Southwest Airlines briefly pauses flights nationwide over computer glitch

Southwest Airlines asked the Federal Aviation Administration to "pause" all of its departures across the country Tuesday morning as the airline worked to resolve what the FAA called a "technical glitch" that delayed about 1,700 flights.

Tuesday's 20-minute pause comes less than four months after a holiday meltdown related to Southwest's internal scheduling technology stranded passengers for days, and just ahead of the opening of what is expected to be a busy summer travel season. While delays are likely to increase throughout the day due to ripple effects from the ground stop, cancellations were minimal. Southwest canceled nine flights amounting to less than 1 percent of overall operations on Tuesday, according to the flight tracking service FlightAware.

"Southwest Airlines pause on departures has been fully canceled," the FAA said in a statement. "Earlier this morning, Southwest requested that FAA pause Southwest departures due to an internal technical issue at Southwest."

Southwest blamed the problem on "data connection issues resulting from a firewall failure," according to a statement.

"Early this morning, a vendor-supplied firewall went down and connection to some operational data was unexpectedly lost. Southwest Teams worked quickly to minimize flight disruptions," the airline said.

DOT Secretary Pete Buttigieg, who has pressed airlines to ensure customers receive adequate refunds after flight disruptions, said in a tweet that "We are here to ensure passengers have strong protections when airline failures like this affect their plans," and directed affected Southwest customers to DOT's Airline Customer Service Dashboard.

Background: Though so far there's no indication that Tuesday's glitch was related to problems with the airline's internal scheduling software that caused the holiday flight havoc late last year, Southwest continues to face scrutiny for how it handled those flights.

In February, Southwest COO Andrew Watterson apologized to Congress for the holiday meltdown that was triggered by winter weather but dragged on for nearly a week due to issues with the airline's scheduling and rebooking systems. Watterson in February promised his airline is now “intensely focused on learning from this event by taking immediate mitigation efforts.”

But the top Senate Democrat overseeing the aviation industry, Senate Commerce Chair Maria Cantwell (D-Wash.) charged that Southwest withheld information from Congress about how it’s handling refunds for customers caught up in its December holiday meltdown, where some 16,000 flights were canceled. Cantwell is seeking specifics on how many passengers were involved, how many were issued cash refunds versus vouchers for future flights, how many were rebooked and when the airline plans to upgrade its internal systems that caused the debacle.

Earlier this month, Southwest released the results of a report detailing failings surrounding the end-of-year meltdown. The report, which was also conducted by an outside consulting firm hired by Southwest, said that “insufficient winter infrastructure” and computer software issues with rescheduling and rebooking passengers and crew were mostly to blame. The airline said a host of steps to improve winter operations will be complete by next winter, while software upgrades are already in place or will be completed by next winter.