All US-bound departures from European airports are suspended until 5am UTC on Saturday, according to a notice from the European traffic control agency, Eurocontrol. This follows a nationwide ground stop declared by the US Federal Aviation Administration (FAA) on Friday afternoon due to a communications failure at air traffic control centres.
The FAA lifted the ground stop later on Friday, with US airspace reopening at 8.15pm ET (0115 GMT). However, transportation secretary Sean Duffy warned that departures would resume gradually and it would take time for airlines to restore normal operations.
More than 6,600 flights were cancelled and 8,600 delayed on Friday, according to FlightRadar24. An additional 1,500 flights have already been cancelled for Sunday. Aviation analysts suggest the four-hour nationwide grounding could disrupt airline schedules for days.
US airlines, including American, United, and Southwest, began resuming flights on Friday night. Delta also stated it was safely resuming flights after the FAA-mandated ground stop was lifted.