Daniel Elwell, the FAA's acting chief, said the agency's technical experts will leave "no stone unturned" as they review Boeing's proposed solution to an issue linked to two fatal crashes since October.
"If it takes a year to find everything we need to give us the confidence to lift the order, then so be it," Elwell told reporters, according to a Bloomberg account of the discussion.
"If there is a crisis in confidence, we hope this will help to show the world that the world still talks together about aviation safety issues," he said.
Boeing is eager to assure airlines and their passengers that its best-selling airplane is safe. The aircraft maker proposed an update in March to a flight control system that's at the center ofin Ethiopia and Indonesia that killed 346 people.
Though the official causes of both accidents have not been determined, investigators. Under scrutiny is a flight control system called MCAS (for Maneuvering Characteristics Augmentation System) that pushes the 737 Max's nose down when it determines that it's too high. from both crashes show that flight crews struggled to take control as the airplanes continually dove just after takeoff.
CNET's Kent German contributed to this report.