Southwest Airlines Co. said it would investigate the cause of an operational emergency that’s seen an “unprecedented number” of aircraft taken out of service for mechanical issues, and indicated the groundings may be related to ongoing contract talks with a labor union.

The disruptions started Feb. 12, days after the airline’s last contract talks with the Aircraft Mechanics Fraternal Association, Southwest said in a statement Tuesday. The carrier declared an emergency on Feb. 15, 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.

Southwest, which has been in contract talks with the union representing its 2,700 mechanics for more than six years, has been frustrated in its efforts to reach a deal as it seeks to keep costs in check. Union members in September rejected an agreement that would have provided both annual pay increases and a bonus. The carrier, having had to take more than double the normal amount of planes out of service daily, said the union “has a history of work disruptions,” resulting in two lawsuits by the airline.

“We will be investigating this current disruption and are exploring all possible remedies,” the Dallas-based airline’s Chief Operating Officer Michael Van de Ven said. The carrier apologized to its customers for canceled flights and, in some cases “extremely long delays.”

Safety is Priority

Southwest has scrapped 519 flights since Feb. 15, according to, 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 and Orlando that originally were covered by the alert.

“Southwest Airline’s scapegoating of its expert aircraft maintenance technicians does not bode well for the airline’s safe operations,” Bret Oestreich, AMFA’s national director, said in a statement. “Safety is, and always will be, our number one priority. For Southwest’s leadership to connect the airline’s self-declared ‘operational emergency’ to collective bargaining negotiations is simply an attempt to divert attention away from the airline’s safety issues.”

‘No Common Theme’

The number of planes taken out of service has continued at more than twice the normal daily average of 20, Southwest said Tuesday, and there’s “no common theme” among the reported mechanical issues. The carrier has about 750 Boeing Co. 737 aircraft and makes nearly 4,000 flights each day.

“Sometimes if you get a hiccup or three hiccups and aircraft need service that’s not part of the regular program, that can throw your schedule off pretty fast,” said Bill Waldock, a crash investigator and professor of safety science at Embry-Riddle Aeronautical University. “If you’re not flying airplanes with passengers in them, you’re not making money.”

In 2017, Southwest accused the union of encouraging members to refuse overtime assignments in order to pressure the company in contract talks. A lawsuit filed by the airline was suspended in 2018 after an initial contract agreement was reached. The proposed contract later was rejected by union members.

Southwest’s mechanics “are working the overtime demanded of them,” the union said, “But Southwest Airlines has the fewest mechanics to aircraft of any major carrier. We will continue to do our job as expert craftsman, for the safety of Southwest’s passengers.”