Boeing 737 MAX 10 Delay: Software Glitch Explained

A known problem, a fresh crisis

Boeing shares fell nearly 7% on September 28 after the head of the Federal Aviation Administration said a software problem would delay certification of the 737 MAX 10, the largest and still-uncertified member of the MAX family, while regulators assess whether the issue poses a safety risk. The drop, confirmed by CNBC's market coverage, came the same day multiple outlets — NBC News, CBS News and Aviation Week among them — detailed a flight-management-computer glitch already affecting in-service 737 MAX 8 and MAX 9 jets, the variants Boeing has been delivering for years.

The core issue: Boeing has acknowledged it identified the glitch in November 2024, nearly two years before it became public, and did not treat it as a safety concern requiring disclosure to airlines at the time, according to reporting cited by Simple Flying and separately corroborated by CBS News' account of the FAA's ongoing investigation. Airlines were only notified of the problem last month, and it took the pending MAX 10 certification decision to bring it into public view.

What actually goes wrong in the cockpit

The glitch lives in versions 14 and 14.1 of the operating software for the 737 MAX's flight management computer, according to details reported by Airways Magazine and NBC News. It can surface in a specific, narrow scenario: a flight crew executes a missed approach — an aborted landing — and then alters the preprogrammed flight path during the go-around. In that sequence, the flight guidance system can incorrectly drop out of VNAV, the automated vertical navigation mode that manages the aircraft's climb and descent profile, and fall back to a simpler, more basic level of automation for pitch control. Pilots would still be flying the airplane, but with less automated support than the system is designed to normally provide during that phase of flight.

The FAA has been careful in its public language not to declare the issue an unambiguous safety emergency while the review is underway. In a statement carried by NBC News, the agency said it was aware of "a potential issue in a software update for the flight computers on certain Boeing 737 MAX airplanes," that it is "working closely with Boeing and the airlines," and that it "will convene a Corrective Action Review Board and will take immediate action if it identifies a safety concern." That measured framing hasn't stopped the story from becoming a fresh flashpoint for a company still working to rebuild regulatory trust after years of MAX-related scrutiny.

Airlines are already pushing back on deliveries

The practical fallout showed up first with Boeing's own customers. According to Aviation A2Z, United Airlines and Southwest Airlines — two of the largest 737 MAX operators in the world — have asked Boeing to hold back deliveries of new MAX jets built with the affected software version, effectively asking for aircraft running older, unaffected software instead while the fix is sorted out. That's a notable request: it signals that at least some major carriers are not satisfied with Boeing's original timeline for addressing the problem and are unwilling to accept newly built aircraft carrying it in the meantime.

That original timeline was itself part of what triggered the broader reaction. Boeing's initial service bulletin reportedly told airlines a permanent software fix wouldn't be ready until 2028, with updated interim pilot-procedure guidance not expected until November, according to Aviation Week and Hoodline. Facing pressure, Boeing says it is now working to accelerate both timelines, though no revised dates were confirmed publicly as of this writing.

How the flight-guidance software issue unfolds during a missed approach

Why the MAX 10 is the pressure point

The 737 MAX 10 is the largest variant in Boeing's single-aisle family and the one still awaiting FAA type certification, years after the smaller MAX 8 and MAX 9 entered service on roughly the same production-line architecture. Any flight-computer software issue affecting the certified variants inevitably becomes a certification question for the MAX 10, since it shares the same core flight management system. FAA leadership's comments, reported by CNBC, made clear the agency will not sign off on the MAX 10 until it has assessed whether this glitch constitutes a certifiable safety issue across the family — a decision that could resolve quickly if the fix is straightforward, or drag the timeline out further if regulators want a validated permanent fix first.

The MAX 10 has already been one of the more delayed programs in Boeing's recent history, slipping past several previously targeted certification windows for reasons ranging from engine anti-ice questions to broader post-MCAS regulatory scrutiny. This latest software issue adds another variable to a process that airlines including United and Delta have been waiting years to see completed, since the MAX 10's higher seat count is central to some carriers' fleet renewal plans.

The disclosure timeline is the part regulators will scrutinize hardest

Separate from the technical fix itself, the nearly two-year gap between Boeing identifying the glitch internally in November 2024 and notifying airlines last month is likely to draw its own scrutiny. Boeing's position, as relayed by Simple Flying and Aviation Week, is that the issue wasn't initially assessed as a safety-of-flight concern warranting immediate disclosure — a judgment call regulators and airlines are now effectively second-guessing given how the FAA has responded since learning of it. For a company still under heightened FAA oversight following the January 2024 Alaska Airlines door-plug blowout, any suggestion that a known flight-guidance defect sat undisclosed for close to two years is a reputational problem independent of the eventual technical fix.

What to watch next

Three things will determine how this plays out. First, whether the FAA's Corrective Action Review Board concludes the glitch is a genuine safety issue requiring mandatory airworthiness directives across the in-service MAX 8 and MAX 9 fleet, rather than a procedural fix handled through updated pilot guidance alone. Second, whether Boeing can meaningfully accelerate its 2028 permanent-fix timeline, and what interim mitigation — likely revised pilot procedures for handling flight-path changes during a missed approach — gets published before then. Third, whether United and Southwest's request to receive jets with older software becomes a broader industry standard among MAX operators, which would complicate Boeing's production and delivery scheduling heading into 2027.

None of the current reporting indicates any in-service incident where the glitch caused an actual loss of control or accident; the concern, as described by the FAA and by outlets including CBS News and Deccan Herald, is about a documented reduction in automation during a specific, narrow flight scenario rather than a reported crash or near-miss tied directly to the software. That distinction matters for how urgently regulators are likely to move, even as it does nothing to quiet questions about why the issue took nearly two years to reach the public.

The stock reaction and what it signals

The nearly 7% single-day drop in Boeing shares on September 28, confirmed by CNBC's market coverage, is a meaningful reaction for a company whose stock had spent much of 2026 recovering from the deeper damage of the 2024 door-plug crisis and the subsequent machinists' strikes. Investors have grown sensitive to anything touching Boeing's certification timelines, since delays translate directly into deferred revenue: airlines that ordered the MAX 10 have built fleet plans and pilot-training schedules around delivery windows that have already slipped multiple times. Any further delay compounds the disruption for those carriers, particularly operators counting on the MAX 10's higher seat count to replace older, smaller narrowbodies as they retire.

Market reaction aside, the episode lands at a delicate moment for Boeing's relationship with the FAA. The agency has operated under a more hands-on oversight posture toward Boeing since the January 2024 Alaska Airlines door-plug incident, including tighter limits on production rates at the Renton factory that builds the 737 family. A newly surfaced, previously undisclosed software issue — even one framed by Boeing as not safety-critical at the time it was found — gives regulators fresh grounds to extend rather than ease that oversight, regardless of how quickly the underlying fix is validated.

How this compares with past MAX software issues

The 737 MAX's history makes any flight-computer software problem an unusually loaded topic. The MCAS flight-control software at the center of the 2018 and 2019 Lion Air and Ethiopian Airlines crashes was also a case where a system behaved in ways pilots weren't fully briefed on, though the current landing-guidance glitch is a materially different failure mode — a loss of a convenience-level automation feature during a specific go-around scenario, not an erroneous flight-control input actively fighting the pilots. Coverage this week has been careful to draw that distinction: the current issue, as understood so far, requires pilots to revert to manual pitch control rather than override an actively malfunctioning system. Even so, the fact that Boeing sat on the finding for close to two years before flagging it is likely to reinforce, rather than dispel, the scrutiny the company has faced over its internal safety reporting culture since 2019.

The bigger picture for Boeing's roadmap

The MAX 10 was already central to Boeing's plan to close the delivery gap with Airbus, which has held a consistent lead in year-to-date deliveries through August 2026. Any additional slip in MAX 10 certification pushes that competitive gap further out, at a time when Boeing has been trying to demonstrate to both investors and regulators that its production and quality systems have stabilized. How quickly the company converts its promise to accelerate the software fix and interim pilot guidance into an actual FAA sign-off will be one of the clearest tests yet of whether that stabilization is real.

Boeing's 737 MAX 10 Certification Slips Again as a Two-Year-Old Software Glitch Surfaces on In-Service Jets