In the United States, Southwest Airlines and American Airlines have 59 of the planes between their two fleets, with 304 on order. Southwest said it has been in touch with Boeing and plans to follow the investigation. It had not made any changes to its operations or inspection protocol as of Sunday, the airline said. American Airlines said it was monitoring the investigation but remained confident in the safety of its aircraft.

Source: Los Angeles Times March 11, 2019 14:55 UTC