Over the past few days, the airline has been forced to cancel hundreds of flights due to mechanical problems.
Southwest said there is no common theme to the issues facing its 750 airplanes.
In a statement released Tuesday, COO Mike Van de Ven said the company had "experienced an unprecedented number of out-of-service aircraft" and went on to suggest that the problems lie with employees that are members of the Aircraft Mechanics Fraternal Association (AMFA) - with whom the airline has been negotiating for six years.
According to FlightAware, Southwest Airlines canceled 186 flights on Tuesday.