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Post by gato on Jan 6, 2024 6:11:31 GMT -5
"Alaska Airlines grounded its fleet of Boeing 737 Max 9 aircraft on Friday after a flight operated by the airline made an emergency landing at Portland International Airport in Oregon that evening because of a midair pressure problem that passengers said blew out a chunk of the fuselage."
One of the passengers, William Shatner, said that the flight attendants had brushed off his warnings that there was a gremlin outside the aircraft, attacking the plane's aluminum skin with a bathroom plunger.
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Post by Leftee on Jan 6, 2024 8:35:27 GMT -5
My own personal opinion (not backed by science or engineering) is that Boeing has clung to the 737 for too long.
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Post by LTB on Jan 9, 2024 18:48:05 GMT -5
What about the B52. First one came out 1954 (B52A) and last one 1961 (B52H). H’s are still flying and recently they updated it’s Radar Systems and Engines with Rolls Royce and looks like they will call it a B52J and expect them to be in service until 2050.
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Post by Ragtop on Jan 9, 2024 19:34:30 GMT -5
I remember watching that episode as a kid. Scared the crap outta me!
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Post by Taildragger on Jan 9, 2024 19:53:19 GMT -5
This was the episode that always stuck with me. The theme was revisited in the excellent, 2014, sci-fi film "Ex Machina".
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chucksmi
Wholenote
Posts: 173
Formerly Known As: Offshore Angler elsewhere
Age: I saw Jerry Live
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Post by chucksmi on Jan 10, 2024 6:17:39 GMT -5
My own personal opinion (not backed by science or engineering) is that Boeing has clung to the 737 for too long. 737's are fantastic aircraft. With modern upgrades they're still the backbone of the industry. This is looking more and more like a maintenance issue as the aircraft was reconfigured. Further, this particular aircraft had had cabin pressure events in the weeks ahead of this. I'm pretty sure we'll see and Airworthiness Directive to check the door plug bolts and that the airline will be required to do a root cause-corrective action excercise. What's good is that the aircraft had a decompression event and landed without further issue. This is the second time a 747 airframe has had an explosive decompression and landed. I call that a good plane. A modern carbon fiber airframe might not fare so well. Chuck |
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Post by Leftee on Jan 10, 2024 8:37:26 GMT -5
I’ve been following the story, and yeah, looks like bolts for the door plug. And there have been others found that were loose.
My current thought process leads me to the questions; were they improperly torqued? Did they shear? What was the failure mode?
Waiting for more information.
The Max version sure seems to have stumbled coming out of the gate.
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Post by Taildragger on Jan 10, 2024 11:35:43 GMT -5
My current thought process leads me to the questions; were they improperly torqued? Did they shear? What was the failure mode? I remember reading several years ago about a spate of helicopter crashes that resulted from import rotor attachment bolts that did not actually live up to their spec markings. Reminded me of the building collapses in third world countries that result from poor-quality concrete ingredients, careless/inconsistent mixing ratios and lack of on site batch testing resulting in poor compression strength and failure. |
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Post by gato on Jan 10, 2024 13:07:59 GMT -5
The following does not apply to this particular incident (or airline), but does pose some interesting questions:
"A new report by the Transport Workers Union says that airlines are increasingly performing heavy maintenance in foreign countries, limiting the number of aircraft maintenance jobs in the U.S.
The report includes estimates that U.S. airlines spend about $2 billion annually on maintenance work in South America, China and Europe.
Foreign repair stations have less Federal Aviation Administration oversight than domestic repair stations as well as lesser standards for worker qualifications and licensing, the report said."
Source: Forbes
Another problem is bogus / counterfeit aircraft parts being discovered, along with forged documentation
"All major US carriers and half a dozen others have identified bogus parts from AOG on their airplanes.
While no flight emergencies have been called due to engine malfunctions, the audacity of the scam, dating back several years, highlights a risky gap in a system that’s made flying the world’s safest form of transportation. And the ease at which safety protocols were breached has prompted soul-searching in an industry where a decades-old system has suddenly revealed worrying loopholes."
Source: Bloomberg
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chucksmi
Wholenote
Posts: 173
Formerly Known As: Offshore Angler elsewhere
Age: I saw Jerry Live
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Post by chucksmi on Jan 10, 2024 13:31:03 GMT -5
I’ve been following the story, and yeah, looks like bolts for the door plug. And there have been others found that were loose. My current thought process leads me to the questions; were they improperly torqued? Did they shear? What was the failure mode? Waiting for more information. The Max version sure seems to have stumbled coming out of the gate. I guess anything is possible, but I'd be REALLY surprised if they failed in shear, since there really wouldn't be any significant shear loading on them. My first guess would be they came loose and fretted away the metal around them. If they were loose it's also unlikey they failed in stress too, since there would be zero preload stress. A loose bolt can handle a higher stress load than a tight one. Chuck |
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Post by gato on Jan 11, 2024 6:04:23 GMT -5
Regarding the installation of the "plug"
One big problem is a relatively inexperienced work force, due to employees not returning from Covid-era furloughs. There’s a steep learning curve in assembling passenger jets, just as there is in putting together a kid’s bicycle, and many of Boeing’s veterans are gone from the factory floor. Richard Healing, a former member of the National Transportation Safety Board who is chief executive of Air Safety Engineering, a consulting company in Lewes, Del., said the Covid pandemic damaged employees’ motivation and attention to detail in many industries across the economy, and Boeing and Spirit.
Spirit installed the plugs, although investigators haven’t determined whether it is responsible for whatever went wrong. Boeing had other issues with Spirit twice in the past year. One case involved fittings that attach the vertical tail fin to the fuselage. In the other, holes were improperly drilled in the aft pressure bulkhead in some Max 8s.
NYT
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