long story short:
1. boeing and spirit both work on planes
2. damaged rivets discovered and lots of back and forth to get them repaired. boeing does the doors and spirit does the rivets.
3. rework on rivets needed door plug to be removed, someone at boeing (who is not onsite) sees that the door plug needs to be removed, escalates this request but notes that work must wait for the next week because the only door person who is qualified to remove plugs is on leave.
4. door manager - on the day of the plug removal - de-escalates the door plug removal request. later that day the door manager, door master and three door crew enter area near the fuselage & door plug - correct documentation of removal not generated and none of them were trained to remove door plug. No one knows who removed the plug.
5. a boeing technician moves a stand that has what he believed to be a door plug bolt on top of it. he "strapped it and let it hang" to the fuselage.
6. Spirit indicates plug was removed and reworks rivets
7. No one checks the door plug was reinstalled correctly
Also, Boeing spun off Spirit in 2005 to juice its own profit margins, so the poor coordination between these two entities is ultimately Boeing's poor judgment. And more specifically that of Harry Stonecipher, perhaps the worst American CEO this side of Jack Welch.
A benefit of being a golden child business to the US government is you don’t have to worry about economic consequences like a normal business. They’ll still make money off gov contracts and the “local jobs” monopoly system that congress protects like the mob.
Yep. A "strategic defense contractor" can do whatever it wants[0], and get away with even more[1] than the United Fruit Company (UFC).[2]
0. https://www.seattletimes.com/business/boeing-lawsuit-alleges...
1. https://thehill.com/newsletters/business-economy/4793579-boe...
Yep. And it's all fruit of the MD management takeover in '94.
https://www.economist.com/news/2014/11/17/the-trouble-with-m...
Boeing also had a rivet problem on Japan Air Lines Flight 123 in 1985 and 520 people died.
> The crash is the deadliest single-aircraft accident in aviation history…caused by a faulty repair by Boeing technicians
Extremely sad to learn this. It could have been prevented.
4. Someone knows who removed the plug, but they're not about to fess up to it because they totally fucked up.
Full NTSB report https://www.ntsb.gov/investigations/AccidentReports/Reports/...
Damn son, thanks
I really love reading NTSB and Coast Guard break-downs... a lot of very interesting engineering!
The Air Force and Navy aviation also usually release public reports outside of internal investigations and/or court-martials on their mishaps.
Pretty neat how you’ve become so good at summarizing what looks stupendously opaque to me.
Thanks.
If a publisher was so inclined, I have like 20 or so of these breakdowns that I would like to put into a (<75pg) book. The goal would be 1-3 page distillations of events for broad appeal. 1 page for the introduction and impact of the event, 1-2 pages for summarization and conceptual distillation.
The goal is a somewhat reductive but sharply results-focused perspective on these events.
Having been on an air crash investigation kind of vibe since the Air India accident, I have conflicting opinions on boeing.
On one hand, their quality control, engineering etc has been declining, not to mention the suspicious deaths of whistleblowers..
But on the other, the fact that each pilot can see and feel immediately what inputs the other is applying is such a huge advantage compared to airbus’ fly by wire.
There are at least 3 accidents on airbus planes which can effectively be attributed to dual input. Loss of situational awareness, highly technical changes in the way the aircraft controls (why would this ever be a good idea), given certain circumstances.
Imagine dying because of the different between ‘pull down’ and ‘push down’. On a boeing, when the captain pushes the nose down, you see immediately what he means. On an airbus, you’re dead by the time the captains input override is acknowledged.
There are definitely pro’s to the airbus system but why cant we add input feedback?
FWIW Airbus has tested a force-feedback side stick. Why they don't already offer it as an option I do not know. Maybe they are calmer now but for decades they took the attitude that "We built an un-crashable airplane because we are smarter than you" and took any criticism as a personal attack.
If you're curious the 757, 767, 777, and 787 are all fly by wire but use both physical linkage under the deck and force-feedback servos to transmit control surface feel back to the pilots. But they also have torque tubes that can be overpowered and ... shocker... in a dual input situation they do the same as Airbus: average the inputs. But at least you have to really yank on the controls to make that happen.
> But on the other, the fact that each pilot can see and feel immediately what inputs the other is applying is such a huge advantage compared to airbus’ fly by wire.
Confusion is still possible on Boeing aircraft[1] (the incident happened with an Air France 777 in 2022. AvHerald has more direct quotes from the official report.)
[1] https://www.flightglobal.com/safety/opposing-dual-inputs-con...
What's the latest on Air India? Fuel Switches were last I saw and if it means one pilot is able to disengage unilaterally, it kind of falls into the same area about design philosophy (I think they are located on diff areas for diff planes).
I suspect this brief lecture (2 parts) on automation dependency will be right up your alley: https://www.youtube.com/watch?v=WITLR_qSPXk
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The NTSB remains very good at its job and should serve as a model for government. A beacon of hope.
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I think even most GOP politicians understand that they fly a lot and have no desire to defund the FAA or the NTSB
You sure about that? They were pitching cuts to air traffic control in the past:
https://www.transportation.gov/briefing-room/national-fact-s...
They have not happened. There is actually a big push to modernize the air traffic control system
The FAA allowed us in the place that Boeing could get itself into this situation. Allowing Boeing to self certify was just bizarre at best. The NTSB report is much too kindly worded for my liking, but that's why I'll never be a political creature
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Are you saying no one important is being DOGEs or that they can all be and the industry will self-police?
It is tough to understand your snark.
Not worth feeding the troll. Starve him out and he'll find his way back to Reddit.
11yo account, ample points. Seems more like your standard snarky HN user who reports every political post and then comments on it.
He appears to command a brigade, going by the vote count. Amusing to watch, but a little sad as well.
It's vastly more likely that the extremely vocal minority you represent are just outnumbered by rational thinking individuals...
That must be it
Part of me wonders if the plug could be designed such that it's obvious when the bolts are missing. Would this have happened if it were impossible to assemble without them, or if it were easy to verify their presence?
Maybe it doesn't matter if a better design is possible - if adequate procedures exist and weren't followed, and oversight fails to catch instances of that, then anything could go wrong.
I believe that's what this directive is for:
"To the Federal Aviation Administration:" " Once you complete the certification of Boeing Commercial Airplanes’ design enhancement for ensuring the complete closure of Boeing 737 mid exit door (MED) plugs following opening or removal, issue an airworthiness directive to require that all in-service MED plug-equipped airplanes be retrofitted with the design enhancement. (A-25-15)"
This article: https://aerospaceglobalnews.com/news/boeing-completes-design..., suggests that the design enhancement will add "secondary retention devices" that "prevent installation of the cabin sidewall panels unless they are properly engaged." The article indicates that the existing bolts will also get lanyards that will "'permanently secure the bolts to the plug' and provide a visual indication' of whether they have been installed correctly."
Apparently, if only one of the four bolts was installed, it may have been sufficient to prevent the accident, according to: https://www.nytimes.com/2025/06/24/us/politics/boeing-alaska...
It sounds like Boeing is doing a design enhancement. I found this article [1] that describes features for the bolts as:
> The fix also includes adding lanyards atop the door-plug bolts to “permanently secure the bolts to the plug” and “provide a visual indication”, says Crookshanks. “They’ll hang there and be visible to a mechanic that had taken the bolts out.”
[1] https://www.flightglobal.com/safety/details-emerge-about-boe...
The general principle would be making other parts with interference fit such that it or they visibly do not align without properly tightening/attaching parts below/about them. For example, the door plug should not sit in the correct position unless door plug bolts are all tightened and untightened door plug bolts shouldn't allow installing other parts like trim pieces to be flush.
Every critical step should be as "idiot-proof" as possible, until better idiots are created who hammer structural parts into position to meet management-mandated arbitrary deadlines.
I don't know if you were joking about the hammer or referring to a Russian assembly worker who used a hammer to install accelerometers in a rocket into a wrong position which caused it to attempt to fly downwards (no people were injured) [1].
[1] https://en.wikipedia.org/wiki/Proton-M#Notable_launch_failur...
No, unfortunately, I'm not joking. The 737 NG and MAX fuselages were assembled inconsistently and badly for 20+ years. Bear straps and other critical parts were percussively persuaded into place.
Note that you can solve that last problem but you need to think outside the box.
Hammering structural parts which don't want to go is hard work and if your workers have union protection you can bet they'll say "No". So what you need are strong union protections so that they feel able to say "No" when asked to do unreasonable things. Does that mean they're going to be a little harder to manage? Maybe, but mostly it means "Rule by fear" doesn't work and leadership might need to learn to inspire not threaten.
Union protections help in one place you're already familiar with. If your pilot says "No, I don't like those clouds at all" and won't fly, the airline can't fire them for that. That's their judgement, if you fire pilots who you feel aren't risking passengers necks to make the line go up you're not going to have any pilots at all.
Historically it helped for traffic control, but that's OK our old friend, Cowboy Actor and Friend of the Working Billionaire, Ronald Reagan smashed that, so now traffic control has the shocking poor working conditions Corporate America loves.
> Once you complete the certification of Boeing Commercial Airplanes’ design enhancement for ensuring the complete closure of Boeing 737 mid exit door (MED) plugs following opening or removal, issue an airworthiness directive to require that all in-service MED plug-equipped airplanes be retrofitted with the design enhancement. (A-25-15)
It sounds like Boeing is currently working on designing and certifying a design enhancement to the MED plug to make it obvious if one is not closed properly. Not sure where to find the details on it though.
The plugs are designed to be semi-permanent because they are only for emergency exits on certain high-capacity seat layouts not used by most US airlines (or any airline that has first class seats I believe). When you have more seats you need more exits.
Given their nature the original intent was probably that they were secured at the factory and never touched. But because they are convenient for access during maintenance/inspection they get used more often.
This issue, the oxygen mask, and the child restraint issue are the NTSB doing the proper "what if things had been slightly different" calculation.
Airline maintenance removes and reinstalls these doors. They could accidentally commit the same error so Boeing should change the design such that the door will not stay in-place when the bolts are removed. Could be as simple as springs that force the plug open without the bolts. If the door won't stay closed without the bolts like a light switch it will be forced to clearly show when it is safe vs not.
Child restraints were mentioned partially because if a lap child had been in that row they'd have been sucked out by the decompression and free-fallen 14000 ft. It was entirely luck that it didn't happen.
Oxygen masks mentioned because the pilots had some trouble getting them on in a timely manner. If the incident had been sudden onset of thick toxic smoke one or both could have passed out before getting the mask on and oxygen flowing. That's like a fire extinguisher with a complicated pin mechanism. Adrenaline dump during emergencies ruins fine motor control, critical thinking, etc. The worst possible time to have something be fiddly and complicated. You want it to be muscle memory. So trivial a 5 year old child could do it without being taught.
And the CVR issue is just the NTSB mentioning that yet again for like the 100th time the CVR circuit breaker was not pulled so we lost the recording and any potential learnings to be had from examining them. This is a problem that just keeps happening over and over. Because it relies on pilots, after a huge emergency, to remember to pull a circuit breaker when they have a thousand far more important things to worry about (not to mention coming down from the adrenaline high) and the thing only keeps the last two hours... which was a standard set when they were continuous loops of wire before the switch to magnetic tape. All the new ones are little computers and flash chips.
> Given their nature the original intent was probably that they were secured at the factory and never touched
Specifically in this case, that factory being Spirit Aerosystems in Wichita where the 737 fuselage is manufactured. Part of the problem here is that Boeing in Renton didn't have processes for removing the MED when necessary on the final assembly line (in this case to rework rivets near the door). Without processes, there was one senior guy on the door team who taught himself how to do it, this was only needed a few times a year, but he was on vacation when this airframe needed the MED removed. Someone else did it (the NTSB couldn't determine who), the work wasn't tracked, and a separate team (the team literally sealing it up so it could be moved outside) put the MED back in but didn't install the bolts (which were gone).
>. If the incident had been sudden onset of thick toxic smoke
Pinpoint "seems reasonable" changes like that without regard for the whole system of interactions are what sank Thresher.
The "sudden onset of thick toxic smoke" is rare. It's either not that toxic or the onset isn't that sudden. You can't just design the system based on assumptions of needing to cover a rare corner case without taking a look at the whole general thing and the frequency of various anomalies and crunching the numbers to see if you're not actually making it worse. I agree that the masks should be simple and reflexive but you absolutely could compromise the whole system if you prioritize reflexive over other attributes without actually taking a full stack look at the tradeoffs in all areas. Aircraft manufactures employ people to think about this stuff and they're frequently why "seems reasonable" changes don't get made.
That's true and part of the reason designing for aerospace applications is tricky.
That sort of thing is also one of the legitimate reasons the FAA can have for not adopting an NTSB recommendation. Requiring a seat for small children is one of those calculations. The FAA ran the numbers and assumed some portion of those parents wouldn't fly and of that portion some would drive. Some portion of flights are for physical or emotional health that would not be handled (you can calculate the increase in suicides from things like missing a loved one's dying moments). And of course driving is way way more lethal. So you have to weigh the deaths from not flying plus deaths from driving against deaths avoided if lap children were prohibited.
> Because it relies on pilots, after a huge emergency, to remember to pull a circuit breaker when they have a thousand far more important things to worry about (not to mention coming down from the adrenaline high) and the thing only keeps the last two hours...
Clearly, relying on people to do this after the incident doesn't work, but.. shouldn't this be in like the post-incident checklist?
Either a checklist for the pilot, or an incident manager... there's got to be a list of things to do, and pull the breaker on the recorder isn't going to be high on the list, but I would think it would be on it.
i think proximate/ultimate breakdown would be more readable here. Proximate cause: poor installation. Ultimate cause: bad docs and quality control.
Don't worry, as a consequence , Boeing is being awarded contract after contract by the current administration.
Remember:
McDonald-Douglass management (of the Jack Welch school) took over at Boeing post-merger. Widgets are widgets and people are just another kind of widget. Job #1 was to screw labor and engineering out of money so that money could go into management's pocket (in the name of shareholders but screwing shareholders is also part of the deal).
They moved HQ away from Seattle specifically so engineers and production personnel couldn't stomp into management's offices and yell at them about safety or anything else.
Then they started outsourcing whatever they could to remove as many people as possible from Boeing's union contracts, corporate benefits, etc and replace those highly paid professionals with the cheapest bodies they could find. After all - the Jack Welch school of thought is the Important People (managers) just need to break down the process (any process) into enough small simple steps that a monkey could do it. Then you could hire the cheapest possible unskilled labor and pay them peanuts but it wouldn't matter because a widget is a widget. People are just widgets. Swap an expensive widget for a cheap one. Duh.
This first came home to roost on the 787 project. Boeing outsourced vast amounts of the project which came back to bite them in the form of delays. They were supposed to start flying in August 2007 and deliver to customers in 2008 but horrible subcontractor designs, rework, unfinished work, etc led to huge assemblies arriving in Everett in a shambles. Repeated delays meant the first aircraft wasn't delivered until September 2011 a full three years behind schedule. Boeing had to buy back in-house a number of their contractors to even make that happen.
That was promptly followed by battery fires that grounded the entire 787 fleet for part of 2013. The first grounding of a transport category airliner since 1979.
Did I mention the 787 had quality problems from 2019 until 2023 (some say ongoing problems even up to today), resulting in missing fasteners (!!!), improperly installed fuel lines, and other issues. For some time they not only had to halt deliveries they had to halt production.
Does any of this sound familiar? It should because the exact same issues plagued the 737 MAX from the start! Rushed engineering without internal peer review or proper consideration (single data source). Rosy assumptions about how pilots would handle various emergencies. Outsourcing to screw labor. Terrible mis-management. Incompetent contractors. Complete lack of process control inside Boeing and complete lack of shits given by Boeing management at any level. Callus lack of regard for any human anywhere (passengers, pilots, airline employees, their own employees)... Boeing knew there was a problem with MCAS and their published guidance wasn't the final word but lied to Ethiopian airlines about it (whos pilots asked some excellent pointed questions). Those lies likely directly leading to the second hull loss event.
Also the same expensive "solutions". Huge re-certification of their process and self-certification procedures. Buying back in-house contractors they originally spun out to cut benefits.
And the 737 MAX itself being a terrible idea, cancelling the clean-sheet A32x competitor in favor of more duct tape and bailing wire on a design with way too many manual reversion modes. On the 787 alternate gear extension is a button press. Dual generator failure auto-starts the APU and deploys the RAT. Electric re-routes automatically. On the 737? LOL nope. All manual. Manual gear means copilot has to stand up, get behind their chair, open a floor panel, then pull three separate cables to about chest-height. Bird ingestion dual engine failure at 1500ft? Not a chance that's happening. But hey according to Boeing's new CEO that is all fine, we aren't doing "the new airplane".
The amount of value destruction of Boeing as a company, Boeing's market share, Boeing's brand, and ultimately Boeing's share price as a result of management trying to screw over labor and taking a short-term view of everything is jaw-dropping.
Nothing has changed at Boeing. They got caught with their hand in the cookie jar. They are doing the absolute bare minimum to make everyone shut up about it and get back to the status quo. How many more times are they going to lose self-certification status? How many more times will they be told to overhaul internal procedures and come up with yet another System to make sure they follow their own rules. All the while management keeps rewarding themselves for outsourcing, cutting pay/benefits, and business as usual. How long will this supposed new quality attitude last? Anyone gonna get promoted to SVP because we didn't have anymore accidents? Gotta weigh that against the exec who outsourced production of control surfaces so we could lay off 500 machinists at $150/hr fully loaded so a contractor can hire $25/hr smucks to do the work thus saving us millions. Gee wonder who's gonna get that promotion after all?
> dDevelop guidance
Good to know it was written by a human and not an LLM.
> We determined that the probable cause of this accident was the in-flight separation of the left MED plug due to Boeing’s failure to provide adequate training, guidance, and oversight necessary to ensure that manufacturing personnel could consistently and correctly comply with its parts removal process, which was intended to document and ensure that the securing bolts and hardware that were removed to facilitate rework during the manufacturing process were properly reinstalled.
A bit OT, but what a gorgeous whale of a sentence! As always, the literary prowess of NTSB writers does not disappoint.
Also, I really appreciate the way they put blame where it belongs. They don't say "manufacturing personnel failed to ...", they say "Boeing failed to provide adequate training, guidance, and oversight necessary to ensure that manufacturing personnel could consistently and correctly ...".
Agreed about properly assigning the root cause to inadequate training but the sentence was unnecessarily complex in not making the first order cause clear until the end. I'd prefer stating up front that the first order cause was "securing bolts and hardware that were removed to facilitate rework" were not reinstalled - and then stating the root cause leading to that being inadequate training.
In the context of a summary I just expect the core sentence to take events in order from the headline failure ("in-flight exit door plug separation") and then work back to the root cause.
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> the sentence was unnecessarily complex
I don’t see it that way. It’s designed for consumption by educated readers. A press release can dumb it down to middle-school reading level so the media can dumb it down to grade-school level for the masses.