The Boeing Co. and the U.S. Federal Aviation Administration began a three-day series of recertification test flights for the updated 737 MAX passenger jet on Monday in Seattle, a long-anticipated step in the effort to bring Boeing's best-selling aircraft back into service after two fatal crashes that prompted the FAA to ground the series and Boeing to halt deliveries.
The 737 MAX is a twin-engine, narrow-body aircraft that Boeing introduced in 2017. After the crashes in October 2018 and March 2109 killed 346 passengers and crew members, it was concluded that the flight-control software (Maneuvering Characteristics Augmentation System, or MCAS) prevented pilots from overriding a movement that accelerated the jets toward the ground — in an effort to prevent engine stalling on takeoff.
Boeing has revised the MCAS, which is the focus of the test flights.
On the first day of testing Boeing pilots together with pilots selected by FAA put a 737 MAX 7 flight-test jet through a series of maneuvers meant to evaluate the MCAS through severe angles of incline and decline, as well as banks, according to local reports.
The FAA is using the certification flights to determine whether it will lift the air-worthiness restriction on the 737 MAX series. That would allow Boeing to reprogram hundreds of aircraft already built, and then to resume deliveries of completed jets.
The return to service for the 737 MAX could take somewhat longer, as new training standard for flight crews would have to be developed and completed, and new FAA regulations would have to be devised for managing the aircraft's updated hardware and software. A similar process would be pursued by air-safety agencies around the world.
One report indicated Boeing aims to have the 737 MAX regain its certification in September.