WASHINGTON — American Airlines briefly grounded flights nationwide Tuesday because of a technical problem just as the Christmas travel season kicked into overdrive and winter weather threatened more potential problems for those planning to fly or drive.
Government regulators cleared American flights to get airborne about an hour after the Federal Aviation Administration ordered a national ground stop for the airline. The order, which prevented planes from taking off, was issued at the airline’s request after it experienced trouble with its flight operating system, or FOS. The airline blamed technology from one of its vendors.
As a result, flights were delayed across American’s major hubs, with only 37% of the airline’s 3,901 domestic and international flights leaving on time, according to Cirium, an aviation analytics company. Nineteen flights were canceled.
Dennis Tajer, a spokesperson for the Allied Pilots Association, a union representing American Airlines pilots, said the airline told pilots at 7 a.m. Eastern that there was an outage affecting the FOS system. It handles different types of airline operations, including dispatch, flight planning, passenger boarding, as well as an airplane’s weight and balance data, he said.
Some components of FOS have gone down in the past, but a systemwide outage is rare, Tajer said.
Hours after the ground stop was lifted, Tajer said the union had not heard about any “chaos out there beyond just the normal heavy travel day.” He said officials were watching for any cascading effects, such as staffing problems.
On social media, however, customers expressed frustrations about delays that caused them or their family members to miss connecting flights. One person asked if American planned to hold flights for passengers to make connections, while others complained about the lack of assistance they said they received from the airline or gate agents.
Cirium noted that the vast majority of flights were departing within two hours of their scheduled departure time. A similar percentage — 36% — were arriving at their destinations as scheduled.
Dallas-Fort Worth, New York’s Kennedy Airport and Charlotte, North Carolina, saw the greatest number of delays, Cirium said. Washington, Chicago and Miami experienced considerably fewer delays.
Meanwhile, the flight-tracking site FlightAware reported that 4,058 flights entering or leaving the U.S., or serving domestic destinations, were delayed, with 76 flights canceled. The site had not posted any American Airlines flights on Tuesday morning, but showed in the afternoon that 961 American flights were delayed.
Amid the travel problems, significant rain and snow were expected in the Pacific Northwest at least into C