Flights were disrupted across parts of the United Kingdom on Monday after a technical problem at the National Air Traffic Services (NATS) control centre in Prestwick, Scotland, marking the second significant air traffic control failure to affect passengers in less than two weeks.

The latest incident affected flights in Scotland, Northern Ireland and northern England, with delays and cancellations reported at several airports, including Glasgow, Edinburgh, Manchester and Belfast.

NATS said the problem occurred early Monday at its Prestwick centre. To maintain safety while engineers investigated, the air traffic control provider imposed restrictions on the number of aircraft entering affected airspace.

The organization later said the fault had been fixed and that it was working with airports and airlines to remove the remaining restrictions.

“This was a connectivity issue with part of our systems network, specific to the operation in Scotland,” NATS said. It stressed that the problem was unrelated to the incident earlier this month.

NATS said airports south of Manchester were broadly unaffected, although flights heading north and services departing Scottish airports experienced delays.

Airlines reported cancellations and warned passengers to expect disruption as schedules were gradually restored. Ryanair said the incident had affected around 25,000 of its passengers, while easyJet and British Airways also reported disruptions.

Monday's failure came just 13 days after a much wider NATS outage on Sept. 8 that caused more than 2,000 flight cancellations and widespread disruption across the UK.

NATS published a preliminary report into that incident on Sept. 18, concluding that it had been caused by a software defect in a small section of the National Airspace System. NATS said a mitigation had been put in place while a permanent fix was being safety-tested and deployed.

The earlier outage had initially prompted reports that erroneous flight data entered by a military aircraft may have triggered the failure. The Financial Times reported that a UK military aircraft had submitted “spurious” flight data that led to the wider system breakdown. NATS' preliminary report, however, identified a software defect as the cause of the incident.

NATS has emphasized that Monday's Prestwick problem was a different incident involving network connectivity rather than the software defect identified in the Sept. 8 outage.

The latest disruption has renewed criticism from airlines over the resilience of Britain's air traffic control infrastructure.

Ryanair again called for action against NATS management, while easyJet said the latest failure raised further questions about the resilience of the system. British Airways said some customers were likely to experience disruption as a result of the technical fault.

UK Transport Secretary Heidi Alexander acknowledged the disruption and said passengers would continue to face knock-on delays even after the technical problem was resolved, as airlines worked to restore their schedules.

The government has already sought greater scrutiny of the Sept. 8 incident, with NATS publishing its preliminary findings and a fuller report still expected.

Monday's outage therefore comes at a particularly sensitive time for Britain's air traffic control system, with airlines and passengers seeking assurances that recent failures will not become a recurring source of disruption.

NATS said safety remained its priority throughout the latest incident and apologized to passengers affected by the disruption, advising travelers to check directly with their airlines for the latest flight information. (ILKHA)