Alaska Airlines grounded all of its Boeing 737-9 aircraft late Friday, hours after a window and piece of fuselage on one such plane blew out in midair and forced an emergency landing in Portland, Oregon.
The incident occurred shortly after takeoff and the gaping hole caused the cabin to depressurize. Flight data showed the plane climbed to 16,000 feet (4,876 meters) before returning to Portland International Airport.
The airline said the plane landed safely with 174 passengers and six crew members.
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 of the aircraft will be returned to service after full maintenance and safety inspections, which Minicucci said the airline anticipated completing within days.
The airline provided no immediate information about whether anyone was injured or the possible cause.
The plane was diverted about about six minutes after taking off at 5:07 p.m., according to flight tracking data from the FlightAware website. It landed at 5:26 p.m.
The pilot told Portland air traffic controllers the plane had an emergency, was depressurized and needed to return to the airport, according to a recording made by the website LiveATC.net.
A passenger sent KATU-TV in Portland a photo showing the hole in the side of the airplane next to passenger seats. Video shared with the station showed people wearing oxygen masks and passengers clapping as the plane landed.
The National Transportation Safety Board said in a post on X, formerly known as Twitter, that it was investigating an event on the flight and would post updates when they are available. The Federal Aviation Administration also said it would investigate.
The Boeing 737-9 MAX involved in the incident rolled off the assembly line and received its certification just two months ago, according to online FAA records.
The plane had been on 145 flights since entering commercial service on Nov. 11, said FlightRadar24, another tracking service. The flight from Portland was the aircraft's third of the day.
Boeing said it was aware of the incident, working to gather more information and ready to support the investigation.
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 and leading to a near two-year worldwide grounding of all Max 8 and Max 9 planes. The planes returned to service only after Boeing made changes to an automated flight control system implicated in the crashes.
Last year, the FAA told pilots to limit use of an anti-ice system on the Max in dry conditions because of concern that inlets around the engines could overheat and break away, possibly striking the plane.
Max deliveries have been interrupted at times to fix manufacturing flaws. The company told airlines in December to inspect the planes for a possible loose bolt in the rudder-control system.