Southwest Airlines

Southwest Airlines is conducting an internal investigation into an incident where a pilot signed off with the phrase "Let's go, Brandon," which conservatives are using to insult President Biden. Morry Gash/AP hide caption

Passengers board a Southwest Airlines airplane at Hollywood Burbank Airport in Burbank, California on October 10, 2021. The airline has continued to cancel or delay hundreds of flights on Monday. Robyn Beck/AFP via Getty Images hide caption

A systemwide outage Monday night affected Southwest Airlines flights across the country. Scott Olson/Getty Images hide caption

A man wearing a mask prepares to board a Southwest Airlines flight at Kansas City International airport in Kansas City, Mo. Southwest and American Airlines are tightening their mask requirements at the end of July by doing away with exemptions for travelers over the age of 2. Charlie Riedel/AP hide caption

All Boeing 737 Max aircraft are grounded while the manufacturer fixes a deadly defect in their flight control system. These Southwest Airlines planes were parked in Victorville, Calif., in March. Mark Ralston/AFP/Getty Images hide caption

A Southwest Airlines Boeing 737 Max lands in Victorville, Calif., in March. Matt Hartman/AP hide caption

Southwest Airlines was among the airlines affected by a contractor's computer outage Monday, forcing hundreds of flights to be delayed. Leah Millis/Reuters hide caption

Southwest Airlines passengers check in at New York's LaGuardia Airport. The Federal Aviation Administration on Wednesday issued an emergency order grounding Boeing 737 Max jets in the wake of the crash of an Ethiopian airliner. Richard Drew/AP hide caption

Last week, Southwest took more than 40 of some 750 aircraft out of service at four locations, spurring flight delays and cancellations. Ted S. Warren/AP hide caption

A Southwest plane taxis at the Seattle-Tacoma International Airport in Seattle. Ted S. Warren/AP hide caption

A crack is seen on a window of Southwest Airlines Flight 957 after an abrupt landing in Cleveland on Wednesday. Rachel Colby/AP hide caption

National Transportation Safety Board investigators examine damage to Southwest Airlines Flight 1380, which left one passenger dead and other injured on April 17. A passenger filed a lawsuit against the airline on Thursday. Handout/Getty Images hide caption

National Transportation Safety Board investigators examine damage to the engine of the Southwest Airlines plane that made an emergency landing at Philadelphia International Airport in Philadelphia on Tuesday. AP hide caption

House Transportation and Infrastructure Committee ranking member Peter DeFazio, D-Ore., questions witnesses Tuesday during a hearing about about oversight of U.S. airline customer service. Chip Somodevilla/Getty Images hide caption