The Southwest Airlines order on 13 December launching the 737 Max programme is a launch of the -8 version. The carrier, which has substitution rights between the -7 and the -8, has chosen to bypass the -7 for now.
Brian Hirshman, SVP Technical Operations, told Flightglobal Pro on 15 December that the carrier is up-gauging its fleet, which it began doing this year with acquisition of the 737-800 for the first time. Southwest, throughout its history since is 1971 birth, has relied on the 737-200/300/500/700, preferring smaller sized aircraft and high frequency as its business model.