The decision came as Boeing struggles to get its best-selling 737 MAX back into service following a worldwide safety ban in March triggered by two crashes that killed a total of 346 people in Ethiopia and Indonesia. It also comes some six months after Muilenburg survived a shareholder motion to split his chairman and CEO roles, part of the intense pressure he has faced during the worst crisis of his four years at the helm of the world's largest planemaker.
"This decision is the latest of several actions by the board of directors and Boeing senior leadership to strengthen the company's governance and safety management processes," the company said. Earlier on Friday, an international aviation panel criticized US regulators and Boeing over the certification of the plane.