Alaska Airlines flight 1282 NTSB preliminary report [pdf]

Also posted on DocumentCloud, since NTSB servers aren&#x27;t responding (as of this comment)<p><a href="https:&#x2F;&#x2F;s3.documentcloud.org&#x2F;documents&#x2F;24410269&#x2F;report_dca24ma063_193617_2_6_2024-2_15_12-pm.pdf" rel="nofollow">https:&#x2F;&#x2F;s3.documentcloud.org&#x2F;documents&#x2F;24410269&#x2F;report_dca24...</a>

A very thorough preliminary report. I&#x27;ve worked for a long time in quality systems, and this is a perfect example of a systemic failure. They&#x27;ve got work being handed off between Boeing employees and 3rd party contractors with insufficient controls in place to verify that very basic tasks are being performed.<p>I&#x27;d be curious to know how many non-conformances they typically see during assembly of a plane and whether management is actually allowing the quality department sufficient independence to investigate these issues and fully resolve them. I&#x27;m guessing that the production personnel are under tremendous time constraints and are constantly pressure the quality assurance people to sign off on whatever paperwork is holding up the line, no matter the safety implications.<p>Also, I think a lot of middle and upper level management needs to lose their jobs over this. I hope this mess ends up in textbooks and gets beaten into the head of every MBA student in the country.

The report seems to mesh with and confirm many details of the anonymous insider account at <a href="https:&#x2F;&#x2F;leehamnews.com&#x2F;2024&#x2F;01&#x2F;15&#x2F;unplanned-removal-installation-inspection-procedure-at-boeing&#x2F;#comment-509962" rel="nofollow">https:&#x2F;&#x2F;leehamnews.com&#x2F;2024&#x2F;01&#x2F;15&#x2F;unplanned-removal-installa...</a>. The bolts were not reinstalled following work on the plug rivets&#x2F;seal. The official system doesn&#x27;t record that work was done requiring the bolts to be removed.

The fact that a critical piece of the evidence was cell phone photos sent between workers coordinating door re-assembly doesn&#x27;t exactly instill a whole lot of confidence in their permit-to-work process. I didn&#x27;t like it when it was medical teams doing shift handover via a Google Doc, and I don&#x27;t like it when it&#x27;s a matter of flight safety either. Or, as Homer might eruditely say: &quot;guess I forgot to put the bolts back in&quot; [1]<p>[1] (<a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=IiNPLIauEig" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=IiNPLIauEig</a>)

&gt; Overall, the observed damage patterns and absence of contact damage or deformation around holes associated with the vertical movement arrestor bolts and upper guide track bolts in the upper guide fittings, hinge fittings, and recovered aft lower hinge guide fitting indicate that the four bolts that prevent upward movement of the MED plug were missing before the MED plug moved upward off the stop pads.<p>Ooofff. No bolts at all! How did this pass Boeing QA?

Looks like the anonymous whistleblower on Airline Pilot Central Forums [0] was legit.<p>[0]: <a href="https:&#x2F;&#x2F;www.airlinepilotforums.com&#x2F;safety&#x2F;146074-boeing-internal-whistleblower-re-max-door.html" rel="nofollow">https:&#x2F;&#x2F;www.airlinepilotforums.com&#x2F;safety&#x2F;146074-boeing-inte...</a>

A lot of comments here are going on about process, as if humans are mindless and otherwise perfectly controllable robots...<p>I&#x27;m going to be contrarian and say that this is exactly the sort of thing that happens when you train humans to be robots: They lose all signs of common sense and critical thinking, and what&#x27;s worse is that on top of that, they&#x27;ll still have their inherent imperfection. Normally the former would counteract the latter, but not if you only make them rigidly follow some process all the time. They stop thinking about what they&#x27;re doing. They stop paying attention to all the other things in their environment they would&#x27;ve noticed, and even if they do, they won&#x27;t question it because they&#x27;ll just assume someone else also following a rigid process will take care of it. They won&#x27;t think &quot;this door plug should&#x27;ve been bolted in place now that the work that needed it opened is done, but where are the bolts?&quot;<p>I&#x27;m not saying to throw out all the process and make them figure everything out, but I think there has to be a balance, similar to how overautomation and reliance on that has also lead to avoidable incidents in aviation.

Summary: Fuselage was delivered to Boeing with some damaged rivets near the door plug. They had to remove the door plug to fix the rivets. Then they reattached the door plug but forgot to reattach the 4 bolts that would keep it in place. Possibly because of a shift change at the plant.<p>There was noticeable damage to the door plug&#x27;s mechanical fittings from the violence of it being blown out of the plane. But the holes where the bolts belonged were pristine. That would not have been true if the holes had had bolts in them.

&gt; The accident airplane was required to be equipped with a CVR that retained, at minimum, the last 2 hours of audio information, including flight crew communications and other sounds inside the cockpit.<p>&gt;The CVR was downloaded successfully; however, it was determined that the audio from the accident flight had been overwritten. The CVR circuit breaker had not been manually deactivated after the airplane landed following the accident in time to preserve the accident flight recording.<p>Classic. If they use CD quality audio at 1411kbps, they can store 2 hours of audio in about 1.2 GB. Given how cheap flash is these days, why not 20x that so that we don&#x27;t have to rely on people pulling circuit breakers after accidents? If there&#x27;s some concern about robustness and recertification, why not require all aircraft to carry two CVRs, one of the old &quot;robust&quot; style for kinetic accidents, and one that&#x27;s less robust but has 20x the capacity, so we can record a full day after less violent accidents?

&gt;[evidences] indicate that the four bolts that prevent upward movement of the MED plug were missing before the MED plug moved upward off the stop pads.<p>Ok<p>&gt;Photos from the interior repair that show the lack of bolts<p>Huh. Well that&#x27;s conclusive.

&gt; The flight crew reported that the cockpit door had opened during the depressurization event. In a revision to the Flight Crew Operations Manual, issued on January 15, 2024, Boeing confirmed that the door functioned as designed.<p>Interesting for terrorists. Cause a rapid decompression, and get easy access to the cockpit.

If people are looking for additional in-depth reading on how this happened, The Air Current did a great write-up on this systemic mistake using internal Boeing sources a month ago that the NTSB report fully supports: <a href="https:&#x2F;&#x2F;theaircurrent.com&#x2F;aviation-safety&#x2F;127-days-the-anatomy-of-a-boeing-quality-failure&#x2F;" rel="nofollow">https:&#x2F;&#x2F;theaircurrent.com&#x2F;aviation-safety&#x2F;127-days-the-anato...</a>

I wonder how close the door plug was to hitting the tailplane or vertical stabilizer&#x2F;rudder?

Depressurization happened around 17:12:33 PST but the aircraft continued to climb until 17:13:41 PST, and the autopilot was configured for 10k ft at 17:13:56 PST. Why did it take the pilots a full minute to begin an emergency descent after the failure? I would expect that the nature of the accident would be clear nearly immediately, at least in the need to descend the aircraft.

&gt; The accident airplane was required to be equipped with a CVR that retained, at minimum, the last 2 hours of audio information, including flight crew communications and other sounds inside the cockpit ... The CVR was downloaded successfully; however, it was determined that the audio from the accident flight had been overwritten. The CVR circuit breaker had not been manually deactivated after the airplane landed following the accident in time to preserve the accident flight recording<p>How the fuck is this still a problem on brand new aircraft?

You gotta wonder how the technician explained away the four leftover bolts after

anyone have a copy hosted? it&#x27;s currently overloaded and not responding

I look forward to reading a report from NTSB&#x27;s internet outage.

Seems to solidly confirm the leak.

&gt; In a revision to the Flight Crew Operations Manual, issued on January 15, 2024, Boeing confirmed that the door functioned as designed.<p>Smells like CISCO

&quot;....after the left mid exit door (MED) plug departed the airplane leading to a rapid decompression&quot;<p>Lol, they said the door plug &quot;departed&quot; instead of &quot;blew the f** off&quot;

What is the analogy of leaving out all bolts from that door?<p>&#x27;Forgetting&#x27; to put in any of the screws holding a gas tank in place in a car?<p>&#x27;Missing&#x27; all welds in one of a skyscraper&#x27;s lower columns?<p>An &#x27;oversight&#x27; of providing rendundant instruments in an airplane with natural tendency to stall?<p>What a hopeless shitshow is going on there behind the company gates that these kind of things can happen in succession?<p>A duck forgot how to swimm, an eagle forgot how to fly, Boieing forgot how to build airplanes?

&gt;The CVR was downloaded successfully; however, it was determined that the audio from the accident flight had been overwritten. The CVR circuit breaker had not been manually deactivated after the airplane landed following the accident in time to preserve the accident flight recording<p>In addition to local storage, why isn&#x27;t the audio(along with location, altitude and some sensor information) also streamed using something like Starlink or Inmarsat to a secure location where you can store more data for cheaper and with more redundancy?