Boeing 737 MAX

The Boeing 737 MAX is a series of narrow-body aircraft developed by Boeing Commercial Airplanes as the fourth generation of the Boeing 737. It succeeds the Boeing 737 Next Generation and incorporates more efficient CFM International LEAP engines, aerodynamic improvements such as split-tip winglets, and structural modifications. The program was announced in August 2011, the first flight took place in January 2016, and the aircraft was certified by the U.S. Federal Aviation Administration (FAA) in March 2017. The first delivery, a MAX 8, was made to Malindo Air in May 2017.

The 737 MAX series includes four main variants—the MAX 7, MAX 8, MAX 9, and MAX 10—with increasing fuselage length and seating capacity. Boeing also developed a high-density version, the MAX 8-200, launched by Ryanair. The aircraft typically seats 138 to 204 passengers in a two-class configuration and has a range of 3,300 to 3,850 nautical miles [nmi] (6,110 to 7,130 km; 3,800 to 4,430 mi). As of September 2025^[update], Boeing had delivered 2,005 aircraft and held orders for 4,808 more. The MAX 8 is the most widely ordered variant. As of September 2025^[update], the MAX 7 and MAX 10 had not yet received FAA certification, and the agency has not provided a timeline for their approval. Its primary competitor is the Airbus A320neo family, which occupies a similar market segment.

Two fatal accidents, Lion Air Flight 610 in October 2018 and Ethiopian Airlines Flight 302 in March 2019, led to the global grounding of the 737 MAX fleet from March 2019 to November 2020. The crashes were linked to the Maneuvering Characteristics Augmentation System (MCAS), which activated erroneously due to faulty angle of attack sensor data. Investigations revealed that Boeing had not adequately disclosed MCAS to operators and identified shortcomings in the FAA's certification process. The incidents caused significant reputational and financial damage to Boeing, including billions of dollars in legal settlements, fines, and cancelled orders.

Following modifications to the flight control software and revised pilot training protocols, the aircraft was cleared to return to service. By late 2021, most countries had lifted their grounding orders. However, the type came under renewed scrutiny after a January 2024 incident in which a door plug detached mid-flight on Alaska Airlines Flight 1282, causing a rapid decompression. The FAA temporarily grounded affected MAX 9 aircraft, and investigations raised further concerns about production quality and safety practices at Boeing.

In 2006, Boeing began to consider replacing the 737 with a "clean sheet" design that could follow the Boeing 787 Dreamliner. In June 2010, executives postponed the decision. On December 1, 2010, Boeing competitor Airbus launched the Airbus A320neo family, which offered better fuel economy and operating efficiency than the 737 NG, thanks to its engines: the LEAP from CFM International and the PW1000G from Pratt & Whitney.

In February 2011, Boeing CEO Jim McNerney said, "We're going to do a new airplane." The company had been developing a new aircraft to replace the 737 as part of its Yellowstone Project. In March 2011, Boeing CFO James A. Bell told investors that the company might re-engine the 737, but later that month Boeing Commercial Airplanes President James Albaugh said that the company was not sure about that. The Airbus A320neo gathered 667 commitments at the June 2011 Paris Air Show, bringing its order backlog to 1,029 aircraft, an order record for a new commercial airliner.

On July 20, 2011, American Airlines, which had long bought only Boeing jets, announced an order for 460 narrowbody jets including 130 A320ceo (current engine option), 130 A320neo, and 100 737NG. Officials also said they would order 100 re-engined 737s with CFM LEAP if Boeing pursued the project.

Faced with the record orders for Airbus and the defection of a long-time customer, on August 30, 2011, Boeing's board of directors approved the launch of the re-engined 737 MAX, which they said would meet or exceed the range of the Airbus A320neo while burning 4% less fuel. Studies for additional drag reduction were performed during 2011, including revised tail cone, natural laminar flow engine nacelle, and hybrid laminar flow vertical stabilizer. To focus on the re-engine project, Boeing abandoned the development of a new design under its Yellowstone Project. Firm configuration for the 737 MAX was scheduled for 2013.