Southwest Air briefly halts flights due to technology issue

Southwest Airlines Co. temporarily halted flights nationwide as it grappled with “intermittent technology issues,” just four months after an operations meltdown drew heavy scrutiny to the budget carrier.

The airline said Tuesday that it was resuming normal operations after requesting a nationwide halt in flying from federal regulators earlier in the day. In an emailed statement, Southwest blamed a failure in a “vendor-supplied firewall” that interrupted the flow of data for flight operations.

While the official ground stop order issued by the US Federal Aviation Administration lasted just 16 minutes, the disruptions emerged earlier and the impact to Southwest’s schedule is likely to linger throughout the day. 

Southwest’s delays swelled to 1,762, or 42% of its Tuesday schedule as of 11:52 a.m. New York time, according to the tracking website FlightAware.com. The airline said there were no cancellations related to the issue as of midday. Customers with reservations Tuesday will be allowed to rebook within 14 days without paying additional charges, Southwest said.

The company disclosed the tech problem in a tweet earlier Tuesday after a number of passenger complaints on the social-media platform of being stuck on planes awaiting departure or not being able to get to gates after landing. Southwest also said there were issues with its website and mobile app.

A secondary firewall at Southwest didn’t function properly after the initial disruption and caused a shutdown of the flight dispatch system that provides routing, fuel and weather information to flight crews, according to the Southwest Airlines Pilots Association.

Shares of Southwest fell as much as 3.9% in New York before paring the decline.

While minor technology snags aren’t unusual for airlines, Southwest’s latest troubles come as the airline faces ongoing scrutiny over a system meltdown in December. The company’s crew scheduling software became overwhelmed by a winter storm, forcing cancellation of 16,700 flights over the final days of the year. The company upgraded a software tool that it uses to plan flight crews to prevent further disruptions.

The Dallas-based airline had to cancel or delay more than 1,400 flights over two days in June 2021 after network connectivity problems interrupted operations. Southwest also had to briefly halt flights in February 2019, delaying around 600, after a glitch in software that automatically downloaded flight plans to the FAA.