European airports were starting to recover on Sunday, September 21 from a cyberattack affecting their check-in systems that has caused flight cancellations and huge delays for thousands of passengers over the past two days.
While Brussels airport said almost one-fifth of Sunday's scheduled departures had been canceled, other affected hubs said their schedules were getting back to normal. London Heathrow and Dublin airports said they were managing passenger flows while they tried to fix the problem with the software.
Dublin airport said it expected to function normally throughout Sunday. Its "team is continuing to support airlines today as they deal with the ongoing disruption caused by a Europe-wide technical issue that is impacting on their check-in and boarding systems," it said in a post on X.
Heathrow Airport said in a statement the "vast majority of flights" continued to be operated thanks to collaboration with the airlines. A Brussels airport spokesperson said 45 of 257 departing flights had been cancelled and passengers could expect delays of "between 30 and 90 minutes."
Airports began reporting problems with passenger check-in software supplied by Collins Aerospace on Friday. The company said on Saturday it was "actively working to resolve the issue and restore full functionality to our customers as quickly as possible." The aviation tech company, which specializes in digital and data processing services, is a subsidiary of the American aerospace and defence group RTX, formerly known as Raytheon.
Cyberattacks and tech outages have disrupted airports around the world in recent years, from Japan to Germany, as air travel increasingly relies on online, interconnected systems. The aviation sector saw a 600-percent increase in cyberattacks from 2024 to 2025, according to a report by French aerospace company Thales released in June.