A war of words erupted Tuesday night between Southwest Airlines and the carrier's mechanics union, reports CBS Dallas. The dueling statements came after Southwest said it cancelled about 180 of its 4,000 flights Tuesday, with more than twice the number of aircraft as usual being taken out of service for maintenance.
The airline said weather was also to blame, but much of the focus has been on maintenance.
According to a Southwest spokesperson, up to 20 of its 750 aircraft are normally out of service each day for unscheduled repairs. But Tuesday, she said, that number more than doubled.
In a statement to CBS News correspondent Kris Van Cleave, Southwest COO Mike Van de Ven had strong words for the Aircraft Mechanics Fraternal Association, saying, "AMFA has a history of work disruptions, and Southwest has two pending lawsuits against the union. We will be investigating this current disruption and exploring all possible remedies."
Southwest and AMFA have been locked in tense contract negotiations.
Related: Southwest Airlines Faces An 'Operational Emergency'
The union countered in a statement of its own, saying, "Southwest Airline's scapegoating of its expert Aircraft Maintenance Technicians does not bode well for the airline's safe operations. 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."
"The FAA has condemned the carrier's 'capitulation of airworthiness' and Southwest has confessed that it has flown passengers in unairworthy aircraft. These glaring issues and the widespread pressuring of aircraft maintenance technicians by the airline were exposed in the recent CBS News report. "
That report revealed that some of the airline's mechanics felt pressured to return jets to service faster.
The uptick in maintenance write-ups for aircraft began last Friday.
The mechanics union and airline have been negotiating a new contract for six-and-a-half years, but union members said this issue is separate from aircraft maintenance.
Since Friday, the airline has declared a State of Operational Emergency at various maintenance stations to make sure mechanics scheduled to work come in so they can return planes to service as soon as possible.
The airline has described the situation as "all hands on deck."
On Tuesday, the company included its Dallas maintenance station.
CBS News obtained a letter to the mechanics from a senior director of the airline's tech operations. It said he was "declaring Dallas in a State of Operational Emergency effective 10:00 a.m. Central. … This is not the type of communication I (or any Leader) want to issue, but it is necessary to get our aircraft back in service in order to serve our Customers."
The mechanics union isn't happy that the letter threatened termination.
In response, AMFA National Director Bret Oestreich said, "I again have never heard of State of Operational Emergency in 28 years in aviation EVER."
Oestreich said after two incidents last year involving uncontained engine failures, the airline ordered numerous inspections of its engines.
Oestreich said, "AMFA Aircraft Technicians and Inspectors completed roughly 9,000… engine fan blade inspections in 30 days… (there was no State of Operational Emergency)."