A Southwest spokesperson said of the carrier's aircraft maintenance policies: "The provider at the San Salvador airport is an experienced Boeing 737 maintenance and overhaul work (provider) and has done past work for us (in the same location). Southwest employees supervise outsourced work that mirrors our Federal Aviation Administration (FAA)-approved maintenance program."

The spokesperson also said that the carrier continually evaluates maintenance providers "to reduce the risk associated with shortages of mechanics, to provide flexibility in heavy maintenance work planned across the coming years and to control costs."