"Southwest Airlines continues to monitor information from Boeing and the Federal Aviation Administration (FAA) on the impending 737 MAX software enhancements and training requirements," Southwest said. "We remain confident that, once certified by the FAA, the enhancements will support the safe operation of the MAX." A few hours later, American announced a similar move after previously grounding the plane through January 15. American said adjusted the timeframe followed "continuous contact" with the Federal Aviation Administration and Boeing. Boeing has said it expects to receive regulatory approval to resume flights in the fourth quarter of 2019, but that timeframe has started to look uncertain as the end of the year approaches. Boeing did not immediately respond to a request for comment Friday. jmb/acb