Boeing has fired the head of its 737 Max aircraft division

(CNN) — Boeing fired Ed Clark, head of its 737 Max airliner program, in January in a dramatic — and frightening — mid-flight explosion that highlighted the plane's continuing problems.

The 737 Max is Boeing's best-selling plane, but it has been a source of constant problems over the past five years, after two crashes in 2019 and 2020 that killed a total of 346 people after 20 months of grounding. Most recently, a door plug on a Boeing 737 Max flown by Alaska Airlines exploded shortly after takeoff, leaving a hole in the side of the plane.

According to a preliminary report by the National Transportation Safety Board (NTSB), four screws that hold the door latch were missing when the plane left the Boeing factory.

The NTSB report did not attribute the missing bolt and blame for the crash, but in a statement to investors before the findings were released, Boeing CEO Dave Calhoun took responsibility for the incident.

“We caused the problemAnd we understand that,” he told investors during a phone call after the company reported its latest quarterly losses. “Boeing is responsible for what happened, regardless of the results.”

A 2019 aerial photo shows a Boeing 737 Max parked on the tarmac at the Boeing factory in Renton, Washington. (Credit: Lindsey Wasson/Reuters/File)

Along with the news of Clarke's departure, Boeing also announced several executive reshuffles in the Commercial Aircraft (PCA) division. He created a new executive position, the rank of BCA senior vice president, and appointed Elizabeth Lund to that position.

Lund was senior vice president and general manager of aircraft programs at BCA, where he oversaw not only the 737 Max, but also other aircraft models produced by the company.

Mike Fleming, who was senior vice president of customer development and programs, will assume Lund's former role. Katie Ringgold, who was vice president of 737 delivery operations, will fill Clark's old position overseeing the MAX program.

In addition to the problems that led to the grounding of the 737 Max 8 and Max 9 after the incidents, Boeing's problems have delayed the certification of two new versions of the plane, the Max 7 and the longer version Max 10.

The CEOs of three major Boeing customers — United Airlines, Southwest and Delta Air Lines — recently said they don't expect to receive new versions of the planes they ordered any time soon. United CEO Scott Kirby called the Alaska Air incident “The drop that broke the glassRegarding his company's predictions for Max 10.