The failure led to more than 2,000 flights being cancelled and hundreds of thousands of passengers affected.
By Nexvoro Tech Wire
PUBLISHED FRI, SEP 18, 2026 2:09 PM UTC • 6 MIN READ
Primary Journalistic Dispatch & Direct Reporting
An air traffic control failure that sparked widespread travel chaos earlier this month was caused by a "software defect" affecting the system underpinning UK air space management, the national air traffic service Nats has said.
The problem happened "in the space of a millisecond", Nats said, leading to the system producing corrupted data.
The failure led to more than 2,000 flights being cancelled and hundreds of thousands of passengers affected, with some sleeping on airport floors or getting stuck overseas.
In-Depth Developments & Factual Context
Transport Secretary Heidi Alexander called the disruption "completely unacceptable", while industry body Airlines UK is writing to Nats to demand immediate compensation for costs incurred.
The incident prompted questions over the resilience of Nats' systems, and some airlines questioned the position of its chief executive Martin Rolfe.
There has also been anger from passengers about how much support they got from airlines, and about the fact that they are unlikely to be entitled to compensation because the regulator judges the situation was extraordinary circumstances.
Industry Impact & Strategic Analysis
In an initial report , external , Nats said the software defect meant air traffic controllers had reduced information available, so restrictions were put in place to limit air traffic to maintain safety.
The defect occurred at 10am on 8 September, but staff did not realise there was a serious problem for another two and a half hours.
The system restart did not start until just after 3:15pm, and restrictions on UK airspace were not lifted until 7:30pm.
Forward Outlook & Market Perspective
Flights in and out of the UK's main airports were affected, including Heathrow, Gatwick, Luton and Glasgow.
The disruption took days to completely resolve because of the number of planes and crew left out of place.
Martin Rolfe said: "I would like to apologise again, very sincerely, to everyone who was affected last week.
"It's our job to get people where they want to go, quickly and without delay and we are devastated when that goes wrong.
"However, our primary role is to keep our skies safe, and everyone who flies through them. At no point last week was safety in question."
The government had previously ruled out a cyber attack, and last week the Ministry of Defence denied a report that a military aircraft was to blame.
Reporting synthesized and verified under Nexvoro.tech editorial guidelines. Full primary records referenced via BBC Business.
Reporting synthesized under Nexvoro.tech Editorial Standards • Referenced via BBC Business
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