FAA Says 737 Max Needs Additional Computer Changes

One issue, a possible fault in a flight control computer, could lead to a loss of control from the horizontal stabilizer. The second could lead the autopilot feature to potentially disengage during final approach.

While neither of the faults have ever been observed in flight, the modifications will eliminate the possibility of them occurring, the FAA said in a statement.

"Both modifications to the FCC software will be incorporated at the same time," the statement said. "Our return to service estimate remains the same at this time, as we work with our supplier to determine when the software modifications will be complete."

The Max has now been grounded more than a year following the second crash in Ethiopia in March, 2019. Boeing has spent that time modifying not just MCAS, but investigating other possible issues that the FAA has flagged including wiring bundles that may be too close together and a potential weakness with a rotor on the Max's engines.

The agency said it's is in regular contact with Boeing about the Max's repairs. "The manufacturer must demonstrate compliance with all certification standards," the agency said. "The aircraft will be cleared for return to passenger service only after the FAA is satisfied that all safety-related issues are addressed."

Though an FAA certification flight for the Max has yet to be scheduled, Boeing said in January that it could resume Max flights by June or July of this year. But the company hasn't said whether the coronavirus pandemic, which has caused it to shut down its factories, might affect that schedule.