Boeing Faces US Safety Investigation Over 737 Midair Blowout (2)

The Federal Aviation Administration opened a formal investigation of Boeing Co.’s aircraft operations following last week’s accident on one of its passenger jets, escalating a quality control crisis at the US planemaker.

The regulator said the company’s production practices must meet demanding safety standards for which it’s accountable. The investigation stems from a midair blowout of a so-called door plug on a 737 Max 9 jet operated by Alaska Airlines on Jan. 5.

“This incident should have never happened and it cannot happen again,” the agency said in a statement.

The probe compounds troubles unfolding at Boeing after ...