# The Great Ongoing Aviation Thread (general and other) (Part 1) **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 23, 2011, 2:17am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499 "2011-10-23T02:17:01Z")\ **Posts on this page:** 20\ **Page:** 257
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [January 9, 2024, 1:49pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5123 "2024-01-09T13:49:00Z")
> [@Kedikat](#): > > the plug is moved upwards to clear them. Also hinges and dogs. It seems there were multiple failures in this incident. Indeed. It appears that the plug did move upwards against mechanical restraint in the process of exiting the aircraft. > **[Alaska Airlines emergency: Fittings at the top of the door plug fractured,...](https://abcnews.go.com/US/alaska-airlines-emergency-fittings-top-door-plug-fractured/story?id=106218951)** > > A door plug fell out of an Alaska Airlines flight Friday, National Transportation Safety Officials said. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 9, 2024, 3:30pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5124 "2024-01-09T15:30:59Z")
> [@Dr.Strangelove](#): > > An adjustment slot doesn’t make much sense to me due to the spring taking up any minor misalignment. But given how the bracket appears to be shoved upward, and that the bolt is undoubtedly a harder material than the bracket, I could easily see it wearing through the bottom of the hole over time, with the tension provided by the spring and vibration providing the energy input. Agreed. > [@Johnny\_L.A](#): > > > [@LSLGuy](#): > > > > Good bet not a single employee or sub-contractor at UAL laid eyes on that work since the airplane was delivered new to them. > > Wasn’t that two months ago? The Alaska jet that lost the door inflight was 2 months old. I don’t know that anyone knows how old was the United jet where the pictures were taken of the intact but misassembled door. > [@Whack-a-Mole](#): > > I thought all modern jet doors were plugs that cannot pop out without taking a chunk of the fuselage with it. Indeed, they are stronger than the rest of the fuselage (kinda like my front door is more durable than the walls around it…it’d probably be easier to break into my home through the walls around my door rather than through the door itself). This has been discussed upthread. On most airliners the passenger and galley doors on the main deck are the type that swing inside the door frame and then seal from the inside. So air pressure is holding the larger door fast against the smaller fuselage opening. Conversely, in almost all cases cargo doors and emergency exit hatches are purely outward opening. They do not translate inside, rotate, then plug the hole. They are hatches held in place _only_ by various latches and dogs while the air pressure inside is trying to swing them open. > [@Zakalwe](#): > > My point above was that, even in the '50s engineers knew that vibration and stress worked bolts loose and took steps to mitigate the issue. the fact that a modern airliner built in 2023 didn’t have that mitigation for a structurally key part in place is beyond ridiculous. I’m not sure I follow you. We are looking at pictures of loose bolts. We do not know what the other end looks like. You don’t safety wire bolts that have nuts on the other end. You safety wire (or cotter-pin) the _nuts_. OTOH, if those bolts go into threaded cavities then yes, safety wire on the bolt _heads_ would 100% be expected. And would be required by FAA certification standards. IMO for now, the fact we see a bolt with no provisions for safety locking all but proves the design has a nut on the back side with some sort of locking on that nut. But which nut and / or locking was omitted during assembly. With the completely predictable results, as you say, that the nuts backed off then the bolts backed out then shit happened. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [January 9, 2024, 3:51pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5125 "2024-01-09T15:51:38Z")
> [@Zakalwe](#): > > > [@LSLGuy](#): > > > > or actually getting out a wrench & sorting out which mechanical thingy isn’t thingifying properly. > > In the US Navy, this is also known as “troubleshooting” aka “hit it hard with said wrench and see if it starts working”… AKA percussive maintenance. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [January 9, 2024, 3:52pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5126 "2024-01-09T15:52:03Z")
> [@Al128](#): > > > [@N9IWP](#): > > > > Curious what the terminal velocity of an iPhone is. > > Brian > > european or african? About 30 mph, according to a postdoctoral researcher at the Institute of Theoretical Astrophysics at the University of Oslo. Scroll down about half way. (Gift link.) > **[Here’s how an iPhone survived a 16,000-foot fall from a plane](https://www.washingtonpost.com/technology/2024/01/08/iphone-survives-16000-foot-fall-alaska-airlines/?pwapi_token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJyZWFzb24iOiJnaWZ0IiwibmJmIjoxNzA0NjkwMDAwLCJpc3MiOiJzdWJzY3JpcHRpb25zIiwiZXhwIjoxNzA2MDcyMzk5LCJpYXQiOjE3MDQ2OTAwMDAsImp0aSI6ImY5ODBkYTdiLWZhMGYtNDc3NS1hNjM4LTc0NjJiNjlmNTA4YiIsInVybCI6Imh0dHBzOi8vd3d3Lndhc2hpbmd0b25wb3N0LmNvbS90ZWNobm9sb2d5LzIwMjQvMDEvMDgvaXBob25lLXN1cnZpdmVzLTE2MDAwLWZvb3QtZmFsbC1hbGFza2EtYWlybGluZXMvIn0.9Lyy7Qcp6VCUiYsBrMS-jYNLgumFPJ6fezF4gp8YupY&itid=gfta)** > > A man on a walk discovered a phone from the Alaska Airlines mishap far from where it had been sucked out a missing door. An expert explains how that’s possible. ---
**Author:** ![racer72](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/racer72/32/3075_2.png) [@racer72](https://boards.straightdope.com/u/racer72)\ **Post date:** [January 9, 2024, 5:36pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5127 "2024-01-09T17:36:08Z")
> [@Richard\_Pearse](#): > > What about the B737-900ER? Or is that a different plug? The fuselage in that area is basically the same in the -900 and the -9. Just read it was loose bolts that caused the issue. Loose bolts have been found in 6 other -9’s at this point. I can honestly say this could be a result of some engineering changes made over the years. There have been changes made to certain Engineering and Quality Assurance specifications that may have been the cause of this, I can’t, well I won’t say anymore based on the NDA I signed when I left the company. I am sure the FAA will find the root cause for this problem and they will let the public know. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [January 9, 2024, 5:50pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5128 "2024-01-09T17:50:59Z")
Seems like the NTSB has concluded that all 12 stop pins failed, which is what allowed the pressure differential to shove the plug upward and disengage from the frame, allowing it to open as if it were intentional and appropriate. > **[NTSB Update: All 12 Door Plug Stops Failed, Leading to Blowout](https://airwaysmag.com/ntsb-as1282-exams-all-12-door-plug-stops-failed/)** > > NTSB chair Jennifer Homendy commenced the final on-site report of the day by discussing the activities of the survival factors group and the findings of the structures group. > The structure group’s exam to date showed that the door did translate upward, meaning all the stop pads became disengaged, fracturing the fittings and allowing the plug to blow out of the fuselage. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [January 9, 2024, 6:01pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5129 "2024-01-09T18:01:06Z")
ISTM what that says is not that all 12 stop pads _failed_, but that they _became disengaged_ due to the door moving up when it should not have. Is it failing if what it’s supposed to hold is no longer where it’s supposed to be held? What would have failed would have been the 4 bolts that should prevent the doorplug from sliding on its tracks, wouldn’t it? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 9, 2024, 6:11pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5130 "2024-01-09T18:11:30Z")
I agree w this interpretation. The stops on the door and the frame were each individually fine. The problem was the dummy door panel was wrongly allowed to translate upwards at which point the parts disengaged from each other and the dummy door panel opened outwards as designed. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [January 9, 2024, 6:14pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5131 "2024-01-09T18:14:53Z")
Thanks. I’m impressed by the free flow of information from the NTSB during the investigation. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [January 9, 2024, 6:17pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5132 "2024-01-09T18:17:00Z")
Yes, the door stops aren’t bolted to any part of the door, as I understand it, and only “failed” in the sense that the door had moved up and cleared the stops. They didn’t fail structurally. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [January 9, 2024, 6:18pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5133 "2024-01-09T18:18:21Z")
And I appreciate you probably have a lot more you _could_ say, but it would be inappropriate to do so, NDA or no NDA. ---
**Author:** ![Zakalwe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zakalwe/32/270_2.png) [@Zakalwe](https://boards.straightdope.com/u/Zakalwe)\ **Post date:** [January 9, 2024, 6:30pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5134 "2024-01-09T18:30:22Z")
> [@LSLGuy](#): > > IMO for now, the fact we see a bolt with no provisions for safety locking all but proves the design has a nut on the back side with some sort of locking on that nut. But which nut and / or locking was omitted during assembly. Okay, I was using the diagram above and the picture and misunderstood where those bolts were. I was assuming they were into threaded cavities. > [@Elendil\_s\_Heir](#): > > AKA percussive maintenance. Thank you! I knew there was a term for it and just blanked on it. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [January 10, 2024, 1:11am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5135 "2024-01-10T01:11:40Z")
The president of Emirates seems to be getting fed up with Boeing’s quality control problems … > **[Emirates executive takes a jab at Boeing, says quality control has been an...](https://africa.businessinsider.com/transportation/emirates-executive-takes-a-jab-at-boeing-says-quality-control-has-been-an-ongoing/v8pt0j3)** > > Boeing is facing another 737 Max plane crisis, and quality control has been a problem "for a long time," this airline president told Bloomberg. ---
**Author:** ![ThisOneGuy](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@ThisOneGuy](https://boards.straightdope.com/u/ThisOneGuy)\ **Post date:** [January 10, 2024, 3:41am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5136 "2024-01-10T03:41:05Z")
> [@PastTense](#): > > Since some of us are a bit weak in Japanese, could those of you who understand the language point out the more interesting comments? Since none of the .JP dopers have risen to this, I thought I’d give it a try. Was actually kinda scary to watch that, even knowing that everybody (in the video at least) made it out Ok. This is my short summary: > [@ANNnewsCH](#): > > Video taken by someone sitting near a rear exit started right after the crash, he thought it would help with any post crash investigation. > > === Start of 8 minute video > > Lots of “stay calm” shouts from flight attendants. > > Came to a stop 30 seconds after collision > > voice over from later interview: it didn’t feel like a collision, just a lot of rattling from touch down on. > > flight attendants say many times to cover mouth and nose, looked for a towel, handkerchief > > many shouts of “don’t get your luggage out” > > “Get low down” > > “We are checking the situation” > > interview: With the help of the flight attendants things called down > > narrator: around 3:48 started to see smoke > > interview: the flight attendants were asking for information > > other passengers saying to stay low and out of the smoke > > FA asking where can be opened, shouts of “Can’t open R3, L3 is no good” “Can the front open? Can the back open?” > > 5:51 fire trucks arrive > > interview around the 6 minute mark smoke became hard, thought everybody was going to die. > > At 6:21 door was opened, told to evacuate forward > > many more shouts of “don’t get your luggage out” > > At the door: two at a time, sit down. > > By 7:00 well away from the plane. > > === end of eight minute video > > Then shorter videos from other passengers. > > The phone connection wasn’t working right, had to shout back and forth to the cockpit “which engine is burning?” > > Later discussion by expert: > > At 16 seconds into the 8 minute video he can see that engine is dragging on the ground, fuel is leaking and burning. > > Explained why it is important not to open the door into a fire, said the flight attendants were making the right call to check before opening the doors. > > Understand why the passengers would want more explanation, but they were probably very busy talking between themselves about how to handle it. Also praised 8 passengers who were in exit rows and helped saying things like “it’s going to be all right, stay calm and follow instructions” > > FA opened only the front doors, the one rear door that was opened by a passenger. > > Pilot was last out after making that everybody was out, had to actually kick several off the plane. He got out at 18 minutes. ---
**Author:** ![Kedikat](https://avatars.discourse-cdn.com/v4/letter/k/ed655f/32.png) [@Kedikat](https://boards.straightdope.com/u/Kedikat)\ **Post date:** [January 10, 2024, 4:06am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5137 "2024-01-10T04:06:01Z")
There is a picture in this thread that shows bolts going into the door stop mounts on the inside frame of the plug. It was stated that these are adjusting mechanisms? But the plug and frame mounts for these are through holes. I assume therefore that the bolts, twelve of them, go through the mounts in some way. Holes in the plug mounts, holes in the frame mounts. They can indeed be used to align the plug. But seem to also be a block to movement. How did all twelve of them fail to not only stop lateral movement but also fail to stop outward movement. It has been reported they failed. Looking at the picture of the open plug hole, it seems it must have been all the plug mounted mounts that failed? I hope they post a picture of the inside of the plug at some point. And/or better explain how twelve devices all failed. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [January 10, 2024, 4:43am UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5138 "2024-01-10T04:43:49Z")
I linked this video upthread, it’s a very good description of the door including photos. The link below should take you to the part where he is describing the 4, only 4, bolts that secure the door. The photo shows all of the stop pads and you can see the adjusting bolts are fitted to each of 12 “stop fittings” on the door itself and the “stop pads” are connected to the door frame. Those bolts do not attach the door in any way to the door frame, they are just to get a nice fit with the fuselage skin. [https://youtu.be/maLBGFYl9\_o?si=JGeLYfvbYvGVX2w7&t=472](https://youtu.be/maLBGFYl9_o?si=JGeLYfvbYvGVX2w7&t=472) @racer72, who is intimately familiar with these doors also described: > The tabs sticking out in the pictures have nothing to do with the hatch being held in place. They are used with threaded adjusters on the hatch to adjust the hatch to flush with the exterior skin panels. So when the NTSB say the tabs failed, what they’re saying is they failed to hold the door in place because the door had slid upwards as it is designed to do when fitted as an actual emergency exit. They didn’t structurally fail and you can see them intact in photos of the incident aircraft, Edit for clarity: The tabs DO hold the door against pressurisation forces, but they are not physically attached to the door by any bolt or anything, they simply form a barrier against the door falling directly out. Instead it must be lifted up to clear the tabs and then it will open outwards. ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [January 10, 2024, 12:02pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5139 "2024-01-10T12:02:19Z")
> [@wolfpup](#): > > [Emirates executive takes a jab at Boeing, says quality control has been an ongoing issue | Business Insider Africa](https://africa.businessinsider.com/transportation/emirates-executive-takes-a-jab-at-boeing-says-quality-control-has-been-an-ongoing/v8pt0j3) problem is: ther’s only Coca-Cola or Pepsi in this market … and from neither of those you can walk out with an airplane … so AL also have limited option-space in terms of purchases… and need to “navigate” those situations … but my gut feeling is : Boeing might move into the equivalent of “_italian car_” mental-space-territory (lots of problems and hidden cost later on) … so many AL might weigh more towards airbus in the medium-long term (strategic decision) ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [January 10, 2024, 12:37pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5140 "2024-01-10T12:37:57Z")
> **[Mid-air blowout can 'never happen again,' Boeing CEO says after Alaska...](https://www.nbcnews.com/news/us-news/alaska-airlines-panel-blowout-boeing-ceo-acknowledges-mistake-rcna133198)** > > “We’re going to approach it with 100% and complete transparency every step of the way,” Dave Calhoun told a town hal with staff. ---
**Author:** ![Kedikat](https://avatars.discourse-cdn.com/v4/letter/k/ed655f/32.png) [@Kedikat](https://boards.straightdope.com/u/Kedikat)\ **Post date:** [January 10, 2024, 1:21pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5141 "2024-01-10T13:21:04Z")
Thank you. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [January 10, 2024, 8:25pm UTC](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499/5142 "2024-01-10T20:25:15Z")
At what point do air carriers suffer from customer rejection of Boeing 737 MAX aircraft? They’d better not get too many more bad headlines about quality, or the carriers using those planes will run into trouble and it’ll kill Boeing’s sales. [Previous page](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499.md?page=256) [Next page](https://boards.straightdope.com/t/the-great-ongoing-aviation-thread-general-and-other-part-1/600499.md?page=258)