“Time is needed for additional work by Boeing as the result of an ongoing review of the 737 Max Flight Control System to ensure that Boeing has identified and appropriately addressed all pertinent issues.”
The FAA also said that it will subject Boeing’s upgraded software for the Max models to “a rigorous safety review.”
“The FAA will not approve the software for installation until the FAA is satisfied with the submission,” the agency said in the statement.
Boeing will also have to convince skeptical regulators in Canada, Europe, China and elsewhere of the system’s safety.
The 737 Max models were grounded on March 13 after similarities began to emerge between the crash on March 10 in Ethiopia and the one on October 29 off the coast of Indonesia. The crashes killed a total of 346 people.
In the first crash, the computerised safety system known as Maneuvering Characteristics Augmentation System, or MCAS, was repeatedly attempting to push down the nose of a Lion Air jet as the result of a faulty sensor.
In the second, MCAS was also activated on an Ethiopian Airlines plane, according to reports last week in Bloomberg News and the Wall Street Journal.