Boeing faces a new obstacle to launching the 737 MAX 10

The U.S. Federal Aviation Administration (FAA) has delayed the certification of the Boeing 737 MAX 10 after discovering a problem in the flight control system software. The regulator will not approve the largest version of the MAX family until it is satisfied that the issue is resolved.

FAA Administrator Brian Bedford announced the decision. As recently as mid-September, Boeing expected to receive certification for the MAX 10 soon, but the new technical issue has changed the schedule.

The fault concerns a new version of the onboard flight control computer software. Under a certain sequence of actions during a go-around—an aborted landing—the automatic vertical navigation system VNAV may disconnect.

This scenario is possible when the aircraft is flying a precision approach with the autopilot engaged, the crew aborts the landing, and then changes the programmed route. After VNAV disconnection, the aircraft reverts to a simpler autopilot pitch mode. Boeing notes that current procedures allow pilots to control the aircraft, but the company is working on a permanent software fix.

As reported by Aviation Week, Boeing informed airlines of the issue back in August. The software is used both in the recently certified 737 MAX 7 and in the MAX 10 certification program.

The FAA is now conducting an additional evaluation of the issue. According to Bedford, MAX 10 certification will resume only after the regulator is satisfied there is no unresolved risk.

The delay is a new hurdle for Boeing, which has been seeking approval for the MAX 10 for years. This is the largest version of the 737 MAX family and one of the company's key aircraft in its competition with Airbus in the narrowbody airliner market.

Source: Air Data News, Aviation Week, Boeing