The Federal Aviation Administration on Thursday said it had opened an investigation into whether Boeing failed to ensure that the 737 Max 9 plane was safe and manufactured to match the design approved by the agency.
The F.A.A. said the investigation stemmed from the loss of a fuselage panel of a Boeing 737 Max 9 operated by Alaska Airlines shortly after it took off on Friday from Portland, Ore., leaving a hole in the side of the passenger cabin. The plane returned to Portland for an emergency landing.
“This incident should have never happened and it cannot happen again,” the agency said.
In a letter to Boeing dated Jan. 10, the F.A.A. said that after the Portland incident it was notified of additional issues with other Boeing 737 Max 9 planes. The letter does not detail what other issues were reported to the agency. Alaska and United Airlines, which operate most of the Max 9s in use in the United States, said on Monday that they discovered loose hardware on the panel when conducting preliminary inspections on their planes.
The National Transportation Safety Board is investigating why the panel, also known as a door plug, flew off the Boeing jet. The safety board is trying to determine if bolts that would have kept the panel in place were missing or were installed incorrectly. The plug is placed where an emergency exit would be if the plane had the maximum number of seats possible.
Before the announcement on Thursday, the F.A.A. had been working with Boeing on revising the company’s instructions for inspecting the grounded 737 Max 9 planes. The announcement of the revision came after reports of loose bolts from two airlines.
“Boeing’s manufacturing practices need to comply with the high safety standards they’re legally accountable to meet,” the F.A.A. said in the statement announcing the investigation.
Dave Calhoun, Boeing’s chief executive, on Tuesday promised transparency in the company’s response to the incident. He also said the company was “acknowledging our mistake” without explaining what he was referring to. Boeing has declined to elaborate on that remark.
Boeing did not immediately respond to a request for comment on Thursday.
United has 79 of the planes and Alaska has 65, but Alaska has had the bigger share of cancellations from the grounding because the Max 9 makes up 20 percent of its fleet.
The new investigation is the latest setback for Boeing, which is one of just two suppliers of large planes for most airlines. The company has struggled to regain the public’s trust after two crashes, in Indonesia and Ethiopia, involving the 737 Max 8 in 2018 and 2019 killed 346 people.
