FAA halts 737 MAX 10 certification over software fault

The US Federal Aviation Administration has put certification of the Boeing 737 MAX 10 on hold because of a software problem on some 737 MAX aircraft. The agency said it will not sign off on the largest variant in the MAX family until it is satisfied the fault has been corrected. No new date for certification has been given.

The issue can occur during a go-around, when a landing is abandoned and the aircraft climbs away. In one scenario that involves a change to the intended flight path, the software may stop the crew from using automated vertical guidance. Pilots still fly the aircraft manually, but the FAA said the situation could add to their workload at a busy point in the flight.

Boeing said it has told operators about the problem and is working on a permanent software fix. The FAA will hold a Corrective Action Review Board to decide whether the fault is an unacceptable safety risk and whether anything further is needed for aircraft already in service. How many aircraft are affected has not been made public.

Airlines have given different accounts. WestJet said it has seen no related event in service and that its procedures and training cover the situation. United Airlines said none of its current aircraft uses the affected software and that it is turning down deliveries fitted with that version while the review continues. Alaska Airlines said its aircraft do not use the software either.

The result is new uncertainty over the MAX 10's certification timeline.