Alaska Airlines grounds Boeing 737-9 planes after aircraft window blows out mid-air

Alaska Airlines grounded its Boeing 737-9 planes after a flight with 177 people onboard made an emergency landing in the US state of Oregon, with passengers reporting a plane window panel blew out after takeoff.

"Following tonight's event on Flight 1282, we have decided to take the precautionary step of temporarily grounding our fleet of 65 Boeing 737-9 aircraft," Alaska Airlines CEO Ben Minicucci said in a statement.

"Each aircraft will be returned to service only after completion of full maintenance and safety inspections," he said, anticipating checks would be finished in a few days.

Flight 1282 departed Portland International Airport on Saturday afternoon before returning safely "after the crew reported a pressurization issue," the Federal Aviation Administration wrote on X.

Videos posted on social media showed the window panel of a plane blown out, with emergency oxygen masks hanging from the ceiling.

Kyle Rinker, a passenger on the flight, told CNN International that a window popped off soon after takeoff.

"It was really abrupt. Just got to altitude, and the window/wall just popped off and didn't notice it until the oxygen masks came off," he told the broadcaster.

Another passenger, Vi Nguyen, told The New York Times that a loud noise during the flight had woken her. 

"I open up my eyes and the first thing I see is the oxygen mask right in front of me," Nguyen told the newspaper. "And I look to the left and the wall on the side of the plane is gone."

"The first thing I thought was, 'I'm going to die,'" she added.

The National Transportation Safety Board, FAA and Alaska Airlines each said they were investigating the incident.

"The aircraft landed safely back at Portland International Airport with 171 guests and 6 crew members," the airline said in an earlier statement.

"While this type of occurrence is rare, our flight crew was trained and prepared to safely manage the situation," it said.

The Boeing 737 Max 9 plane took off at 5:07 p.m., heading to Ontario, California, before returning to the Portland airport around 20 minutes later, according to the flight tracking website FlightAware.

The plane had been certified airworthy in October, according to the FAA registry website.

Boeing wrote on X that it was gathering more information and a technical team stood ready to support the investigation.

In his statement, Minicucci said Alaska Airlines was "working with Boeing and regulators to understand what occurred." (AFP)