FAA rules 737 FMS software safe and unblocks 737 Max 10

An FAA panel has determined that an FMS software anomaly on the Boeing 737 does not constitute an unsafe condition, lifting earlier certification delays for the 737 Max 10. FAA head Bryan Bedford had initially announced a hold on the largest variant to evaluate the issue.

The glitch affects FMS software releases U14.0 and U14.1. Following a missed approach, vertical navigation (VNAV) can disengage during the subsequent approach under specific conditions. When this occurs, pitch control reverts to a basic automation mode. The FAA stated that flight crews retain aircraft control and receive clear system status indications.

A Special Airworthiness Information Bulletin published on October 3 indicates the behavior affects both 737 NG models (-600, -700, -800, -900, -900ER) and 737 Max variants (Max 7, 8, 9, 8200). The FAA does not deem an AD necessary at this stage, advising operators to apply operational procedures issued by Boeing.

Several US carriers have avoided U14 and U14.1 for years due to reported functional degradations and flight crew workload during critical phases. In 2022, a U14 software glitch contributed to a United Airlines flight landing on an incorrect runway, prompting the airline to revert to software introduced nearly a decade ago.