FAA finds Boeing 737 MAX software glitch poses no safety risk

FAA determination

The FAA’s Corrective Action Review Board determined that the software glitch on some Boeing 737 MAX aircraft poses no safety risk. The board’s assessment was based on pilots retaining full control and receiving clear, unambiguous indications during the event.

Glitch description

The glitch affects MAX aircraft using a certain version of the flight software and occurs when a pilot alters the preprogrammed flight path. It causes the aircraft to switch from vertical navigation mode to a simpler level of automation, requiring pilots to manually perform extra steps for landing on the next approach.

WestJet first flagged the issue during an entry‑into‑service test flight, noting that vertical navigation mode disengaged during approach. WestJet uses the affected software version U14.1 and has received no reports of the condition during normal line operations.

Impact on MAX 10 certification

The FAA said it is delaying certification of the MAX 10 until it completes an analysis of the software issue. The agency believes the MAX 10 could be certified as soon as later this month, in line with earlier expectations.

The FAA has not yet cleared the MAX 10 for passenger flight.

Boeing response

Boeing notified operators of the issue in August, and the FAA said on September 26 it would study whether the software glitch posed a safety concern. The FAA said it would consider appropriate action if it receives new information about the issue.