Southwest Airlines resumed its flights late Tuesday morning after “intermittent technology issues” forced a brief nationwide ground stop.
Southwest announced it resumed operations around 11:35 a.m., about an hour after the Federal Aviation Administration paused all flights, citing a tech glitch “with one of their internal systems.”
“Southwest has resumed operations after temporarily pausing flight activity this morning to work through data connection issues resulting from a firewall failure,” the Dallas airline said in a prepared statement.
“Early this morning, a vendor-supplied firewall went down and connection to some operational data was unexpectedly lost.”
Though the hold was brief, it still snarled airline traffic, leaving airports from New York City to Dallas behind schedule and backed up.
According to the flight tracking website Flight Aware, Southwest had canceled nine flights and delayed 1,728 more — or 41% of its schedule — as of early Tuesday afternoon.
The airline encouraged all flyers to check on their flight status “and explore self-service options” for travel as it continued working to address the technical failure.
It’s not the first time operations for the aircraft carrier have plunged into chaos in recent months. More than 16,700 Southwest flights were canceled and 2 million passengers were left stranded between December 20 and 29 — ruining travel plans for many during the holiday season — due to the harsh winter weather conditions. The airline at the time also attributed the massive disruption to changes to its staff scheduling computer systems.
Southwest said it upgraded the software after it became overwhelmed by changing crew assignments amid one of the busiest travel times of the year.
The December meltdown cost the airline carrier more than $1 billion, and the Transportation Department is investigating.
The issues on Tuesday did not appear to be related to the same software involved in the breakdown late last year.