The FAA will delay approval of the Boeing 737 MAX 10 after engineers identified a new software glitch in the aircraft, according to a report by The Wall Street Journal. The finding pushes back certification of the largest variant in the MAX family at a moment when Boeing is counting on the model to defend its position in the narrowbody market against the Airbus A321neo.

The 737 MAX 10 remains the only MAX variant still without FAA certification. The MAX 7, the other uncertified member of the family, faces its own timeline pressure under a US statutory deadline requiring modern cockpit-alerting systems by the end of 2022 — a deadline Congress subsequently extended, with conditions, to include aircraft certified by mid-2030 or so, contingent on flight tests beginning before the end of 2022. The MAX 10's certification path has therefore been tied directly to that legislative clock, and any additional software-related delay compresses the remaining schedule margin.

The nature of the software glitch reported by the Journal bears directly on the certification standard Boeing must now meet. Under the provisions attached to the 2020 legislation that extended the deadline, new deliveries of MAX 7 and MAX 10 aircraft must incorporate an enhanced engine-indication and crew-alerting system (EICAS). Installing that system in the MAX 10 forced Boeing into a broader redesign of the flight deck's software architecture than originally planned, and the resulting rework has been a recurring source of schedule slippage.

The certification delay carries measurable commercial consequences. The MAX 10 holds a substantial share of Boeing's MAX backlog, with commitments from carriers including United Airlines, Delta Air Lines, Alaska Airlines, and lessors such as Avolon. United, the largest MAX 10 customer, has repeatedly warned it will begin substituting A321neos for MAX 10 orders if certification continues to slip, and the airline's fleet planning now assumes meaningful MAX 10 deliveries arrive later than Boeing's official guidance. Each quarter of delay shifts delivery slots for an aircraft that competes in the most demanded segment of the single-aisle market.

For Boeing, the setback lands amid a broader effort to stabilize 737 production output following the January 2024 Alaska Airlines door-plug accident and the ensuing FAA cap on MAX production rates. Certification of the MAX 10 does not by itself raise that cap, but each new technical finding adds to the certification workload the FAA and Boeing must clear before the program can convert backlog into deliveries.

The FAA's position also signals how the agency now treats Boeing certification programs in the wake of the MAX grounding. Regulators have said they will take whatever time is required to complete detailed reviews, and delegations of certification authority to Boeing have been curtailed since 2019. A software fault serious enough to hold up approval, rather than being resolved through routine rectification, indicates the issue touches systems within the amended compliance basis for the type certificate.

Boeing has not publicly revised its MAX 10 entry-into-service guidance in response to the reported finding, and the FAA declines to discuss open certification items in detail. The carrier implications now hinge on how quickly Boeing can resolve the software issue and demonstrate compliance: until the glitch is fixed and verified, the largest MAX remains uncertified, un-delivered, and exposed to further substitution by the A321neo in carrier fleet plans.