Alaska Airlines has grounded all Boeing 737-9 MAX passenger planes hours after a window and chunk of fuselage blew out of a flight in mid-air shortly after take-off in the US state of Oregon.
Photos and videos from passengers showed a gaping hole in the side of the plane next to passenger seats, with oxygen masks deployed.
The Boeing 737-9 MAX was diverted after reaching 16,000ft about six minutes after taking off at 5.07pm, according to flight tracking data from FlightAware. It made an emergency landing at Portland International Airport at 5.26pm.
Alaska Airlines said the plane landed safely with 174 passengers and six crew members.
The flight from Portland to Ontario, California, “experienced an incident this evening soon after departure”, the company said.
“While this type of occurrence is rare, our flight crew was trained and prepared to safely manage the situation.”
The Federal Aviation Administration (FAA) said the plane landed safely after the crew reported a pressurisation issue. It said it would investigate.
Footage and photos taken inside the plane show the night sky through the hole in the aircraft’s fuselage.
The nearest seat is missing its cushion and insulation material can be seen around the gap.
Exterior photos suggest the rear mid-cabin exit door separated from the aircraft during the flight.
The MAX 9 features a rear cabin door behind the wings that can be “activated in dense seating configurations to meet evacuation requirements”, according to FlightRadar24, but these are permanently “plugged” or deactivated on Alaska Airlines planes.
The National Transport Safety Board said it was investigating the incident in a post on X.
The Boeing 737-9 MAX came off the assembly line and received its certification just two months ago, according to online FAA records.
It had been on 145 flights since entering commercial service on 11 November, according to FlightRadar24. The flight from Portland was the aircraft’s third of the day.
Last week, Boeing said it was urging airlines to inspect all 737 MAX planes for a possible loose bolt in the rudder control system.
The FAA said it was closely monitoring Boeing 737 MAX inspections and would consider additional action if more loose or missing hardware was found.