Hawaiian Airlines, which was bought by Alaska Air Group last year, said its flights were operating as scheduled. The outage did affect Horizon Air, Alaska's regional carrier. In July, Alaska grounded all of its flights for about three hours after the failure of a critical piece of hardware at a data center.

All Alaska Airlines flights were grounded Thursday night as the airline worked to address an information technology problem, the Federal Aviation Administration said.

In a statement, the airline apologized to its passengers and clarified that the outage was not a cybersecurity event.