A Boeing 737 MAX sits outside the hangar during a media tour of the Boeing 737 MAX at the Boeing plant in Renton, Washington December 8, 2015.
"We're getting closer and closer," Watterson said of the certification work.
However, delays in certification have forced Southwest to convert dozens of orders for 150-seater MAX 7 aircraft into the larger 175-seater MAX 8 variant.
Both the MAX 7 and the largest model MAX 10 are waiting for the FAA's certification, with MAX 10 slated for its first delivery in 2024.
"The fact that the number of open items is converging, not diverging like it was probably a year ago, shows that they're getting closer and closer," Watterson said.
Persons:
Matt Mills McKnight, Andrew Watterson, Watterson, We're, Dave Calhoun, they're, Rajesh Kumar Singh, David Shepardson, Valerie Insinna, Diane Craft
Organizations:
Boeing, REUTERS, Rights, Southwest Airlines, U.S . Federal Aviation Administration, Reuters, FAA, Federal Aviation Administration, Airbus, Thomson
Locations:
Renton , Washington, Dallas, Southwest, Washington