Federal regulators cleared American Airlines flights to resume early Tuesday following a brief nationwide grounding caused by a systemwide technical glitch affecting all U.S. routes.
The airline blamed the disruption on a "technical issue” that caused delays for flights across the U.S. Boarding for flights resumed around 1300GMT.
"We apologize to our customers for the inconvenience,” it said in a statement.
The Federal Aviation Administration (FAA) also lifted its nationwide ground stop order for American Airlines flights.
The FAA confirmed that American had requested the ground stop but referred all further inquiries to the airline for additional information.
American Airlines had grounded all its flights across the U.S. early Monday due to an unspecified technical problem, impacting thousands of passengers traveling the day before Christmas.
The airline gave no specific reason for the nationwide halt, but tried to reassure impacted customers online, saying: "Our team is currently working to get (repairs) done ... in the shortest possible time."
