The Federal Aviation Administration is investigating a Boeing 737 Max software glitch that could remove access to part of the aircraft’s automated flight guidance during an aborted landing.
The issue can arise in a rare missed-approach scenario when a pilot is using the autopilot on a precision approach and alters the pre-programmed flight plan. It affects versions 14 and 14.1 of the flight management computer operating system.
Under those circumstances, the aircraft’s vertical navigation system, known as VNAV, may disengage. VNAV is designed to maintain the planned altitude at different waypoints along a flight path.
The autopilot would continue to operate, Boeing said, but pilots would need to take additional steps during the subsequent approach. The situation would typically occur at low altitude, near an airport, when the cockpit crew was already facing a high workload.
“Last month, we informed all 737 operators about a software issue where pilots may not have access to automated flight guidance during a specific landing scenario,” a Boeing spokesman said. “We shared information with operators that reinforced existing pilot procedures for safely handling such cases. Our engineers are working on a software update to permanently address the issue.”
Boeing has told airlines the glitch is not an immediate safety concern and said pilots are trained to land safely without VNAV. One airline source questioned whether the issue could create an unwelcome distraction during a critical phase of flight, asking: “How busy do you want your crew to be? Are you introducing distractions at the worst possible moment?”
The FAA said it was working with Boeing and the airlines and would convene a Corrective Action Review Board. The regulator said it would take immediate action if the review identified a safety concern.
Southwest Airlines and United Airlines have told Boeing they will not accept new aircraft fitted with the affected operating system, choosing an earlier version instead. Alaska Airlines, American Airlines, Southwest and United said their aircraft already in service do not use the software version in question.
Boeing was first notified of the problem by an airline in November 2024. After reviewing it, the company concluded in February 2025 that it was not a safety issue, but further information from operators later prompted a formal safety review.
The findings have been sent to the FAA for consideration by its review board. Boeing’s original bulletin said a software fix would be available in 2028, with updated pilot procedures due in November, although the manufacturer is now working to bring forward both measures.
The investigation could further delay certification of the 737 Max 10, the largest version of the aircraft, and deliveries of the recently certified 737 Max 7. The Max 7 was certified with software version 14, while the Max 10 used version 14.1 during certification testing.
The 737 Max remains central to Boeing’s recovery efforts. The aircraft was involved in two crashes in 2018 and 2019 that killed 346 people after defective software was identified, and a mid-flight door-panel blowout on an Alaska Airlines flight in January 2024 was blamed on manufacturing errors.
