United Airlines grounded a large number of its flights in the U.S. on Wednesday evening after it says it discovered a technical issue in its network.
United told Scripps News Group in a statement that it had stopped departures of all its main flights from U.S. airports on Wednesday due to a "technology issue."
The stop did not apply to some regional partner operations run under United Airlines and did not apply to any United Airlines aircraft currently airborne to their destination.
United said later on Wednesday evening it was making progress restoring its systems, but warned that delays were likely to continue.
As of early Thursday morning, some flights remained canceled or delayed. FlightAware reported that 4% of United Airline flights for Thursday had been canceled, while another 4% of flights for the delay had been delayed.
"We are working with customers to get them to their destinations after a technology disruption on Wednesday evening," the airline said in a second statement. "The underlying technology issue has been resolved, and, while we expect residual delays, our team is working to restore our normal operations."
Wednesday evening, the Federal Aviation Administration listed ground stops in effect for United Airlines flights at airports including Denver International Airport in Colorado, Newark Liberty International Airport in New Jersey and O'Hare International Airport in Chicago.
