Boeing CEO Dennis Muilenburg resigns

Boeing CEO Dennis Muilenburg testifies at a hearing in front of congressional lawmakers on Capitol Hill in Washington, DC on October 30, 2019. (Photo by Olivier Douliery / AFP) (Photo by OLIVIER DOULIERY/AFP via Getty Images)

(CNN) Boeing CEO Dennis Muilenburg has stepped down after a tumultuous year, in which the 737 Maxairplane and Starliner spacecraft encountered numerous issues and delays.