Preliminary NTSB Report Finds Four Bolts Were Missing from Alaska Airlines Flight 1282

A preliminary report on Alaska Airlines Flight 1282, released Feb. 6 by the National Transportation Safety Board (NTSB), says four bolts that prevent upward movement of the door plug were missing.

Jennifer Homendy, NTSB chair, told CNN’s Poppy Harlow on CNN This Morning Wednesday: “There is no way that this plane should have been delivered with four safety critical bolts missing. There’s a problem in the process.”

The NTSB’s investigative team conducted a post-accident examination of the aircraft structure, flight deck, cabin interior, cabin safety systems, and pressurization system. 

Responses to the following questions are found in the report:

Who manufactured and installed the door plug?

The accident mid exit door (MED) plug was manufactured by Spirit AeroSystems Malaysia on March 24, 2023, and was received at Spirit AeroSystems Wichita on May 10, 2023.

The MED plug was then installed and rigged on the fuselage (Spirit AeroSystems Fuselage Line 8789) before it was shipped to Boeing on August 20, 2023. The fuselage arrived at Boeing’s Renton, Washington, facility on August 31, 2023. The MED plug is primarily constructed of aluminum and is installed in the fuselage by means of two upper guide fittings and two lower hinge fittings. The two upper guide fittings are located on the upper sides of the plug and engage with two upper guide rollers that are fixed to the upper sides of the fuselage opening. Two lower hinge guide fittings are fixed to the lower section of the plug and engage with the two lower hinge fittings that are attached to the bottom of the fuselage opening at the lower hinge bracket assemblies.

Once the plug is in place, it is secured from moving vertically by a total of four bolts. There is a bolt installed through each upper guide fitting and each lower hinge guide fitting. Once these bolts are installed, they are secured using castle nuts and cotter pins. Outboard motion of the plug is prevented by 12 stop fittings (six along each forward and aft edge) installed on the fuselage door frame structure.

The door plug is only intended to be opened for maintenance and inspection, which requires removing the vertical movement arrestor bolts and upper guide track bolts. The strap assemblies below the second stop pad from the top restrict the plug from opening further than 15 degrees, suitable for maintenance and inspection purposes.

Who’s investigating?

In response to the accident, the NTSB traveled to Portland. As part of the investigative process, the NTSB invited qualified parties to participate in the investigation. These included Alaska Airlines, Air Line Pilots Association (ALPA), Association of Flight Attendants – CWA (AFA CWA), Federal Aviation Administration (FAA), the Boeing Company (Boeing), Spirit AeroSystems, and the International Association of Machinists Union (IAM). The parties were formed into specialized investigative groups led by NTSB group chairs in the areas of Operations, Structures, Materials/Metallurgy, Systems, Survival Factors/Cabin Safety, Flight Recorders (flight data recorder [FDR]) and cockpit voice recorder [CVR]), and Manufacturing Records/Human Performance. The chair of the NTSB traveled with the investigative team and acted as the agency spokesperson.

Flight 1282 – what happened?

On January 5, 2024, about 5:14 p.m. Pacific Standard Time, Alaska Airlines Flight 1282, a Boeing 737-9, N704AL, returned to Portland International Airport (PDX), Portland, Oregon, after the left mid exit door (MED) plug departed the airplane leading to a rapid decompression. The airplane landed on runway 28L at PDX without further incident, and all occupants (two flight crewmembers, four cabin crewmembers, and 171 passengers) deplaned at the gate. Seven passengers and one flight attendant received minor injuries. The flight was operated under Title 14 Code of Federal Regulations (CFR) Part 121 as a scheduled domestic passenger flight from PDX to Ontario, California (ONT). ​​​

Boeing Feb. 6 Statement: 

Boeing appreciates the U.S. National Transportation Safety Board’s work and will review their findings expeditiously. And we will continue to cooperate fully and transparently with the NTSB and the FAA investigations.

Boeing President and CEO Dave Calhoun said, “Whatever final conclusions are reached, Boeing is accountable for what happened. 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.”

Boeing is taking immediate action to strengthen quality. First, the company has implemented a control plan to ensure all 737-9 mid-exit door plugs are installed according to specifications:

• Instituted new inspections of the door plug assembly and similar structures at our supplier’s factory and on Boeing’s production line.
• Added signage and protocol to fully document when the door plug is opened or removed in our factory, ensuring it is reinstalled and inspected prior to delivery.

Moreover, Boeing is implementing plans to improve overall quality and stability across the 737 production system, including:

• Layering additional inspections further into the supply chain and collaborating with suppliers on production enhancements.
• Performing more work on airplanes at their assigned positions.
• Dedicating multiple days for our 737 teams to focus on and implement quality improvements.
• Launching an independent assessment to bolster the quality management system at Boeing Commercial Airplanes by a highly experienced safety expert.

In addition to these Boeing actions, we are opening our factory to 737 customers to conduct their own additional reviews, and will fully and transparently support the FAA’s investigation, audit and oversight actions.

“This added scrutiny – from ourselves, from our regulator and from our customers – will make us better. It’s that simple,” said Calhoun.  

Spirit AeroSystems Feb. 6 Statement:

As we review the NTSB’s preliminary report, we remain focused on working closely with Boeing and our regulators on continuous improvement in our processes and meeting the highest standards of safety, quality and reliability.

Alaska Airlines Feb. 6 Statement:

The National Transportation Safety Board (NTSB) released its preliminary report today, Feb. 6, involving Alaska Airlines Flight 1282. This is part of the NTSB’s established process during an investigation that it continues to lead.

Alaska’s safety and technical representatives, along with Boeing representatives, remain in close contact with the NTSB. Since this remains an ongoing investigation, we are limited in the details we can release or confirm. We defer questions to the NTSB.

Safety is always our top priority. As this investigation moves forward, we have full confidence in the safety of our operation and aircraft.