The flight left Portland, Oregon, on Jan. 5 bound for Ontario International Airport in San Bernardino County, California, when the door plug blew off.
The door panel on an Alaska Airlines Boeing 737 that fell off midair had no bolts installed on the door plug, according to preliminary findings released Tuesday by the National Transportation Safety Board.
A picture of the plane in a factory in Renton, Washington, revealed the lack of bolts, the NTSB said.
“Photo documentation obtained from Boeing shows evidence of the left-hand MED plug closed with no retention hardware (bolts) in the three visible locations,” the report said, using an acronym for the middle exit door.
However, it was not clear at what stage in the manufacturing process the plane was in when the photo was taken.
The faulty plug was manufactured by Spirit AeroSystems Malaysia on March 24, 2023, and was received at Spirit AeroSystems Wichita on May 10, 2023, the report said. The plug was then installed and rigged on the Spirit AeroSystems Fuselage Line 8789 before it was shipped to Boeing on Aug. 20, 2023. The fuselage arrived at Boeing’s Renton facility on Aug. 31, 2023, according to the report.
In a statement Tuesday, Boeing said it appreciates the NTSB’s work and will review the findings “expeditiously” while continuing to cooperate with investigations by the NTSB and Federal Aviation Administration.
“Whatever final conclusions are reached, Boeing is accountable for what happened,” Boeing President and CEO Dave Calhoun said in the statement. “An event like this must not happen on an airplane that leaves our factory. We simply must do better for our customers and their passengers. We are implementing a comprehensive plan to strengthen quality and the confidence of our stakeholders. It will take significant, demonstrated action and transparency at every turn — and that is where we are squarely focused.”
The flight, carrying 177 people, left Portland, Oregon, on Jan. 5 bound for Ontario International Airport in San Bernardino County, California, when the door plug blew off, leaving a gaping hole in the side of the aircraft. Many passengers described hearing a “loud bang” shortly after takeoff. A photo from one passenger showed a panel missing from the side of the fuselage. The plane was forced to make an emergency landing in Portland, Oregon.
The FAA grounded all 171 Boeing 737 Max 9 airplanes operating in the U.S. amid the NTSB’s investigation. The FAA also said it was increasing its oversight of Boeing production and manufacturing.
In his testimony to the House Transportation and Infrastructure Aviation Subcommittee on Tuesday, FAA Administrator Mike Whitaker offered more details on the increased scrutiny now underway at Boeing.
“We’re proposing to expand the oversight approach to include both audits and inspection which is why we’re moving inspectors into the facilities,” Whitaker said. “We know what we need to do next, which is to have more on-the-ground presence to verify what’s going on.”
Whitaker added the Jan. 5 incident has prompted the FAA to determine if there are any issues with production at Boeing.
“There have been issues in the past and they don’t seem to be getting resolved so we feel we need a heightened sense of oversight to get after that,” he said. “I think we’re gonna need more boots on the ground, we’re gonna need more inspectors. We don’t have many inspectors on the aircraft certification side of the house.”
Earlier this month, Alaska Airlines and United Airlines confirmed plans to return their fleet of Boeing 737 Max 9 planes to service. Alaska said in an earning report that it was preparing to complete inspections of its fleet and that each aircraft would be returned to service after passing inspection.