UK transport secretary calls NATS outage avoidable as cancellations pass 2,000

Transport Secretary Heidi Alexander told the Commons that the air-traffic failure that wrecked two days of British flying was avoidable. She has ordered the Civil Aviation Authority to run an independent investigation of National Air Traffic Services, the company that handles most UK traffic. After meeting NATS chief executive Martin Rolfe she said a cyberattack could be ruled out. "I do not believe this issue was unavoidable," she told MPs. The government has given NATS a week to produce its own inquiry.

The fault appeared at 13:46 BST on Tuesday at the Swanwick centre in Hampshire, one of two main NATS sites. Engineers restored the flight-processing system by about 19:30. The backlog did not clear. Cirium, the aviation analytics firm, counted more than 1,750 cancellations on Tuesday and at least 291 on Wednesday. By Wednesday evening the running total of flights cancelled or unable to depart since the glitch first showed stood above 2,000. Flightradar24's Tuesday figure was about 1,300 UK cancellations, with a further 256 on Wednesday. The two trackers differ on method. Both describe the worst two-day British traffic failure in years.

Heathrow, Gatwick, Stansted, Manchester, Birmingham, Edinburgh, Luton, Bristol and Belfast City all reported disruption. Heathrow paused departures around midday on Tuesday, restarted, then hit more trouble in the afternoon. On Wednesday the airport said flights were operating but that aircraft and crews were still out of place. Gatwick said services had resumed and that a full return to normal would take time. Ryanair cancelled 260 flights on Tuesday, affecting 48,000 passengers, and put its loss so far at £3 million. Chief executive Michael O'Leary said the cause matched the 2023 shutdown. British Airways cancelled or diverted 100 flights on Tuesday and 190 on Wednesday.

Rolfe apologised and told BBC Radio that NATS does not believe the event was a cyberattack. That statement matters because the last major British ATC collapse, in August 2023, was blamed on a flight-plan processing failure that overwhelmed a system when it received a badly filed plan. Unions and airlines have argued for three years that Swanwick still runs too much of the country's traffic on software that has not been rebuilt. Alexander's line that the failure was avoidable accepts that argument without yet naming a software vendor, a budget line or a person.

The passenger effect is ordinary and ugly. People sat on stands at Heathrow Terminal 5. Connections through Europe and North America broke. Crews ended up in the wrong cities, which is why Wednesday's cancellations continued after the computers came back. Compensation rules under UK law and UK261-style rights cover delay and cancellation when the cause is inside the airline's or the ATC provider's control. NATS is a regulated monopoly with a government golden share. Who pays the hotel bills will be fought in claim letters for months.

Heathrow is one of the densest hubs on earth. A four-hour hole in its departure stream moves metal across three continents. That is why a Hampshire computer fault became a second-day story in Paris, Dublin and New York. Alexander now has two clocks: the week she gave NATS, and the longer CAA inquiry. Rolfe has to explain why a known class of failure happened again. Airlines have to put aircraft back on the right ramps. Passengers have to decide whether a ticket through London in the next fortnight is a reasonable bet.