How will aviation authorities around the world go about certifying Boeing's 737 Max as airworthy again? How soon can the troubled plane be cleared to fly passengers again?
Those are the central questions up for discussion as about five dozen aviation safety officials representing more than 33 countries meet in Fort Worth, Texas.
The discussions are critical as Boeing says it has completed a software fix for an automated flight control system that is linked to two deadly crashes, one in Indonesia last fall and a second in Ethiopia in March. The crashes killed a total of 346 people and led authorities globally to ground the plane.
U.S. aviation safety officials want to reassure the flying public that the plane will be made safe to fly again while at the same time they try to restore confidence in their own safety review process.
Close to 400 Max planes worldwide are sitting idle. Airlines have removed the new plane from their flight schedules through early to mid-August, forcing them to cancel some flights that would have been on Max planes through most of the busy summer travel season.
Last month, Boeing, the FAA and some airlines hinted that a software fix and pilot training could be completed and the Max could be flying again as soon as August. But as the meeting of global aviation regulators began, the top U.S. aviation safety official cast doubt on hopes for a quick and smooth recertification process for Boeing's fastest-selling commercial jet ever.
Acting FAA Administrator Daniel Elwell told reporters the safety review of Boeing's software fix "takes as long as it takes" to get it right.
"The 737 Max will fly again when we have gone through all of the necessary analysis to determine that it is safe to do so," Elwell said, adding that his agency will not be rushed to lift the order grounding the plane.
"We leave no stone unturned and if it takes a year to find everything we need to give us the confidence to lift the order then so be it," Elwell said in a news conference late Wednesday. "I'm not tied to a timetable."
Elwell acknowledged travelers have a lot of concerns about the safety of Boeing's 737 Max and the process by which the FAA originally certified the plane. Critics say Boeing rushed its development to compete with a similar new model from European rival Airbus, cutting corners along the way. News reports indicate the FAA's review of the plane and a new automated flight control system missed critical flaws. Safety experts and members of Congress question whether the FAA relied too heavily on Boeing's own employees and analysis for its safety reviews.
"Is public confidence shaken right now? Maybe," Elwell told reporters. But he expressed confidence that the process now in place is the best in the world and that safety reviews will be thorough and done right.
Nonetheless, aviation safety authorities in Europe, Canada, China and elsewhere indicated they will conduct their own independent reviews of Boeing's software fix and have their own conditions that will need to be met before they will lift orders grounding the Max.
Elwell said the meeting today with his foreign counterparts will have a rigorous give and take as "we will be sharing with them the safety analysis that will form the basis for our return-to-service decision." But he denied there is any tension with other aviation authorities.
"We have peace with other regulators; we're talking to them constantly," he said. "You want to make this like we're at war with the other countries over this. We're not."