FAA suggests changes for grounded Boeing 737 MAX

The US Federal Aviation Administration (FAA) has suggested four key design changes to the Boeing 737 MAX jet to allow it to resolve security issues and return to service.

The aviation authority said on Monday that it had requested for changes to flight-control software and flight-crew operating procedures, among other things. The FAA has also proposed a sensor system test and "operational readiness" flight before the planes return to operation.

Boeing responded by saying that it was "continuing to make steady progress towards the safe return to service, working closely with the FAA and other global regulators."

Scrutiny on a software system

The changes are mainly directed towards preventing the unwanted activation of software designed to control the aircraft's pitch (the angle of the nose in flight) called MCAS (Maneuvering Characteristics Augmentation System).

Not only will the system be directed by a pair of sensors in future, rather than just one, an alert system should also be devised to warn pilots of potential problems with those censors. The FAA also proposes that operators check the systems before departure to identify possible issues.

The FAA said that these changes should all combine to minimize "dependence on pilot action and the effect of any potential single failure."

In the 2018 and 2019 crashes that led to the 737 MAX being grounded, the MCAS system had mistakenly activated and pushed the plane's nose down in response to a single misfiring sensor, with pilots unable to override the corrections.

Boeing now has to collect public comments on the changes for 45 days and finalize new pilot-training procedures. Other regulators, for instance in Canada and Europe, may also have their own concerns or requirements before allowing the plane back into the skies.

The US company had earlier said that it expected the 737 MAX to be recertified in time to resume deliveries sometime during the third quarter in 2020.  Boeing had resumed production of the 737 MAX earlier this year. The company planned to ramp up production of the jetliner this year and start deliveries by October.

The more than 18 months with the 737 MAX — briefly Boeing's best-selling aircraft — grounded is estimated to have cost the US planemaker more than $19 billion (roughly €16 billion), while Boeing still faces criminal and congressional investigations into two plane crashes that claimed 346 lives.

am/msh (Reuters, AP)