DALLAS (CBSDFW.COM) – Southwest Airlines has filed a lawsuit against its mechanics union, the Aircraft Mechanics Fraternal Association in an escalation of the growing battle between the Dallas-based airline management and its mechanics.

Southwest Airlines accuses the union of encouraging mechanics to write up issues that Southwest said has no effect on the safety of flights.

Southwest blames the union for doing it to try to gain leverage in ongoing contract negotiations.

“Today’s action does not alter our goal of reaching an agreement that benefits our hardworking Maintenance Employees nor does it change the Company’s unwavering commitment to Safety,” said Vice President Labor Relations Russell McCrady. “Southwest is–hands down–one of the best companies in the world to work for and we will not stray from our focus on rewarding our mechanics, while we work to shield our Employees and Customers from unnecessary disruptions within the operation.”

For two weeks, the airline has struggled with delays and cancellations because its had more of its aircraft out of service unexpectedly for repairs.  

CBS 11 has reached out to the mechanics union for comment about the lawsuit and is awaiting a response. 

 But the union has previously has said safety is its top priority and that contract negotiations and maintenance write-ups are separate issues.  

Last month, a CBS News investigation revealed some mechanics felt pressured by the airline to return aircraft to service more quickly.

As CBS 11 reported last week, the FAA has stepped up oversight of Southwest’s maintenance, a standard policy whenever any airline is experiencing labor issues.  

(credit: Daniel Slim/AFP/Getty Images)