7 ms·

Well yes but Boeing also said it "would not result in a safety of flight condition." There's a lot of gray going on here.

hahahahhaah 8mo ago
Yeah saved boeing losing face and sales by requiring all the planes be grounded and fixed. Just eye it up every 5 years, if you want to.
- itopaloglu83 8mo ago
  And that’s how McDonnell Douglas took over Boeing from the inside and eroded its engineering mindset altogether.
dralley 8mo ago
The FAA has not determined that this flaw did lead to a safety of flight condition. Investigation is still ongoing.
autoexec 8mo ago
A former air accident investigator who works as an aviation safety consultant said "It's extraordinary that Boeing concluded that a failure of this part would not have safety consequences," and said the report was "disturbing" Doesn't seem like gray to me. It seems a company who has a history of cutting corners and ignoring or downplaying safety problems did exactly that in this case too which resulted in the deaths of many people. UPS made an error here as well in trusting Boeing when they said it wasn't a safety issue and they should have installed the revised bearing assembly out of an abundance of caution, but I don't know much they would have known back in 2011 about the changes at Boeing that prioritized profit over safety following the merger with McDonnell Douglas
- jacquesm 8mo ago
  I think every company operating Boeing aircraft should have reviewed their stance on Boeing directives in light of MCAS and the aftermath by now. If they did not that is a failure of sorts as well.
  - palmotea 8mo ago
    > I think every company operating Boeing aircraft should have reviewed their stance on Boeing directives in light of MCAS and the aftermath by now. If they did not that is a failure of sorts as well. Actual question: would an airline have the engineering competence to second-guess an airplane manufacturer's engineering guidance? They operate airplanes but don't build them, and I'd assume they'd out of necessity need to trust the manufacturer's judgement.
    - cryptonector 8mo ago
      They can hire people (or companies) who can give them that guidance, yes.
    - ses1984 8mo ago
      Maybe the airline doesn’t but their insurance company should, if not directly than indirectly.
      - nradov 8mo ago
        That's not how it works. Insurers don't have the resources or technical competence to second guess aircraft manufacturer maintenance guidelines.
        ses1984 8mo ago
        When it’s your hundreds of millions of dollars on the line, you go find experts who have the competence needed to do a proper risk analysis.
    - jacquesm 8mo ago
      They certainly have a responsibility towards their passengers that goes beyond their relationship with Boeing. Passengers trust airlines with their lives, with Boeing they have 'just' a business relationship. Airlines have every reason to be skeptical of their supplier even if they do not have the engineering competence to second guess them. They could for instance look through their past communications with the manufacturer and see for themselves which advisories they agree with because for instance they are obviously not safety critical, this would then allow them hire specialists to evaluate the remainder for a second opinion.
- cmurf 8mo ago
  Laws that limit liability promote “cost of doing business“ mentality as if lives are acceptable losses. This is how you get mentally and morally weak bean counters running companies instead of engineers with a conscience. It’s an engineering company and yet it’s run like a bank that just so happens to have an engineering branch.
  - lazide 8mo ago
    Lives have ALWAYS been acceptable losses vs money, it’s just a matter of how much money. $5mln? $100mln? Old school, $50?
    - autoexec 8mo ago
      This is exactly why laws need to exist to ensure that human lives are prioritized by companies to a reasonable extent. Companies can often make a lot of money if they can get away with doing things that kill their customers, and we've repeatedly seen them do exactly that. In order to protect the public, corporate greed needs to be constrained by laws and legal consequences just like they're used to help to constrain the greed of muggers and thieves. In the US we've done a pretty poor job of doing that and it's resulted in countless lives lost and every living person and animal on earth being poisoned. It's long past time our government and its legal system took their responsibility to public safety more seriously.
- nobodyandproud 8mo ago
  > out of an abundance of caution I’m sorry, but this phrase has worn out its welcome.
  - autoexec 8mo ago
    How? I'm not particularly attached to it, but it seems to continue to be a commonly used expression and this is the first time I've seen someone raise an objection to its use.
    - nobodyandproud 8mo ago
      Because the phrase and mindset leads to the wrong lessons and actions. In aviation, there is little room for error. It’s also the case that resources and time are limited. So there are multiple constraints. We both agree that Boeing is the big problem. I’d also say its a problem of the FAA and the aviation industry. But UPS? Why would they be taking action “out of an abundance of caution”? The worst you can say for UPS is they could have sought a second opinion out of “an abundance of caution”, and recommendations of next actions and how. Keep in mind UPS core competency isn’t aerospace and aeronautical engineering. Would they even be able to assess the risk of changing said bearings en masse? The actual lesson here is that most of the advisories and self-certifying from Boeing over the past 30 years need to be reconsidered; most likely redone, by independent third parties and also an FAA with a mandate to be fully independent.
  - encrypted_bird 8mo ago
    Care to say why? Seems like a perfectly fine phrase to me.
bombcar 8mo ago
Apparently they expected it to blow up on the ground, so technically the plane wasn't flying yet ...
somat 8mo ago
I am wondering what the exact fail mode here is. Because my naive conclusion after looking at the part in question is exactly the same "would not result in a safety of flight condition." if the bearing cracked at the point in question it is going nowhere, the bearing is still captive in its housing. hell it looks like it could have been designed as two pieces and it would work the same. the large bolt is what is holding the engine on. The best I can come up with is that a split bearing causes increased wear on the mounting bracket and nobody noticed for a long time. Anyhow, here is the ntsb update in question https://www.ntsb.gov/investigations/Documents/DCA26MA024%20Investigative%20Update.pdf https://www.ntsb.gov/investigations/Documents/DCA26MA024%20I...
- jacquesm 8mo ago
  That's indeed a very naive conclusion. Once that bearing is gone the stress that it would normally allow to escape on account of rotation would be directly transferred to the metal around it and to the bolts holding the whole thing in place. Guess what broke first? So if that bearing went that's not quite a smoking gun yet but it would definitely be a step closer to a root cause.
  - ethbr1 8mo ago
    After watching the below video, it's the excess bearing play and thus no-longer-constrained force directions that would seem to be the issue. With a proper tolerance bearing in place, the force is constrained so that other parts are only stressed in directions they're well suited to handle (because the bearing takes the load). Once the bearing develops excess tolerance, you've got a bucking engine that (to your point) is directly loading other parts in unexpected ways/directions, eventually causing failure. The fact that Boeing supposedly modeled this and came up with non-safety critical in the event of bearing breakage... curious how that will turn out.
    - jacquesm 8mo ago
      > The fact that Boeing supposedly modeled this and came up with non-safety critical in the event of bearing breakage... curious how that will turn out. They'd have to show at least one plane with a bearing gone that still flies as intended. I suggest we break one on purpose, put the full complement of Boeing execs on that plane to prove its safety given the alternative of retracting that statement.
otikik 8mo ago
What's gray? To me it looks like written proof of incompetence.
jjk166 8mo ago
Which may have been a very reasonable conclusion based on what they knew of the issue. The letter sent out reported a split of the bearing race. A split bearing race won't prevent it from supporting the load. It's easily possible that Boeing's simulation of an aircraft operating with a split bearing race was fine. The NTSB investigation found that for this crash, not only did the bearing race crack, but also that the bearing lugs, which hold the bearing in place, were fractured. I don't have access to the original text of the letter Boeing sent out, but based on the NTSB report, it sounds like only the issue with the bearing race was previously identified. The two may very well be related, but that doesn't mean that the lug fractures are an expected result of the race failure - perhaps some contributing factor made the lugs more susceptible than predicted. It also remains possible that the bearing damage is a red herring; the aircraft was nearing the end of its service life and had known structural issues in other parts of the pylon. The fact is that for more than a decade after the bearing race issue was reported, it didn't result in a safety of flight condition. The insinuation that Boeing was deliberately trying to hide or downplay a known issue is simply unwarranted. It would be irresponsible for the NSTB not to mention a known issue that could have potentially been relevant, it's not evidence the issue was improperly handled.

hahahahhaah 8mo ago

Yeah saved boeing losing face and sales by requiring all the planes be grounded and fixed. Just eye it up every 5 years, if you want to.

itopaloglu83 8mo ago
And that’s how McDonnell Douglas took over Boeing from the inside and eroded its engineering mindset altogether.

dralley 8mo ago

The FAA has not determined that this flaw did lead to a safety of flight condition. Investigation is still ongoing.

autoexec 8mo ago

A former air accident investigator who works as an aviation safety consultant said "It's extraordinary that Boeing concluded that a failure of this part would not have safety consequences," and said the report was "disturbing" Doesn't seem like gray to me. It seems a company who has a history of cutting corners and ignoring or downplaying safety problems did exactly that in this case too which resulted in the deaths of many people. UPS made an error here as well in trusting Boeing when they said it wasn't a safety issue and they should have installed the revised bearing assembly out of an abundance of caution, but I don't know much they would have known back in 2011 about the changes at Boeing that prioritized profit over safety following the merger with McDonnell Douglas

jacquesm 8mo ago
I think every company operating Boeing aircraft should have reviewed their stance on Boeing directives in light of MCAS and the aftermath by now. If they did not that is a failure of sorts as well.
- palmotea 8mo ago
  > I think every company operating Boeing aircraft should have reviewed their stance on Boeing directives in light of MCAS and the aftermath by now. If they did not that is a failure of sorts as well. Actual question: would an airline have the engineering competence to second-guess an airplane manufacturer's engineering guidance? They operate airplanes but don't build them, and I'd assume they'd out of necessity need to trust the manufacturer's judgement.
  - cryptonector 8mo ago
    They can hire people (or companies) who can give them that guidance, yes.
  - ses1984 8mo ago
    Maybe the airline doesn’t but their insurance company should, if not directly than indirectly.
    - nradov 8mo ago
      That's not how it works. Insurers don't have the resources or technical competence to second guess aircraft manufacturer maintenance guidelines.
      - ses1984 8mo ago
        When it’s your hundreds of millions of dollars on the line, you go find experts who have the competence needed to do a proper risk analysis.
  - jacquesm 8mo ago
    They certainly have a responsibility towards their passengers that goes beyond their relationship with Boeing. Passengers trust airlines with their lives, with Boeing they have 'just' a business relationship. Airlines have every reason to be skeptical of their supplier even if they do not have the engineering competence to second guess them. They could for instance look through their past communications with the manufacturer and see for themselves which advisories they agree with because for instance they are obviously not safety critical, this would then allow them hire specialists to evaluate the remainder for a second opinion.
cmurf 8mo ago
Laws that limit liability promote “cost of doing business“ mentality as if lives are acceptable losses. This is how you get mentally and morally weak bean counters running companies instead of engineers with a conscience. It’s an engineering company and yet it’s run like a bank that just so happens to have an engineering branch.
- lazide 8mo ago
  Lives have ALWAYS been acceptable losses vs money, it’s just a matter of how much money. $5mln? $100mln? Old school, $50?
  - autoexec 8mo ago
    This is exactly why laws need to exist to ensure that human lives are prioritized by companies to a reasonable extent. Companies can often make a lot of money if they can get away with doing things that kill their customers, and we've repeatedly seen them do exactly that. In order to protect the public, corporate greed needs to be constrained by laws and legal consequences just like they're used to help to constrain the greed of muggers and thieves. In the US we've done a pretty poor job of doing that and it's resulted in countless lives lost and every living person and animal on earth being poisoned. It's long past time our government and its legal system took their responsibility to public safety more seriously.
nobodyandproud 8mo ago
> out of an abundance of caution I’m sorry, but this phrase has worn out its welcome.
- autoexec 8mo ago
  How? I'm not particularly attached to it, but it seems to continue to be a commonly used expression and this is the first time I've seen someone raise an objection to its use.
  - nobodyandproud 8mo ago
    Because the phrase and mindset leads to the wrong lessons and actions. In aviation, there is little room for error. It’s also the case that resources and time are limited. So there are multiple constraints. We both agree that Boeing is the big problem. I’d also say its a problem of the FAA and the aviation industry. But UPS? Why would they be taking action “out of an abundance of caution”? The worst you can say for UPS is they could have sought a second opinion out of “an abundance of caution”, and recommendations of next actions and how. Keep in mind UPS core competency isn’t aerospace and aeronautical engineering. Would they even be able to assess the risk of changing said bearings en masse? The actual lesson here is that most of the advisories and self-certifying from Boeing over the past 30 years need to be reconsidered; most likely redone, by independent third parties and also an FAA with a mandate to be fully independent.
- encrypted_bird 8mo ago
  Care to say why? Seems like a perfectly fine phrase to me.

bombcar 8mo ago

Apparently they expected it to blow up on the ground, so technically the plane wasn't flying yet ...

somat 8mo ago

I am wondering what the exact fail mode here is. Because my naive conclusion after looking at the part in question is exactly the same "would not result in a safety of flight condition." if the bearing cracked at the point in question it is going nowhere, the bearing is still captive in its housing. hell it looks like it could have been designed as two pieces and it would work the same. the large bolt is what is holding the engine on. The best I can come up with is that a split bearing causes increased wear on the mounting bracket and nobody noticed for a long time. Anyhow, here is the ntsb update in question https://www.ntsb.gov/investigations/Documents/DCA26MA024%20Investigative%20Update.pdf https://www.ntsb.gov/investigations/Documents/DCA26MA024%20I...

jacquesm 8mo ago
That's indeed a very naive conclusion. Once that bearing is gone the stress that it would normally allow to escape on account of rotation would be directly transferred to the metal around it and to the bolts holding the whole thing in place. Guess what broke first? So if that bearing went that's not quite a smoking gun yet but it would definitely be a step closer to a root cause.
- ethbr1 8mo ago
  After watching the below video, it's the excess bearing play and thus no-longer-constrained force directions that would seem to be the issue. With a proper tolerance bearing in place, the force is constrained so that other parts are only stressed in directions they're well suited to handle (because the bearing takes the load). Once the bearing develops excess tolerance, you've got a bucking engine that (to your point) is directly loading other parts in unexpected ways/directions, eventually causing failure. The fact that Boeing supposedly modeled this and came up with non-safety critical in the event of bearing breakage... curious how that will turn out.
  - jacquesm 8mo ago
    > The fact that Boeing supposedly modeled this and came up with non-safety critical in the event of bearing breakage... curious how that will turn out. They'd have to show at least one plane with a bearing gone that still flies as intended. I suggest we break one on purpose, put the full complement of Boeing execs on that plane to prove its safety given the alternative of retracting that statement.

otikik 8mo ago

What's gray? To me it looks like written proof of incompetence.

jjk166 8mo ago

Which may have been a very reasonable conclusion based on what they knew of the issue. The letter sent out reported a split of the bearing race. A split bearing race won't prevent it from supporting the load. It's easily possible that Boeing's simulation of an aircraft operating with a split bearing race was fine. The NTSB investigation found that for this crash, not only did the bearing race crack, but also that the bearing lugs, which hold the bearing in place, were fractured. I don't have access to the original text of the letter Boeing sent out, but based on the NTSB report, it sounds like only the issue with the bearing race was previously identified. The two may very well be related, but that doesn't mean that the lug fractures are an expected result of the race failure - perhaps some contributing factor made the lugs more susceptible than predicted. It also remains possible that the bearing damage is a red herring; the aircraft was nearing the end of its service life and had known structural issues in other parts of the pylon. The fact is that for more than a decade after the bearing race issue was reported, it didn't result in a safety of flight condition. The insinuation that Boeing was deliberately trying to hide or downplay a known issue is simply unwarranted. It would be irresponsible for the NSTB not to mention a known issue that could have potentially been relevant, it's not evidence the issue was improperly handled.