London Heathrow, the UK’s busiest airport, is grappling with a second consecutive day of disruption after a cyber attack on a critical airline IT system forced carriers to abandon automated check-in and boarding.
The problems began late on Friday when Collins Aerospace, a US-based supplier of airline technology, confirmed its Muse system, which allows multiple airlines to share check-in desks and boarding gates, had been hit by a “cyber-related disruption”.
The outage rippled through Heathrow’s terminals, with some airlines forced to check passengers in manually, leading to long queues and flight delays well into Saturday night.
Travellers spoke of hours-long waits, uncertainty and missed connections.
Lucy Spencer, due to fly with Malaysia Airlines, said she queued for more than two hours as staff “checked people in over the phone”.
Monazza Aslam, travelling with her elderly parents, said they “missed [their] connecting flight after waiting since the early hours of the morning”.
According to flight tracker FlightAware, 47 per cent of Heathrow’s departing flights were delayed on Saturday, with more than a dozen cancellations logged by Sunday morning.
Among them were services to Brussels, Berlin and Frankfurt.
Heathrow, which has been deploying extra staff to manage crowds in check-in halls, stressed that the “vast majority” of flights had still departed.
“Work continues to resolve and recover from Friday’s outage of a Collins Aerospace airline system that impacted check-in”, a spokesperson said.
“We apologise to those who have faced delays… we encourage passengers to check the status of their flight before travelling to Heathrow and to arrive no earlier than three hours for long-haul flights and two hours for short-haul”.
British Airways, which operates from Terminal 5, has continued largely unaffected thanks to its own back-up IT systems.
Europe-wide disruption
The fallout has not been confined to Heathrow.
Brussels Airport said on Sunday that it had asked airlines to cancel half their departing flights due to “heavily disrupted” check-in operations.
Forty-four flights were scrapped on Sunday morning alone.
Berlin Brandenburg also reported long queues and at least eight cancellations, with passengers urged to use online or self-service check-in where possible.
The European Commission, which oversees airspace management through Eurocontrol, said it was “closely monitorin”” the incident but that there was no sign of a “widespread or severe attack”.
Aviation safety and air traffic control systems remain unaffected.
The UK’s National Cyber Security Centre confirmed it is working with Collins Aerospace, Heathrow, the Department for Transport and law enforcement to assess the impact.
Transport secretary Heidi Alexander said she was receiving “regular updates” but has so far resisted calls to attribute blame.
The Liberal Democrats urged ministers to confirm whether Russia was suspected, following recent tensions after the alleged violation of Estonian airspace by Russian jets.
‘Fragile’ aviation IT systems under scrutiny
Collins Aerospace, owned by defence giant RTX, has not disclosed the source of the attack or when systems will be fully restored. It stressed the disruption was “limited to electronic customer check-in and baggage drop” and that manual workarounds were available.
Cybersecurity experts warn the incident is a stark reminder of the sector’s vulnerabilities.
“This recent cyberattack highlights the increasing risks within aviation as airports and airlines rely on interconnected systems for efficiency”, said Vykintas Maknickas, chief executive of NordVPN’s travel eSIM app Saily. “The problem is resilience. A single attack on one vendor can trigger widespread disruption across multiple airports”.
The episode follows a string of recent IT crises in UK aviation.
In July, a faulty software update from cybersecurity firm CrowdStrike grounded flights across the US and spilled into European hubs.
Earlier this year, an outage at air traffic control provider NATS caused the cancellation of more than 150 flights, while a power cut near Heathrow in March forced the closure of the airport and disrupted 270,000 passenger journeys.
Looking ahead
For now, passengers at Heathrow and across Europe are being advised to prepare for more queues and possible cancellations while Collins Aerospace works to restore its systems.
Brussels Airport has already warned of “difficult operations” continuing into Monday, and at Heathrow, overnight departures – including flights to Doha, Abu Dhabi and Kuala Lumpur – took off hours late, jeopardising onward connections.
Aviation analysts warn that while airlines can fall back on manual systems, the disruption underscores how dependent the sector has become on shared technology.
If outages are prolonged, even a temporary workaround may not be enough to keep Europe’s skies running smoothly.
