Boeing falls 4.3% on a 737 MAX software glitch; its permanent fix is currently slated for 2028

Boeing shares fell 4.3% to $189.50 on Monday afternoon, per Nasdaq, after the company confirmed a flaw in flight software on some 737 MAX jets and the Federal Aviation Administration said it would convene a Corrective Action Review Board, its standard process for deciding whether an issue is a safety concern.

The problem sits in versions 14 and 14.1 of the jet's flight management computer software. If a crew aborts a landing and then changes the programmed flight path, the automated vertical navigation mode can drop out and fall back to a simpler mode, leaving pilots to manage altitude limits themselves, Aviation Week reported. Boeing says it is not a safety concern, the autopilot keeps working, and pilots are trained to land without that mode. The Wall Street Journal first reported the issue.

What the headline gets wrong

"Software glitch on the 737 MAX" reads like a problem with the planes in the air. For the biggest U.S. operators it is not. Alaska, American, Southwest and United each said none of their in-service MAX jets use the affected software, according to CBS reporting summarized by Airways. Boeing told Airways it had no aircraft figures to share, so how many undelivered jets carry the software, or whether any airline outside the U.S. flies with it, is not known.

The exposure is in the new jets, which is where the stock is priced. Southwest and United have asked Boeing not to deliver aircraft with the flawed software and would take ones with an earlier version instead, Aviation Week reported.

The numbers behind the drop

2028. Boeing told Airways it "anticipates the next software update in 2028" and is trying to accelerate that. Until then, it is working with airlines on a procedure to let pilots turn the automated mode back on.

The 737-7. The FAA certified the smallest MAX on Aug. 3 with version 14 of the software. Southwest accounts for nearly all of its order book and had been set to start taking it this fall, Airways reported, citing CBS. It is not yet clear whether it can be delivered with older software.

The 737-10. The largest MAX flew its certification testing on version 14.1. Alaska, which has 105 on order and options for 35 more, said last week it expected FAA approval by the end of September. As we reported, the 737-10 is about 31% of Boeing's 737 backlog, so the timing of that approval touches a large share of Boeing's future 737 deliveries. The FAA's statement did not say whether the review board must finish first.

Nearly two years. An airline first flagged the condition to Boeing in November 2024, and Boeing concluded in February 2025 that it was not a safety issue, Airways reported, citing CBS. New information from operators this year led to a formal safety review, whose findings went to the FAA this month, FLYING reported.

What traders are watching

Three things: whether the FAA's review board delays the 737-10 sign-off, whether Southwest takes 737-7s on older software this fall, and whether Boeing pulls the 2028 fix forward. The stock's 52-week range is $176.77 to $254.35, so Monday's move leaves it about 7% above the low. Separately, voting by Boeing's SPEEA engineers on a revised contract closes on Oct. 1.

Sources: Aviation Week; Airways; FLYING; Nasdaq. This is market information, not investment advice.