The U.S. 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 last week in mid-air, forcing an emergency landing, the regulator said on Thursday.
The FAA has grounded 171 Boeing (BA.N) jets with the same panel pending safety inspections. Most are operated by U.S. carriers Alaska Airlines and United Airlines <UAL.O>.
The incident was the latest in a series of events that have shaken confidence in the aircraft manufacturer. Talks continued on Thursday between Boeing, the FAA and airlines on revised inspection and maintenance instructions from Boeing that the FAA must approve before airlines can resume flying the planes.
The FAA said the Alaska Airlines 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" under FAA rules. The agency cited "additional discrepancies" in other 737 MAX 9 planes.
“We will cooperate fully and transparently with the FAA and the NTSB on their investigations," Boeing said in a statement.
Boeing shares were down 1.8% on Thursday. They are down more than 10% since the incident.
On Monday, both Alaska and United said 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 hudndreds of flights since Saturday with the planes grounded, with United canceling about 200 and Alaska Air 158 on Thursday.
A growing number of U.S. lawmakers expressed broader concerns about Boeing and questions about its manufacturing quality control.
"Given the previous tragic crashes of Boeing 737 Max aircraft, we are deeply concerned that the loose bolts represent a systemic issue with Boeing’s capabilities to manufacture safe airplanes," wrote Senators Ed Markey, JD Vance and Peter Welch to Boeing CEO Dave Calhoun.
Boeing declined to comment on the letter. On Tuesday, Reuters reported that the planemaker 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).
Calhoun told CNBC on Wednesday that a "quality escape" was at issue that led to the MAX 9 being in the air that suffered the cabin blowout.
The Alaska Airlines flight, which had been in service for just eight weeks, took off from Portland, Oregon, on Friday and was flying at 16,000 feet (4,900 m) when the panel tore off the plane. Pilots returned the 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 said.
On Wednesday, U.S. Transportation Secretary Pete Buttigieg declined to say when the FAA may allow the planes to resume flights but said Boeing must ensure its planes are "100% 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 grounded all MAX planes for 20 months after 346 people died in crashes in Ethiopia and Indonesia linked to poorly designed cockpit software.
The crisis eroded Boeing's 50% share of the passenger jet market and the company ended 2023 in second place behind rival Airbus (AIR.PA) in aircraft deliveries for the fifth year running.
On Thursday, Airbus posted record annual jet orders, booking nearly 2,100 net new orders in 2023 while Boeing booked 1,314 net new orders. Airbus CEO Guillaume Faury told reporters it was closely monitoring the investigation of its rival.
"We will be taking each and every learning and we would expect Spirit to do exactly the same," he added.
Brazilian airline Gol (GOLL4.SA) said quality issues across the aviation industry must be assessed and risk mitigation plans put in place.
Panama's civil aviation authority said it had temporarily prohibited operations of 21 of Copa Airlines' Boeing 737 MAX 9.
