United Airlines will retire 80 older, less fuel-efficient narrowbody aircraft in 2027 as it prepares for first Boeing 737 MAX 10 deliveries mid-to-late that year. The carrier expects to take up to 20 MAX 10s in 2027, with 147 more on order, replacing legacy narrowbodies on high-density trunk routes where the MAX 10’s 230-seat capacity boosts gauge and margins. Boeing’s MAX 10 flight tests are 98% complete, anti-ice fixes finalized, and FAA certification targeted for 2026, enabling 2027 entry into service. This fleet reduction supports a broader cabin refresh aimed at cutting costs and improving operational efficiency across United’s short- and medium-haul network.