This is the second Nats issue this month – here’s what happened last timepublished at 11:33 BST
11:33 BST
Flight delays set back travellers around the country earlier this month after an air traffic control failure caused by a “software defect” prompted Nats’ system to produce corrupted data.
The issue led to 2,000 cancelled flights at the UK’s main airports, with hundreds of thousands of passengers impacted.
Questions are growing over the resilience of Nats’ systems, and Airlines UK, an industry body, has called for immediate compensation for costs incurred
Separately, there are calls for Nats chief executive Martin Rolfe to resign – though he told the BBC last week that he won’t step aside, calling the software defect “very, very obscure.”
“You can fly to almost anywhere from almost any airport at almost any time. If that stops, even for a moment, then you get huge disruption.”
Transport Secretary Heidi Alexander called the widespread disruption “completely unacceptable”.
In 2023, a computer shutdown over the August bank holiday weekend caused chaos for 700,000 passengers.
There was another, smaller Nats outage in 2025, which caused 150 cancellations.