A second technical failure in less than two weeks disrupted flights across the United Kingdom on Monday, forcing cancellations and delays at airports from Glasgow and Belfast to Manchester and parts of London. The fault at National Air Traffic Services’ Prestwick control center was fixed by late morning, but airlines warned that the effects would continue as aircraft and crews fell out of position.

The incident was described as a connectivity problem and was separate from the software defect that caused much broader disruption earlier this month, according to reports from Reuters and the Associated Press. Even after the system returned, the operational backlog meant travelers faced continuing uncertainty over departures and connections.

Flights cut while controllers restored service

NATS imposed traffic restrictions while engineers worked on the equipment at Prestwick, which manages airspace over Scotland and parts of the North Atlantic. The restrictions reduced the number of aircraft that could be handled safely and rippled into airports outside the immediate area. Glasgow, Belfast and Manchester were among the most visibly affected, while Gatwick and London City also reported disruption.

By 8:58 a.m. British time, 24 flights had been canceled, according to Reuters. Later tallies moved higher as airlines revised schedules: the Guardian reported at least 35 cancellations, while aviation-data estimates cited by the Independent counted roughly 200 flights canceled or delayed. Those measures describe different points in the day and different categories, but together show that the impact grew after the initial fault.

Airlines warn of network-wide effects

EasyJet canceled flights and said repeated technical problems showed weaknesses that required urgent action. British Airways warned customers to expect disruption, and Ryanair said the outage affected about 25,000 of its passengers. Those airline assessments were carried independently by AP, the Financial Times and Reuters.

The practical problem did not end when the equipment came back online. Airlines had already delayed departures, canceled rotations and moved aircraft away from planned positions. Restoring normal schedules therefore required more than reopening airspace. The Financial Times reported that traffic through Scottish airspace was sharply restricted during the incident and that some transatlantic departures were also constrained, helping explain why recovery extended beyond the repair itself.

Scrutiny intensifies after another outage

The timing made Monday’s failure especially consequential. A separate NATS software defect earlier in September led to about 2,000 cancellations and widespread disruption. NATS said the Prestwick fault was unrelated, a distinction reported by both Reuters and the Associated Press. For passengers and airlines, however, two major interruptions in such a short period raised a broader question about resilience across the air-traffic network.

Ryanair renewed its call for NATS chief executive Martin Rolfe to resign, while easyJet pressed for faster improvements. The Guardian and the Independent both reported those demands. Transport Secretary Heidi Alexander acknowledged passenger frustration and said the problem had been resolved, but the recurrence ensures that the review of NATS systems will now face sharper public and industry attention.

What affected passengers can expect

Travelers whose flights were canceled are generally entitled to a refund or rerouting under U.K. passenger protections. Compensation is a separate question. The U.K. Civil Aviation Authority says disruptions caused by air-traffic-control problems are ordinarily treated as extraordinary circumstances, meaning passengers should not assume they qualify for additional cash compensation even when a cancellation occurs with little notice. The regulator’s guidance advises dealing directly with the airline and retaining receipts for reasonable expenses.

Passengers scheduled to fly through affected airports should rely on their airline’s live status tools rather than the airport timetable alone. A departure can remain delayed after the underlying technical fault is fixed because the arriving aircraft or crew is still elsewhere. Rebooking options may also tighten as displaced travelers compete for seats on later services.

The disruption can also affect travelers whose own airports appear to be operating normally. An aircraft scheduled for an evening departure in London, Amsterdam or Dublin may have spent the morning caught in northern airspace restrictions. Travelers making connections face added risk because a short first-leg delay can erase the margin between flights. Airlines may substitute aircraft or crews as schedules recover, so gate assignments and departure estimates can continue changing even after a flight is no longer formally listed as delayed.

A repaired fault, but not a resolved concern

Monday’s failure was smaller than the earlier September breakdown, yet its significance lies in repetition. The new incident affected a different system at a different control center, according to NATS, but it again translated a technical problem into cancellations across multiple airports. Reports from AP, Reuters and the Financial Times agree that airlines expect the disruption to outlast the repair.

That leaves two immediate tests. NATS must explain the connectivity failure and demonstrate that backup arrangements can prevent another short outage from spreading through the network. Airlines, meanwhile, must clear the accumulated schedule without creating a second day of disruption. For travelers, the safest conclusion is that the system is operating again, but the timetable may take considerably longer to recover.