Europe Air Travel Outlook After Cyberattack

Published on Sep 21, 2025, 7:35 am CDT

6 min read

A cyberattack on a common check-in platform rippled across major European hubs on September 20, 2025, forcing manual processing, slowing baggage drop, and triggering selective cancellations. While recovery is underway, airports warn of lingering queues and knock-on delays, especially at London Heathrow Airport (LHR), Brussels Airport (BRU), Berlin Brandenburg Airport (BER), and Dublin Airport (DUB). Schedule integrity is improving, but aircraft rotations and crew duty limits mean the effects will likely carry into the morning wave on September 22. Travelers should build in buffers, verify flight status frequently, and prioritize online check-in.

Key Points

Why it matters: A single vendor outage exposed systemwide fragility, slowing throughput at multiple hubs.
Travel impact: Longer lines, sporadic cancellations, and misconnected journeys through September 22.
What's next: Recovery continues today, with Brussels trimming departures and other hubs easing delays.
MUSE check-in software disruption affected electronic check-in and bag drop, not air traffic control.
Online check-in reduced friction where accepted; manual counters remain a bottleneck.

Snapshot

Collins Aerospace confirmed a cyber-related disruption to its MUSE, multi-user check-in software late on September 19, triggering manual processing at multiple airports on September 20. By September 21, delays had eased in London and Berlin, but Brussels still reported significant schedule cuts, with cancellations and 30 to 90-minute delays in some cases. Dublin flagged ongoing impacts in Terminal 2, particularly for Aer Lingus departures. The European Commission said flight safety and air traffic control were unaffected, underscoring that the incident was confined to passenger processing systems. Expect residual disruption through the Monday morning peak as airlines work aircraft and crews back into position and clear baggage backlogs established during manual operations. See our earlier report for context, Flight Delays in Chicago and Europe While Dallas Recovers.

Background

MUSE is a common-use platform that lets multiple airlines share the same counters and kiosks for check-in, boarding pass printing, and baggage tags. When the software goes offline, airports fall back to manual processing. That shift immediately reduces passenger throughput per position and lengthens lines, particularly at first-wave and banked departure peaks. On September 20, London Heathrow Airport (LHR), Brussels Airport (BRU), and Berlin Brandenburg Airport (BER) confirmed impacts, with Dublin Airport (DUB) noting knock-ons in Terminal 2. Airlines prioritized departures with available crews and gates while deferring some flights to smooth terminal flow. Brussels adopted a pre-emptive cancellation strategy to prevent late-in-the-day scrubs and terminal gridlock. Because aircraft and crews were out of position by Saturday night, residual delays are likely to persist into September 22's morning departures, even as systems stabilize. Travelers should expect longer queues where manual processing remains in effect.

Latest Developments

Check-in systems stabilize, but bottlenecks remain at peak times

Heathrow and Berlin report improving operations as airlines blend online check-in with staffed counters to move passengers faster. Where accepted, mobile boarding passes help bypass some kiosk functions, though bag-tagging and document checks still slow lanes. Brussels remains the slowest to recover, after adopting schedule reductions to manage queues. Expect the longest lines at traditional peaks, early morning and late afternoon, and on wide-body banks with higher document-check needs. Even where departures operate, gate changes and retimings can ripple across the day as airlines work rotations back to normal. Crews nearing duty limits may force isolated cancellations if earlier legs ran late. For today, plan to arrive early, keep digital passes downloaded, and travel with carry-on where practical to avoid baggage-drop queues.

Brussels trims departures to clear the backlog

To reduce last-minute cancellations and terminal congestion, Brussels cut a portion of Sunday's departures, with delays commonly in the 30 to 90-minute range. This proactive thinning improves predictability but keeps near-term seat supply tight on some routes. In contrast, Berlin reports fewer cancellations after introducing manual workarounds, and Heathrow says most flights are operating with delays concentrated around the check-in bottleneck. Dublin warns of continued lines at Terminal 2, where Aer Lingus traffic is densest. Across hubs, baggage systems are catching up, but misrouted and late-loaded bags may take additional time to reach carousel belts, particularly for late-evening arrivals. Expect some reaccommodation into Monday morning as airlines protect connections and rebuild aircraft positioning.

What travelers should do today and Monday morning

Follow your airline's alerts closely and refresh flight status often. Check in online as soon as the window opens, download your boarding pass, and print a hard copy if possible. Arrive within standard airport guidance, two hours for short-haul and three hours for long-haul, unless your airline directs otherwise. Build extra buffer time through London Heathrow Airport (LHR), Brussels Airport (BRU), Berlin Brandenburg Airport (BER), and Dublin Airport (DUB), and avoid tight self-made connections. If your flight is canceled or you misconnect, EU Regulation 261 requires care and rebooking; cash compensation may not apply where the cause qualifies as an extraordinary circumstance. Keep receipts for reasonable meals and incidentals if delays extend, and confirm baggage status before leaving the airport if you checked luggage.

Analysis

This episode is a textbook example of a single vendor layer creating a shared-risk surface across multiple airports. Common-use platforms like MUSE deliver efficiency in normal times, but when they fail, throughput drops everywhere they are deployed. Saturday's pivot to manual counters reduced check-in capacity, which in turn throttled gate-to-gate performance, increased taxi-out variability, and pushed crew pairings toward duty limits. Airports responded in three ways. First, they staffed up to manage lines and hand-process document checks. Second, carriers prioritized aircraft and crews to protect long-haul departures, where recovery is slowest. Third, Brussels deliberately trimmed the schedule to avoid late-day scrubs and baggage gridlock, trading capacity for stability. By Sunday, the pattern looked familiar. Heathrow and Berlin showed steady recovery, while Brussels still absorbed the steepest delays. The operational math points to a tail that extends into September 22's morning banks, particularly where Saturday's rotations ended late. Travelers who check in online, travel carry-on, and accept reaccommodation onto later departures will have a smoother path through the residual turbulence. From a policy lens, the incident underscores the need for diversified failover, offline kiosk modes, and periodic live drills that maintain throughput during cyber incidents without overwhelming terminal spaces.

Final Thoughts

Expect a two-day recovery curve, with today's queues easing by midday at most hubs and a smaller echo at Monday's first wave. Protect yourself by checking in online, traveling light, and building buffer time through LHR, BRU, BER, and DUB. If you are canceled, pursue rebooking and care under EU 261, understanding that compensation may not apply if the cyberattack is deemed an extraordinary circumstance. With better vendor redundancy and tested manual playbooks, Europe can blunt the next blow. Until then, plan conservatively to beat the worst of the European air travel disruption.