Southwest & United Airlines Won’t Accept New Boeing 737 MAX Aircraft With Affected Software

Key Points:

• Southwest Airlines and United Airlines have refused to accept new Boeing 737 MAX aircraft equipped with a recently identified flight-management-computer (FMC) software issue that can cause automated vertical navigation (VNAV) to disengage during specific missed-approach scenarios.
• The problematic software versions 14 and 14.1 affect certain 737 MAX models, including the MAX 7 and MAX 10, but existing MAX fleets operated by these airlines do not have these versions installed.
• Boeing considers the issue not an immediate safety threat and has issued guidance reinforcing pilot procedures while developing a permanent software fix; the FAA is currently reviewing the problem through a Corrective Action Review Board (CARB).
• The software issue complicates delivery plans for new MAX aircraft, particularly impacting Southwest's MAX 7 orders and potentially delaying FAA certification of the MAX 10, which had been expected soon.
• Boeing aims to release a software update by 2028 but is working to accelerate this timeline based on operator feedback, with the FAA's review outcome determining any required corrective actions.