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United and Alaska Find Loose Bolts on Boeing 737 Max 9 Planes (theguardian.com) 155

UnknowingFool writes: Following the incident on Alaska Airlines 1282 on Friday where a door plug blew off mid-flight, the FAA ordered all Boeing 737 Max 9 airplanes to be grounded and the door plugs to be inspected. Both United Airlines and Alaska Airlines have now reported finding loose parts on their planes with United specifically listing "bolts" whereas Alaska only referred to "hardware." Both airlines have repaired the situation and put the planes back into service. It remains to be answered why the parts were loose and what further issues could arise.
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United and Alaska Find Loose Bolts on Boeing 737 Max 9 Planes

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  • by Joe_Dragon ( 2206452 ) on Tuesday January 09, 2024 @02:29PM (#64144877)

    who let the cost cutting PHB take over boeing?

    • by sdinfoserv ( 1793266 ) on Tuesday January 09, 2024 @03:00PM (#64144985)
      Boeing went from an engineering driven company, to a profit driven company. One example is that to cut costs, Boeing eliminated in house project managers to contracted project managers. https://www.jacobs.com/newsroo... [jacobs.com]
      Contract driven project management results in cheapest by a nickel contractors. As they gain experience and their value/price goes up, they don't win the next bid. Thus no knowledge gain across projects - classic corporate penny pinching that leads to this type of crap.
      • by jbengt ( 874751 )

        One example is that to cut costs, Boeing eliminated in house project managers to contracted project managers. https://www.jacobs.com/newsroo [jacobs.com]... [jacobs.com]

        That's a project/construction manager for construction of buildings/facilities, not for manufacturing aircraft. Having been in the consulting engineer side of construction for more than 40 years, I know that it's a very common practice for companies to hire outside entities for project management and construction management when expanding or remodelin

    • by TigerPlish ( 174064 ) on Tuesday January 09, 2024 @03:09PM (#64145017)

      who let the cost cutting PHB take over boeing?

      When Douglas bought Boeing with Boeing's own money, Boeing's tried-and-true leadership bailed out and Douglas' incapable, inept cost-cutting management moved in and changed the company culture.

      That was 1997.

      There were political motivations for this. At the time, Douglas was looking to China for potential partners. USA can't have that, no sir, so they forced this ill-advised merger.

      And here we are. I'd rather fly in a 30 year old 757 with way too many hours on its hobbs meter than set foot on any post-merger design of Boeing's.

      • When Douglas bought Boeing with Boeing's own money, Boeing's tried-and-true leadership bailed out and Douglas' incapable, inept

        Note that they weren't inept, they were inept at building airplanes. They were good at office politics. These things go hand-in-hand.

    • who let the cost cutting PHB take over boeing?

      The plug would have likely been initially installed at the manufacturer Spirit Aero. Boeing does final assembly of the aircraft after the fuselage is shipped to them. The question (still unanswered, but it will be) is who is responsible for checking the bolt's tightness. As I recall, in some cases, on some aircraft, the plug(s) may be removed to install some interior equipment (and reinstalled afterwards), but I am not familiar with the final assembly on the 737 Max 9 to know if that happened in this ca

      • Re: (Score:2, Interesting)

        by unrtst ( 777550 )

        Mostly agree, but this bit:

        In the end, Boeing takes the hit (in the public's eyes) as it is their aircraft.

        Maybe in some eyes, but what I heard was a door blew off an Alaska Airlines flight. "The bolts weren't fastened tight enough at the factory" is not an excuse that will fly with me (a guy who checked every bolt on my new bike, and rechecks them periodically, and that's just a damn bicycle).

        Fast forward to this article and we see that the airlines themselves when and checked the bolts, found them to be loose, tightened them, and returned them to service! Um... if those are user serv

        • Um... if those are user serviceable parts (Boeing told the airlines to check them; they didn't send out their engineers to check them), why haven't they been checked before?

          Because accessing those bolts requires removing two rows of seats, multiple panels, five technicians and between four and eight hours.

        • by ceoyoyo ( 59147 )

          "The bolts weren't fastened tight enough at the factory" is not an excuse that will fly with me (a guy who checked every bolt on my new bike, and rechecks them periodically, and that's just a damn bicycle).

          Do you x-ray the welds too?

          If checking the bolts is on the manufacturer's maintenance schedule and it wasn't done, then the airline is at fault. If it's not, or it wasn't recommended in the interval, then it's not. It is not a good idea to have every airline making up its own maintenance schedule from scr

          • If checking the bolts is on the manufacturer's maintenance schedule and it wasn't done, then the airline is at fault. If it's not, or it wasn't recommended in the interval, then it's not. It is not a good idea to have every airline making up its own maintenance schedule from scratch, because it is not just a damn bicycle.

            The plane that had the issue was delivered in October 2023. I am pretty sure it has very few things to check on its maintenance schedule especially a bolt behind an interior panel that no one accesses.

            • by ceoyoyo ( 59147 )

              Certain things on aircraft are inspected before and after every flight. On the 737 the maintenance A Check occurs every 500 flight hours, which on a heavily utilized airliner could be almost once a month, but is typically more like every two months.

              You're right, interior bolts wouldn't be on any of the frequent maintenance schedules, which is why airlines shouldn't be messing with them on delivery, as the OP suggested.

          • This particular aircraft that the door plug blew out on was only two months past initial flight certification. It's basically a brand new airplane.

            Alaska isn't totally without fault here either - it's not been reported that particular aircraft had the depressurization warning light come on a few times in previous flights, so it was restricted from flying an over-ocean route so they could emergency land if there was a depressurization event.

            Sorry, if that light comes on, you better positively find out why b

        • Um... if those are user serviceable parts (Boeing told the airlines to check them; they didn't send out their engineers to check them), why haven't they been checked before?

          On almost all transport (cars, trains, boats, aircraft, and even bycycles), the manufacturer sets out a maintenance schedule to be performed on a regular interval, and not before each and every trip. If every item was checked before every flight there would be more like one flight per aircraft about once every few months (the heavy maintenance can take over two months for some aircraft).

          Those forms of transport also come with extensive documentation as to how to perform that maintenance when it is neede

          • More than that, Alaska Airlines took delivery of this particular aircraft in October. It's a brand new airplane - to think that you would have to start tearing apart the fuselage to check the bolts on a god damn door plug of a 2 month old aircraft is ludicrous.

            This is nothing but another huge Boeing quality control issue.

            Oh, and apparently United has now found several MAX 9 aircraft with loose door plug bolts as well.

            This is not a "routine maintenance" issue. It's shitty manufacturing that they were very

    • There's just something *wrong* about moveable escape hatches.

    • if any one took the fall, they figured it was cheaper to ask for an exemption!
    • Capitalism, that's who!

    • by hey! ( 33014 )

      More face-saving than cost-saving. Possibly personal-bonus-saving.

      Boeing management promised to deliver so many planes in 2023, and as the year drew to a close they were behind, so they ordered the production lines to sprint [reuters.com] to meet the promises.

      Some of the things that ended up getting cut like quality control checks probably did save money in the short term, but nobody in his right mind could possibly think rushing to build something complex as an airliner is going to end well.

  • strikes again.
  • by sjames ( 1099 ) on Tuesday January 09, 2024 @02:36PM (#64144895) Homepage Journal

    Just look at all the loose nuts in the seats.

  • by Roger W Moore ( 538166 ) on Tuesday January 09, 2024 @02:38PM (#64144903) Journal
    ...given that there seems to be more than one screw loose in Boeing's management. First, they cut corners in the flight software leading to two crashes, then they had to warn pilots about not using the de-icing system too much otherwise it could overheat, now they have door panels blowing out. If anti-lemon laws applied to aircraft I suspect there would be airlines queuing up for refunds.
    • Re:Not surprising... (Score:5, Informative)

      by dgatwood ( 11270 ) on Tuesday January 09, 2024 @03:49PM (#64145115) Homepage Journal

      ...given that there seems to be more than one screw loose in Boeing's management. First, they cut corners in the flight software leading to two crashes, then they had to warn pilots about not using the de-icing system too much otherwise it could overheat, now they have door panels blowing out. If anti-lemon laws applied to aircraft I suspect there would be airlines queuing up for refunds.

      Congrats. You've noticed half of the problems that the MAX line has experience in its first six years.

      • MCAS
      • Anti-icing and risk of damaging the engine cowling
      • Door panels with loose screws
      • Extra drill holes in rear pressure bulkhead
      • Loose nuts/bolts on rudders
      • One of the engines caught fire last June right after landing because of a fuel leak

      That last one could have been a maintenance mistake, but the other five are clearly design or manufacturing mistakes, and the sixth one might be (still under investigation, I think).

      • by dgatwood ( 11270 )

        "has experienced"

        Swears at keyboar.

      • That last one could have been a maintenance mistake

        Boeing's shitty record aside, they do not make engines. If the leak was in the engine then it was more likely the fault of another company's shitty practices.

  • Obvious answer (Score:2, Informative)

    by Kisai ( 213879 )

    If the defect is found across multiple aircraft then it goes back to the question of why this "door" was plugged in the first place.

    I've watched enough aircraft accident reconstruction videos to know that if this "blew out", then the plug was not designed like the door it was supposed to replace (eg larger on the interior part of the aircraft.) And what very very likely is the reason is that the airlines wanted more passenger space so they removed the rear emergency door. They just didn't design a plug to f

    • "If the defect is found across multiple aircraft then it goes back to the question of why this "door" was plugged in the first place."

      A 'plug-door' means that the door is hold closed and tight by the difference in air pressure, meaning these doors open to the inside, like in subs, to the outside.

      But these model has doors opening the the outside, so I guess it's just shitty locks.

      • These were not plug-doors but door plugs meaning they were never meant to be opened. The door was plugged and the interior of the plane did not hint that there was a door behind it as there were seats next to it. Not sure why but the plug had bottom hinges on them held with 2 additional bolts. From what I can tell, the plugs were held in place by 4 additional bolts that United and Alaska reported as loose on other planes.
      • Re:Obvious answer (Score:5, Informative)

        by EvilSS ( 557649 ) on Tuesday January 09, 2024 @03:59PM (#64145145)
        This video has a good technical breakdown of the door and how it (is supposed to) works. https://www.youtube.com/watch?... [youtube.com]
    • There was a notorious accident caused by a cargo door being changed from an open-inwards and bigger on the inside door (plug door) to one that wasn't. The reason was inward opening doors had less cargo space to make room for the door, the new doors allowed more cargo space. The problem was the locking mechanism had to fool proof. Well it turned out that not only could the door appear to be locked when it wasn't but ground crew could force the locking lever into place even if it wasn't locked.

      https://en.w [wikipedia.org]

    • The plug exists for the fact that depending on the seating arrangement used by the airline they may or may not be required to have a second emergency exit door.

      As I have read several times about this is that this is not new to the MAX and has been the standard on 737 for a long time so either something changed in the design or some type of step is being missed. I am thinking something about the fastening design changed and is becoming loose over flight cycles.

      • As I have read several times about this is that this is not new to the MAX and has been the standard on 737 for a long time so either something changed in the design or some type of step is being missed. I am thinking something about the fastening design changed and is becoming loose over flight cycles.

        A possibility but the plane that had the issue was delivered to Alaska in October 2023 so that leads me to believe there was a problem with installation and QA. Installation as there should be a specification on the minimum torque required to tighten the bolts that should not become loose in 3 months. QA in that being that a structural component, it have been inspected and tested at least once before it went to the customer.

        • by dgatwood ( 11270 )

          A possibility but the plane that had the issue was delivered to Alaska in October 2023 so that leads me to believe there was a problem with installation and QA. Installation as there should be a specification on the minimum torque required to tighten the bolts that should not become loose in 3 months. QA in that being that a structural component, it have been inspected and tested at least once before it went to the customer.

          Not even three months. Alaska probably had final fit-and-finish work to do upon delivery. The plane's first commercial flight was on November 11. Nothing comes loose in 8 weeks unless it started out that way.

    • Re:Obvious answer (Score:5, Informative)

      by slarabee ( 184347 ) on Tuesday January 09, 2024 @04:00PM (#64145147)

      And what very very likely is the reason is that the airlines wanted more passenger space so they removed the rear emergency door.

      About 180 degrees from reality. More passengers = more emergency doors.

      There are international standards on how quickly an aircraft can be completely evacuated in case of an emergency. Evacuation times directly correlate with the ratio of meat bags that need to squeeze out emergency exits to the number of emergency exits. Airlines have great latitude in how interior seating is configured in the aircraft they order. This particular airframe, if the airline wants maximum seating, would need that 'plug' to be a working emergency exit. Alaska Airlines chose to tilt the scales a little bit in favor of passenger comfort and have their aircraft delivered from the factory with fewer seats crammed in. Those fewer seats drop the aircraft to a maximum passenger count low enough that they are not required to have this be a working emergency exit.

      Boeing does not want to have different fuselages just for different seat configurations. What they do when an airline orders a plane configured with a low enough maxiumum passenger count is 'plug' it. Remove the mechanisms that allow for a manual opening. Remove the emergency slide. Skin the inside with a cosmetic pannel that makes the interior look like a normal cabin wall. The restraining mechanisms that keep the door from opening in flight are still there. The hinges are still there. It is still a door. It just has no way for someone to try to open it and four bolts with cotter pins on the nuts are installed to physically keep the door from moving.

      Outstanding question is whether those four bolts were just missing or if the cotter pins were missing and the nuts on the bolts vibrated themselves off over time. The fact that two airlines who have ripped open the inside of their planes for inspection have reported either 'losse bolts' or 'loose parts' could be taken as 'bolts are there but the nuts were coming off'.

      • The fact that two airlines who have ripped open the inside of their planes for inspection have reported either 'losse bolts' or 'loose parts' could be taken as 'bolts are there but the nuts were coming off'.

        That would be unfortunately the best scenario is that someone did not do a good job in installation and QA. It would be worse if the real reason was the nuts cannot hold the bolts. Or cheaper bolts/nuts were used. Or Boeing changed the spec to use different bolts and nuts than previous generations, etc.

        • by genixia ( 220387 )

          The nuts are castle nuts with cotter pins. When installed correctly, the cotter pins do not move or bend in use, so work hardening fatigue should not be an issue. The question is, what broke?

          The reports that for the 3 previous flights had recorded cabin pressurization issues suggest that the plug was no longer sealed against the fuselage. That implies that either the seal failed (unlikely, IMO), one or more of the bolts yielded or snapped, a the castle nut(s) somehow loosened.

          The fact that other airlines

          • Yes as I said improper installation is the best scenario I can imagine. Faulty parts in the supply chain is problematic especially if they are not immediately distinguishable from good parts. How many of these bolts are in other parts of planes? As for Alaska, it was also fortunate that they were not at higher altitude as the decompression might have ripped a large section of plane than a plug.
          • by Mal-2 ( 675116 )

            Could they fix the problem by giving every plane a proper evacuation door rather than making it optional? I haven't been hearing about problems from the ones that took the option, so perhaps the problem exists in the plugs but not the doors. That would mean they'd have to provide the (almost certainly costlier) option and perhaps not charge for it, but at least they'd be able to continue producing and shipping.

    • by hey! ( 33014 )

      The door was plugged because in some seating arrangements a door has to go there but in other seating arrangements you don't want a door. So you build all the fuselages the same and then put door in some and a plug in the others.

      There's nothing inherently wrong with the idea of a plug that screws in where a door sometimes goes. It should be at least as safe from a design standpoint as having an actual door there. The problem is that it doesn't matter how sound your *design* is if the *assemblers* don't in

  • by cirby ( 2599 ) on Tuesday January 09, 2024 @02:45PM (#64144927)

    Then it's either astounding laziness/ineptitude, or someone did it on purpose.

    There's going to be detailed records of who worked on what - and who signed off on those actions.

    • by Anonymous Coward on Tuesday January 09, 2024 @03:02PM (#64144997)

      It's worse than that. It's extremely unlikely that a "loose bolt" would allow that door to come off. It's multiple bolts with castle nuts and cotter pins. Being "loose" would not make them fall out AND the door needs to be lifted up off of "hooks" that go over the structure that the bolts go through.

      So all of the cotter pins would have to be missing for the nut to unscrew all the way then all of the bolts would have to somehow have to slide out, then the door would have to move up and over the hooks. The last part is easily possible but all of those nuts and bolts falling out is damn near impossible even with the poorest quality control.

      I'm thinking there is a possibly the bolts weren't even installed.

    • Detailed records cost time and money. Watch the investigation find no records or botched paperwork. So in the end it’s really nobody’s fault so nobody can take the blame.

    • I do not know for sure but this has to be a systemic failure. I would speculate that a structural component like bolts that hold a critical component has specifications like minimum torque so they do not become loose. Any work involving structural components should have also been inspected and passed by QA. It will be interesting where the multiple failures occurred.
    • Then it's either astounding laziness/ineptitude, or someone did it on purpose.

      That may be an immediate cause, but it's not the root cause. The root cause is poor QA/QC practices that allow a lazy/inept/malevolent person to cause this issue.

  • One thing that gets me is why is the plug even there? It doesn't seem to be suitable for normal access and its presence seems to create a structural weakness. Is this a side effect of the way th 737 Max 9 is manufactured?

    • by Midnight Thunder ( 17205 ) on Tuesday January 09, 2024 @02:49PM (#64144945) Homepage Journal

      Did a bit more hunting and found the following article:

      https://www.travelcodex.com/wh... [travelcodex.com]

      The relevant paragraph states:

      Airlines can order an aircraft with whatever number of seats that can legally fit in that aircraft. It is for this reason that the door plug exists on the Boeing 737 MAX 9. Most 737 MAX 9 aircraft have less than 190 seats so the standard four exit doors and four overwing exits will satisfy the emergency egress requirement. RyanAir orders their Boeing 737 aircraft with high-density seating where there are 199 seats or more. On the RyanAir aircraft, the plug door is an actual full-functioning exit door. All airlines flying the MAX 9, have opted for the less-expensive door plug instead of a full-functioning exit door because these aircraft have less than 190 seats. It is interesting to note that the airline that has the functioning exit door, RyanAir does not fly the 737MAX 9. They currently fly a high-density seating 737 MAX 8-200 with 199 seats. This unique MAX 8 aircraft does have full-functioning doors at row 28.

    • One thing that gets me is why is the plug even there? It doesn't seem to be suitable for normal access and its presence seems to create a structural weakness. Is this a side effect of the way th 737 Max 9 is manufactured?

      The plug is used when the airline selects a seating configuration that does not require another emergency exit. AFAIK none of the US airlines need that exit door due to their seating choices so all have plugs (while in some other countries the airline packs as many people as possible into the plane so requires the plug to be replaced by an emergency exit).

      Using a plug allows some weight savings, and also make the experience of being in that row more consistent in the airplane.

      Other models/versions of

    • by ibpooks ( 127372 )

      The plugged door on the Max 9 is optional depending on how many seats the airline decides to put in. The aircraft is certified for a range of different seating configurations, and in the most dense variations an additional exit door is necessary given the number of passengers. In the seating config Alaska uses, the extra exit door is not required, so it is plugged.

    • One thing that gets me is why is the plug even there?

      The Boeing 737 Max 9 has 10 doors in base configuration; however, all doors are only required by safety regulations if the plane has maximum seating capacity. For some airlines, they have multiple seating classes so they do not seat maximum capacity and are not required to have all 10 doors. So they will plug the door and put a row of seats there. This specific door makes more sense as the front and rear doors are used for loading the plane and supplies. The wing doors also do not make sense to plug either.

  • In an earlier article I said it was too early to assign blame. Let's see, in the past month, loose rudder bolts and now loose bolts found again. It seems evident that Boeing has lost its way. This 737 Max debacle has already killed 346 people and it looks like that count may continue to rise unless these piles of junk are pulled from service. There is no way in hell I would ever fly on recent Boeing aircraft. Airlines would be best to avoid Boeing like the plaque from this point forward. Boeing is done, bot

    • by ibpooks ( 127372 )

      Literally every aircraft of every manufacturer ever built has an extensive list of inspect, eddy test, dye pen, replace, retorque, calibrate, rebuild, lubricate items on the mandatory maintenance lists. Some of these are airworthiness directives, some manufacturer service bulletins, some airline SOPs, some maintenance manual checklists, some just in the experience of seasoned mechanics. Just because a few of them have made the news on Boeing aircraft doesn't mean the list is any smaller or less impactful

  • Have you seen the price of threadlocker lately?

    I for one am prepared to give Boeing a complete pass on this one.

  • Some loktite red and slap it on them bolts. Good as fixed.
  • All the bolts in first class torqued down real good though
  • Damn, aviation figured this out decades ago, it needs to be designed for an use rivets.

    https://aviation.stackexchange... [stackexchange.com]

  • with United specifically listing "bolts" whereas Alaska only referred to "hardware."

    I wonder if Alaska Airlines didn't want to use a more specific term because the door was being held on with drywall screws.

  • Someone on Reddit speculate: https://www.reddit.com/r/boein... [reddit.com]

    Spirit assembled these units for temporary installation as required to plan, and so these bolts were never final torqued and the crown nuts on the other side are not wired.

    This is because planning called for Boeing to disassemble the fitting during installation,

    and then Boeing was to reinstall the fitting, and included in the reinstall procedure were the steps to final secure and pin or wire the nuts on the far side.

    Someone at Boeing figured out

    • [process failure deleted for brevity]

      If that's what caused this, then more proof that bureaucracy kills. smh. Project / planning failure.

      Even more stunning -- this airplane had lit indicators before about pressurization issues and the airline chose to still fly it in revenue service.

      That's like one of us running the car with the CEL / MIL not just lit -- but flashing.

  • I have a broken one in my workshop too.

  • by tiqui ( 1024021 ) on Wednesday January 10, 2024 @02:37AM (#64146107)

    There is supposed to be a somewhat hostile (at least SKEPTICAL) relationship between a regulatory authority like the FAA and an entity it regulates, like Boeing. Human beings are flawed, corruptible, temptable, and yes just plain lazy and greedy. As a result, any large entity full of humans is going to be at risk of bad behaviors. This means Boeing needs the FAA to look at them and their work with a skeptical eye. It also means congress needs to do proper oversight and look at the FAA with a skeptical eye. There was another skeptical eye that was required, but which totally failed - the federal government's anti-trust folks NEVER should have allowed Boeing to merge with its only remaining domestic competitor. I would argue that the Pentagon also should never have purchased aircraft from any company not also making civilian aircraft (this would have forced Lockheed to stay in the commercial market, including as an airline builder in order to be able to still feed at the Pentagon's giant cost-plus program funding trough).

    With Lockheed dropping out of civilian airliner production after the L1011, and then Boeing merging with McDonnell Douglas, The USA only had one builder of passenger planes, and thus it became both a national security matter and a matter of national economic policy that Boeing needed protection. With that, the un-written rule in government became that Boeing could not be harmed. The FAA could scold them, but was never going to come down on them hard enough to put them at real risk. In that environment, it's not surprising that the FAA allowed Boeing to inspect and certify its own work. This might have worked as long as the old Boeing people were still around, but the WWII generation are gone, the generation that did the 747 and the original 737 are gone, and the hired-gun executives (many of whom came over from MD in the merger, but some of whom are post-merger with ZERO corporate memory of the old safety-first Boeing teams) are mostly "bean counters" rather than aircraft designers and builders. Your average maker of small propeller-driven planes is probably more scrutinized by the FAA at this point than Boeing. Just consider that, after TWO fatal 373Max crashes and all the public outcry, one would have expected the FAA to give the entire Max program a safety colonoscopy, but clearly that did not happen. Just like it did not happen when 767-based air tankers were delivered to the USAF with loose TOOLS banging about in the airframes.

    My European friends may choose to chuckle over this, but the European regulatory overseers have a similar relationship with Airbus (which similarly replaces multiple legacy European airliner builders). Air France 447 comes to mind with its known pitot tube problems. Just as the American regulators cannot be seen sabotaging the remaining American airframer, the European regulators cannot be seen destroying Airbus. And given the alliances across the Atlantic, American regulators need to accept the European stuff and European regulators need to work with and accept the American stuff. This is very BAD and more manufacturers are needed competing on BOTH sides of the Atlantic, not only to restore some normal market forces, but also to make it so that no single plane builder is too vital to its economy and government to be allowed to fail.

Keep up the good work! But please don't ask me to help.

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