Boeing CEO Dave Calhoun intends to leave the company by the end of the year, and the company’s chairman and head of the commercial airplane unit are also leaving, Paralel.Az reports citing CNN.

The chairman, Larry Kellner, will not stand for re-election to the board. The board has elected board member Steve Mollenkopf to succeed him. Stan Deal, CEO of Boeing Commercial Airplanes, is retiring and Stephanie Pope, chief operating officer of that unit, is taking his place effective immediately.

Boeing has been buffeted by more than five years of problems with its airplanes, including two fatal crashes of the 737 Max in 2018 and 2019 that killed 346 people, and most recently a door plug that blew out of the side of an Alaska Airlines 737 Max in January, leaving a gaping hole in the side of the plane. The problems have led to multiple groundings for safety issues and more than $31 billion in cumulative losses.

In a letter to Boeing employees Monday, Calhoun called the Alaska Airlines incident “a watershed moment for Boeing.”

“The eyes of the world are on us,” he said in announcing his departure plans. “We are going to fix what isn’t working, and we are going to get our company back on the track towards recovery and stability.”