Now that he’s in charge, Mr. Calhoun has become more willing to openly criticize Mr. Muilenburg. He said the former chief executive had turbocharged Boeing’s production rates before the supply chain was ready, a move that sent Boeing shares to an all-time high but compromised quality.

“I’ll never be able to judge what motivated Dennis, whether it was a stock price that was going to continue to go up and up, or whether it was just beating the other guy to the next rate increase,” he said. He added later, “If anybody ran over the rainbow for the pot of gold on stock, it would have been him.”

Mr. Muilenburg declined to comment.

Mr. Calhoun and the rest of Boeing’s board never seriously questioned that strategy, in part because before the first Max crash off the coast of Indonesia in October 2018, the company was enjoying its best run in years. What’s more, the board believed that Mr. Muilenburg, an engineer who had been at Boeing for his entire career, was so deeply informed about the business that he was a good judge of the risks involved in ramping up production.

“If we were complacent in any way, maybe, maybe not, I don’t know,” Mr. Calhoun said. “We supported a C.E.O. who was willing and whose history would suggest that he might be really good at taking a few more risks.”

It was only after the Max was grounded last March following a crash in Ethiopia that Mr. Muilenburg’s optimistic approach became viewed as a liability. Airlines grew livid after he repeatedly voiced overly optimistic timetables about when the Max would return to service. The head of the Federal Aviation Administration, Stephen Dickson, was so frustrated that he reprimanded Mr. Muilenburg in a private meeting and publicly told F.A.A. employees to resist pressure from the company.

“They felt like they were being pushed into a timeline,” Mr. Calhoun said of the F.A.A., adding that the “regulator was never there alongside of us, but apparently our team didn’t quite come up to grips with that.”

One of Mr. Calhoun’s initial tasks as chief executive was to go on an apology tour, holding a series of what he called “greet-and-mend opportunities.” The first stop was the White House.