The Federal Aviation Administration is launching a formal investigation into the Boeing 737 Max 9 after a cabin panel blew off an Alaska Airlines ALK.N flight while in mid-air last week, forcing an emergency landing, the regulator said Thursday.
The FAA grounded 171 Boeing jets installed with the same panel after the landing, most of which are operated by U.S. carriers Alaska Airlines and United Airlines, pending safety inspections.
It is still unclear when the planes will be cleared to fly again, and the incident is the latest in a series of events that have shaken the industry's confidence in the aircraft manufacturer.
The FAA said the Alaska Airlines Max 9 incident "should have never happened and it cannot happen again." It told Boeing of the investigation in a letter on Wednesday "to determine if Boeing failed to ensure completed products conformed to its approved design and were in a condition for safe operation in compliance with FAA regulations" and after learning of "additional discrepancies."
"We will cooperate fully and transparently with the FAA and the NTSB on their investigations," Boeing said in a statement about the investigation.
Boeing did not respond to a request for comment. Its shares were down 1.2% on Thursday.
Both Alaska and United said on Monday they had found loose parts on multiple grounded aircraft during preliminary checks, raising new concerns about how Boeing's best-selling jet family is manufactured. The two carriers have canceled numerous flights with the planes grounded.
The carriers still need revised inspection and maintenance instructions from Boeing that must be approved by the FAA before they can begin flying the planes again.
Boeing on Tuesday told staff the findings were being treated as a "quality control issue" and checks were under way at Boeing and supplier Spirit AeroSystems SPR.N, Reuters reported previously.
Boeing CEO Dave Calhoun told CNBC on Wednesday that a "quality escape" was at issue in the Max 9 cabin blowout.
The Alaska Airlines flight had taken off from Portland, Oregon, on Friday and was flying at 16,000 feet (4,900 meters) when the panel tore off the plane, which had been in service for only eight weeks. Pilots returned the full jet to Portland, with only minor injuries suffered by people on board.
Boeing's manufacturing practices "need to comply with the high safety standards they're legally accountable to meet," the FAA added.
U.S. Transportation Secretary Pete Buttigieg declined to say on Wednesday when the FAA may allow the planes to resume flights but said it would only be when safe.
"The only consideration on the timeline is safety," Buttigieg told reporters. "Until it is ready, it is not ready. Nobody can or should be rushed in that process."
In 2019, global authorities subjected all Max planes to a wider grounding that lasted 20 months after crashes in Ethiopia and Indonesia linked to poorly designed cockpit software killed a total of 346 people.
Boeing ended 2023 in second place behind rival Airbus in aircraft deliveries for the fifth year running, after seeing its roughly 50% share of the market eroded by the earlier crisis. Airbus posted record annual jet orders on Thursday, booking nearly 2,100 net new orders in 2023, while Boeing booked 1,314 net new orders.
