American Airlines temporarily grounded US flights due to a technical glitch.

American Airlines A technical glitch grounded its U.S. flights Tuesday morning, halting travel during what carriers expect to be a record holiday demand period.

As of 7:55 a.m. ET, the ground stop had been lifted, an American Airlines spokesperson told CNBC. The ground stop lasted less than an hour.

American said the issue arose from a vendor-provided platform. The system is connected to important data such as aircraft weight and balance, which is required before the flight leaves the gate.

“The issue has been resolved and flights have resumed,” the carrier said in a statement. “We sincerely apologize to our customers for the inconvenience this morning caused.”

The Federal Aviation Administration said American had requested a ground stop.

Airlines routinely request ground stops, which actually hold flights, so that destination airports aren’t overwhelmed by flights that don’t have parking space when the disruptions occur. In addition to technical problems, ground stops are installed for thunderstorms and other severe weather.

American was running a shorter schedule on Christmas Eve than on other days around the Christmas holiday. A spokeswoman said the carrier had no cancellations related to the issue.

Airlines’ patchwork systems of key technology platforms have recently gained more attention following mass flight cancellations e.g. Southwest2022 year-end meltdown during the holiday season and DeltaThe struggle to recover from Crowd strike closed this past summer.

Correction: The ground stop was issued on Tuesday. An older version gave the time incorrectly.