The media stalking the crew and the passengers just so they can be the “first” to report some sensationalized news that probably isn’t even true is gross.
Agreed. Chances are good that no one in that cabin knew that things were relatively stable once the pressure evened out, and so of course it would have been terrifying!! Let those poor people have a bit of time and speak when and if they want to.
“We found today that the cockpit door IS designed to open during rapid decompression…” What the heck ??? You’re the NTSB and this is something super basic that you should have known. I’m just a member of the public and I know this. You are completely incompetent if you just found this out “today” as you state. Lord help us.
It was excrutiatingly difficult to listen to the explanations, without visual demonstrative tools, by those that are not mechanically educated to those that are not mechanically educated. As a retired A&P, my opinion is that there is lots of room for improvement. That being said, their efforts to disseminate information are admirable. I hope they can achieve better techniques soon. Cheers from Texas.
NTSB [and NASA] are part of a tiny minority of agencies chartered for doing real jobs for the benefit of the public. Most other federal agencies fail because they are given arbitrary rulemaking and enforcement authority that is inevitably becomes self serving bureaucracy that puts public interest second to politics and gameing budgets. Said bureaucracy is not part of the original framework and intent of the federal constitution's division of powers; thus these agencies are really a square peg in a round hole and all this leads to a lack of viable direct individual acountability and waste.
@@farmeronthedell Not having any direct powers is the only thing that keeps the NTSB from becoming as rotten as all of the other alphabet swamp-soup. Beside that, not everything the NTSB recommends is good policy anyway, if for no other reason they have a very narrow focus and don't nessesarilly consider broader society-wide aspects of human action let alone legal and philisophical issues like delegated powers, case law, and natural rights.
This is the kind of professionalism I like to see. It's a pity so many want to gut the budgets and power of these agencies which have made such a positive difference.
@@revelry1969 I've studied how it functions in the past couple of days, and I found the high-five explanation sufficient for a layperson audience. Sure, you can talk about forces, and I'm sure some of the people on that panel would've been happy to, but it's a good enough explanation imo.
@@SPIDERman9051They’re three days into the investigation they’re still gathering information. All she’s trying to do is stop the media from latching onto that theory and blowing it up.
She's good from the standpoint that you could probably give her a class on just about anything, and she would do an acceptable job at a press conference, but she really doesn't understand the technical aviation details. When she said, earlier in the day, or maybe even yesterday, that the plane was not permitted to fly over water, I had wished then that she had said the airplane was forbidden from flying ETOPS as it "technically" has nothing to do with water. That would have saved a lot of dumb media questions because, of course, no one outside of the industry has any idea how ETOPS works.
So what she was trying to say about the bolts is that the stop blocks are what technically hold the plug in place, and that the bolts help keep the plug from moving up and over those stops. Close your door handle, and the latch holds the door closed, but a door lock helps prevent the latch from being unlatched. The stop blocks are the latch. The clotter pins and the bolts serve as a lock.
@markplatt1784 Correct. The reporters’ questions show uncertainty in the difference, and it can seen like the bolts are what hold it in place, but it’s not. Her on-the-spot comparison to a high five makes sense, but doesn’t explain the job of the bolts. I’m not faulting her for that. She’s got a lot going on and has been doing a great job so far, and I’m still thrilled that she spend five solid minutes basically blasting the FAA for not even considering ordering the retrofitting of planes to have 25hr CVRs.
the question... could the door plug be installed and having made several flights without actually using any bolts during the installation. Each time just held in place by position and pressure. (same thing for the cotter pins)
@@delwoodkelp8590 Yes. That doesn’t mean it would be a good thing to do. It means it was luck that nothing had happened before. You could walk with a bunch of dishes balanced in one hand and trust that the downward pressure of gravity, akin to the outward pressure of the inside of the cabin, to hold them to your hand (or the stops), and barring anything unforeseen or sudden, they’ll probably be fine for a short time. But one bump, one bit of normal use, and you’ve jeopardized that. To protect against dropping those dishes, you use a backup to gravity, like a hand on top of them, or a clotter pin and bolt. Your hand on top of that stack is technically a backup to gravity, not the thing keeping the dishes on your hand. Sure, you COULD rely on just gravity alone every time, but will you? Knowing how easily the slightest thing can cause then to crash down when a way to safeguard against disaster is as easy as your other hand? Or a clotter pin and bolt? FOUR of them should have been quadruple assurance. Even ONE of those in place should have kept that plug from being able to shift upward.
@@NoelleTakestheSky This is the exact reason why I always tie my shoes before standing and walking. Gravity holds me in my shoes, but my backup is laces....(though I don't use cotter pins to keep the laces in place.)
She's good at PR-speak, but IMO she's not nearly as clear and concise as a person in her position should be. And she needs to defer to the structural dude more often.
Appreciate the highlighting of the cabin crew in this briefing. My parents are both F/As with another airline and my dad was literally in tears today thinking about having four unaccompanied minors seated in different locations across the plane during a decompression. It’s truly an impossible responsibility to place upon the crew. They did a damn good job but they’ll need a lot of support going forward.
Great job NTSB and Chair! Giving updates as the information/facts are at the moment. Plainly stating we don't speculate/jump to conclusions. This 'briefing' is just that brief with easy to understand terms and well discussed topic. We will have to wait for awhile until the final report is done after the thourough investigate. Well done - thanks All for keeping us safe.
Didn't sound like she thought through what they were going to say... They gave some details about damaged roller guides that they've seen on the door plug that was recovered. Today's news would have been full of how Boeing's door roller guides had failed and caused this near catastrophe. Calls for all Boeings to be grounded as a similar roller guide is on many of their other types of door. Luckily a journalist was on his game and asked the very pertinent question of was this the cause of the door plug blowing out or is it just something that got damaged when the door plug got blown out. When asked, they said it was the latter but in their preplanned communication they were not going to say that. You think that's a great communicator?
@@alanm8932 A part that's called a "guide" is not a load-bearing part. Its failure might lead to something not going into place when operated (i.e., a door not closing, which would have been obvious in this case), not a failure under load of a part that is already in place. I think they tend to assume the journalists covering their press conferences are aviation reporters who know such things. Besides, they made previous statements about the role of the roller guides.
These press conferences are so good. Well done to the NTSB. What an important organisation and how wonderful that they are so open and honest with their communication. I wish them well with their investigation.
For anyone who still has issues understand how the door plug works: Do you have a TV remote where the battery cover is removed by sliding it in one direction and then lifting it up? That plug worked the same. The primary difference is that what goes "click" and holds the cover closed isn't a plastic spring but 4 locking bolts.
Check out "The Boeing 737 Technical Channel" - they released a video in the last few days with labeled photos of the mechanism, and explain very clearly how it works.
@@paulmorissette5863 Blancolirio got them from The Boeing 737 Technical Channel who had the video out a few days ago - days before blancolirio used them in his video (I'm sure he got permission, but still he wasn't the one that had those diagrams up first)
The real question is the loose bolts found on the other planes, is that the retaining lock bolts with the castellated nuts and cotter pins, or is it the bolts that hold the hinge assembly that slides on the hinge pins to the door plug? The picture that has made it to the internet seems to show it's the bolts that hold the hinge assembly to the door plug that are loose, and in this case it sounds like the retaining bolts/castle nuts/cotter pins were completely missing. It actually seems like there are 2 separate issues with these door plugs surfacing.
T'his is a great question! I wish you were a journalist. Similarly, some designs using castellated nuts on bolts are not meant to be tightened very tight because the bolt passes through a cast aluminum or magnesium fitting with "ears" that you don't want to put too much of a compression load on. The upper bolts that trap the guide roller kind of look like that might be the case there. Unfortunately, they only brought one NTSB person who actually knew the technical aspects.
This question was answered in an article on the air current. Go check it out. UA reported finding fasteners holding the lower hinfe brackets , as well as the upper guide track and pins to be loose / Not properly screwed in. These are not bolts with castle nuts at all. these are also fasteners that would never be removed in order to open the door plug.
Right. The 4 locking bolts with the castellated nuts and cotter pins can be as loose as is possible without the nut coming off; they will still do 100% of their job. The bolts that connect the hinge to the door should be tightened to spec for the door to not disconnect from the hinge...
Another danger revealed by the incident lurking when emergency de- pressurization occurs…the auto opening of the cockpit door violently sucked/swung open with the same force that dislodged the door plug. The violent force banged the door of the adjacent lavatory damaging its lock and locked in. Also caused loose items in the cockpit flying out including the manual for emergency procedures that pilots depend upon. Potential IRREVERSIBLE CORRECTIVE ACTIONS? 1. Disable the auto opening of the cockpit door, drill holes in it but add a secondary auto opening sliding door. The holes will balance the cockpit de-pressurization with the cabin. 2. Replace the current auto open swing door to an auto sliding door. 3. Ensure the emergency manual is not loose and other important materials. (The crew can also master the emergency procedures to not need the manual or just use short-contracted written steps posted permanently in view of both pilots.) This can injure anybody caught in between the cockpit and lavatory doors and can trap anyperson using the lavatory when de-pressurization occurs.
Glad to see some new subscibers! This is a great channel, and I really appreciate the Board meetings, press briefs, B-roll, and outreach. Keep up the great work media team!
If the bolts were never installed, someone from Boeing is going to have a bad day. Someone signed off that they were there. The only other possibility is faulty bolts that sheared and failed. Hopefully more information soon!
These bolts MAY have not been re-installed by a later maintenance operation. The NTSB will be able to tell if the bolts were ever torqued to spec by inspecting the surfaces of the bolt holes. They will also be able to tell if the bolts were there but fractured, causing marring of the bolt holes in a different way. This is an exceedingly unlikely scenario. If they were installed, then the question becomes when and by whom were they removed. Note that these 4 bolts, especially the top 2 bolts, DO NOT NEED TO BE TIGHT to fulfill their function. They simply need to be THERE, and the nut they attach to is a castle nut which locks in place with a cotter pin to ensure it doesn't spin off in vibration.
Here’s the deal either the bolts sheered or weren’t there. If they sheered the fittings will show it. My money is the bolts were left out. Loose bolts with a cotter pit in the castellated nut is not gonna gonna concern me. Bolts with no cotter pins is another story
@@cuisinart7899 This was a brand new plane, not on the line long enough for “later maintenance.” I believe it rolled out to AS on October 31st, and had its first flight in mid November. Not enough time to have enough hours for maintenance. This was an error in manufacturing.
Likely a second party service by a under trained worker forgetting the bolts. If properly qualified then they need to up their qualification requirement regarding paying attention to detail.
Excellent presentation, thank you. Memo for future events, can you please request microphones and attendees step up. We, the interested audience, would get a lot from the questions asked. Thank you
They've been doing a good job of repeating the questions into the mic before answering on previous days, but a few today were missed. I think they're tired! They've had a few long days in a row now.
I have to say that Jennifer Homendy is the best example of a leader I think I've ever seen. She instills absolute confidence in the NTSB when you hear her speak. She comes across incredibly well briefed (which proves she listens carefully), is an excellent communicator, is not shy to defer to specialists in her team, is not shy to call out the authorities for lack of action, is not shy to call out the press for hounding the crew so soon after a very scary event. You can tell she is highly intelligent, strong, compassionate and knows how to lead! Very impressive!
This is a wonderful briefing from the NTSB, nobody questions the capability they have of investigating and finding the issue that caused the accident. The problem is... Why so many security issues with Boeing airplanes on the last few years? Seems like the lobby power of this company has amazing reach and that allows them to get planes approved without all the safety measures required. It seems that profit is waaaaaay over safety on the boeing manufacturing policies in the last decade. We are talking about human lives here. Hold executives accountable for lives lost, then you will start observing the changes we need for aviation to be as safe as it has always tried to be, except when these money starving robots took over the leadership of aviation.
Funny thing is, back in the 80s & 90s they used to come to my airline (Eastern Airlines) to ask if we could look at a particular item with our electron microscope because our lab had more capability than theirs. When the administrator mentioned "microscope" today, it made me wonder if they are still relying on the help of some other airline, or if they finally got their own equipment. There is only one person on that stage today who has demonstrated any technical knowledge.
Was thinking that I was the only one, they're trying to calm down the mass hysteria, which i can totally understand as there is a lot on the line with this incident worldwide, same business involved, you almost have to wonder how hard line they are going to be.
I'm going to shout out to Bob as well. I'm over the pond in Scotland and have been reading about Bob's discovery. I simply can't imagine being the one to find such a vital piece of the aircraft just lying in my garden 😮 Bob will absolutely be a star with his pupils for many years to come!
That's precisely how we change the world, one door at a time. Bob door, fantastic! Must tell that NTSB spokeswoman. I think every student in his class, and everyone at his school, would be so proud forever to have him as teacher -- just might be our futue pilots?@@Teribus13
I agree with the last part. But assuming they were installed they would not have to have failed all at once. They could have fallen out one after another over a couple of weeks. The last remaining lock bolt could have prevented to door from translating upwards as there are no significant forces acting upon it
13:06 "We are still looking for the bottom hinge fitting…" If this part separated from the door frame because of improperly torqued bolts, the door might have rotated outward from the bottom enough to be sheared off due to the airstream, fracturing the upper roller guides.
Either that or a maintenance procedure which Alaska Airlines didn’t perform correctly. There’s aircraft maintenance people who have already said the plugs are routinely removed to allow for interior maintenance and fitting out which would include using the opening for air tool lines, power cables, communication cabling, ventilation piping and the like.
@@65gtotrips The plane was delivered at the end of October 2023 - there shouldn't be much maintenance activities happening on a 10 to 12 week old airplane requiring that door to be removed since it was delivered. As far as I understand, Boeing is the one that fits all the interior and seats, and should be handing over a ready to fly aircraft to the airline.
@@gorak9000 They had contactor in Oklahoma city install satellite internet antenna and returned the plane on Dec 7th. Thats exactly when first cabin pressure anomaly was reported. That shop must have taken that plug off and did not put those 4 locking bolts back.
@@antronx7 Ooh, that's new info I hadn't heard before - that could be very significant if they removed the door plug for some reason! I can't see what advantage there would be to removing that plug though, vs just moving in whatever they needed through one of the normal doors. You'd probably also have to remove and re-install at least one row of seats too to even make it worthwhile to open that plug. But running cables from the antenna to inside the cabin somewhere would be another penetration of the pressure vessel that is the inside of the cabin - maybe a contributing factor with the door, or it could be a contributing factor to the pressurization errors only, or it could be neither or both!
The question is was that door plug removed to facilitate installing seats/interior etc on the acft and in rush to get it assembled and out the door to Alaskan Air bolts were left out or weren’t cotter pinned etc
The answer is likely yes. Either at Boeing at manufacturing or Alaska Airlines. It’s important to note this particular aircraft is basically brand new being commissioned to fly in October 2023 and being accepted by Alaska Airlines approximate to October 2023.
What a lovely lady Jennifer Homendy is. Respectful of her team and those around her. Clearly a great leader, doesn't take all the credit, passes to those who are more capable to answer specifics, but totally leading the process. I would enjoy working with... or for... this lady.
Outstanding job from these people at NTSB. Truly inspiring. The Q&A is, by far, the most amazing part. A truly transparent exercise. I wish other public servants behave like this team, specially high level ones.
The bolts do not carry a structural load; they simply keep the plug, and the fuselage's "fittings" aligned and mated. The fittings do all work. What happened to the bolts, that allowed the plug to move out of alignment is the question. They seemed to have trouble explaining this.
Yeah, pretty sure what happened to them is they were never there in the first place. The question is how was such an omission not flagged during assembly? The s/n of each bolt and nut should have to be recorded into the system before the insulation and trim is allowed to be installed, covering it all up.
I read this much differently. See the article on the air current website. United airlines reported finding fasteners that hold the lower hinge bracket, The upper guide tracks, and the pins to the door and the fuselage to be loose / not screwed in. If any of those parts come loose then the retaining bolts become useless
Because they don't know for sure yet. They have to complete the investigation. They could have not been installed, fallen out, been the wrong size, etc. etc. Investigators will know soon enough.
Chances are, the stop bolts were not there. If so, then QA inspection procedures failed. Those QA failures would have far-reaching implications for the entire manufacturing process, not just the door plugs.
Jennifer said that the tracks broke off. That could mean the lock bolts were in place but the fasteners holding either the track or the pin were loose and what failed. I can see the bottom lock bolts through the hinge ripping the hinge once the top of the door was free. I have not seen a close-up of that lower hinge hanging out of the plane yet.
Only the current economic system. Boards of Directors should only be full-time workers. Why would anyone expect an Amgen executive (i.e., Big Pharma) to know anything about running an aircraft company. No single human is accountable, it's fundamentally capitalism, profit, money, and greed.
I’m going out on the limb to say they won’t find the bolts because they weren’t installed. That plug wouldn’t have shifted up if the stop bolts were there. It’s a huge weak link in the chain but only because protocol was not followed by someone fitting out the interior. All they need to do is look at the serial number build manifest which will show those parts as being necessary as part of the build.
You did hear Jennifer say that the tracks broke off, right? If the bolts were not there the door would have just come free rather than breaking the tracks. And it probably would have happened a lot sooner than it did. I think that the fasteners holding either the track or the pins were the failure point, Because they were loose. Consistent what United airlines reported finding. Perhaps the tracks are missing along with the bolts!
@@gutrali The track fractured but it was provisionally discussed that this component was not fractured before the plug blowing, but the upward movement of the plug on the hinges caused the fracturing of the track. If the lower bolts were in place this would have prevented the upward motion preventing the fracturing. The door/plug has to go upwards to disengage from the track pins to come off. Boeing is a total mess and needs sorting out before more people are killed on their aircrafts.
@@gutraliGuide tracks are not air pressure load bearing. The 12 stop pads are. Bottom 2 hinge locking bolts would have kept the door from sliding up had they been installed.
@@antronx7 Not if the bracket holding the hinge to the door had loose bolts that came out, Which is what United airlines reported finding on more than one of their planes. Along with loose fasteners holding both the guide track and the pin to the upper portion of the door and fuselage. These were the portions that the NTSB reported breaking. If the upper portion of the door comes loose from the fuselage I'm pretty sure the bottom hinge bolts will be ripped right out as the door is pulled away. This is made even easier if the fasteners holding the bracket are loose to begin with....
Just a correction: ETOPS used to means Extented Twin-Engine Operations, but not anymore. Now it is just "Extended Operations". Indeed, the ETOPS FAA regulations does apply to airplanes with three or four engines.
Thank you to the NTSB. One thing I think of, is if the door to the cockpit is designed to open during an event like this, couldn't someone with ill intent cause a rapid decompression then storm the cockpit? Why would it be designed to open in an event like this? I understand the cockpit would need to equalize but why the entire door?
I hardly believe this could (or even would) be pulled off by anyone. Rapid decompressions don't go unnoticed and can't be done intentionally without intervention (that assuming the decompression is being forced by someone in the cockpit). A straightforward way to do this intentionally could be, for example, overspeeding the aircraft to its structural limits, causing the plane to tear apart. Depending on which part of the fuselage is torn off, the plane quickly decompresses or it simply freefalls to the ground. Now, aside from cockpit, the second way to cause a rapid decompression is through an explosion. Both are catastrophic scenarios on their own and therefore using them just to make a door open mid-flight seems illogical. Point being, if someone were to storm the cockpit to cause a disaster, this decompression-triggered door mechanism would hardly be the means for it. The very act of rapidly decompressing an aircraft is a disaster by itself and can only be made by a violent force, which would never go unnoticed. If the plane is capable to keep flying after a rapid decompression (which was the case for this flight) and the pilots are fine, the other crew members (sometimes even passengers) could intervene and try to suppress the person or group (IF they even managed to get inside the plane in the first place, being a terrorist group) while the pilots fly the plane back to the airport. This whole scenario is not exactly impossible, but tremendously unlikely.
This briefing makes it clear that the all the humans involved (at both Alaska Airlines and the NTSB) refused to believe the airplane's pressure monitoring system when it was sending out warning signals and changing into its alternate operating modes as this door plug was slowly loosening up over time and allowing cabin air pressure to uncontrollably escape for weeks as the plane was flying. No one seemed concerned about the air pressure losses on a brand new airplane. WTF? They all turned a blind eye to it and said "let's just let the backup system deal with the air loss."
@blancolirio mentioned that the default assumption is a software or computer fault, but the pressurization system will ALSO give the exact same fault if it's losing pressure too fast.
@@KaneYork When the primary system indicated a fault. Aircrew switched to the backup which did not show a fault. Please explain how door plug affected one but not the other.
Nice job on a relatively complex topic. Other videos have used sketches or diagrams to illustrate the restraining system (lock pads, roller / tracks, springs & bolts). This will no doubt be developed during the investigation but would surely have added value to the briefing. That said I don’t know about proprietary restrictions.
my two cents. has to be an issue with the stop bolts. such as they were never there, they were installed wrong, too long, too short. or the holes were of the wrong tolerance (hogged out?), the beauty of the FAA is everything, down to every bolt nut and washer, has traceability. and the paperwork follows that aircraft. who worked it and who signed it off, and who signed off the sign off.
I have a feeling what happened is they put the door plug in, the lock bolts were missing, and someone else installed the insulation and interior panels covering it all up and they got missed. It's probably 2 separate people or 2 separate crews that do the bolts vs installing the trim panels - probably a lack of ensuring the door plug installation is complete before proceeding to install the interior trim panels by the other crew. There should still be a missing sign off on the actual door plug installation though.
I don't think this is the case because they said that the tracks broke off. The door would have come loose a lot sooner if there were zero fasteners holding it in. I think that the fasteners holding the track or the pins were loose enough to eventually cock outwards enough to compromise the door seal. At that point the decompression forced the tracks to break off in the door to fly. The retaining bolt in the tracks would be irrelevant at that point, and the lower two lock bolts could simply be ripped up off of the top part of the hinge (We have never been shown a close-up of the condition of the hinge sticking out of the lower part of the door hole from the fuselage. There could very well be damaged there we haven't been told about yet)
That's why there's checklists and sign offs though. I think you're right - the bolts weren't installed, and then someone else went and installed the insulation and the interior trim and covered it all up. But how did an uncompleted check list or sign off allow the plane to ever leave the factory?
I suspect you are very close to the actual answer. If there is a lot of work going on near those doors, they might be opening and closing them through various shifts with the understanding that the last person who closes the door should put the 4 bolts back in because they will no longer be repeatedly opening and closing it. Might have happened where the last guy closed the door, thinking more work was still ahead, and the next shift came in, saw it closed, didn't really have any additional work, and thought everything was good to go. Some piece of paper work should prevent mistakes like that, but things have been missed like this before. I think that if I was still working as an airline mechanic, and I had to temporarily close that door, I'd hang 2 orange streamers near 1 of the 4 bolts such that one streamer hung outside the aircraft, and one inside.
The NTSB would be better served if they would show slides/photos of what they are describing, so many media outlets will get this entirely wrong in their reports to the public...UGH
Questions I did not hear, and this may have been because the media present are not aware of the basic design of the 737 airframe. The first is that 737 door plugs are fitted only on some planes operated by a few carriers. Most carriers have the full compliment of doors, in order that they can maximize the passenger capacity. Alaska choose to reduce the capacity to below that where the extra door is needed, and give their passengers more leg room, as do United on some planes. As the 737 airframe is a very old design, this is not the first version to have door plugs fitted, and the design has not changed much, and incidents of this type have not happened before, so why on this nearly brand new plane? It seems unlikely that the bolts preventing the plug from sliding up fractured, otherwise parts of the bolts would have been retained on the plane. This conference confirms the bolts are completely missing. That is very odd. Other carriers report finding loose bolts. It is really easy to see from the threaded insert whether a bolt was ever fitted, because inserting a bolt leaves marks on the receiving thread. My final question is this, and I suspect this is already known by maintenance crews and pilots. Have pilots on other 737s reported 'ghost' air pressure warnings where the maintenance crews were unable to find the cause? I have a feeling the answer is yes, and so, by now, the NTSB should already be calling on pilots and maintenance crews to search back (in records or memory) for such incidents).
i have an associate's in sociology and a casual interest in airplanes. here's what i think the ntsb should be doing to investigate this accident (part 1/26)
My son was on this plane. 16 years old-minor & his first solo flight. Not once did any Alaska crew make sure he was ok or reach out to him. Seems they are covering their butts by saying they made sure the minors were ok. Very scary for us & luckily we had family that could make their way back to the airport to pick him up.
From an NPR interview on Jan 9 or 10. "HOMENDY: Well, we know what broke. The components on the top of the door plug fractured, which allowed the plug to be violently expelled from the plane. The bolts that hold those components in place - we don't know whether those bolts themselves also fractured, were loose or whether they weren't even installed on the door. And that's something we're going to have to determine when we get that door plug to the lab." This is ALL WRONG. The broken guide pieces broke BECAUSE they were struck by the door, which has ALREADY slipped off the load pads and was making its bid for freedom. The fractures did not allow the door to come loose, they were a result of the door becoming misaligned, presumably due to missing bolts, and being forced out of the frame by the aerostatic pressure. This woman is a freaking MENACE. She should not be allowed to speak on ANY technical issue. Let her spout her PR fluff, but keep here the hell away from the hard engineering!
The easiest comparison would be with a multi-lug rotating bolt locking mechanism. On the door plug system the engagement surfaces are aligned by vertical translation. On the bolt accordingly by rotation. Every other component only provides retaining and guiding functions without any load bearing capabilities.
Thank you NTSB for an open honest discourse which will inspire both confidence and trust from the public. Can you send some people over to train the medical profession please as they are the complete opposite.
My only complaint is that, there was not enough microphones so they didn't have to keep swapping positions to speak, and one or two mic's in the room to hear the asked questions.
I find it odd that all aircraft doors are designed to be "pressure assist" seal, and they only open inwards (have to be installed from the inside). Why in the heck did these "door plugs" get designed to be installed from the outside? Why not make a door plug that looks alot like a door, and has the same trusted interface? I question why anyone would design a door plug that doesn't install from the inside - the plug should install like doors do, from the inside, so that it CANNOT come out!
How the NTSB staff had difficulty conveying these relative simple mechanisms on the plug-door is painful to watch. They should have included an illustration/drawing of the plug-door for this media brief. Given what were revealed so far the odds of none of the four bolts and nuts that function as stop pins to prevent the door from translate upwards were not installed. Once the door creeped upwards by the lift assist springs the stop fittings were no longer aligned to support the massive force that want to blow the door out. That left the upper hinge guide tracks and roller, and the two lower hinges to withstand the massive force as well as the aerodynamic drag force flying at circa 250 mph at the time. The fractures found on the upper guide tracks are the result of that. Evenything right now is pointing toward problems in the manufacturing of the plane, unless the plug-door had been worked on during Alaska maintenance.
@@ImperrfectStranger No the high-five isn’t a great analogy. After looking at this for hours, here’s my attempt to explain how the mechanism operates. If you research how the plug operates, it’ll become obvious to you or anyone with a mechanical aptitude. This may sound a bit convoluted but there’s plenty of photos and videos of how this is occurring. Briefly before all this stuff below. The movement when removing the plug is upwards and out. Installation is inwards and down. Removal = remove the retainer bolts. Install = install the retainer bolts. It’s all quite safe if the bolts are present, not to mention rather ingenious. There’s the (2) bottom hinges (one each side) for movement to and from, and at the top there’s (2) (L & R) roller pins on the fuselage which engage (2) (L & R) curved slotted raceways on the plug itself, acting as a latch mechanism. The two lower hinges have ‘helper’ springs such that the spring’s force pushing upwards help to move the mass of the plug as the plug is pushed outward by human means. The plug which has (6) ears on each side, is pushed into the fuselage via the (2) hinges above and past the fuselage’s (6) ears which are static in the opening, as the plug is moved downward; As this is happening, the curved raceways engage the rollers on the plug’s frame, where the (6) ears on each side of the plug overtake (overlap) the static ears on the fuselage, thus creating a ‘plug’. The plug is now in. Then the (4) bolts (2) which are placed through holes drilled through the lower (2) hinges and the hinge pins themselves, and the upper (2) surfaces having been drilled as well, all accept these AN aircraft grade bolts, which lock the entire plug into place using (4) AN castle nuts and hardened AN cotter pins such that the bolts cannot vibrate loose. These are hefty aircraft grade fasteners. The plug is now secured for pressurization. As the pressure differential increases, the (12) total ears push from the inside to outside onto the (12) static ears on the fuselage. This is what actually takes the forces of the air pressure and translating those forces into the strong frame and the rest of the fuselage. Again, the (4) bolts are designed to prevent vertical movement upwards; If the (4) bolts aren’t installed, then the plug is able to move vertically upward allowing the ears to move past each other. In maintenance, the (4) AN retaining bolts are removed such that the plug can move upward with the help of the force of the springs, then past the ears in an outward movement, whereby the plug is then opened. There’s about a 15 degree by about say 10 inches (not exactly sure) gap where the plug is attached to the fuselage with braided cabling to allow temporary access, or the entire plug can rotate down and out of the way.
very simple question. Did anyone remove or adjust the door/plug after delivery. Who was the last person to touch the door. The big question is why Alaska allowed this plane in service with pressurization warning lights activating on previous occasions. Alaska did not allow the plane to be flown long distance over water due to this issue but somehow it is deemed OK to fly over land without a resolution to the warning light issue. Also I find it quite coincidental that the two seats next to the plug were empty on a nearly full flight. Were they left empty on purpose?
Wow, Reuters. That was one heck of a scenario. I would suggest looking into the difference between the "aircraft de-icing system" (i.e. mechanical systems built into the aircraft) and the procedure of "ground de-icing" (i.e. the airplane being sprayed with liquid before takeoff). two completely different systems/processes. Only the latter of which causes delays on the ground.
@@Travisesty The issue is why weren’t they there in the first place? We know they weren’t there, and so that’s the path to travel down to find the root.
As they said, the bolts could have been installed but ejected during the decompression. Keep in mind these bolts aren't "bolts" like when you are building something, but more like large pins designed to prevent the door from moving up. They do nothing structural in the assembly. It's like when you put out wheel chocks to prevent your car from moving. This is why even the reports of loose bolts isn't that big of a deal because as long as the nut is in place the bolt can spin as freely as it wants. The door isn't going to move.
This comments section seems to be oddly lacking in apologies from the people from yesterday who were complaining, without a shred of evidence, that Alaska Airlines was “ignoring maintenance” and/or “putting passengers at risk by keeping the plane flying”… when, in fact, maintenance procedures of the triple-redundant pressurization system had been followed BY THE LITERAL BOOK, and Alaska Airlines went above and beyond what was required by the letter of the law by placing an additional ETOPS restriction on the aircraft in the name of keeping their passengers safe. I won’t hold my breath. People love to play internet expert and point fingers, even when they have not a clue how aircraft systems nor airline maintenance works.
I agree with you, but the real question will come once data is retrieved from the pressurization controller. Did the warning come up because there was an actual issue with the pressure, or did Boeing ship a plane that's about 12 weeks old with no door lock bolts AND a faulty pressurization controller? If there was a legit pressurization issue, then the maintenance procedure that checks the cause of the alarm, and incorrectly deemed it a failed controller instead of a real issue needs to be reviewed as well.
First of all, it still has not been determined that the two events are related. I understand that it seems probably. Second, the pressurization controller being faulty would have had zero impact on this event occurring. Even if the mechanics had decided to replace the pressurization controller before the flight out of an abundance of caution, or as a troubleshooting measure, the door plug still would have departed the aircraft. Pressurization controllers malfunction and/or fail all the time. Sometimes sensors throw erroneous readings and trigger false alarms. Sometimes the controllers hard fail and require alternate or manual reversion. I’ve seen it happen in almost every type of pressurized aircraft I’ve flown in the last 20 years. That’s why the system is triple redundant, and that’s why the manufacturer and the FAA have permitted airlines via the aircraft Minimum Equipment List to continue operations even if one of the controllers is malfunctioning. Pressurization issues are notoriously hard to duplicate on the ground because conditions on the ground are very different from those at altitude. Sometimes they cause intermittent problems that can be difficult to diagnose. There isn’t an aircraft mechanic on the planet that would see a logbook entry about a wonky pressurization controller and think, “Hmmm, I better check the bolts on that inaccessible door plug on this 2 month old aircraft.” When you hear hoofs on the ground, you think horse, not zebra. Aircraft maintenance procedures cannot possibly account for a scenario such as this. The fate of this event was written the day that door plug was installed in the fuselage. It’s a miracle it didn’t happen sooner.
@@AdAstraPerLlama Couldn’t a leaking pressure seal in, say, an improperly secured door plug, cause pressure instability while climbing or descending? Would it be unreasonable to consider these pressure fluctuations might cause the pressure controller to struggle to maintain pressure within acceptable parameters, act “wonky” and illuminate the trouble light? I’m pretty sure that nobody is saying that the pressure controller caused the plug to depart the aircraft. I think most people are wondering if the light coming on could have been an indication that there were issues with the pressure vessel. Perhaps issues that ought to have been investigated on an airframe with less than 200 compression cycles.
@@maybeafterlunch You’re misunderstanding what I’m saying. Yes, of course a large leak could cause the pressurization system to indicate a problem. But pressurization system issues are common, and the system worked fine when put into alternate. That’s very common info for a mechanic to see in a maintenance logbook when chasing a possibly pressurization issue. When mechanics troubleshoot issues such as these, they use the info they get from the flight crew about the problem and pattern match it to similar issues they’ve seen in the past. There would be no reason to suspect that part of the pressure vessel was fault/improperly installed at that time with the info they had. There are many common failure points in a pressurization system that they would likely try to repair or replace before anyone would suspect that the pressure vessel was compromised on a brand new aircraft. Again, when you hear hoofs on the ground you think horse, not zebra. Also, typically when a pressure vessel is compromised in some way, loud/high pitch noise will be reported by passengers or flight attendants on previous flights. That’s not the case here. To put it in terms you can better relate to, say your brand new car throws a check engine light. You take it to your trusty independent mechanic you’ve been using for years. He scans the code and it says that the engine temporarily experienced low fuel pressure. He manually checks the fuel pressure at the manifold and it checks good, and the car runs perfectly fine. He resets the code and tells you to keep an eye on it for any other issues. A month later the light comes on again, so you bring it back to him. He scans the code, same thing. He again manually checks the fuel pressure at the manifold and the engine is still running perfectly fine. No obviously faulty parts. Now he’s probably going to say something like “I suspect one of the many sensors could be faulty” or “could be an intermittent problem with the fuel pump” or any other number of parts. But, again, the car is running fine. Now he could begin replacing the dozens of parts in the fuel system one by one until he finds the problem. But each time he replaces one of the expensive parts you’ll have to leave the car with him for a while, which isn’t ideal, and the parts are expensive, so it would be silly to begin replacing parts if you aren’t even sure what’s causing the error in the first place. Again the car is running fine and he can’t seem to replicate the light coming on. But he’s a good mechanic, so he says, “Look, the car is running fine. Let’s keep an eye on it for any other clues as to what’s going on, but just to be safe don’t take it on any long road trips for now. Wouldn’t want you to have a problem in the middle of nowhere. I know you have to get to work now, so let’s schedule a more convenient time for you to come back and I’ll try to dig into it a bit more.” You leave the mechanic and on the drive home the fuel tank explodes. You walk away from the car unhurt, but obviously shaken from the experience. After further investigation it is discovered that there was a major problem with the fuel tank when it was manufactured at the factory just two months ago. The problem was on the topside of the fuel tank, tucked up underneath the car where no one could see or suspect a thing. Now, tell me, are you going to get all bent out of shape at your trusty old mechanic because the car had a manufacturing issue that he couldn’t have possibly known about or even suspected? If you had demanded that he replace the fuel pressure sensor before the car exploded, would it have changed the outcome of the scenario? The answer to both of those questions is “no”.
@@AdAstraPerLlama If my mechanic resets the warning light and sends me on my way, only for me to become stranded, or worse, because he couldn’t be bothered to download the available data and find out why the light came on multiple times? I would definitely be bent out of shape. That’s the entire purpose of most warning lights. “You need to download my data, and/or perform maintenance items; There is a problem.” “You need to take action, other than covering the light with tape” My previous reply was relating to your statement “Second, the pressurization controller being faulty would have had zero impact on this event occurring.” “Even if the mechanics had decided to replace the pressurization controller before the flight out of an abundance of caution, or as a troubleshooting measure, the door plug still would have departed the aircraft.” You might want to reread my reply based on this context. Nobody is saying the controller ejected the door. The light indicated a problem. Instead of downloading the data from the controller, it was simply reset and/or taken out of service THREE TIMES. The problem causing the light to illuminate will now be determined by the NTSB, since Alaska’s protocol seems to be resetting systems instead of immediately investigating why a warning light came on during multiple flights. When the NTSB completes their investigation we might find they were isolated events We might find they were related to one another. Or the results may be inconclusive. < I appreciate your comments and have learned from them. I hope you will not take my postulation as argumentative derision. Thank you for taking the time to share your knowledge and experiences>
Ms. Homindy and her team demonstrated competence, clear communication and empathy to all involved. I would like to see NTSB to have oversight on FAA's governance over Boeing to restore public confidence that a competent organization is overseeing quality of our critical air transportation system.
Her vertical patty-cake example was horrible. The stop pins and plates are perpendicular to the sides of the door frame which puts them in a horizontal position.
This women, I apologize for not knowing her name, or position; is an absolute Rock Star!!! 👏👏👏. This is probably the one person I trust the most in the government.
Did the head of the NTSB just inform the world that the cockpit door is designed to open during a rapid depressurization? She said as well that the flight crew had no knowledge that this happens by design. Things that make you go-hmmm!
Seems some people don’t understand that those latches were made to withstand HUMANS trying to breech them, and to withstand that at least long enough for other passengers to stop that person. Those doors aren’t impenetrable against all forces. Not to sound pro-Boeing when I’m actually pretty ticked at them right now, but that’s actually the one thing Boeing can’t be faulted for here. And if this is made to open BY DESIGN, rather than being something that merely COULD happen, then it’s on Boeing to make that a part of their manual.
I've only heard before that in the door there is a panel that is supposed to open and equalize the pressure during such decompression event. I guess the door latch will also open if the event is fast enough.
@@NoelleTakestheSky that's the point... Boeing said it's an intentional design feature and the NTSB is stating nobody was ever made aware of it. that's a problem.
So it's what everybody said had happened from the first day. Boeing didn't put the 4 safety bolts back in after they removed the door to install the seats.
@OneAdam12Adam I'm a little unclear of the steps to the process. It seems like the plane is built with the plug in place and then at some point it is determined where the seats go. The plug is then removed to Install the seats and then the plug is reinstalled. I'm not sure who installs the seats.
737 Max -9 has door blank fitted when manufactured . Depending on how the seating numbers are configured determines the number of emergency exit door are required if an airline adds more seats then the blanks are removed and they become a standard emergency door if an airline reduces its seating number then emergency door is removed and door blank is reinstalled Boeing designed the aircraft for multi configurations but in one size cheers
@tonyde6423 It is clear that the blank is put in initially, a compression test is done and then at some point the blank is removed for the seats to be installed. I have the impression this doesn't happen where the frame is initially made. I think the airline might reconfigure this seats themselves but I'm not sure. I'm confused why Boeing would do this at different locations. The one fact that is clear is that the plug is put in, then removed, then reinstalled at some point. I just don't know by who. that's my question.
NTSB did a poor job communicating the facts. The 4 missing locking bolts lock the roller pin, attached to the airframe, into the door track, attached to the door plug. If the bolts are installed, the door can not move upward and open. The door plug on this airplane moved upward and blew out. It is not possible for the door to move upward if the bolts were in place in the door track. The bolts were missing.
They should've had a projector, and shown the video from "The Boeing 737 Technical Channel" from a couple of days ago - he has good annotated pictures showing how it all works - even an electrical engineer can understand how it works from that video :)
@vondiesel3070 Likely, but it seems like this administrator really likes to talk to the press, so they needed something to talk about until they can track down that one signature of the last guy to install the plug. I would not want to be that guy!
every other news organization and youtube commenter is already saying this. the NTSB exists to deliver evidence-based conclusions. let them do their job.
It would be nice to know if the cotter pins were in place on the nuts that were loose on the United planes. The nuts shouldn't be able to come off the bolts with cotter pins installed.
You did hear them say that the tracks broke off right? The bolts being in place would be irrelevant if the tracks broke off completely. I think now this speaks to the fasteners holding the tracks to the door being loose, which is also something United airlines reported finding on their plans
No I must have missed that. I thought they just found cracks in the tracks. Anyway I was referring to the United planes not the plane that lost the plug door. It's also not clear which bolts United found that were loose. Were they the four bolts that keep the door plug from moving up or other bolts that hold the hinges, guides or tracks?
@@ManCaveMachining see the article on the air current site. UA found the fasteners holding the lower hinge bracket to the fuselage were not screwed all the way in. If this bracket came off, then the bolt preventing the lower half of the door from moving upwards on the hinge would become ineffective. They also found loose fasteners holding the upper guide track as well as the guide pin. This was all found on aircraft That were still flying..... That's a devastating blow to Boeing because even if the door is opened for maintenance or retrofitting, The bolts that were found loose would never be removed. They are installed once from the factory and they remain installed unless the plug is swapped out with a real emergency door
Theres rumor going around reddit that a contractor in Oklahoma had the plane for 10 days to install satellite internet antenna and returned the plane on dec 7th. Coincidentally thats when first cabin pressure anomaly was noted. Then it was reported 2 morw times in January. Alaska Air maintenance dismissed it as air leaking through this new antenna. So the blame is likely with Alaska Air and their contractor.
@@someguy9778Installing an antenna often requires removing the interior, running wire, testing everything for interference, etc. It's not like installing a car stereo in your Pinto. It's likely the satellite antenna seem on the top of fuselage just above the plug door photos.
There wasn't a cabin pressure anomaly. A warning light came on. Once while still taxing on the ground. So this was suspected as caused by a malfunction of some sensor, the crew switched to the backup system and the light went out. So that is an indication of a problem in some sensor, but not of any actual pressure loss, a serious (or even any) air leak.
@@michaelm5772 Could have been due to improper seal of the plug door but it would have to be really messed up and not correctly closed versus simply leaving 4 locking bolts uninstalled.
interesting that the cockpit door openned during the event. Not sure how the locking/latching mechanizim failed (door bowed or frame bowed?), but with the 911 security improvements, you would think that would be prevented (although decompression is a very violent, forceful event).
The cockpit door is something like 75x18 inches, for an area of 1350 square inches. If the cabin pressure lost 4 psi in a second or two, you could very reasonably end up with several thousand pounds force on the door, easily enough to banana a door designed to stop a person from getting in the cockpit.
Actually, watch a little longer, the cockpit door is designed to pop open during a rapid depressurization event as a "fuse" to prevent worse structural damage.
saw another video where they said they have blow-out panels in the doors to equalize the pressure. From the updates, seems the whole door popped open, not the blow-out panels. Stuff you learn!
@NTSBgov Which bolts? (@34:46) The bolts in the mechanisms that prevent the upwards translation or the bolts holding the plug to the stop fittings (the actual heavy bolts)?
The "stop fittings" and "stop pads" aren't "heavy bolts" - they're metal castings on the door and on the opening that align and don't allow the door to move outwards. When the door moves upwards, the "stop fittings" aren't aligned with the "stop pads" anymore and the door can move outwards. The lock bolts prevent the door from moving up and down so the "stop fittings" and "stop pads" stay engaged with each other (aka those lock bolts have very little load on them - only the weight of the door, and any additional forces due to vertical movement (acceleration).
Yea I know, I caught that. The NTSB is in the limelight and they don’t want to catch the heat from the press, and rightfully so because it’s their job to investigate; It’s the manufacturer, customer, and FAA responsibility for maintenance protocol and procedure.
@@gorak9000 right, because the stop fittings and pads are essentially just opposing tabs that meet up when the door is slid down into place. Now if the four bolts were not in place, as I understand it, the springs at the hinge, would force the door up, and potentially out at some point.
@@JohnHallgren Yeah, the springs are there to make the door "lighter than it actually is" and easier to open - the same way the springs in your garage door counterbalance the weight of the door itself so you, or the opener motor, don't have to work as hard. So the springs themselves won't push the door up and out, but they make it so less external force is needed - a little turbulence is probably enough. You also have to overcome the friction between the stop fittings and the stop pads - the higher the altitude, the more pressure difference between the inside and outside, so there would be more friction holding the door in too. At the lower altitude, it actually takes less force to overcome the friction and get the door to pop out
The 12 stop fittings/pads take all the pressure of the plug trying to push outward against the frame during pressurization differentials (flight). The 4 locking bolts ONLY serve to prevent vertical movement of the plug roller track off of the upper guide roller (at the top of the plug) and the plug hinge guide fitting off of the lower hinge bracket (at the bottom of the plug). The plug must be able to travel vertically at these points so the the stop fittings on the plug can move vertically enough to clear the stop pads on the frame and release the door. My uneducated opinion is that it is EXTREMLY likely there were NO locking bolts in place at all. Why? Because there is very little to no shearing pressure on the bolts by design - 4 independent bolts would all have to sheared off and under low shearing pressure. If they were installed "improperly", for instance only hand tight with no locking pin then the likelihood that they all could have spun loose several rotations each and then all 4 bolts slide out out position is just not realistic. Simply 1 bolt in place would prevent vertical movement. I'm going to venture that somebody at the Boeing factory or somewhere else didn't install the bolts to secure the plug from moving vertically. More than likely everything was basically mechanically held in place by friction and the weight of the plug and with primary force being outward and not upward during pressurization all was good for some number of flights until just the right combination of pressure differential and jarring of the aircraft knocked the plug vertically enough that the top protruded up and out and was caught by passing air flowing along the exterior hull which ripped the plug out causing fracturing of the guide rollers on the plug. In summary NO BOLTS at all installed.
That's the most plausible scenario and pretty much everyone understands that is the case, but NTSB doesn't want to issue a statement like that and take the small risk of having to walk it back later. Better to let the aviation talking heads on the news or youtube read between the lines and do the speculating.
Explaining the plug should not be this hard. It sounds very similar to a battery cover on a toy. Put one side in first, close it flat , slide it over, put the screw in. No screw, the cover might pop off. At first I was confused about the "plug". I know now its not a door that came off. They didn't want a door there, but the plane comes with the opening for one anyway. Instead they use a door shaped cover to block the opening. The "plug" was what they were calling that cover.
Here is a video from an known aviation guy explaining it better th-cam.com/video/WhfK9jlZK1o/w-d-xo.html And it’s a door, not a cover, but intended to not be opened regularly or often, if at all. An actual exit door would have a lot of additional hardware on it, like latches and smaller window, and such .
@@JohnHallgren Did you read my comment? They're were referring to the "door" as a "plug". They weren't saying "door" every time. Which is why I said, "At first I was confused..." . So I explained why. Then you just tell me it's a door...okay. Also you linked a 13min video presentation explaining the "plug/door". Close-up pictures, and printed diagrams even. What I started my comment with was, "Explaining the plug should not be this hard". I think a video of the "plug/door" opening or closing would have been a better idea. Not sure what you are saying.
What's up with all the touchy-feely? Little has been investigated so far, and there is much work yet to be done... 🤔... "Just the facts, maam." Also, why didn't they prepare diagrams/images on paper, or computerrized slideshow, to demonstrate the technical aspects to the non-technical audience/reporters ("a picture speaks a thousand words")? This was neither well prepared for nor organized.
"why didn't they prepare diagrams/images on paper, or computerized slideshow, to demonstrate the technical aspects to the non-technical audience" Exactly.
"why didn't they prepare diagrams/images on paper, or computerrized slideshow" because it happened two days earlier and the NTSB is a publicly-funded investigative body, not a hollywood cgi studio also, believe it or not, employees of an organization do not pause whenever their leader gives a press conference. there's an interesting structure called "leadership," which speaks on behalf of their employees so said employees can continue to perform their duties.
@@schmal911, you don't make any sense. The fact that I have immediate access to such images from the Internet, which I did verify via a quick Google search, and, moreover such images have been in use by many TH-camrs since the day the incident took place, makes your point moot.
Excellent point. If anyone wants to see how flashy high-tech 3d cgi virtual reality compromises research and transfer of knowledge and fact, look no further than the KPIX (CBS) weather virtual studio floor and the brainchild of Paul Heggen -- it is an embarrassment to human intelligence. NTSB is one of our national treasures.@@schmal911
The media stalking the crew and the passengers just so they can be the “first” to report some sensationalized news that probably isn’t even true is gross.
Agreed. Chances are good that no one in that cabin knew that things were relatively stable once the pressure evened out, and so of course it would have been terrifying!! Let those poor people have a bit of time and speak when and if they want to.
3 people died? Or 4?
Lots of important information here. Thanks for posting!
What do you think of the the reinforced cockpit door blowing open?
@@TheJttvis supposed to do that.
Juan, Your explanation and graphics today were 1000x better and easier to understand. Look forward to your next update! Thank you!
Trust your reporting more than almost anyone Juan Brown. Great Channel @blancolirio
“We found today that the cockpit door IS designed to open during rapid decompression…”
What the heck ???
You’re the NTSB and this is something super basic that you should have known. I’m just a member of the public and I know this.
You are completely incompetent if you just found this out “today” as you state. Lord help us.
Big thumbs up for NTSB, true servants of the People
Too bad all of them are in Boeing's pocket.
@@rexdavis9671 is that why another Federal admin (the FAA), grounded every MAX9 after an accident with 0 injuries and 0 fatalities?
They grounded for ability to look at that part and ensure a maintenance team secured all the bolts.
So you are telling that you understood what ?
dude are you serious, it is seriously not looking that way haha
Shoutout to all the NTSB staff who have given such clear communication. True professionalism in briefing!!
Agreed, I was glad to have caught this live. I just wish we could chat during the stream.
It was excrutiatingly difficult to listen to the explanations, without visual demonstrative tools, by those that are not mechanically educated to those that are not mechanically educated. As a retired A&P, my opinion is that there is lots of room for improvement. That being said, their efforts to disseminate information are admirable. I hope they can achieve better techniques soon. Cheers from Texas.
@@TexasKid747 You are def right. It was painful.
NO, THEY JUST TALK !
Enough of these people !
I wish all federal agencies were as competent as the NTSB. Love the transparency and thoroughness.
NTSB [and NASA] are part of a tiny minority of agencies chartered for doing real jobs for the benefit of the public.
Most other federal agencies fail because they are given arbitrary rulemaking and enforcement authority that is inevitably becomes self serving bureaucracy that puts public interest second to politics and gameing budgets. Said bureaucracy is not part of the original framework and intent of the federal constitution's division of powers; thus these agencies are really a square peg in a round hole and all this leads to a lack of viable direct individual acountability and waste.
It's a shame the NTSB has no regulatory powers and has to rely on the FAA to implement its recommendations.
@@farmeronthedell Not having any direct powers is the only thing that keeps the NTSB from becoming as rotten as all of the other alphabet swamp-soup.
Beside that, not everything the NTSB recommends is good policy anyway, if for no other reason they have a very narrow focus and don't nessesarilly consider broader society-wide aspects of human action let alone legal and philisophical issues like delegated powers, case law, and natural rights.
My kids died there
This is the kind of professionalism I like to see. It's a pity so many want to gut the budgets and power of these agencies which have made such a positive difference.
Imagine if Boeing and FAA was the same
These guys are not pros. They can’t even explain the function. Talking about hi fiving. Geez you people are so easy to fool
@@revelry1969the general public are ignorant and are very impressionable. The chair person is a politician.
@@revelry1969 I've studied how it functions in the past couple of days, and I found the high-five explanation sufficient for a layperson audience. Sure, you can talk about forces, and I'm sure some of the people on that panel would've been happy to, but it's a good enough explanation imo.
@@Fs3i blah. Weak. It’s not a hi five
Kudos to the NTSB for these updates. They are true professionals and a great example of folks who genuinely care. Thanks!!!
Many thanks to the NTSB for all of their hard work to improve safety! Your professionalism will prevent future accidents and save lives.
Jennifer Hominy is an OUTSTANDING representative of our government. We need our politicians to model their behavior after hers.
shes trying hard not to link cabin pressure alarms to the catastrophic depressurization event, THAT IS wrong.
@@SPIDERman9051They’re three days into the investigation they’re still gathering information. All she’s trying to do is stop the media from latching onto that theory and blowing it up.
SHE IS NOTHING ! She just list a serie of events I bet she doenst understand !
When the agency makes statements based on an incomplete record, it is usually a bad idea. It takes discipline to wait to make conclusions.
She's good from the standpoint that you could probably give her a class on just about anything, and she would do an acceptable job at a press conference, but she really doesn't understand the technical aviation details. When she said, earlier in the day, or maybe even yesterday, that the plane was not permitted to fly over water, I had wished then that she had said the airplane was forbidden from flying ETOPS as it "technically" has nothing to do with water. That would have saved a lot of dumb media questions because, of course, no one outside of the industry has any idea how ETOPS works.
So what she was trying to say about the bolts is that the stop blocks are what technically hold the plug in place, and that the bolts help keep the plug from moving up and over those stops. Close your door handle, and the latch holds the door closed, but a door lock helps prevent the latch from being unlatched. The stop blocks are the latch. The clotter pins and the bolts serve as a lock.
@markplatt1784 Correct. The reporters’ questions show uncertainty in the difference, and it can seen like the bolts are what hold it in place, but it’s not. Her on-the-spot comparison to a high five makes sense, but doesn’t explain the job of the bolts. I’m not faulting her for that. She’s got a lot going on and has been doing a great job so far, and I’m still thrilled that she spend five solid minutes basically blasting the FAA for not even considering ordering the retrofitting of planes to have 25hr CVRs.
the question... could the door plug be installed and having made several flights without actually using any bolts during the installation. Each time just held in place by position and pressure. (same thing for the cotter pins)
@@delwoodkelp8590 Yes. That doesn’t mean it would be a good thing to do. It means it was luck that nothing had happened before. You could walk with a bunch of dishes balanced in one hand and trust that the downward pressure of gravity, akin to the outward pressure of the inside of the cabin, to hold them to your hand (or the stops), and barring anything unforeseen or sudden, they’ll probably be fine for a short time. But one bump, one bit of normal use, and you’ve jeopardized that. To protect against dropping those dishes, you use a backup to gravity, like a hand on top of them, or a clotter pin and bolt. Your hand on top of that stack is technically a backup to gravity, not the thing keeping the dishes on your hand. Sure, you COULD rely on just gravity alone every time, but will you? Knowing how easily the slightest thing can cause then to crash down when a way to safeguard against disaster is as easy as your other hand? Or a clotter pin and bolt?
FOUR of them should have been quadruple assurance. Even ONE of those in place should have kept that plug from being able to shift upward.
Sounds like who ever removed the plug to fit the cabin really missed getting the plug properly reinstalled when the work was complete.
@@NoelleTakestheSky This is the exact reason why I always tie my shoes before standing and walking.
Gravity holds me in my shoes, but my backup is laces....(though I don't use cotter pins to keep the laces in place.)
Jennifer Homindy is so great at communicating with the public.
🤣
Her nickname is "Scooter" 🛵
She's good at PR-speak, but IMO she's not nearly as clear and concise as a person in her position should be. And she needs to defer to the structural dude more often.
Sincerely, the Babylon Bee.
Also good at sharing the podium and letting the right people speak about details she doesn’t have a full grasp of.
Appreciate the highlighting of the cabin crew in this briefing. My parents are both F/As with another airline and my dad was literally in tears today thinking about having four unaccompanied minors seated in different locations across the plane during a decompression. It’s truly an impossible responsibility to place upon the crew. They did a damn good job but they’ll need a lot of support going forward.
They alive?
Great job NTSB and Chair! Giving updates as the information/facts are at the moment. Plainly stating we don't speculate/jump to conclusions. This 'briefing' is just that brief with easy to understand terms and well discussed topic. We will have to wait for awhile until the final report is done after the thourough investigate. Well done - thanks All for keeping us safe.
Didn't sound like she thought through what they were going to say...
They gave some details about damaged roller guides that they've seen on the door plug that was recovered.
Today's news would have been full of how Boeing's door roller guides had failed and caused this near catastrophe. Calls for all Boeings to be grounded as a similar roller guide is on many of their other types of door.
Luckily a journalist was on his game and asked the very pertinent question of was this the cause of the door plug blowing out or is it just something that got damaged when the door plug got blown out.
When asked, they said it was the latter but in their preplanned communication they were not going to say that.
You think that's a great communicator?
@@alanm8932 A part that's called a "guide" is not a load-bearing part. Its failure might lead to something not going into place when operated (i.e., a door not closing, which would have been obvious in this case), not a failure under load of a part that is already in place. I think they tend to assume the journalists covering their press conferences are aviation reporters who know such things. Besides, they made previous statements about the role of the roller guides.
These press conferences are so good. Well done to the NTSB. What an important organisation and how wonderful that they are so open and honest with their communication. I wish them well with their investigation.
For anyone who still has issues understand how the door plug works:
Do you have a TV remote where the battery cover is removed by sliding it in one direction and then lifting it up? That plug worked the same. The primary difference is that what goes "click" and holds the cover closed isn't a plastic spring but 4 locking bolts.
Is this like an over wing exit ?
Having some pictures or diagrams sure would help media and the general public understand how the components work 😊
Justa suggestion , I’m Thankful for the incredible work y’all are doing
Check out "The Boeing 737 Technical Channel" - they released a video in the last few days with labeled photos of the mechanism, and explain very clearly how it works.
Blancolirio has those..
Definitely such a talk should be supported by diagrams or schematics of the plug closing mechanism/ structure.
@@paulmorissette5863 Blancolirio got them from The Boeing 737 Technical Channel who had the video out a few days ago - days before blancolirio used them in his video (I'm sure he got permission, but still he wasn't the one that had those diagrams up first)
The real question is the loose bolts found on the other planes, is that the retaining lock bolts with the castellated nuts and cotter pins, or is it the bolts that hold the hinge assembly that slides on the hinge pins to the door plug? The picture that has made it to the internet seems to show it's the bolts that hold the hinge assembly to the door plug that are loose, and in this case it sounds like the retaining bolts/castle nuts/cotter pins were completely missing. It actually seems like there are 2 separate issues with these door plugs surfacing.
T'his is a great question! I wish you were a journalist. Similarly, some designs using castellated nuts on bolts are not meant to be tightened very tight because the bolt passes through a cast aluminum or magnesium fitting with "ears" that you don't want to put too much of a compression load on. The upper bolts that trap the guide roller kind of look like that might be the case there. Unfortunately, they only brought one NTSB person who actually knew the technical aspects.
This question was answered in an article on the air current. Go check it out. UA reported finding fasteners holding the lower hinfe brackets , as well as the upper guide track and pins to be loose / Not properly screwed in. These are not bolts with castle nuts at all. these are also fasteners that would never be removed in order to open the door plug.
Right. The 4 locking bolts with the castellated nuts and cotter pins can be as loose as is possible without the nut coming off; they will still do 100% of their job. The bolts that connect the hinge to the door should be tightened to spec for the door to not disconnect from the hinge...
Another danger revealed by the incident lurking when emergency de- pressurization occurs…the auto opening of the cockpit door violently sucked/swung open with the same force that dislodged the door plug.
The violent force banged the door of the adjacent lavatory damaging its lock and locked in.
Also caused loose items in the cockpit flying out including the manual for emergency procedures
that pilots depend upon.
Potential IRREVERSIBLE CORRECTIVE ACTIONS?
1. Disable the auto opening of the cockpit door, drill holes in it but add a secondary auto opening sliding door. The holes will balance the cockpit
de-pressurization with the cabin.
2. Replace the current auto open swing door to an
auto sliding door.
3. Ensure the emergency manual is not loose
and other important materials. (The crew can also
master the emergency procedures to not need
the manual or just use short-contracted written
steps posted permanently in view of both pilots.)
This can injure anybody caught in between the cockpit and lavatory doors and can trap anyperson using the lavatory when de-pressurization occurs.
FAA is the agency that has the authority to ground all these type of plane's. If the NTSB recommends grounding them, it's up to the FAA.
They did, hours before you posted this comment.
Glad to see some new subscibers! This is a great channel, and I really appreciate the Board meetings, press briefs, B-roll, and outreach. Keep up the great work media team!
Jennifer Homendy is such a gem.
Maybe the hardest working government agency head in the US. So many accidents. Thank you for everything you do.
If the bolts were never installed, someone from Boeing is going to have a bad day. Someone signed off that they were there. The only other possibility is faulty bolts that sheared and failed. Hopefully more information soon!
Sounds more likely a post cabin install failure to properly replace that plug.
These bolts MAY have not been re-installed by a later maintenance operation. The NTSB will be able to tell if the bolts were ever torqued to spec by inspecting the surfaces of the bolt holes. They will also be able to tell if the bolts were there but fractured, causing marring of the bolt holes in a different way. This is an exceedingly unlikely scenario. If they were installed, then the question becomes when and by whom were they removed. Note that these 4 bolts, especially the top 2 bolts, DO NOT NEED TO BE TIGHT to fulfill their function. They simply need to be THERE, and the nut they attach to is a castle nut which locks in place with a cotter pin to ensure it doesn't spin off in vibration.
Here’s the deal either the bolts sheered or weren’t there. If they sheered the fittings will show it. My money is the bolts were left out. Loose bolts with a cotter pit in the castellated nut is not gonna gonna concern me. Bolts with no cotter pins is another story
@@cuisinart7899 This was a brand new plane, not on the line long enough for “later maintenance.” I believe it rolled out to AS on October 31st, and had its first flight in mid November. Not enough time to have enough hours for maintenance. This was an error in manufacturing.
Likely a second party service by a under trained worker forgetting the bolts. If properly qualified then they need to up their qualification requirement regarding paying attention to detail.
I am very pleased and impressed with the NTSB and specifically the chair. This is exceptional government transparency. She is a credit to the DOT.
The NTSB has not been under the DOT since 1974-75. It's a completely independent agency.
Excellent presentation, thank you. Memo for future events, can you please request microphones and attendees step up. We, the interested audience, would get a lot from the questions asked. Thank you
They've been doing a good job of repeating the questions into the mic before answering on previous days, but a few today were missed. I think they're tired! They've had a few long days in a row now.
I feel so bad for the flight attendants. I could never go back to working on an airplane again.
I have to say that Jennifer Homendy is the best example of a leader I think I've ever seen. She instills absolute confidence in the NTSB when you hear her speak. She comes across incredibly well briefed (which proves she listens carefully), is an excellent communicator, is not shy to defer to specialists in her team, is not shy to call out the authorities for lack of action, is not shy to call out the press for hounding the crew so soon after a very scary event. You can tell she is highly intelligent, strong, compassionate and knows how to lead! Very impressive!
This is a wonderful briefing from the NTSB, nobody questions the capability they have of investigating and finding the issue that caused the accident. The problem is... Why so many security issues with Boeing airplanes on the last few years? Seems like the lobby power of this company has amazing reach and that allows them to get planes approved without all the safety measures required.
It seems that profit is waaaaaay over safety on the boeing manufacturing policies in the last decade. We are talking about human lives here.
Hold executives accountable for lives lost, then you will start observing the changes we need for aviation to be as safe as it has always tried to be, except when these money starving robots took over the leadership of aviation.
Amen.
Funny thing is, back in the 80s & 90s they used to come to my airline (Eastern Airlines) to ask if we could look at a particular item with our electron microscope because our lab had more capability than theirs. When the administrator mentioned "microscope" today, it made me wonder if they are still relying on the help of some other airline, or if they finally got their own equipment. There is only one person on that stage today who has demonstrated any technical knowledge.
Was thinking that I was the only one, they're trying to calm down the mass hysteria, which i can totally understand as there is a lot on the line with this incident worldwide, same business involved, you almost have to wonder how hard line they are going to be.
How many people died?
Great Job Jennifer and Team! Solid! .. and go Bob! :-)
I think that this sort of openness from the NTSB is what is missing from our equivalent bodies in the United Kingdom. (AAIB, MIAB and RIAB)
I'm going to shout out to Bob as well. I'm over the pond in Scotland and have been reading about Bob's discovery. I simply can't imagine being the one to find such a vital piece of the aircraft just lying in my garden 😮
Bob will absolutely be a star with his pupils for many years to come!
I think we should rename this type of part a 'bob' rather than a plug or door, to his great honor.
@@paulsherman51 would that be great, if instead of a door plug it became known as a bob door?
That's precisely how we change the world, one door at a time. Bob door, fantastic! Must tell that NTSB spokeswoman. I think every student in his class, and everyone at his school, would be so proud forever to have him as teacher -- just might be our futue pilots?@@Teribus13
@@paulsherman51 perhaps one (or more) of his students may become a future NTSB investigator? 🤔
With great hope. How can we suggest they go there for show&tell, q&a day to that class? who to call or contact? @@Teribus13
Almost impossible for all 4 safety bolts to fail simultaneously. They were never installed.
I agree with the last part. But assuming they were installed they would not have to have failed all at once. They could have fallen out one after another over a couple of weeks. The last remaining lock bolt could have prevented to door from translating upwards as there are no significant forces acting upon it
Agree 100%, there were no bolts
Possible no cotter pins were installed, or possibly only 1 bolt or 2, we really don't know. This plane flew 41,000 hours since October.
@@someguy9778 41,000 hours? You might want to go over your math again.
@@ManCaveMachiningGreat Scott!
13:06 "We are still looking for the bottom hinge fitting…" If this part separated from the door frame because of improperly torqued bolts, the door might have rotated outward from the bottom enough to be sheared off due to the airstream, fracturing the upper roller guides.
It is amazing the plug did not come off sooner with the door guide safety bolts missing. NO WAY they sheared! The factory goofed up.
Either that or a maintenance procedure which Alaska Airlines didn’t perform correctly. There’s aircraft maintenance people who have already said the plugs are routinely removed to allow for interior maintenance and fitting out which would include using the opening for air tool lines, power cables, communication cabling, ventilation piping and the like.
@@65gtotrips The plane was delivered at the end of October 2023 - there shouldn't be much maintenance activities happening on a 10 to 12 week old airplane requiring that door to be removed since it was delivered. As far as I understand, Boeing is the one that fits all the interior and seats, and should be handing over a ready to fly aircraft to the airline.
@@gorak9000 They had contactor in Oklahoma city install satellite internet antenna and returned the plane on Dec 7th. Thats exactly when first cabin pressure anomaly was reported. That shop must have taken that plug off and did not put those 4 locking bolts back.
@@antronx7 Ooh, that's new info I hadn't heard before - that could be very significant if they removed the door plug for some reason! I can't see what advantage there would be to removing that plug though, vs just moving in whatever they needed through one of the normal doors. You'd probably also have to remove and re-install at least one row of seats too to even make it worthwhile to open that plug. But running cables from the antenna to inside the cabin somewhere would be another penetration of the pressure vessel that is the inside of the cabin - maybe a contributing factor with the door, or it could be a contributing factor to the pressurization errors only, or it could be neither or both!
@@gorak9000 access?
The question is was that door plug removed to facilitate installing seats/interior etc on the acft and in rush to get it assembled and out the door to Alaskan Air bolts were left out or weren’t cotter pinned etc
The answer is likely yes. Either at Boeing at manufacturing or Alaska Airlines. It’s important to note this particular aircraft is basically brand new being commissioned to fly in October 2023 and being accepted by Alaska Airlines approximate to October 2023.
Alaska Airlines. No”n”.
What a lovely lady Jennifer Homendy is. Respectful of her team and those around her. Clearly a great leader, doesn't take all the credit, passes to those who are more capable to answer specifics, but totally leading the process. I would enjoy working with... or for... this lady.
Very good and transparent briefing.
Outstanding job from these people at NTSB. Truly inspiring. The Q&A is, by far, the most amazing part. A truly transparent exercise. I wish other public servants behave like this team, specially high level ones.
The bolts do not carry a structural load; they simply keep the plug, and the fuselage's "fittings" aligned and mated. The fittings do all work. What happened to the bolts, that allowed the plug to move out of alignment is the question. They seemed to have trouble explaining this.
They were not installed.
Yeah, pretty sure what happened to them is they were never there in the first place. The question is how was such an omission not flagged during assembly? The s/n of each bolt and nut should have to be recorded into the system before the insulation and trim is allowed to be installed, covering it all up.
I read this much differently. See the article on the air current website. United airlines reported finding fasteners that hold the lower hinge bracket, The upper guide tracks, and the pins to the door and the fuselage to be loose / not screwed in. If any of those parts come loose then the retaining bolts become useless
Because they don't know for sure yet. They have to complete the investigation. They could have not been installed, fallen out, been the wrong size, etc. etc. Investigators will know soon enough.
Chances are, the stop bolts were not there. If so, then QA inspection procedures failed. Those QA failures would have far-reaching implications for the entire manufacturing process, not just the door plugs.
What QA? Are there even QA inspectors anymore?
@teresadofredo9908 don't be facetious
It will not have any implications..no voice recording.no proof . Like all things corporate lives mean nothing, the bottom dollar will be protected.
Jennifer said that the tracks broke off. That could mean the lock bolts were in place but the fasteners holding either the track or the pin were loose and what failed. I can see the bottom lock bolts through the hinge ripping the hinge once the top of the door was free. I have not seen a close-up of that lower hinge hanging out of the plane yet.
@@rickybungalow8839 In fact, Boeing *DID* get rid of QA at some plants. Workers are expected to self inspect, but no extra time to do it.
When one door closes , another one opens up.
Great work by NTSB. Looks like maintenance inspections or work are not being done properly, the way they're suppose be done. Who's accountable ?
Only the current economic system. Boards of Directors should only be full-time workers. Why would anyone expect an Amgen executive (i.e., Big Pharma) to know anything about running an aircraft company. No single human is accountable, it's fundamentally capitalism, profit, money, and greed.
I’m going out on the limb to say they won’t find the bolts because they weren’t installed. That plug wouldn’t have shifted up if the stop bolts were there. It’s a huge weak link in the chain but only because protocol was not followed by someone fitting out the interior. All they need to do is look at the serial number build manifest which will show those parts as being necessary as part of the build.
You did hear Jennifer say that the tracks broke off, right? If the bolts were not there the door would have just come free rather than breaking the tracks. And it probably would have happened a lot sooner than it did. I think that the fasteners holding either the track or the pins were the failure point, Because they were loose. Consistent what United airlines reported finding. Perhaps the tracks are missing along with the bolts!
@@gutrali The track fractured but it was provisionally discussed that this component was not fractured before the plug blowing, but the upward movement of the plug on the hinges caused the fracturing of the track. If the lower bolts were in place this would have prevented the upward motion preventing the fracturing. The door/plug has to go upwards to disengage from the track pins to come off. Boeing is a total mess and needs sorting out before more people are killed on their aircrafts.
@@gutraliGuide tracks are not air pressure load bearing. The 12 stop pads are. Bottom 2 hinge locking bolts would have kept the door from sliding up had they been installed.
@@antronx7 Not if the bracket holding the hinge to the door had loose bolts that came out, Which is what United airlines reported finding on more than one of their planes. Along with loose fasteners holding both the guide track and the pin to the upper portion of the door and fuselage. These were the portions that the NTSB reported breaking. If the upper portion of the door comes loose from the fuselage I'm pretty sure the bottom hinge bolts will be ripped right out as the door is pulled away. This is made even easier if the fasteners holding the bracket are loose to begin with....
@@gutrali Now we just have to wait and see the results of NTSB investigation. Hopefully they can fast track it.
Just a correction: ETOPS used to means Extented Twin-Engine Operations, but not anymore. Now it is just "Extended Operations". Indeed, the ETOPS FAA regulations does apply to airplanes with three or four engines.
Thank you to the NTSB. One thing I think of, is if the door to the cockpit is designed to open during an event like this, couldn't someone with ill intent cause a rapid decompression then storm the cockpit? Why would it be designed to open in an event like this? I understand the cockpit would need to equalize but why the entire door?
I hardly believe this could (or even would) be pulled off by anyone. Rapid decompressions don't go unnoticed and can't be done intentionally without intervention (that assuming the decompression is being forced by someone in the cockpit).
A straightforward way to do this intentionally could be, for example, overspeeding the aircraft to its structural limits, causing the plane to tear apart. Depending on which part of the fuselage is torn off, the plane quickly decompresses or it simply freefalls to the ground.
Now, aside from cockpit, the second way to cause a rapid decompression is through an explosion.
Both are catastrophic scenarios on their own and therefore using them just to make a door open mid-flight seems illogical.
Point being, if someone were to storm the cockpit to cause a disaster, this decompression-triggered door mechanism would hardly be the means for it. The very act of rapidly decompressing an aircraft is a disaster by itself and can only be made by a violent force, which would never go unnoticed. If the plane is capable to keep flying after a rapid decompression (which was the case for this flight) and the pilots are fine, the other crew members (sometimes even passengers) could intervene and try to suppress the person or group (IF they even managed to get inside the plane in the first place, being a terrorist group) while the pilots fly the plane back to the airport. This whole scenario is not exactly impossible, but tremendously unlikely.
This briefing makes it clear that the all the humans involved (at both Alaska Airlines and the NTSB) refused to believe the airplane's pressure monitoring system when it was sending out warning signals and changing into its alternate operating modes as this door plug was slowly loosening up over time and allowing cabin air pressure to uncontrollably escape for weeks as the plane was flying. No one seemed concerned about the air pressure losses on a brand new airplane. WTF? They all turned a blind eye to it and said "let's just let the backup system deal with the air loss."
@blancolirio mentioned that the default assumption is a software or computer fault, but the pressurization system will ALSO give the exact same fault if it's losing pressure too fast.
@@KaneYork When the primary system indicated a fault. Aircrew switched to the backup which did not show a fault. Please explain how door plug affected one but not the other.
Nice job on a relatively complex topic.
Other videos have used sketches or diagrams to illustrate the restraining system (lock pads, roller / tracks, springs & bolts). This will no doubt be developed during the investigation but would surely have added value to the briefing. That said I don’t know about proprietary restrictions.
my two cents. has to be an issue with the stop bolts. such as they were never there, they were installed wrong, too long, too short. or the holes were of the wrong tolerance (hogged out?), the beauty of the FAA is everything, down to every bolt nut and washer, has traceability. and the paperwork follows that aircraft. who worked it and who signed it off, and who signed off the sign off.
I have a feeling what happened is they put the door plug in, the lock bolts were missing, and someone else installed the insulation and interior panels covering it all up and they got missed. It's probably 2 separate people or 2 separate crews that do the bolts vs installing the trim panels - probably a lack of ensuring the door plug installation is complete before proceeding to install the interior trim panels by the other crew. There should still be a missing sign off on the actual door plug installation though.
I don't think this is the case because they said that the tracks broke off. The door would have come loose a lot sooner if there were zero fasteners holding it in. I think that the fasteners holding the track or the pins were loose enough to eventually cock outwards enough to compromise the door seal. At that point the decompression forced the tracks to break off in the door to fly. The retaining bolt in the tracks would be irrelevant at that point, and the lower two lock bolts could simply be ripped up off of the top part of the hinge (We have never been shown a close-up of the condition of the hinge sticking out of the lower part of the door hole from the fuselage. There could very well be damaged there we haven't been told about yet)
It looks like someone went to lunch and when he came back, he forgot where he left off......and forgot to install the bolts.
That's why there's checklists and sign offs though. I think you're right - the bolts weren't installed, and then someone else went and installed the insulation and the interior trim and covered it all up. But how did an uncompleted check list or sign off allow the plane to ever leave the factory?
I suspect you are very close to the actual answer. If there is a lot of work going on near those doors, they might be opening and closing them through various shifts with the understanding that the last person who closes the door should put the 4 bolts back in because they will no longer be repeatedly opening and closing it. Might have happened where the last guy closed the door, thinking more work was still ahead, and the next shift came in, saw it closed, didn't really have any additional work, and thought everything was good to go. Some piece of paper work should prevent mistakes like that, but things have been missed like this before. I think that if I was still working as an airline mechanic, and I had to temporarily close that door, I'd hang 2 orange streamers near 1 of the 4 bolts such that one streamer hung outside the aircraft, and one inside.
The NTSB would be better served if they would show slides/photos of what they are describing, so many media outlets will get this entirely wrong in their reports to the public...UGH
for their final report? sure. for their daily update? not really necessary considering they're a comparatively tiny government entity.
I really hope she gets some time off here soon, seems she’s been all over the past 4 weeks.
Questions I did not hear, and this may have been because the media present are not aware of the basic design of the 737 airframe. The first is that 737 door plugs are fitted only on some planes operated by a few carriers. Most carriers have the full compliment of doors, in order that they can maximize the passenger capacity. Alaska choose to reduce the capacity to below that where the extra door is needed, and give their passengers more leg room, as do United on some planes. As the 737 airframe is a very old design, this is not the first version to have door plugs fitted, and the design has not changed much, and incidents of this type have not happened before, so why on this nearly brand new plane? It seems unlikely that the bolts preventing the plug from sliding up fractured, otherwise parts of the bolts would have been retained on the plane. This conference confirms the bolts are completely missing. That is very odd. Other carriers report finding loose bolts. It is really easy to see from the threaded insert whether a bolt was ever fitted, because inserting a bolt leaves marks on the receiving thread. My final question is this, and I suspect this is already known by maintenance crews and pilots. Have pilots on other 737s reported 'ghost' air pressure warnings where the maintenance crews were unable to find the cause? I have a feeling the answer is yes, and so, by now, the NTSB should already be calling on pilots and maintenance crews to search back (in records or memory) for such incidents).
i have an associate's in sociology and a casual interest in airplanes. here's what i think the ntsb should be doing to investigate this accident (part 1/26)
Door was blown from outside, that's why there on extra body
My son was on this plane. 16 years old-minor & his first solo flight. Not once did any Alaska crew make sure he was ok or reach out to him. Seems they are covering their butts by saying they made sure the minors were ok. Very scary for us & luckily we had family that could make their way back to the airport to pick him up.
My kids where there too
It would have been helpful to use digital graphics in order to explain the door stops, bolts, pins, etc
A picture is worth a 1,000 words
@@johnduffy532go to @blancolirio for a clear explanation from an ATP pilot & A&P mechanic. The NTSB Chair isn't certified as either.
you could also take 5 seconds to google it and find plenty of diagrams made by other people
The Boeing 737 Technical Channel by @ChrisBrady737 is also excellent. @johnduffy532 @SquawkCode
From an NPR interview on Jan 9 or 10.
"HOMENDY: Well, we know what broke. The components on the top of the door plug fractured, which allowed the plug to be violently expelled from the plane. The bolts that hold those components in place - we don't know whether those bolts themselves also fractured, were loose or whether they weren't even installed on the door. And that's something we're going to have to determine when we get that door plug to the lab."
This is ALL WRONG. The broken guide pieces broke BECAUSE they were struck by the door, which has ALREADY slipped off the load pads and was making its bid for freedom. The fractures did not allow the door to come loose, they were a result of the door becoming misaligned, presumably due to missing bolts, and being forced out of the frame by the aerostatic pressure.
This woman is a freaking MENACE. She should not be allowed to speak on ANY technical issue. Let her spout her PR fluff, but keep here the hell away from the hard engineering!
NTSB should never allow a plane to fly that has multiple unknown losses of pressure.
The easiest comparison would be with a multi-lug rotating bolt locking mechanism. On the door plug system the engagement surfaces are aligned by vertical translation. On the bolt accordingly by rotation. Every other component only provides retaining and guiding functions without any load bearing capabilities.
Thank you NTSB for an open honest discourse which will inspire both confidence and trust from the public. Can you send some people over to train the medical profession please as they are the complete opposite.
Thank you for the service you perform
NTSB team are maginficent. Wish if they would have used diagrams as well for their breifing.
My only complaint is that, there was not enough microphones so they didn't have to keep swapping positions to speak, and one or two mic's in the room to hear the asked questions.
I find it odd that all aircraft doors are designed to be "pressure assist" seal, and they only open inwards (have to be installed from the inside). Why in the heck did these "door plugs" get designed to be installed from the outside? Why not make a door plug that looks alot like a door, and has the same trusted interface? I question why anyone would design a door plug that doesn't install from the inside - the plug should install like doors do, from the inside, so that it CANNOT come out!
How the NTSB staff had difficulty conveying these relative simple mechanisms on the plug-door is painful to watch. They should have included an illustration/drawing of the plug-door for this media brief. Given what were revealed so far the odds of none of the four bolts and nuts that function as stop pins to prevent the door from translate upwards were not installed. Once the door creeped upwards by the lift assist springs the stop fittings were no longer aligned to support the massive force that want to blow the door out. That left the upper hinge guide tracks and roller, and the two lower hinges to withstand the massive force as well as the aerodynamic drag force flying at circa 250 mph at the time. The fractures found on the upper guide tracks are the result of that.
Evenything right now is pointing toward problems in the manufacturing of the plane, unless the plug-door had been worked on during Alaska maintenance.
They didn't describe how the stop fittings on the door plug go inboard of the door frame fittings. high-fiving is meaningless to the reporters.
Agreed.
@@ImperrfectStranger No the high-five isn’t a great analogy. After looking at this for hours, here’s my attempt to explain how the mechanism operates. If you research how the plug operates, it’ll become obvious to you or anyone with a mechanical aptitude. This may sound a bit convoluted but there’s plenty of photos and videos of how this is occurring.
Briefly before all this stuff below. The movement when removing the plug is upwards and out. Installation is inwards and down. Removal = remove the retainer bolts. Install = install the retainer bolts.
It’s all quite safe if the bolts are present, not to mention rather ingenious.
There’s the (2) bottom hinges (one each side) for movement to and from, and at the top there’s (2) (L & R) roller pins on the fuselage which engage (2) (L & R) curved slotted raceways on the plug itself, acting as a latch mechanism. The two lower hinges have ‘helper’ springs such that the spring’s force pushing upwards help to move the mass of the plug as the plug is pushed outward by human means.
The plug which has (6) ears on each side, is pushed into the fuselage via the (2) hinges above and past the fuselage’s (6) ears which are static in the opening, as the plug is moved downward; As this is happening, the curved raceways engage the rollers on the plug’s frame, where the (6) ears on each side of the plug overtake (overlap) the static ears on the fuselage, thus creating a ‘plug’.
The plug is now in. Then the (4) bolts (2) which are placed through holes drilled through the lower (2) hinges and the hinge pins themselves, and the upper (2) surfaces having been drilled as well, all accept these AN aircraft grade bolts, which lock the entire plug into place using (4) AN castle nuts and hardened AN cotter pins such that the bolts cannot vibrate loose. These are hefty aircraft grade fasteners.
The plug is now secured for pressurization. As the pressure differential increases, the (12) total ears push from the inside to outside onto the (12) static ears on the fuselage. This is what actually takes the forces of the air pressure and translating those forces into the strong frame and the rest of the fuselage.
Again, the (4) bolts are designed to prevent vertical movement upwards; If the (4) bolts aren’t installed, then the plug is able to move vertically upward allowing the ears to move past each other.
In maintenance, the (4) AN retaining bolts are removed such that the plug can move upward with the help of the force of the springs, then past the ears in an outward movement, whereby the plug is then opened. There’s about a 15 degree by about say 10 inches (not exactly sure) gap where the plug is attached to the fuselage with braided cabling to allow temporary access, or the entire plug can rotate down and out of the way.
We are entering a period in Aviation, where the best qualified doesnt matter, but who looks right - more accidents will result!
Next will be you
Very impressed with the NTSB & there report
Sounds like no one bolted it in! 🤦
very simple question. Did anyone remove or adjust the door/plug after delivery. Who was the last person to touch the door. The big question is why Alaska allowed this plane in service with pressurization warning lights activating on previous occasions. Alaska did not allow the plane to be flown long distance over water due to this issue but somehow it is deemed OK to fly over land without a resolution to the warning light issue. Also I find it quite coincidental that the two seats next to the plug were empty on a nearly full flight. Were they left empty on purpose?
If I had to guess, being a new plane, Alaska notified Boeing and Boeing told them to not fly over water until we figure this out. Just a guess......
Everything on a plane is so important for saving a life !
Yea! The video didn't cut off mid-sentence!
Wow, Reuters. That was one heck of a scenario. I would suggest looking into the difference between the "aircraft de-icing system" (i.e. mechanical systems built into the aircraft) and the procedure of "ground de-icing" (i.e. the airplane being sprayed with liquid before takeoff). two completely different systems/processes. Only the latter of which causes delays on the ground.
They should also check to see if the ice in the beverage carts is somehow involved.
Reuters. What did you expect?
Relevant parts 17:30 and 25:36. The 4 stop bolts were not found. Thank you NTSB for letting us know this crucial piece of information.
That’s them telling ya the issue without flat out telling you what happened
@@Travisesty The issue is why weren’t they there in the first place? We know they weren’t there, and so that’s the path to travel down to find the root.
As they said, the bolts could have been installed but ejected during the decompression. Keep in mind these bolts aren't "bolts" like when you are building something, but more like large pins designed to prevent the door from moving up. They do nothing structural in the assembly. It's like when you put out wheel chocks to prevent your car from moving. This is why even the reports of loose bolts isn't that big of a deal because as long as the nut is in place the bolt can spin as freely as it wants. The door isn't going to move.
@@flyingdaytrader They were not there that's the problem. Bottom spring hinge locking bolts would not blow out if they were installed.
Let them know if you find the bolts!
Alaska Air, after what came out related to flight 261 crash in 2000, should not exist. FAA should have shuttered them
This comments section seems to be oddly lacking in apologies from the people from yesterday who were complaining, without a shred of evidence, that Alaska Airlines was “ignoring maintenance” and/or “putting passengers at risk by keeping the plane flying”… when, in fact, maintenance procedures of the triple-redundant pressurization system had been followed BY THE LITERAL BOOK, and Alaska Airlines went above and beyond what was required by the letter of the law by placing an additional ETOPS restriction on the aircraft in the name of keeping their passengers safe.
I won’t hold my breath. People love to play internet expert and point fingers, even when they have not a clue how aircraft systems nor airline maintenance works.
I agree with you, but the real question will come once data is retrieved from the pressurization controller. Did the warning come up because there was an actual issue with the pressure, or did Boeing ship a plane that's about 12 weeks old with no door lock bolts AND a faulty pressurization controller? If there was a legit pressurization issue, then the maintenance procedure that checks the cause of the alarm, and incorrectly deemed it a failed controller instead of a real issue needs to be reviewed as well.
First of all, it still has not been determined that the two events are related. I understand that it seems probably. Second, the pressurization controller being faulty would have had zero impact on this event occurring. Even if the mechanics had decided to replace the pressurization controller before the flight out of an abundance of caution, or as a troubleshooting measure, the door plug still would have departed the aircraft. Pressurization controllers malfunction and/or fail all the time. Sometimes sensors throw erroneous readings and trigger false alarms. Sometimes the controllers hard fail and require alternate or manual reversion. I’ve seen it happen in almost every type of pressurized aircraft I’ve flown in the last 20 years. That’s why the system is triple redundant, and that’s why the manufacturer and the FAA have permitted airlines via the aircraft Minimum Equipment List to continue operations even if one of the controllers is malfunctioning. Pressurization issues are notoriously hard to duplicate on the ground because conditions on the ground are very different from those at altitude. Sometimes they cause intermittent problems that can be difficult to diagnose.
There isn’t an aircraft mechanic on the planet that would see a logbook entry about a wonky pressurization controller and think, “Hmmm, I better check the bolts on that inaccessible door plug on this 2 month old aircraft.” When you hear hoofs on the ground, you think horse, not zebra. Aircraft maintenance procedures cannot possibly account for a scenario such as this. The fate of this event was written the day that door plug was installed in the fuselage. It’s a miracle it didn’t happen sooner.
@@AdAstraPerLlama Couldn’t a leaking pressure seal in, say, an improperly secured door plug, cause pressure instability while climbing or descending? Would it be unreasonable to consider these pressure fluctuations might cause the pressure controller to struggle to maintain pressure within acceptable parameters, act “wonky” and illuminate the trouble light?
I’m pretty sure that nobody is saying that the pressure controller caused the plug to depart the aircraft. I think most people are wondering if the light coming on could have been an indication that there were issues with the pressure vessel. Perhaps issues that ought to have been investigated on an airframe with less than 200 compression cycles.
@@maybeafterlunch You’re misunderstanding what I’m saying. Yes, of course a large leak could cause the pressurization system to indicate a problem. But pressurization system issues are common, and the system worked fine when put into alternate. That’s very common info for a mechanic to see in a maintenance logbook when chasing a possibly pressurization issue. When mechanics troubleshoot issues such as these, they use the info they get from the flight crew about the problem and pattern match it to similar issues they’ve seen in the past. There would be no reason to suspect that part of the pressure vessel was fault/improperly installed at that time with the info they had. There are many common failure points in a pressurization system that they would likely try to repair or replace before anyone would suspect that the pressure vessel was compromised on a brand new aircraft. Again, when you hear hoofs on the ground you think horse, not zebra. Also, typically when a pressure vessel is compromised in some way, loud/high pitch noise will be reported by passengers or flight attendants on previous flights. That’s not the case here.
To put it in terms you can better relate to, say your brand new car throws a check engine light. You take it to your trusty independent mechanic you’ve been using for years. He scans the code and it says that the engine temporarily experienced low fuel pressure. He manually checks the fuel pressure at the manifold and it checks good, and the car runs perfectly fine. He resets the code and tells you to keep an eye on it for any other issues. A month later the light comes on again, so you bring it back to him. He scans the code, same thing. He again manually checks the fuel pressure at the manifold and the engine is still running perfectly fine. No obviously faulty parts. Now he’s probably going to say something like “I suspect one of the many sensors could be faulty” or “could be an intermittent problem with the fuel pump” or any other number of parts. But, again, the car is running fine. Now he could begin replacing the dozens of parts in the fuel system one by one until he finds the problem. But each time he replaces one of the expensive parts you’ll have to leave the car with him for a while, which isn’t ideal, and the parts are expensive, so it would be silly to begin replacing parts if you aren’t even sure what’s causing the error in the first place. Again the car is running fine and he can’t seem to replicate the light coming on. But he’s a good mechanic, so he says, “Look, the car is running fine. Let’s keep an eye on it for any other clues as to what’s going on, but just to be safe don’t take it on any long road trips for now. Wouldn’t want you to have a problem in the middle of nowhere. I know you have to get to work now, so let’s schedule a more convenient time for you to come back and I’ll try to dig into it a bit more.”
You leave the mechanic and on the drive home the fuel tank explodes. You walk away from the car unhurt, but obviously shaken from the experience. After further investigation it is discovered that there was a major problem with the fuel tank when it was manufactured at the factory just two months ago. The problem was on the topside of the fuel tank, tucked up underneath the car where no one could see or suspect a thing.
Now, tell me, are you going to get all bent out of shape at your trusty old mechanic because the car had a manufacturing issue that he couldn’t have possibly known about or even suspected? If you had demanded that he replace the fuel pressure sensor before the car exploded, would it have changed the outcome of the scenario? The answer to both of those questions is “no”.
@@AdAstraPerLlama
If my mechanic resets the warning light and sends me on my way, only for me to become stranded, or worse, because he couldn’t be bothered to download the available data and find out why the light came on multiple times? I would definitely be bent out of shape.
That’s the entire purpose of most warning lights. “You need to download my data, and/or perform maintenance items; There is a problem.” “You need to take action, other than covering the light with tape”
My previous reply was relating to your statement “Second, the pressurization controller being faulty would have had zero impact on this event occurring.”
“Even if the mechanics had decided to replace the pressurization controller before the flight out of an abundance of caution, or as a troubleshooting measure, the door plug still would have departed the aircraft.”
You might want to reread my reply based on this context. Nobody is saying the controller ejected the door. The light indicated a problem. Instead of downloading the data from the controller, it was simply reset and/or taken out of service THREE TIMES.
The problem causing the light to illuminate will now be determined by the NTSB, since Alaska’s protocol seems to be resetting systems instead of immediately investigating why a warning light came on during multiple flights.
When the NTSB completes their investigation we might find they were isolated events We might find they were related to one another. Or the results may be inconclusive.
< I appreciate your comments and have learned from them. I hope you will not take my postulation as argumentative derision. Thank you for taking the time to share your knowledge and experiences>
Ms. Homindy and her team demonstrated competence, clear communication and empathy to all involved. I would like to see NTSB to have oversight on FAA's governance over Boeing to restore public confidence that a competent organization is overseeing quality of our critical air transportation system.
As much as I’d love to see the NTSB given stronger teeth to make change, power corrupts. I’m happy the agency is independent and mission driven.
Her vertical patty-cake example was horrible. The stop pins and plates are perpendicular to the sides of the door frame which puts them in a horizontal position.
@@txkflier No, the contact surface between the door and stop pads is not horizontal.
@@peterwmdavisNo, they're round on tabs that are horizontal.
@@txkflier 🤡
Reactivate the door warning light for the plugs.
Jennifer for president!!!!!
Well. They got the issue now for the cause. This is going to be an interesting report. I love these professionalism!
Nothing but grandstanding
0:44 official start
This women, I apologize for not knowing her name, or position; is an absolute Rock Star!!! 👏👏👏. This is probably the one person I trust the most in the government.
Jennifer Homendy? Chairman of the NTSB. She has been on the board since 2018.
Suggestion: have visual aids for discussing door plug, stops, bumpers, track, hinges, bolts. Video, or even still sequence, might be best.
I bet they will, I doubt they had time.
you're right. they need to halt this investigation and pour their manpower into making animations so us smooth brains can understand it better
Great work NTSB , thank you !
I wish some of these reported asked if they thought it may be a similar case to the locking mechanism failure of united 811
Did the head of the NTSB just inform the world that the cockpit door is designed to open during a rapid depressurization? She said as well that the flight crew had no knowledge that this happens by design. Things that make you go-hmmm!
Seems some people don’t understand that those latches were made to withstand HUMANS trying to breech them, and to withstand that at least long enough for other passengers to stop that person. Those doors aren’t impenetrable against all forces. Not to sound pro-Boeing when I’m actually pretty ticked at them right now, but that’s actually the one thing Boeing can’t be faulted for here.
And if this is made to open BY DESIGN, rather than being something that merely COULD happen, then it’s on Boeing to make that a part of their manual.
I've only heard before that in the door there is a panel that is supposed to open and equalize the pressure during such decompression event. I guess the door latch will also open if the event is fast enough.
@@NoelleTakestheSky that's the point... Boeing said it's an intentional design feature and the NTSB is stating nobody was ever made aware of it. that's a problem.
The Chairwoman is a good leader, not a boss, not a supervisor. Competent at explaining the details and enabling the experts to speak.
Legend has it that the phone is still sitting the podium.
I AM REALLY CONFUSED NOW
So it's what everybody said had happened from the first day.
Boeing didn't put the 4 safety bolts back in after they removed the door to install the seats.
Are we sure boeing installed the seats?
Subcontractors?
@OneAdam12Adam I'm a little unclear of the steps to the process.
It seems like the plane is built with the plug in place and then at some point it is determined where the seats go. The plug is then removed to Install the seats and then the plug is reinstalled. I'm not sure who installs the seats.
737 Max -9 has door blank fitted when manufactured . Depending on how the seating numbers are configured determines the number of emergency exit door are required if an airline adds more seats then the blanks are removed and they become a standard emergency door if an airline reduces its seating number then emergency door is removed and door blank is reinstalled Boeing designed the aircraft for multi configurations but in one size cheers
@tonyde6423 It is clear that the blank is put in initially, a compression test is done and then at some point the blank is removed for the seats to be installed. I have the impression this doesn't happen where the frame is initially made. I think the airline might reconfigure this seats themselves but I'm not sure. I'm confused why Boeing would do this at different locations.
The one fact that is clear is that the plug is put in, then removed, then reinstalled at some point. I just don't know by who. that's my question.
Great job by the cockpit crew to safely land the jet under extreme conditions. Saving everyone's lives.
What’s interesting is the airplane’s first flight was 10/15/23 and it had flown 145 flights since then.
NTSB did a poor job communicating the facts. The 4 missing locking bolts lock the roller pin, attached to the airframe, into the door track, attached to the door plug. If the bolts are installed, the door can not move upward and open. The door plug on this airplane moved upward and blew out. It is not possible for the door to move upward if the bolts were in place in the door track. The bolts were missing.
Exactly.
They should've had a projector, and shown the video from "The Boeing 737 Technical Channel" from a couple of days ago - he has good annotated pictures showing how it all works - even an electrical engineer can understand how it works from that video :)
There’s only two bolts on the tracks, as the other two bolts are down below holding the slide at springs in place.
@vondiesel3070 Likely, but it seems like this administrator really likes to talk to the press, so they needed something to talk about until they can track down that one signature of the last guy to install the plug. I would not want to be that guy!
every other news organization and youtube commenter is already saying this. the NTSB exists to deliver evidence-based conclusions. let them do their job.
It would be nice to know if the cotter pins were in place on the nuts that were loose on the United planes. The nuts shouldn't be able to come off the bolts with cotter pins installed.
You did hear them say that the tracks broke off right? The bolts being in place would be irrelevant if the tracks broke off completely. I think now this speaks to the fasteners holding the tracks to the door being loose, which is also something United airlines reported finding on their plans
No I must have missed that. I thought they just found cracks in the tracks. Anyway I was referring to the United planes not the plane that lost the plug door. It's also not clear which bolts United found that were loose. Were they the four bolts that keep the door plug from moving up or other bolts that hold the hinges, guides or tracks?
@@ManCaveMachining see the article on the air current site. UA found the fasteners holding the lower hinge bracket to the fuselage were not screwed all the way in. If this bracket came off, then the bolt preventing the lower half of the door from moving upwards on the hinge would become ineffective. They also found loose fasteners holding the upper guide track as well as the guide pin. This was all found on aircraft That were still flying..... That's a devastating blow to Boeing because even if the door is opened for maintenance or retrofitting, The bolts that were found loose would never be removed. They are installed once from the factory and they remain installed unless the plug is swapped out with a real emergency door
Wow that's scary. Makes you wonder how many other bolts/nuts could be loose.@@gutrali
Theres rumor going around reddit that a contractor in Oklahoma had the plane for 10 days to install satellite internet antenna and returned the plane on dec 7th. Coincidentally thats when first cabin pressure anomaly was noted. Then it was reported 2 morw times in January. Alaska Air maintenance dismissed it as air leaking through this new antenna. So the blame is likely with Alaska Air and their contractor.
10 days to install an antenna?
@@someguy9778Installing an antenna often requires removing the interior, running wire, testing everything for interference, etc. It's not like installing a car stereo in your Pinto. It's likely the satellite antenna seem on the top of fuselage just above the plug door photos.
There wasn't a cabin pressure anomaly.
A warning light came on. Once while still taxing on the ground.
So this was suspected as caused by a malfunction of some sensor, the crew switched to the backup system and the light went out. So that is an indication of a problem in some sensor, but not of any actual pressure loss, a serious (or even any) air leak.
@@michaelm5772 Could have been due to improper seal of the plug door but it would have to be really messed up and not correctly closed versus simply leaving 4 locking bolts uninstalled.
I think that all the emergency exits should be checked as the mechanism are similar, loose bolts on the hinges is troubling
interesting that the cockpit door openned during the event. Not sure how the locking/latching mechanizim failed (door bowed or frame bowed?), but with the 911 security improvements, you would think that would be prevented (although decompression is a very violent, forceful event).
The cockpit door is something like 75x18 inches, for an area of 1350 square inches. If the cabin pressure lost 4 psi in a second or two, you could very reasonably end up with several thousand pounds force on the door, easily enough to banana a door designed to stop a person from getting in the cockpit.
Actually, watch a little longer, the cockpit door is designed to pop open during a rapid depressurization event as a "fuse" to prevent worse structural damage.
saw another video where they said they have blow-out panels in the doors to equalize the pressure. From the updates, seems the whole door popped open, not the blow-out panels. Stuff you learn!
@NTSBgov Which bolts? (@34:46) The bolts in the mechanisms that prevent the upwards translation or the bolts holding the plug to the stop fittings (the actual heavy bolts)?
The 4 bolts holding the plug in would be the only ones touched since the fuselage left by train to Boeing.
The "stop fittings" and "stop pads" aren't "heavy bolts" - they're metal castings on the door and on the opening that align and don't allow the door to move outwards. When the door moves upwards, the "stop fittings" aren't aligned with the "stop pads" anymore and the door can move outwards. The lock bolts prevent the door from moving up and down so the "stop fittings" and "stop pads" stay engaged with each other (aka those lock bolts have very little load on them - only the weight of the door, and any additional forces due to vertical movement (acceleration).
Yea I know, I caught that. The NTSB is in the limelight and they don’t want to catch the heat from the press, and rightfully so because it’s their job to investigate; It’s the manufacturer, customer, and FAA responsibility for maintenance protocol and procedure.
@@gorak9000 right, because the stop fittings and pads are essentially just opposing tabs that meet up when the door is slid down into place.
Now if the four bolts were not in place, as I understand it, the springs at the hinge, would force the door up, and potentially out at some point.
@@JohnHallgren Yeah, the springs are there to make the door "lighter than it actually is" and easier to open - the same way the springs in your garage door counterbalance the weight of the door itself so you, or the opener motor, don't have to work as hard. So the springs themselves won't push the door up and out, but they make it so less external force is needed - a little turbulence is probably enough. You also have to overcome the friction between the stop fittings and the stop pads - the higher the altitude, the more pressure difference between the inside and outside, so there would be more friction holding the door in too. At the lower altitude, it actually takes less force to overcome the friction and get the door to pop out
The 12 stop fittings/pads take all the pressure of the plug trying to push outward against the frame during pressurization differentials (flight). The 4 locking bolts ONLY serve to prevent vertical movement of the plug roller track off of the upper guide roller (at the top of the plug) and the plug hinge guide fitting off of the lower hinge bracket (at the bottom of the plug). The plug must be able to travel vertically at these points so the the stop fittings on the plug can move vertically enough to clear the stop pads on the frame and release the door. My uneducated opinion is that it is EXTREMLY likely there were NO locking bolts in place at all. Why? Because there is very little to no shearing pressure on the bolts by design - 4 independent bolts would all have to sheared off and under low shearing pressure. If they were installed "improperly", for instance only hand tight with no locking pin then the likelihood that they all could have spun loose several rotations each and then all 4 bolts slide out out position is just not realistic. Simply 1 bolt in place would prevent vertical movement. I'm going to venture that somebody at the Boeing factory or somewhere else didn't install the bolts to secure the plug from moving vertically. More than likely everything was basically mechanically held in place by friction and the weight of the plug and with primary force being outward and not upward during pressurization all was good for some number of flights until just the right combination of pressure differential and jarring of the aircraft knocked the plug vertically enough that the top protruded up and out and was caught by passing air flowing along the exterior hull which ripped the plug out causing fracturing of the guide rollers on the plug. In summary NO BOLTS at all installed.
That's the most plausible scenario and pretty much everyone understands that is the case, but NTSB doesn't want to issue a statement like that and take the small risk of having to walk it back later. Better to let the aviation talking heads on the news or youtube read between the lines and do the speculating.
How can they be certain that other models are not affected in some way given the quality issues highlighted here??
Doesn't the -900 have the same door plug?
@@SquawkCode it does, because the company you're fanboying for used to be competent at what they did.
Ты следующий
good work
Explaining the plug should not be this hard. It sounds very similar to a battery cover on a toy. Put one side in first, close it flat , slide it over, put the screw in. No screw, the cover might pop off. At first I was confused about the "plug". I know now its not a door that came off. They didn't want a door there, but the plane comes with the opening for one anyway. Instead they use a door shaped cover to block the opening. The "plug" was what they were calling that cover.
Here is a video from an known aviation guy explaining it better th-cam.com/video/WhfK9jlZK1o/w-d-xo.html
And it’s a door, not a cover, but intended to not be opened regularly or often, if at all.
An actual exit door would have a lot of additional hardware on it, like latches and smaller window, and such .
@@JohnHallgren Did you read my comment? They're were referring to the "door" as a "plug". They weren't saying "door" every time. Which is why I said, "At first I was confused..." . So I explained why. Then you just tell me it's a door...okay. Also you linked a 13min video presentation explaining the "plug/door". Close-up pictures, and printed diagrams even. What I started my comment with was, "Explaining the plug should not be this hard". I think a video of the "plug/door" opening or closing would have been a better idea. Not sure what you are saying.
What's up with all the touchy-feely? Little has been investigated so far, and there is much work yet to be done... 🤔... "Just the facts, maam."
Also, why didn't they prepare diagrams/images on paper, or computerrized slideshow, to demonstrate the technical aspects to the non-technical audience/reporters ("a picture speaks a thousand words")? This was neither well prepared for nor organized.
"why didn't they prepare diagrams/images on paper, or computerized slideshow, to demonstrate the technical aspects to the non-technical audience"
Exactly.
"why didn't they prepare diagrams/images on paper, or computerrized slideshow"
because it happened two days earlier and the NTSB is a publicly-funded investigative body, not a hollywood cgi studio
also, believe it or not, employees of an organization do not pause whenever their leader gives a press conference. there's an interesting structure called "leadership," which speaks on behalf of their employees so said employees can continue to perform their duties.
@@schmal911, you don't make any sense. The fact that I have immediate access to such images from the Internet, which I did verify via a quick Google search, and, moreover such images have been in use by many TH-camrs since the day the incident took place, makes your point moot.
Excellent point. If anyone wants to see how flashy high-tech 3d cgi virtual reality compromises research and transfer of knowledge and fact, look no further than the KPIX (CBS) weather virtual studio floor and the brainchild of Paul Heggen -- it is an embarrassment to human intelligence. NTSB is one of our national treasures.@@schmal911
The info is online on YT.