to the number of flights into and out of airports including Heathrow and Gatwick being limited.

How the NATS air traffic control system failed

In a statement issued yesterday afternoon, NATS said it had suffered a “flight planning issue”.

This “affected the system’s ability to automatically process flight plans, meaning that flight plans had to be processed manually,” the company said. This “cannot be done at the same volume, hence the requirement for traffic flow restrictions”. 

Though now back up and running, flights yesterday were subject to cancellations and delays. Heathrow said passengers travelling on Tuesday should contact their airline before journeying to the airport, while a spokesperson for Gatwick said the airport hoped to resume normal service at some point today.

Julie Kennedy, operations director at NATS, said the system apologised for the disruption the incident has caused and said it would “take some time” for flights to return to normal.

The UK’s air traffic control system problem mirrors a similar outage that occurred in the US in January, which grounded flights across the country for the first time since the 9/11 terrorist attacks.

This incident saw files unintentionally deleted from the Notice to Air Missions (NOTAM) IT system, which is used to send information to pilots ahead of flights. It is thought the deletion occurred when engineers were working to correct a synchronisation issue between the live primary pilot messaging database and a backup version. It took several hours to get the system back up and running.

Did the UK air traffic control system suffer a cyberattack?

NATS has not published details on what caused the error in its system, leading to speculation that it may have suffered a cyberattack. Hacking gangs, particularly those aligned to Russia, have been vocal about targeting critical national infrastructure belonging to countries allied to Ukraine.

Tech Monitor has contacted the company for comment. Government officials quoted by The i said that there were no signs of “untoward” activity on the NATS network, but that they were keeping an open mind about what led to the problem.

Earlier this month NATS announced it was investing in its IT networks and cybersecurity defences through a new partnership with BT. The seven-year deal will see the telco create “a future-fit strategic network architecture to support air traffic operations in the UK”.

BT will “take responsibility for the consolidation and modernisation of NATS’ critical data network as well as manage digital networking and cyber security across its sites.” It is also developing “an enhanced cybersecurity capability with NATS, which will include a new proactive central coordination point for cyber resilience.”

“NATS is implementing a truly transformational technology programme to keep the skies safe and support our customers worldwide,” Tim Bullock, supply chain and facilities management director at NATS, said at the time.

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