(Reuters)

Several flights were delayed on Tuesday (April 18) after the Federal Aviation Administration (FAA) issued a halt of departures for all Southwest Airlines Co. flights due to equipment issues.

The carrier blamed a technology failure for causing a one-hour nationwide stoppage of its flights, another snafu for Southwest 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 FAA, the governing body of civil aviation in the United States, later announced a resumption of service by the airlines.

“This morning, Southwest Airline experienced a technical issue with one of their internal systems. At the airline’s request, the FAA paused SouthWest’s departures as they resolved the issue,” the FAA said.

According to data from flight tracker FlightAware, 43 per cent of Southwest’s flights were delayed as of Tuesday afternoon.

“Southwest has resumed operations after temporarily pausing flight activity this morning to work through data connection issues. We offer our heartfelt apologies to customers whose journey with us today might be delayed,” the airline said in a travel advisory.

This nationwide ground stop comes at a time when the airline was forced to cancel more than 16,700 flights in December which the airline attributed to software issues.