Heathrow and several other major European airports are recovering from a weekend cyber attack that left a spate of flight cancellations and technical challenges.
Airlines that use US-based Collins Aerospace's systems were forced to manually check in passengers with the recovery still in operation on Monday morning.
Heathrow, where more than 20 flights were cancelled, said the “vast majority” of flights continued to operate and said the situation was not something it had direct control over.
“We are supporting airlines to make sure passengers check in; some airlines are working on manual contingencies,” a spokesperson said.
