A cyberattack on a key provider of airline check-in and boarding systems has snarled travel at major European airports, forcing staff to process passengers manually, and triggering delays and cancellations. Collins Aerospace on September 20 confirmed that a “cyber-related disruption” to its MUSE software is causing delays at some airports. MUSE — short for Multi-Use System Environment — powers electronic check-in, boarding, and baggage drop for airlines and airports. The outage prevents passengers from using kiosks or self-service baggage systems, but airlines can still process travelers manually at staffed counters. According to aviation data provider Cirium, 16 departures and 13 arrivals were canceled on September 20 across London Heathrow, Berlin Brandenburg and Brussels airports.