PORTLAND, Ore. — Alaska Airlines and United Airlines grounded all of their Boeing 737 Max 9 jetliners again on Sunday while they waited to be told how to inspect the planes to prevent another inflight blowout like the one that damaged an Alaska jet.
Alaska Airlines had returned 18 of its 65 737 Max 9 aircraft to service Saturday, less than 24 hours after part of the fuselage on another plane blew out three miles (4.8 kilometers) above Oregon.
The reprieve was short-lived.
The airline said Sunday that it received a notice from the Federal Aviation Administration that additional work might be needed on those 18 planes.
Alaska said that it had canceled 170 flights — more than one-fifth of its schedule — by mid-afternoon on the West Coast because of the groundings.
“These aircraft have now also been pulled from service until details about possible additional maintenance work are confirmed with the FAA,” the airline said in a statement. “We are in touch with the FAA to determine what, if any, further work is required.”
United Airlines said it had scrapped about 180 flights Sunday while salvaging others by finding other planes not covered by the grounding.
Alaska and United are the only U.S. airlines that fly the Max 9.
United said it was waiting for Boeing to issue what is called a multi-operator message, which is a service bulletin used when multiple airlines need to perform similar work on a particular type of plane.
Boeing is working on a bulletin but had not yet submitted it to the FAA, according to a person familiar with the situation. Producing a detailed, technical bulletin frequently takes a couple days, the person said. The person spoke on condition of anonymity because the company and regulators have not publicly discussed the process.
Boeing declined to comment.
A panel used to plug an area reserved for an exit door on the Max 9 blew out Friday night shortly after Alaska Airlines flight 1282 took off from Portland, Oregon. The depressurized plane, carrying 171 passengers and six crew members, returned safely to Portland International Airport with no serious injuries.
Hours after the incident, the FAA ordered the grounding of 171 Max 9s including all those operated by Alaska and United until they could be inspected. The FAA said inspections will take four to eight hours.
Boeing has delivered 218 Max 9s worldwide, but not all of them are covered by the FAA order. They are among more than 1,300 Max jetliners — mostly the Max 8 variant — sold by the aircraft maker. The Max 8 and other versions of the Boeing 737 are not affected by the grounding.
U.S. Sen. Maria Cantwell, D-Wash., chair of the Senate’s Commerce, Science and Transportation Committee, said she agreed with the decision to ground the Max 9s.
“Safety is paramount. Aviation production has to meet a gold standard, including quality control inspections and strong FAA oversight,” she said in a statement.
Investigators from the National Transportation Safety Board searched Sunday for the paneled-over exit door that blew out from flight 1282. They have a good idea of where it landed, near Oregon Route 217 and Barnes Road in the Cedar Hills area west of Portland, NTSB Chair Jennifer Homendy said at a news conference late Saturday.
“If you find that, please, please contact local law enforcement,” she said.
Early Sunday afternoon, some local residents were scouring a patch of land with dense thickets, sandwiched between busy roads and a light rail train station. The area is located across from a sprawling hospital complex.
Searcher Adam Pirkle said he had ridden 14 miles (22 kilometers), maneuvering his bicycle through the overgrowth. “I’ve been looking at the flight track, I was looking at the winds,” he said. “I’ve been trying to focus on wooded areas.”
Daniel Feldt navigated the same thickets on foot, equipped with binoculars after descending from the roof of a parking garage beside the light rail station. “I was up on the parking garage and scanning everything. Didn’t see any holes in the bushes that looked obvious where something had fallen through,” he said.
Gavin Redshaw even brought his drone for an aerial view but hadn’t found anything either by Sunday afternoon. “Lots of trash, but no door,” he said.
There has not been a fatal crash involving a U.S. passenger carrier within the country since 2009 when a Colgan Air flight crashed near Buffalo, New York, killing all 49 people on board and one person on the ground. In 2013, an Asiana Airlines flight arriving from South Korea crashed at San Francisco International Airport, killing three of the 307 people on board.
Flight 1282 took off from Portland at 5:07 p.m. Friday for a two-hour flight to Ontario, California. About six minutes later, the chunk of the fuselage blew out as the plane was at about 16,000 feet (4.8 kilometers). One of the pilots declared an emergency and asked for clearance to descend to 10,000 feet (3 kilometers), the altitude where the air would have enough oxygen to breathe safely.
Videos posted by passengers online showed a gaping hole where the paneled-over exit had been and passengers wearing masks. They applauded when the plane landed safely about 13 minutes after the blowout. Firefighters then came down the aisle, asking passengers to remain in their seats as they treated the injured.
It was extremely lucky that the airplane had not yet reached cruising altitude, when passengers and flight attendants might be walking around the cabin, Homendy said.
“No one was seated in 26A and B where that door plug is, the aircraft was around 16,000 feet and only 10 minutes out from the airport when the door blew,” she said. The investigation is expected to take months.
The aircraft involved rolled off the assembly line and received its certification two months ago, according to online FAA records. It had been on 145 flights since entering commercial service Nov. 11, said FlightRadar24, another tracking service. The flight from Portland was the aircraft’s third of the day.
Aviation experts were stunned that a piece would fly off a new aircraft. Anthony Brickhouse, a professor of aerospace safety at Embry-Riddle Aeronautical University, said he has seen panels of fuselage come off planes before, but couldn’t recall one where passengers “are looking at the lights of the city.”
The Max is the newest version of Boeing’s venerable 737, a twin-engine, single-aisle plane frequently used on U.S. domestic flights. The plane went into service in May 2017.
Two Max 8 jets crashed in 2018 and 2019, killing 346 people. All Max 8 and Max 9 planes were grounded worldwide for nearly two years until Boeing made changes to an automated flight control system implicated in the crashes.
The Max has been plagued by other issues, including manufacturing flaws, concern about overheating that led FAA to tell pilots to limit use of an anti-ice system, and a possible loose bolt in the rudder system.
Koenig reported from Dallas. Bohrer reported from Juneau, Alaska. Associated Press reporters Terry Spencer in Fort Lauderdale, Florida, and Audrey McAvoy in Honolulu, Hawaii, contributed.