The head of the US Federal Aviation Administration raised the possibility that it could take months longer to certify the grounded Boeing 737 Max as safe to fly, as fractious global regulators gathered to discuss fixes to flight software implicated in two deadly crashes.
Speaking on the eve of a meeting of 30 international air regulators on Thursday, Daniel Elwell, the acting FAA chief, said the agency was still waiting for Boeing to submit a software update aimed at preventing air disasters such as those in Indonesia and Ethiopia which killed 346 people.
He told reporters the FAA has also not yet decided whether pilots will be required to undergo simulator training on the updated Max, a move that could substantially delay a return to service but which some global regulators may insist upon.