Boeing said on Wednesday that it was shaking up the leadership in its commercial airplanes unit after a harrowing incident last month during which a piece fell off a 737 Max 9 jet in flight.

Ed Clark, the head of Boeing’s 737 Max program, which includes the Max 9, is leaving immediately, Stan Deal, the chief executive of the commercial airplanes unit, said in a memo to employees. Boeing, which also announced other leadership changes, has been under pressure from regulators, airlines and members of Congress to prove that it is committed to making safe planes.