British Airways flights due to depart from the US on Monday night were grounded for several hours.
The airline said the problem has now been resolved after investigating a technical issue with its third-party flight planning supplier.
BA passengers reported waiting for hours in airports.
The airline said it aimed to get aircraft departing as quickly as possible, adding it was sorry for any disruption to its customers’ plans.
Passengers took to Twitter to report waiting at New York JFK airport for more than three hours.
One passenger said: “All British Airways flights grounded due to an issue with their flight mapping system and now we have multiple alarms going off in departures.”
Others said they had been sitting on aircraft parked on runways for hours, before being moved back to the airport, the BBC reported.
A BA spokesperson said: “Our teams have now resolved a temporary issue that affected some of our long-haul flight planning systems overnight, which resulted in delays to our schedule.
“We’re sorry for the disruption caused to our customers’ travel plans.”
The airline kept passengers up to date with developments and provided refreshments.
Short-haul flights were not affected.