The National Transportation Safety Board is set to determine the probable cause of the Alaska Airlines door plug blowout during a public meeting Tuesday morning, nearly 18 months after the mid-flight emergency that exposed critical safety gaps in Boeing's manufacturing process.
The board will vote on the probable cause and safety recommendations for the January 5, 2024 incident, when a door plug separated from Flight 1282's Boeing 737 Max 9 minutes after takeoff from Portland International Airport. The final report will be available in several weeks, the NTSB said.
The NTSB's preliminary investigation revealed that four bolts designed to prevent the door plug from detaching were missing when the aircraft left Boeing's factory12. Boeing records showed that Spirit AeroSystems employees replaced damaged rivets on the door plug at Boeing's Renton, Washington facility on September 19, 2023, but failed to reinstall the critical bolts13.
"The four bolts that prevent upward movement of the MED plug were missing before the MED plug moved upward off the stop pads," according to the NTSB's preliminary report24. Photo documentation from Boeing showed the plug was closed with no bolts in three visible locations, with laboratory analysis confirming the fourth bolt was also missing1.
The door plug blew out at 16,000 feet, creating a gaping hole in the aircraft carrying 171 passengers and six crew members12. First officer Emily Wiprud described the moment to CBS News: "The first indication was an explosion in my ears and then a whoosh of air"3.
Passenger Sieysoar Un, sitting behind the door plug with her 12-year-old son, told ABC News: "We literally thought that we were going to die"2. Her son's phone and stuffed animal were sucked out of the aircraft, and another teenager's shirt was torn off his body2.
The crew successfully executed an emergency landing with seven passengers and one flight attendant sustaining minor injuries4.
The incident prompted the Federal Aviation Administration to ground 171 Boeing 737 Max 9 aircraft globally for inspections12. Boeing CEO Dave Calhoun took responsibility, telling investors in January 2024: "We caused the problem"3.
Boeing has since implemented additional quality controls, paused production for comprehensive reviews, and is developing design changes to make door plugs more secure34. The company expects to retrofit planes currently in service within a year, according to Boeing executive Elizabeth Lund4.
"Boeing is accountable for what happened," Calhoun said during the company's earnings call3.
