A cyberattack targeting check-in systems hit several major European airports on Saturday, including Brussels, Berlin and London’s Heathrow, leading to long queues, cancellations and delays across multiple hubs.
At least three busy European air hubs warned of flight delays and cancellations.
At least 10 flights were cancelled out of Brussels Airport and another 17 delayed by over an hour after the system was hit by a "cyberattack" late Friday, the airport said.
"We have become aware of a cyber-related disruption to our MUSE software in select airports," airport service provider Collins Aerospace told AFP.
"The impact is limited to electronic customer check-in and baggage drop and can be mitigated with manual check-in operations," Collins Aerospace added.
Brussels airport said the attack was still having a "large impact" on flight schedules Saturday morning.
According to the BBC, aviation watchdog Eurocontrol said airlines had been asked to cancel half their flights to and from Brussels between 0400 GMT on Saturday and 0200 GMT on Sunday because of the attack.
Only manual check-in and boarding was taking place at Brussels, which advised passengers to check their flight status with airlines before going to the airport on Saturday.
AFPTV images showed large queues at Brussels as passengers monitored announcement boards showing many flight delays.
London's Heathrow Airport, the busiest in Europe, said its check-in and boarding systems, also provided by Collins Aerospace, were hit by a "technical issue" that "may cause delays for departing passengers".
"They didn't tell us anything. It's always crowded here, but today is like extra," said a 41-year-old architect, who gave her first name as Rowan.
"If the system is down they should delay the flight. That's what I'm hoping," she added, waiting in the packed check-in area at Heathrow's Terminal 4 for a Saudia Airlines flight to Jeddah.
Another woman waiting for an Air Algerie flight to Algeria said she had waited for over an hour to check in.
"They said they're doing everything manually. That's all they've told us," said the 30-year-old, asking not to give her name.
Freelance journalist Tereza Pultarova was booked on a flight to Amsterdam with a connection onto a KLM flight to Cape Town.
"They were checking in people at the rate of, like, one person per 10 minutes," she said, adding it looked like she would miss a once-in-a-lifetime work trip to the Karoo desert which would probably head off without her.
"It was just insane, the queue wasn't moving."
The Berlin Airport website read that "due to a technical issue at a system provider operating across Europe, there are longer waiting times at check-in."
Collins Aerospace said 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 defense group RTX (formerly 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.
"From airlines and airports to navigation systems and suppliers, every link in the chain is vulnerable to attack," the report warned, pointing out that the strategically and economically important sector had become a "prime target" for cyberattacks.
In July, Australian airline Qantas was targeted by hackers, who broke into a system containing sensitive data on six million customers. In December 2024, Japan Airlines was also targeted.
