Boeing 737 MAX 9

The Boeing 737 MAX 9 is a narrow-body, single-aisle commercial jetliner and the second-largest member of the 737 MAX family. It is a direct successor to the 737-900ER, featuring CFM International LEAP-1B engines, advanced winglets, and airframe improvements that deliver significant fuel efficiency gains over previous-generation 737s. The MAX 9 entered service in 2018 and is optimized for medium- to long-haul routes within the narrow-body segment. It can seat up to approximately 220 passengers in a high-density single-class layout, though typical two-class configurations accommodate around 178 passengers. The 737 MAX family, including the MAX 9, was grounded globally between March 2019 and late 2020 following two fatal crashes of the smaller MAX 8 variant linked to the MCAS flight control system. The MAX 9 faced additional scrutiny in January 2024 when a door plug blew out on an Alaska Airlines flight, prompting a temporary grounding of MAX 9 aircraft and subsequent inspections.