Nats says millisecond software defect caused 2,000+ cancellations and mass delays in UK
Coveragetap to expand ▾Spectrum: Mostly Center🌍Europe: 1 · Other: 1
- 'Millisecond' software error caused air traffic outage that grounded thousands of flights - Sky News
- Nats said a software defect produced corrupted data "in the space of a millisecond."
- The failure caused more than 2,000 flight cancellations.
- Flight chaos affecting hundreds of thousands caused in ‘millisecond’ by software error - inkl
- Flight chaos for hundreds of thousands was caused in ‘millisecond’ by software error - The Guardian
- Hundreds of thousands of passengers were delayed by the outage.
- Airlines UK demanded compensation following the disruption.
- The BBC article was published on 18 September 2026.
Nats says a software defect produced corrupted data in the space of a millisecond and that failure precipitated the cancellation of more than 2,000 flights across UK airspace, leaving hundreds of thousands of passengers delayed.
The company’s account frames the incident as a technical anomaly that unfolded in a fraction of a second; industry and government responses have focused on accountability and compensation.
Airlines UK immediately demanded compensation for carriers and passengers hit by the disruption, and Transport Secretary Heidi Alexander described the disruption as "completely unacceptable," putting pressure on Nats leadership and prompting fresh scrutiny of executive responsibility.
Nats acknowledged the defect publicly and the outage has raised questions about the tenure of Nats chief executive Martin Rolfe, a political and commercial consequence the company must now manage. For travellers the effect was immediate: mass cancellations and cascading delays through UK airports that overwhelmed airline recovery plans and passenger services (per BBC).
At this stage, reporting is limited to Nats’ explanation and the public reactions recorded by industry and government; independent technical forensic details and a regulator-led timeline have not been published in the source material.
The focus now shifts to whether Airlines UK’s compensation demand leads to concrete payouts and whether UK transport authorities or aviation regulators will launch formal inquiries that could define who bears financial and managerial responsibility (per BBC).
Left- and right-leaning outlets are covering this story differently — in which facts to emphasize, which context to include, and how to frame causes and consequences.

