Unraveling the Alaska Airlines Boeing 737-9 Depressurization Incident: A Comprehensive Timeline


The recent incident involving a missing door plug on an Alaska Airlines Boeing 737-9 has sparked concerns and raised questions about the safety of the aircraft model. This article delves into the timeline of events, investigations, industry responses, and provides insights into the purpose of the door plug and its significance.

The incident, which occurred on 05 January 2024, sent shockwaves through the aviation industry. Passengers and crew members onboard the flight experienced a sudden depressurization, leading to a chaotic and potentially dangerous situation. The missing door plug was identified as the cause of the incident, prompting immediate investigations by both Alaska Airlines and the Federal Aviation Administration (FAA).

In the following sections, we will explore the timeline of events leading up to the incident, the investigations conducted by Alaska Airlines and the FAA, the industry's response, and the measures taken to prevent future occurrences.

The Troubled History of the Boeing 737 Max:

The Boeing 737 Max has had a tumultuous past, marred by safety concerns and tragic accidents. The series of events began with the crashes of Lion Air Flight 610 in 2018 and Ethiopian Airlines Flight 302 in 2019, both involving the Boeing 737 Max 8, the predecessor to the 737-9. These incidents shed light on significant issues with the angle of attack (AOA) sensor, a critical component of the aircraft's flight control system.

Investigations into the crashes revealed that faulty AOA sensors provided incorrect data to the aircraft's automated systems, causing the planes to enter a dangerous flight mode known as MCAS (Maneuvering Characteristics Augmentation System) activation. This led to a loss of control and ultimately resulted in the tragic accidents.

In response to these incidents, aviation authorities around the world, including the Federal Aviation Administration (FAA), grounded the entire Boeing 737 Max fleet for an unprecedented period of over 600 days. This grounding was necessary to address the safety concerns and ensure that appropriate modifications and enhancements were made to the aircraft's systems.

Boeing 737 MAX family of airliners.

The Boeing 737 MAX family of airliners. The MAX 8 was the first release with the MAX 9, the aircraft in this incident following later. The MAX 8 and MAX 10 have yet to be released.

The Alaska Airlines Flight 1282 Incident:

On January 5, 2024, Alaska Airlines Flight 1282, a Boeing 737 Max 9, departed from Portland International Airport with its destination set for Ontario, California. However, shortly after takeoff, a door plug on the fuselage became dislodged, resulting in a sudden depressurization of the cabin. As a result, the flight crew made the decision to perform an emergency landing back in Portland.

Despite the alarming situation, the swift actions of the flight crew ensured the safety of all 171 passengers and six crew members on board. Thankfully, there were no major injuries reported as a result of the incident.

The occurrence of a fuselage blowout and subsequent cabin depressurization is a serious matter that requires thorough investigation. The National Transportation Safety Board (NTSB) and other relevant authorities will conduct a detailed air safety investigation to determine the root cause of the incident. This investigation will likely focus on factors such as aircraft maintenance issues, door plug failure, and any other contributing factors that may have led to the depressurization event.

Boeing 737-9 MAX cockpit

From the cockpit. These are the communications with the tower.

Alaska Airlines pilot: “Seattle Alaska 1282, we just depressurized, we’re declaring an emergency. We need to descend down to 10,000. We just need to depressurize...and we need to return back to Portland.”

Alaska Airlines pilot: “Hey Portland approach Alaska 1282 emergency aircraft we’re now leveling 12,000 and left turn heading 340.”

Air traffic controller: “1282 foreign approach. Good afternoon. You still have information zero?”

Alaska Airlines pilot: “Yeah, we do have information zero, we’d like to get lower, if possible.”

Air traffic controller: “Possibility 1282 descend and maintain 7,000.”

Air traffic controller: “Alaska 1282 did you declare an emergency or did you need to return to …”

Alaska Airlines pilot: “Yes, we are in an emergency, we are depressurized, we do need to return back to, we have 177 passengers. Fuel is 18-eight.”

Alaska Airlines pilot: “Our fuel is 18,900 pounds and we have 177 passengers on board.”

Air traffic controller: “Alaska 1282 roger. And do you need time to burn off some fuel before you land?”

Alaska Airlines pilot: “Negative.”

Air traffic controller: “Alaska 1282 so you’re ready for the approach now? Runway 28 left OK?”

Alaska Airlines pilot: “We need about ten minutes. Alaska 1282.”

Air traffic controller: “Roger, just let me know when you’re ready.”

Alaska Airlines pilot: “We’ll let you know. Alaska 1282.”

Air traffic controller: “Coming in a little bit, uh, unreadable, very quiet. The only information we have is a pressurization issue and 177 passengers and 18,900 pounds of fuel, and as of right now, we do not know the intentions of the aircraft.”

Air traffic controller: “The emergency aircraft will be the next arrival, they are on a two-mile final you can expect access to the runway.”

Unfolding Events:

Following the emergency landing on Friday, January 5, the National Transportation Safety Board (NTSB) promptly initiated an investigation into the Alaska Airlines Boeing 737-9 depressurization incident. The NTSB's investigation aims to determine the root cause of the incident and identify any contributing factors.

On Saturday, January 6, in response to the incident, Alaska Airlines made the decision to temporarily ground its entire fleet of 65 Boeing 737-9 aircraft for inspections. These inspections were conducted to ensure the safety and airworthiness of the aircraft. Fortunately, the initial inspections revealed no concerning findings, allowing Alaska Airlines to resume service with its Boeing 737-9 fleet.

In conjunction with Alaska Airlines' actions, the Federal Aviation Administration (FAA) issued an emergency airworthiness directive on the same day. This directive grounded certain Boeing 737 MAX 9 aircraft worldwide for specific inspections. The FAA's directive aimed to ensure the safety of these aircraft and prevent any potential similar incidents.

On Monday, January 8, United Airlines conducted inspections on its fleet of Boeing 737 MAX 9 aircraft. During these inspections, loose bolts were discovered on multiple aircraft, raising concerns about the production process. This finding further emphasizes the importance of thorough inspections and maintenance to ensure the safety of passengers.

Industry Response and Impact:

The Alaska Airlines Boeing 737-9 depressurization incident had significant repercussions on the aviation industry. One of the immediate impacts was the widespread cancellations and groundings of flights. Nearly 700 flights were canceled nationwide, affecting major airlines such as Alaska Airlines, United, Turkish Airlines, Copa Airlines, and Aeroméxico. This disruption caused inconvenience for passengers and highlighted the need for swift action to address safety concerns.

The incident also had a notable effect on Boeing's stock value. On Monday, January 8, Boeing shares experienced a significant drop of 9% as a result of the ongoing investigations and safety concerns surrounding the Boeing 737-9 aircraft. This decline in stock value reflects the impact of the incident on investor confidence in the company.

One of the challenges faced during the investigation was related to the cockpit voice recorder. The overwritten data on the recorder complicated the investigation process, emphasizing the need for extended recording times.

The Door Plug and its Significance:

The purpose of the Door Plug on Boeing 737 aircraft is to meet federal requirements for emergency exits. Some Boeing 737s, including the Max 9 variant, have emergency exits on the fuselage behind the wings. However, larger variants with more seats require additional exits. To accommodate this, Alaska Airlines and United Airlines configure their 737 Max 9s with fewer than 180 seats, eliminating the mid-cabin exits and replacing them with a permanent plug that is the size of an exit door.

Boeing 737 MAX over wing emergency exit

This is an image of the regular over wing emergency exit on the Boeing 737 MAX. With the Boeing 737 MAX 9, which is the current largest version of the type, there is an additional emergency exit behind the main wings on each side of the cabin. For airlines that order the higher density seating version of the 737-9 this emergency must be operable. Airlines that opt for a lower seating density, such as Alaska Airlines, the exit is not required. In this case the exit is hidden from the cabin interior by a wall panel. A plug, or non opening door is fitted to the outer shell of the aircraft to cover the door opening.

Ongoing Investigations and Safety Measures:

The Alaska Airlines Boeing 737-9 depressurization incident has prompted ongoing investigations and the implementation of safety measures to prevent similar incidents in the future. The National Transportation Safety Board (NTSB) has been actively involved in the investigation, and their findings have shed light on the significance of examining all components and witness marks for a thorough investigation.

One key finding by the NTSB is the location of the missing door plug. This discovery emphasizes the importance of meticulously examining all components of an aircraft during investigations. By thoroughly inspecting witness marks and other evidence, investigators can gain valuable insights into the sequence of events that led to the incident.

In response to the incident, Boeing has issued instructions for enhanced inspections of the door plug on their Boeing 737 aircraft. These instructions are currently awaiting approval from the Federal Aviation Administration (FAA). Additionally, Alaska Airlines and United Airlines, who also operate the Boeing 737-9, are seeking clearance to begin inspections on their respective fleets.

Renewed Safety Concerns:

The Alaska Airlines Boeing 737-9 depressurization incident has prompted a renewed focus on the overall safety of Boeing's Max aircraft. This incident has reignited discussions about past issues and the need for continuous improvements in aviation safety protocols.

The incident serves as a reminder that despite advancements in technology and safety measures, there is always room for improvement. It highlights the importance of thorough inspections, maintenance practices, and ongoing monitoring of aircraft components to ensure the highest standards of passenger safety.


The Alaska Airlines Boeing 737-9 depressurization incident has brought to light significant challenges for the aviation industry in ensuring the safety of the 737 Max series. As the investigation into this incident continues, it is crucial for the industry to take proactive measures to address any potential issues and enhance air safety.

Ongoing inspections and thorough maintenance practices will play a vital role in identifying and rectifying any potential vulnerabilities in the aircraft's systems. The incident has prompted regulatory bodies, such as the Federal Aviation Administration (FAA), to closely examine the safety protocols and procedures surrounding the 737 Max series.

Lessons learned from this incident will undoubtedly shape the future of Boeing's flagship aircraft. The NTSB findings from the investigation will provide valuable insights into the root causes of the depressurization incident and guide the implementation of necessary changes to prevent similar incidents in the future.


Alaska Airlines Boeing 737-9 Max Decompression Incident: Ongoing Investigation and Industry Ramifications


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