FAA Highlights Boeing 737 Vertical Navigation Software Issue

The FAA has detailed a software issue affecting Boeing 737 vertical navigation, advising operators to follow Boeing's guidance.

The Federal Aviation Administration (FAA) has issued a safety information bulletin regarding a flight-management software issue affecting vertical navigation on Boeing 737 aircraft. This advisory concerns older 737 models from the -600 series upwards, including all certified 737 Max variants. The issue involves an error in flight-management computer software versions U14 or U14.1, impacting missed approaches that navigate to non-associated waypoints. This situation can cause a switch from vertical navigation (VNAV) mode to a simpler automation level for pitch control. Pilots aiming to use VNAV for subsequent approaches need to perform additional procedural steps. While the FAA advises following Boeing's guidance, it does not mandate operator action, as both Boeing and the FAA have determined the issue does not pose an unsafe condition. This information was reported by FlightGlobal.