The Federal Aviation Administration briefly issued a nationwide ground stop for all American Airlines flights the morning of Christmas Eve, as the airline said a "technical issue" was affecting flights.
The FAA said the ground stop was issued at the airline's request, on one of the busiest travel days of the year.
American Airlines later explained the hourlong ground stop was due to an issue with systems operated by DXC Technology, an operational systems vendor that "maintains our flight operating system."
The flight operating system allows for flights to be coordinated and dispatched, the airline said.
The issue was hardware related and was resolved in the morning.
“That issue has been resolved and flights have resumed,” the airline said. “We sincerely apologize to our customers for the inconvenience this morning. It’s all hands on deck as our team is working diligently to get customers where they need to go as quickly as possible.”
Just before 8 a.m. ET, American Airlines said the ground stop has been lifted and flights were starting to board, which the FAA confirmed.
American Airlines noted the airline has 3,900 scheduled flights Tuesday, a little over half of the more than 6,400 flights scheduled Monday.
Earlier, American Airlines had said: "Our teams are working to resolve the issue as quickly as possible, and we apologize to our customers for the inconvenience."
Social media users delayed at their gates had reported issues with having their boarding passes scanned.
X users asked American Airlines when the issue would be resolved. The airline responded: “Our team is currently working to get this done. An estimated timeframe has not been provided, but they’re trying to fix it in the shortest possible time.”