Boeing Knew About New 737 MAX Software Glitch For Nearly Two Years—United And Southwest Won’t Accept Aircraft With It

Boeing reportedly knew about a 737 MAX software problem for nearly two years before notifying operators last month. Now Southwest and United want newly delivered aircraft to have the older software instead. That news came as the Boeing 737 MAX 10 is awaiting final FAA signoff, and the agency says they will defer that as a result. Certification was believed to literally be days away. After a missed approach, the pilot changes the programmed flight path. The flight management software can then incorrectly switch vertical navigation, or VNAV, to a simpler automation mode such as vertical speed or level change. The crew may need to use those modes or fly manually. Boeing says pilots are trained to handle the situation safely. It’s developing both a software correction and a procedure to restore VNAV. This matters because a go-around already involves changing the aircraft’s flight path and preparing for another approach. An unexpected automation change adds something for the crew to recognize and manage at a crucial stage of flight. What’s striking is that Boeing discovered the glitch two years ago and it’s just now coming to light. November 2024: Boeing learned of the glitch, initially determining that it didn’t meet the criteria for a safety review. Late August 2026: Airlines operating the aircraft were notified. September: Further airline feedback prompted a formal review, with findings shared with the FAA. The story became public September 26. Early 2028: Initial target for a permanent software fix. Boeing is trying to accelerate that. The FAA says it will convene a Corrective Action Review Board and act immediately if it identifies a safety concern. Boeing’s position is that existing procedures allow safe operation. Southwest and United are willing to accept aircraft using the previous software. They aren’t refusing to take new MAXs. But they aren’t willing to take them with the current software. American, Alaska, Southwest and United all fly 737 MAXs but not yet with the affected software.