Travelers across Europe faced a weekend of confusion and mounting frustration as a cyberattack crippled check-in systems at several major airports, causing widespread delays and cancellations that spilled into the new week. The incident, which began late on Friday, September 19, 2025, left thousands of passengers stranded or scrambling for alternatives, while airlines and airport staff scrambled to keep flights moving using manual workarounds and backup laptops.
The brunt of the disruption was felt at Brussels Airport, where, according to the Associated Press, officials asked airlines to cancel nearly 140 departing flights scheduled for Monday, September 22, 2025. The airport had already canceled 25 outbound flights on Saturday and 50 on Sunday. The reason? Collins Aerospace, a U.S.-based software provider whose systems are central to passenger check-in, boarding pass printing, baggage tagging, and luggage dispatch, was unable to deliver a new secure version of its check-in system after the attack.
Brussels wasn’t alone. Airports in Berlin, London, and Dublin also saw their electronic check-in systems grind to a halt. At London’s Heathrow and Berlin’s Brandenburg airports, the situation began to ease by Sunday, with arrivals and departures returning to a more normal rhythm. But in Brussels and Dublin, the chaos continued. Aer Lingus, Ireland’s national airline, reported that its operations were “significantly impacted,” leading to both delays and cancellations from Dublin Airport on Sunday. Around a dozen Aer Lingus flights, both inbound and outbound, were affected by lunchtime, and the airline warned customers to monitor their phones and its website for updates.
“Customers will be communicated with directly if they are impacted by any flight cancellations,” Aer Lingus said in a statement, as reported by The Irish Times. “We appreciate the patience and cooperation of our customers as we continue to manage this unfortunate disruption.”
The technical woes stemmed from a cyberattack on Collins Aerospace’s MUSE software—a system used by numerous airlines at airports worldwide. RTX Corp., the parent company of Collins Aerospace, acknowledged the incident in an emailed statement, noting, “The impact is limited to electronic customer check-in and baggage drop and can be mitigated with manual check-in operations.” The company added it was working to fix the issue as quickly as possible but did not specify who might be behind the attack.
Airport staff across the continent were forced to improvise. In Brussels, spokesperson Ihsane Chioua Lekhli told Reuters that the attack had affected only the computer systems at check-in desks, not self-service kiosks. Teams responded by turning to backup systems and pulling out laptop computers to keep operations afloat. “For now, we have no idea on the timing, we’re taking it day by day,” she said on Sunday, underscoring the uncertainty that hung over the recovery effort.
To avoid long queues and last-minute cancellations, Brussels Airport asked airlines to cancel half of their scheduled departing flights on Sunday. As a result, the airport was able to maintain about 85% of scheduled departures over the weekend, thanks to extra staff and the fact that self bag drop and online check-in remained operational. Still, passengers were repeatedly urged to check their flight status before heading to the airport and to use alternative check-in methods whenever possible.
The ripple effects were felt far beyond Belgium. Dublin Airport operator DAA said it was supporting airlines as they dealt with “ongoing disruption caused by a Europe-wide technical issue that is impacting on their check-in and boarding systems.” Graeme McQueen, a spokesperson for Dublin Airport, advised passengers requiring check-in or bag drop to allow extra time. “Dublin Airport is expecting to operate a full schedule today, but passengers are advised to contact their airline directly for updates on their flight,” he said.
Meanwhile, at Berlin’s Brandenburg Airport, the official website warned of longer waiting times at check-in and encouraged travelers to use online check-in, self-service kiosks, and fast bag drop services. Heathrow Airport echoed the sentiment, stating, “Work continues to resolve and recover from Friday’s outage of a Collins Aerospace airline system that impacted check-in. We apologize to those who have faced delays, but by working together with airlines, the vast majority of flights have continued to operate.”
The European Commission, the executive branch of the European Union, sought to reassure the public, confirming that aviation safety and air traffic control were unaffected by the attack. “There was currently no indication of a widespread or severe attack,” a spokesperson said, adding that the origin of the incident remained under investigation. British and German cyber defense authorities also reported being in contact with their respective airports as the situation unfolded.
While the precise perpetrators remain unknown—whether hackers, criminal organizations, or state actors—security experts have pointed out the broader implications. Rafe Pilling, director of threat intelligence at cybersecurity company Sophos, told The Irish Times that the incident highlighted “the fragile and interdependent nature of the digital ecosystem underpinning air travel.” Such sweeping outages, he noted, are typically the result of ransomware attacks or deliberate digital sabotage, both of which have become increasingly common as the aviation sector grows more reliant on interconnected online systems.
Indeed, the frequency of such attacks is rising at a staggering rate. According to a June 2025 report by French aerospace company Thales, the aviation sector saw a 600% increase in cyberattacks from 2024 to 2025, as reported by AFP. This surge underscores the urgent need for improved cybersecurity measures in a sector where technical failures can have immediate, real-world consequences for millions of travelers.
Despite the chaos, there were glimmers of resilience. Many airports managed to keep the majority of their flights operating by reverting to manual check-in processes—a labor-intensive but effective fallback. “The impact is limited to electronic customer check-in and baggage drop and can be mitigated with manual check-in operations,” RTX Corp. reiterated, as cited by multiple outlets.
Still, for affected passengers, the experience was far from seamless. Long lines, handwritten boarding passes, and the uncertainty of last-minute cancellations tested the patience of even the most seasoned travelers. Airlines and airports promised to keep customers updated via text messages, websites, and rolling announcements, but for many, the weekend’s events served as a stark reminder of how quickly digital vulnerabilities can upend even the best-laid travel plans.
As the investigation into the cyberattack continues, airports and airlines across Europe are left to pick up the pieces and reassess their digital defenses. For now, passengers are advised to remain vigilant, check with their airlines before traveling, and allow extra time for check-in—just in case.