Southwest Airlines Co.'s operational emergency stretched into a fifth day Tuesday, with double the normal number of planes taken out of service daily because of mechanical issues.
The carrier notified workers Feb. 15 of the situation, saying maintenance employees risked being fired if they declined to take overtime assignments or failed to show up for work as scheduled, unless they have a doctor's note. The Dallas-based carrier has been in contract talks with the union representing mechanics for more than six years.
Southwest has canceled 519 flights since Feb. 15, according to FlightAware.com, although the total includes flights grounded by weather. A breakdown by cause wasn't available. The carrier on Tuesday added its Dallas maintenance center to those in Houston, Las Vegas, Phoenix, Arizona, and Orlando, Florida, that originally were covered by the alert.