⚡A report by NATS found that a legacy software defect lasting a millisecond caused the UK air traffic control outage that led to over 2,000 flight cancellations.

What it means

A preliminary report from NATS, the UK's air traffic control service, has identified a previously unknown software defect in a legacy system as the cause of a major outage on September 8, 2026. The defect corrupted flight data in a single millisecond, triggering a six-hour shutdown that led to over 2,000 flight cancellations and disruption for hundreds of thousands of passengers. The report exonerates any incorrect human actions, pinning the blame entirely on the software flaw.

Accuracy & sourcesSourced

The claim is based on NATS's own preliminary investigation report, which has been formally released and is the authoritative source for its findings. Major news outlets (BBC, Guardian, AP) are reporting directly from the report, so the reporting sits close to the primary source. As a preliminary report, it may be updated, but the core conclusion is solid for now.

How new

Genuinely new: the NATS report was published on September 18, 2026, detailing an outage that occurred on September 8, 2026, with news coverage appearing within hours.

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