Flight chaos caused by software defect, says air traffic control body
The failure led to more than 2,000 flights being cancelled and hundreds of thousands of passengers affected.
Flight disruption caused by software defect, says air traffic control body
Thousands of passengers were delayed by the NATS outage
A failure in an air traffic control system that triggered widespread travel disruption earlier this month was caused by a "software defect", the UK's National Air Traffic Services (Nats) has said.
The failure resulted in more than 2,000 flights being cancelled and hundreds of thousands of passengers being affected, with some forced to sleep on airport floors or left stranded overseas.
Flights to and from the UK's major airports were impacted, including Heathrow, Gatwick, Luton and Glasgow.
The incident raised concerns about the resilience of Nats' systems, and some airlines questioned the position of its chief executive Martin Rolfe.
The government had already ruled out a cyber attack, and last week the Ministry of Defence rejected a report claiming a military aircraft was responsible.
In an initial report, Nats said the defect occurred in the system which "underpins the management of UK airspace".
The issue happened "in the space of a millisecond", Nats said, causing the system to generate corrupted data.
Air traffic controllers then had less information available, so restrictions were introduced to limit air traffic in order to maintain safety.