Southwest Airlines Plans to Retire All 571 Boeing 737 Next Generation Jets by End of 2031 in Shift to All-MAX Fleet
Why It MattersThe largest 737 NG operator's phase-out ties its pace to Boeing's MAX delivery cadence and will feed a large supply of used narrowbodies to the secondary and conversion markets.
At its September 2024 Investor Day, Southwest Airlines committed to retiring all 571 Boeing 737 Next Generation (NG) aircraft by the end of 2031 in favor of an all-737 MAX fleet. Southwest operates 450 NG aircraft in active service, made up of 262 737-700s and 188 737-800s, making it the largest operator of the type worldwide. The plan is intended to cut the average age of the operating fleet from about 11.5 years to 5 years.
The airline cites efficiency and capacity as the reasons. Manufacturer projections indicated the 737 MAX 8 burns about 14% less fuel than NG aircraft, and a Southwest 737-700 seats 143 passengers in a single-class configuration versus 175 on the MAX 8. The retirements are not driven by structural limits, as many of the airframes retain substantial structural and calendar life.
The pace depends on Boeing's delivery cadence and certification timelines. Southwest retired 55 NG aircraft in 2025 (48 737-700s and 7 737-800s) while taking delivery of 55 new MAX 8s, with roughly 66 MAX deliveries and 60 retirements planned for subsequent periods. Chief Financial Officer Tom Doxey said Southwest still has more than 450 NG airframes that will be phased out gradually, well into the next decade.
The retired aircraft are expected to find demand on the secondary market among regional carriers and lessors. IBA data show operators completed 265 737-800 passenger-to-freighter conversions between January 2020 and August 2026. Southwest has also invested in cabin refurbishments for select 737-700s slated for extended service, including updated seating materials, modernized cabin lighting and refreshed bulkheads.
