Dennis Muilenburg remained as CEO but lost his second title as Boeing chairman on the same day that an international panel of regulators criticized the US Federal Aviation Administration, or FAA, for its review of the Boeing 737 Max's anti-stall system. That system has been implicated in two crashes that killed a total of 346 passengers and crew in 2018 and 2019.

The board on Friday removed Muilenburg as chairman so he can focus on running Boeing after the 737 Max crisis, the company said. But Muilenburg remains CEO of the company, as well as its president and director.

Earlier on Friday, a panel of international aviation regulators issued a report critical of the process by which Boeing and the FAA gave the Max approval to fly. The group said Boeing failed to adequately inform the FAA about changes to a key flight-control system.

The Joint Authorities Technical Review, or JATR, said the FAA evaluated the anti-stall device piecemeal without regard to its overall performance, making it difficult to determine if it complied with regulations.

The head of the FAA, Steve Dickson, said in a statement, "We welcome the unvarnished and independent review.

The JATR included aviation regulators from China, Australia, Brazil, Canada, European Union, Indonesia, Japan, Singapore, United Arab Emirates, and the United States. It was headed by Christopher Hart, a former chairman of the National Transportation Safety Board.

Last April, the FAA asked regulators from the nine countries and the EU to review the US regulator's oversight and approval of the Boeing 737 Max's automated anti-stall device. Investigators believe the device may have erroneously pointed the nose of the plane down to gain speed to prevent a midair stall and into a fatal plunge.

In a 69-page report, JATR said the device "was not evaluated as a complete integrated function in the certification documents submitted to the FAA. The lack of unified top-down development and evaluation of the system function and its safety analyses, combined with the extensive fragmented documentation, made it difficult to assess whether compliance was fully demonstrated."

The review said the FAA needs to reform its practice of delegating key parts of certification to industry engineers to assure safety.

"With adequate FAA engagement and oversight, the extent of delegation does not in itself compromise safety," JATR said in its report. However, in the case of the Boeing 737 Max, the FAA had insufficient knowledge of the functioning of the anti-stall device, the report said. Coupled with its limited involvement, the FAA was unable to the provide an independent assessment of the adequacy of anti-stall system, the report concluded.

US Congressman Peter DeFazio, a Democrat from Oregon and chairman of the House Committee on Transportation and Infrastructure, which conducted hearings on the crashes, said JATR's report raised "new and disturbing questions" about certification of the Max.

"Much of what we're seeing in the JATR report aligns with information coming to light in our committee's own investigation - that undue pressure may have been placed on individuals at the FAA and Boeing to get the Max into service as quickly as possible," he said in a statement. "We need to get answers about what went wrong and why, and more importantly how we can assure it will never happen again."

James Hall, managing partner Hall& Associates in Washington and former chairman of the National Transportation Safety Board, told China Daily: "I hope Congress will limit the delegation of responsibility without active oversight in future reviews". Hall add: "I think the report will lead the new FAA administrator to review, restructure, and refund safety programs."

Robert Mann, president of R.W. Mann & Co, an aviation consulting firm in Port Washington, New York, said innovations by aircraft manufacturers often outpace the ability of regulators to evaluate them. It therefore made sense for Boeing to participate in the review. But the key is balance and oversight.

"This is a shared issue between Boeing and the FAA," he said.

Mann said the Max's problems can be corrected, but how the fixes are approved will determine how quickly the plane returns to service.

Major US airlines don't anticipate the plane will return to service until January.

John Cochran, professor emeritus of aerospace engineering at Auburn University and president of Eaglemark, an aviation consulting firm, said the FAA needs to expand its staff.

"The FAA lacks the personnel to do what needs to be done," Cochran told China Daily. "The criticism is justified, but the FAA has built a sterling reputation over the years and has become the lead regulator in the world. Oversight is the biggest problem. They'll fix it, but it will take some time."