“If it’s not Boeing, I’m not going,” reads the popular slogan for many fans of the Chicago-based planemaker.Boeing loyalists who follow that mantra can continue flying Southwest well into the next decade, as the airline announced a massive order for additional Boeing 737 MAX aircraft on Monday.To start, Southwest will accelerate the retirement of the legacy Boeing 737-700 aircraft, and replace it with 100 next-generation 737 MAX 7 planes. The carrier is slated to become the launch carrier for the MAX 7 variant of Boeing’s beleaguered jet, with the first 30 scheduled to be delivered in 2022.Want more airline-specific news? Sign up for TPG’s free new biweekly Aviation newsletter!Monday’s announcement also includes an additional 155 options for more MAX 7 or MAX 8 aircraft from 2022 to 2029, depending on demand and growth opportunities throughout the decade. The announcement gives Southwest a total of:349 MAX firm orders (200 MAX 7 and 149 MAX 8)270 MAX options for MAX 7 or MAX 8 aircraft for years 2021 through 2031Southwest CEO Gary Kelly said in a statement that “Southwest Airlines has been operating the Boeing 737 series for nearly 50 years, and the aircraft has made significant contributions to our unparalleled success. Today’s commitment to the 737 MAX solidifies our continued appreciation for the aircraft and confirms our plans to offer the Boeing 737 series of aircraft to our Employees and Customers for years to come.“Of the MAXes operated in the U.S., Southwest offers one of the more comfortable onboard experiences. American Airlines has crammed up to 172 seats in its densified MAX 8 jets, and many flyers complain about the tight coach configuration, with 30 inches of pitch.On the other hand, Southwest fits 175 seats on its MAX 8 — but it’s in an all-coach arrangement with 32 to 33 inches of pitch.MAX is back: Southwest has no plans to rebrand the Boeing 737 MAXSign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.Southwest’s confidence in the MAX is a big boost to Boeing, following the plane’s nearly two-year grounding after two fatal crashes that took 346 lives. The crashes were largely blamed on faulty sensors and the flight-control management software.To recertify the MAX, all jets must undergo a four-hour software update to the automated flight control system, dubbed the “MCAS” or maneuvering characteristics augmentation system. Additionally, all pilots must complete a two-hour simulator-based training exercise that runs through all types of emergencies, including a stall, runaway trim, go-around, incorrect angle-of-attack reading and more.More: A pilot and mechanic explain what’s needed to bring the 737 MAX backSouthwest became the last U.S. carrier to restart flying the MAX on March 11, following American Airlines in December 2020, United Airlines in February 2021 and Alaska Airlines on March 1.But Southwest’s move doesn’t just bolster confidence in the MAX. It’s also a big win for Boeing — Southwest has historically had an all-Boeing fleet.However, in recent months, the airline was reportedly in talks with Boeing’s arch-rival, Airbus for possible 737 replacements, including the Airbus A220. Of course, those discussions could have been part of a broader effort to secure a better deal with Boeing. Whatever the case, Boeing ultimately won.“We are proud to continue our tradition of being the world’s largest operator of an all-Boeing fleet,” Kelly’s statement concluded.