SIGforum.com    Main Page  Hop To Forum Categories  The Lounge    What's with Airplanes this Week?
Page 1 2 3 4 5 6 7 
Go
New
Find
Notify
Tools
Reply
  
What's with Airplanes this Week? Login/Join 
Member
posted Hide Post
quote:
Originally posted by kkina:
I wonder how far the phones were found from where the door plug landed. New app: Find My Door(plug)


Not sure, but it was the same neighborhood, as I saw one of the finders post on Nextdoor that she'd found one in her yard.
 
Posts: 719 | Registered: February 24, 2006Reply With QuoteReport This Post
Lost
Picture of kkina
posted Hide Post
According to the latest NTSB briefing, the door plug did shift upward somehow to exit the airframe, damaging the upper roller guides in the process (it was not breaking of the roller guides that caused the ejection).

They also seemed to downplay the cabin pressure alerts that occurred on previous flights, but it's all really still up in the air (NPI).




ACCU-STRUT FOR MINI-14
"First, Eyes."
 
Posts: 17027 | Location: SF Bay Area | Registered: December 11, 2003Reply With QuoteReport This Post
A Grateful American
Picture of sigmonkey
posted Hide Post
So, now the "science" of what can cause the uplift to the door, (cabin pressure/outside pressure delta at various scheduling of the cabin pressure regulation primary/secondary, mechanical "failsafe") as well as what caused the upper trunnion guides to fail? Was it the failure of the "locking" (securing hardware of bolt/washers/castellated nut/cotter pin) or did the mounts where the trunnions were mated with?

Similar mechanical "locking" are used for landing gear upclocks, landing gear doors, cargo and other "doors", where a roller/trunnion engage in a receiving structure "think hand in glove", except in this instance the "hand in glove" has a "pin" driven thought the hand in glove, once it is in place. And is a "hard" securing method, only to be disassembled at a specific calendar time, operational hourly time, or cycle time (take off and landing being one cycle for example).

The door plug assembly should not have been able to move up enough under any circumstance to permit the door stops to become out of alignment to the point that they no longer could contain the door plug.

However, the statement by the NTSB Chair regarding the "feature" of the door plug to depart under "decompression scenarios" is intriguing. That is something I did not perceive to be as a possible design function. Only that if a tremendous overpressure event occurred in side the cabin (such as an explosive detonated inside the cabin) that such a "feature" would make sense to rapidly dissipate any overpressure to maintain cabin/hull/structural integrity, at the sacrifice of the two door plugs (or, even actual escape doors).




"the meaning of life, is to give life meaning" Ani Yehudi אני יהודי Le'olam lo shuv לעולם לא שוב!
 
Posts: 44534 | Location: ...... I am thrice divorced, and I live in a van DOWN BY THE RIVER!!! (in Arkansas) | Registered: December 20, 2008Reply With QuoteReport This Post
Seeker of Clarity
Picture of r0gue
posted Hide Post
It's painful to listen to the stupid questions from the press. Shouldn't you be at least as interested as I am, if you are assigned to this story, such that YOU would watch a few YouTubes on the flight out to interview the NTSB? I'll answer. YES, yes you should. There would be no easy way to avoid a two video Juan Brown briefing if you cared to do a YT search.

It is also painful to listen to this woman's inability to clearly and concisely articulate this very simple mechanical concept without the aid of the gentleman to her left (our right). And without the high five of the gentleman to her right (our left). Good God woman!, you have two hands!!! You don't need to ask that guy for a high five to pull this off.

Cue the MEMEs. <facepalm>




 
Posts: 11434 | Registered: August 02, 2004Reply With QuoteReport This Post
Frangas non Flectes
Picture of P220 Smudge
posted Hide Post
Talked with someone I know at Boeing who has a lot of experience with the problems at hand. The punchline is, Boeing doesn't do the door plugs, Spirit Aerosystems does, and they have their own inspectors. You know who else is responsible for inspecting the airframe before Boeing takes delivery? That's right, the FAA.


______________________________________________
Carthago delenda est
 
Posts: 17751 | Location: Sonoran Desert | Registered: February 10, 2011Reply With QuoteReport This Post
No More
Mr. Nice Guy
posted Hide Post
In hindsight the repeated pressurization warnings are a clue. That is if what is being reported is true and the ETOPS restriction was in fact due to repeated pressurization issues.

However, pressurization problems are not uncommon, and in my experience were caused by the pressurization system itself or a damaged door seal. One would not suspect at first that a bolted on part isn't really bolted on. Mechanics can't fix something that does not present as broken, and on the ground the plug door would, by gravity, be sitting properly.

If it turns out the bolt hardware was missing or broken, it seems to me the pilots and mechanics would never be able to detect it in normal line operations.
 
Posts: 9781 | Location: On the mountain off the grid | Registered: February 25, 2002Reply With QuoteReport This Post
Member
Picture of erj_pilot
posted Hide Post
quote:
Originally posted by r0gue:
It's painful to listen to the stupid questions from the press.
Isn't it??

But we all know TRUE "journalism" in this country has been dead for decades. You and I would probably be considered "Mensa" in the journalism world, but then I'm sure we'd both be cancelled quickly, as you and I would SEEK THE TRUTH. Not all that common in today's world. But I digress......



"If you’re a leader, you lead the way. Not just on the easy ones; you take the tough ones too…” – MAJ Richard D. Winters (1918-2011), E Company, 2nd Battalion, 506th Parachute Infantry Regiment, 101st Airborne

"Woe to those who call evil good, and good evil... Therefore, as tongues of fire lick up straw and as dry grass sinks down in the flames, so their roots will decay and their flowers blow away like dust; for they have rejected the law of the Lord Almighty and spurned the word of the Holy One of Israel." - Isaiah 5:20,24
 
Posts: 11066 | Location: NW Houston | Registered: April 04, 2012Reply With QuoteReport This Post
To all of you who are serving or have served our country, Thank You
Picture of Jelly
posted Hide Post
blancolirio update..

 
Posts: 2681 | Registered: March 15, 2004Reply With QuoteReport This Post
Lost
Picture of kkina
posted Hide Post
^I was just about to post Juan's 3rd installment.

Bolts still missing, but EM micro-analysis of the door should reveal witness marks indicating breakage failure, or even if the bolts had ever been installed in the first place.

He also delves further into the possible significance of the earlier pressurization warnings than the NTSB is able at this time.



ACCU-STRUT FOR MINI-14
"First, Eyes."
 
Posts: 17027 | Location: SF Bay Area | Registered: December 11, 2003Reply With QuoteReport This Post
blame canada
Picture of AKSuperDually
posted Hide Post
The roller guide bracket with loose bolts has been showing up in several A&P forums over the past couple of days. Blocolirio showed the picture in his latest video. I saw that 2 days ago. 3 of the 4 visible bolts were clearly loose. As in not even touching the lock washer level loose. That failure makes sense to me. I suspect whomever was responsible for checking or final torquing those at the factory didn't do it.


~~~~~~~~~~~~~~~~~~~~~~~~~
"The trouble with our Liberal friends...is not that they're ignorant, it's just that they know so much that isn't so." Ronald Reagan, 1964
~~~~~~~~~~~~~~~~~~~~~~~~~~
"Arguing with some people is like playing chess with a pigeon. It doesn't matter how good I am at chess, the pigeon will just take a shit on the board, strut around knocking over all the pieces and act like it won.. and in some cases it will insult you at the same time." DevlDogs55, 2014 Big Grin
~~~~~~~~~~~~~~~~~~~~~~~~~~

www.rikrlandvs.com
 
Posts: 13991 | Location: On the mouth of the great Kenai River | Registered: June 24, 2007Reply With QuoteReport This Post
Be not wise in
thine own eyes
Picture of kimber1911
posted Hide Post
Think this will be an issue of bolts simply not installed. Loose bolts, concerning but not likely the cause of failure.

Was it just luck that the two seats next to the door plug were unoccupied, or was it complaints of a whistling sound?

FYI on a KC-135 wet paper towels will fix the whistling of a poorly fitting over-wing hatch (door).



“We’re in a situation where we have put together, and you guys did it for our administration…President Obama’s administration before this. We have put together, I think, the most extensive and inclusive voter fraud organization in the history of American politics,”
Pres. Select, Joe Biden

“Let’s go, Brandon” Kelli Stavast, 2 Oct. 2021
 
Posts: 5294 | Location: USA | Registered: December 05, 2004Reply With QuoteReport This Post
Quit staring at my wife's Butt
Picture of XLT
posted Hide Post
When one door closes another door opens - Boeing
 
Posts: 5696 | Registered: February 09, 2003Reply With QuoteReport This Post
Seeker of Clarity
Picture of r0gue
posted Hide Post
Ok, my first guess on page one was garbage bolts/supply chain corruption. I'd given them the benefit of the doubt. That was unwise of me.

That door wasn't bolted in and every one of those on-site investigators know it already. They'll prove it under the scopes.

They're all worked up about the sleeve attachment bolts, but the sleeve was on, so don't get that.

I've re-insourced critical functions at my organization in the past. In one particular case I'd discovered significant deficiencies in maintenance and an immediate $700k savings. I realize that one one data point in a million, but it set my opinion to how tremendously hard it is to manage QC on highly technical functions without deep immersion and management and frankly, key management having emotional ownership on said function. It could seem to me that the fuselage is a pretty central component to your identity as an aircraft maker.

They'll get past this. But it creeps me out.

A good opportunity in the near term for a robotic AI driven inspection as a QC.




 
Posts: 11434 | Registered: August 02, 2004Reply With QuoteReport This Post
Peace through
superior firepower
Picture of parabellum
posted Hide Post
 
Posts: 109389 | Registered: January 20, 2000Reply With QuoteReport This Post
Lost
Picture of kkina
posted Hide Post
Wow. The airline industry has finally gone to the...well, you know.



ACCU-STRUT FOR MINI-14
"First, Eyes."
 
Posts: 17027 | Location: SF Bay Area | Registered: December 11, 2003Reply With QuoteReport This Post
Unflappable Enginerd
Picture of stoic-one
posted Hide Post
More at link:
Boeing Whistleblower: Production Line Has “Enormous Volume Of Defects” Bolts On MAX 9 Weren’t Installed

quote:
Current Boeing employee here – I will save you waiting two years for the NTSB report to come out and give it to you for free: the reason the door blew off is stated in black and white in Boeings own records. It is also very, very stupid and speaks volumes about the quality culture at certain portions of the business.

…With that out of the way… why did the left hand (LH) mid-exit door plug blow off of the 737-9 registered as N704AL? Simple- as has been covered in a number of articles and videos across aviation channels, there are 4 bolts that prevent the mid-exit door plug from sliding up off of the door stop fittings that take the actual pressurization loads in flight, and these 4 bolts were not installed when Boeing delivered the airplane, our own records reflect this.

…As a result, this check job that should find minimal defects has in the past 365 calendar days recorded 392 nonconforming findings on 737 mid fuselage door installations (so both actual doors for the high density configs, and plugs like the one that blew out). That is a hideously high and very alarming number, and if our quality system on 737 was healthy, it would have stopped the line and driven the issue back to supplier after the first few instances.

…Now, on the incident aircraft this check job was completed on 31 August 2023, and did turn up discrepancies, but on the RH side door, not the LH that actually failed. I could blame the team for missing certain details, but given the enormous volume of defects they were already finding and fixing, it was inevitable something would slip through- and on the incident aircraft something did. I know what you are thinking at this point, but grab some popcorn because there is a plot twist coming up.

The next day on 1 September 2023 a different team (remember 737s flow through the factory quite quickly, 24 hours completely changes who is working on the plane) wrote up a finding for damaged and improperly installed rivets on the LH mid-exit door of the incident aircraft.

…Because there are so many problems with the Spirit build in the 737, Spirit has teams on site in Renton performing warranty work for all of their shoddy quality, and this SAT promptly gets shunted into their queue as a warranty item. Lots of bickering ensues in the SAT messages, and it takes a bit for Spirit to get to the work package. Once they have finished, they send it back to a Boeing QA for final acceptance, but then Malicious Stupid Happens! The Boeing QA writes another record in CMES (again, the correct venue) stating (with pictures) that Spirit has not actually reworked the discrepant rivets, they *just painted over the defects*. In Boeing production speak, this is a “process failure”. For an A&P mechanic at an airline, this would be called “federal crime”.

…finally we get to the damning entry which reads something along the lines of “coordinating with the doors team to determine if the door will have to be removed entirely, or just opened. If it is removed then a Removal will have to be written.” Note: a Removal is a type of record in CMES that requires formal sign off from QA that the airplane been restored to drawing requirements.

If you have been paying attention to this situation closely, you may be able to spot the critical error: regardless of whether the door is simply opened or removed entirely, the 4 retaining bolts that keep it from sliding off of the door stops have to be pulled out. A removal should be written in either case for QA to verify install, but as it turns out, someone (exactly who will be a fun question for investigators) decides that the door only needs to be opened, and no formal Removal is generated in CMES (the reason for which is unclear, and a major process failure). Therefore, in the official build records of the airplane, a pressure seal that cannot be accessed without opening the door (and thereby removing retaining bolts) is documented as being replaced, but the door is never officially opened and thus no QA inspection is required.


__________________________________

NRA Benefactor
I lost all my weapons in a boating, umm, accident.
http://www.aufamily.com/forums/
 
Posts: 6375 | Location: Headland, AL | Registered: April 19, 2006Reply With QuoteReport This Post
Lost
Picture of kkina
posted Hide Post
^I actually entertained this general idea. First theory was the bolts were never installed in the first place. But I also wondered that they had been installed, but later removed for whatever reason and never re-installed.

The door is currently being examined, and microscopic analysis would be able to determine if bolts had never been installed at all. But it would not reveal if they had been removed but never returned.

I also wondered if a shift change had contributed to a failing in process continuity, which the above disclosure implicates. (This has happened before, with catastrophic consequences.)



ACCU-STRUT FOR MINI-14
"First, Eyes."
 
Posts: 17027 | Location: SF Bay Area | Registered: December 11, 2003Reply With QuoteReport This Post
Lost
Picture of kkina
posted Hide Post
Here's Juan's briefing in case the information article posted by stoic-one was tl;dr for you. Also some nice animation videos at the end.




ACCU-STRUT FOR MINI-14
"First, Eyes."
 
Posts: 17027 | Location: SF Bay Area | Registered: December 11, 2003Reply With QuoteReport This Post
Member
posted Hide Post
Are these the same MAX airplanes that had the autopilot malfunctions a while back?

I dont fly much but always complained about getting an old plane. Now, I hope to get the old planes.


 
Posts: 5472 | Location: Pittsburgh, PA, USA | Registered: February 27, 2001Reply With QuoteReport This Post
Lost
Picture of kkina
posted Hide Post
Yes, same model that suffered 2 fatal crashes. The problem was with the MCAS system (Maneuvering Characteristics Augmentation System), an automated software to prevent stalls. It turned out that faulty Angle-of-Attack signals would trip the system to drive the nose down, with no way for the pilots to override as they plummeted into the ground.



ACCU-STRUT FOR MINI-14
"First, Eyes."
 
Posts: 17027 | Location: SF Bay Area | Registered: December 11, 2003Reply With QuoteReport This Post
  Powered by Social Strata Page 1 2 3 4 5 6 7  
 

SIGforum.com    Main Page  Hop To Forum Categories  The Lounge    What's with Airplanes this Week?

© SIGforum 2024