By Rajesh Kumar Singh and Aishwarya Nair
(Reuters) -Southwest Airlines Co's said a technology failure caused a one-hour nationwide stoppage of its flights on Tuesday, another snafu for the carrier after a software problem over the Christmas holiday stranded thousands.
The Dallas-based carrier's flights resumed after a vendor-supplied computer network firewall went down Tuesday morning and connection to some operational data was "unexpectedly" lost. Southwest said this forced it to temporarily pause all flights.
The U.S. Federal Aviation Administration (FAA) said on Twitter that it paused Southwest's departures at the carrier's request, "as they resolved the issue." The FAA referred questions on the matter to Southwest.
Data from flight tracker FlightAware showed 47% of Southwest's flights were delayed as of late afternoon on Tuesday. Many delayed flights were expected to be canceled later in the day.
The airline asked those whose flights were canceled to request a refund.
Shares of the airline closed down 0.8% at $32.06.
Southwest has been under fire ever since a staffing crisis due to bad weather during the Christmas holidays overwhelmed its crew scheduling software, disrupting travel plans for 2 million customers.
The holiday disruption led to over 16,700 flight cancellations, costing the company more than $1 billion.
"This is another demonstration that Southwest Airlines (NYSE:LUV) needs to upgrade their systems and stop the negative impacts to individual travelers,” said Senator Maria Cantwell in a statement.
Cantwell led a Feb. 9 committee hearing where she questioned Southwest's chief operating officer on a timeline for technology upgrades to help prevent future cancellations.
In March, Southwest said investments in technology, which will total more than $1.3 billion this year, and expenses related to mass cancellations were likely to increase costs in the near term.
A sharp rebound in travel demand from pandemic lows has exposed the fragility of the aviation system. The FAA had to halt flights nationwide in January due to a systems outage.
Government investigators are looking into a series of near collisions of planes in the sky and on the ground, and an increasing number of unruly passengers are under criminal invesigation for violent and threatening incidents.