Alaska Airlines Gives Boeing a Big Order With an Eye to Expansion

Alaska Airlines, the fifth-largest passenger airline in the United States, said on Wednesday that it would buy dozens more Boeing planes in the coming years as it aims to rapidly expand its fleet and convert it to a single aircraft family.

The airline plans to buy 52 Boeing 737 Max planes through 2026, in addition to 94 already on order. The planes are a mix of the Max 9 and Max 10 variants and will help Alaska achieve its goal of becoming an all-737 operator by the end of next year. The airline also has an option to buy 105 more planes by the end of the decade.

“This is the biggest fleet announcement in Alaska’s history,” said Nat Pieper, an Alaska executive who oversees fleet and airline alliance strategy. “This deal with Boeing ensures access for us for sufficient aircraft through 2030 for our replacement needs, and for our growth levels that we anticipate achieving in that time.”

Flying a single type of plane yields benefits to airlines, making it easier to reassign pilots, swap planes and maintain a uniform inventory of parts. Alaska expects to save about $75 million to $100 million annually from the simplification of its fleet, Mr. Pieper said. Southwest Airlines, the nation’s third-largest carrier, also operates an all-737 fleet.

Alaska’s order comes as its position in the industry is under threat. JetBlue Airways, the sixth-largest domestic airline, plans to buy Spirit Airlines. If that deal goes through, JetBlue would easily leapfrog Alaska in market share, though it is unlikely to immediately threaten Alaska’s strength on the West Coast.

The new Max jets will allow Alaska to expand its hold there while also adding more transcontinental service, Mr. Pieper said. The Max 8 variant has fewer seats than the Max 9, but more range, making it well suited to longer flights, such as those between the West Coast and Hawaii, he said. The Max 10 has the most seats, optimal for heavily trafficked routes.

Alaska and Boeing share a strong bond: Alaska is headquartered in Seattle, where Boeing produces the Max and other planes. The airline had previously flown only Boeing aircraft, but acquired dozens of planes produced by Airbus, Boeing’s rival, when it bought Virgin America in 2016. Alaska said it expected to replace those Airbus planes with Boeings by the end of next year, an example of how long it can take to finalize airline mergers and acquisitions.

Alaska’s regional subsidiary, Horizon Air, uses dozens of jets made by Embraer and…