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wjcandee
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Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 11:54 am

NY Times wrote a remarkably-thorough article on the MCAS system and the Lion Air crash, giving a good history of the MCAS system's development and the assertions by both sides about the adequacy of its presentation to pilots. https://www.nytimes.com/2019/02/03/worl ... ilots.html

Among other interesting facts: The EASA originally wanted more info about it to be given to pilots, but caved and went along with the FAA. Brazil, however, required differences training on it from the get-go, despite pressure from Boeing and the FAA, seeing the system for what it was. I don't know if Poland also required it, but LOT gave its pilots training on the system from the beginning; the article doesn't mention this. Also, the article reveals that although the pilots of the flight before the accident flight disconnected the runaway trim using the trim switches, their write up suspected something else as the cause, because they had no idea about MCAS.

Two things the article didn't punch hard enough, in my view: the half-assed engineering of the system (single point of catastrophic failure and the inhibiting of the runaway trim disconnection that normally occurs when you pull the yoke full-aft), and how far from Boeing's usual paradigm it departed -- i.e. something that will override the pilots in manual flight. Also, that it uses the stabilizer in an unusual way -- almost like a stick-pusher -- which is also a very-different engineering paradigm. It's one thing to have runaway trim or an error in the speed trim system, but if you don't know that there's a system that's gonna fight you repeatedly and keep trying to push the nose down, then it isn't gonna be at the top of your list of potential causes of what you're experiencing, and to think that the stabilizer is doing this may not be first in one's mind. That a couple hundred people died because Boeing wanted to save a couple of hours of training to make the MAX more marketable...what can I say?

My own feeling is this: faced with a bucking, malfunctioning aircraft, pilots often have to figure out in seconds what might be going wrong, in order to respond properly to it. If you don't know a dang thing about one potential cause, your ability to respond properly is dramatically-reduced, especially if one method of responding (yoke pull full aft) is inhibited without you knowing about that. We train pilots on systems so that they can diagnose. That there's a checklist somewhere that includes flipping off the trim switches is woefully-insufficient in my view. How far did Sully and Jeff get down their checklist? The APU activation that arguably made it possible to save the aircraft was way down the checklist -- Sully did it instinctively. The ditch switch was further down it. They didn't reach either.
Last edited by wjcandee on Mon Feb 04, 2019 12:11 pm, edited 1 time in total.
 
B737900ER
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 12:04 pm

The aircraft was unairworthy. It never should have flown. Blame MCAS all you want, but the system was broken. Any critical system that’s unairworthy is unsafe and if you don’t fix it you’re on the disaster count down.

Imagine the scenario where you have four engine flameouts in a row due to fuel contamination. After each reported flameout the mechanics signed it off as ops check good without even running the engine. Would you then blame the engine manufacturer when it flames out again and crashes? That’s the same thing going on here. Everybody points the finger at Boeing, but Lion air had a known fight safety hazard and ignored it. Four times. And you and the NYT are going to let them get away with it.
 
wjcandee
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 12:16 pm

B737900ER wrote:
The aircraft was unairworthy. It never should have flown. Blame MCAS all you want, but the system was broken. Any critical system that’s unairworthy is unsafe and if you don’t fix it you’re on the disaster count down.

Imagine the scenario where you have four engine flameouts in a row due to fuel contamination. After each reported flameout the mechanics signed it off as ops check good without even running the engine. Would you then blame the engine manufacturer when it flames out again and crashes? That’s the same thing going on here. Everybody points the finger at Boeing, but Lion air had a known fight safety hazard and ignored it. Four times. And you and the NYT are going to let them get away with it.


So there was a printout somewhere that said, "MCAS is broken" that the maintenance people ignored?

Or is diagnosing a sick aircraft an art? And if the speed trim system checks out normal after an AOA sensor is replaced, I'm trying to understand why maint would have suspected MCAS.

I'm sorry to say that my own belief is that this could quite-readily have happened to WN or AA. Debate all you want whether "as easily" as Lion Air, which is what Boeing wants you to think. But I think the American carriers and Boeing got lucky that this happened overseas first.

And nobody is letting anybody get away with anything, I assure you. To turn it on its head, you're trying to "let Boeing get away with it". And Boeing is doing a very animated tapdance trying to absolve itself from blame, which is pretty-disgraceful. Does anyone there really believe that the design of that system (particularly the one-sensor approach) was in any way adequte? I'm pretty-sure there are some Boeing engineers who are distraught over what happened here, because they have pride in their work and the legacy of their company. Just like the Thiokol guys were about the space shuttle explosion -- they knew immediately what had happened because they were telling their managers over and over not to launch.
 
B777LRF
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 12:29 pm

Lion Air is a basket case of corruption, poor standards, poor regulatory oversight, understaffing, severe engineering shortfalls and P2F pilots. Throw MCAS in the mix, and you have a lethal cocktail just waiting to go off. It was almost inevitable that an airline such as this would be the first to 'suffer' from an accident involving MCAS, and not e.g. AA or SW.
Signature. You just read one.
 
B737900ER
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 12:40 pm

wjcandee wrote:
B737900ER wrote:
The aircraft was unairworthy. It never should have flown. Blame MCAS all you want, but the system was broken. Any critical system that’s unairworthy is unsafe and if you don’t fix it you’re on the disaster count down.

Imagine the scenario where you have four engine flameouts in a row due to fuel contamination. After each reported flameout the mechanics signed it off as ops check good without even running the engine. Would you then blame the engine manufacturer when it flames out again and crashes? That’s the same thing going on here. Everybody points the finger at Boeing, but Lion air had a known fight safety hazard and ignored it. Four times. And you and the NYT are going to let them get away with it.


So there was a printout somewhere that said, "MCAS is broken" that the maintenance people ignored?

Or is diagnosing a sick aircraft an art? And if the speed trim system checks out normal after an AOA sensor is replaced, I'm trying to understand why maint would have suspected MCAS.

I'm sorry to say that my own belief is that this could quite-readily have happened to WN or AA. Debate all you want whether "as easily" as Lion Air, which is what Boeing wants you to think. But I think the American carriers and Boeing got lucky that this happened overseas first.

And nobody is letting anybody get away with anything, I assure you. To turn it on its head, you're trying to "let Boeing get away with it". And Boeing is doing a very animated tapdance trying to absolve itself from blame, which is pretty-disgraceful. Does anyone there really believe that the design of that system (particularly the one-sensor approach) was in any way adequte? I'm pretty-sure there are some Boeing engineers who are distraught over what happened here, because they have pride in their work and the legacy of their company. Just like the Thiokol guys were about the space shuttle explosion -- they knew immediately what had happened because they were telling their managers over and over not to launch.

They had reported airspeed disagrees on four flights. At WN or AA after one disagree the aircraft would have been taken out of service until you had a verified repair. That means hooking up a box, pumping up the system and verifying the airspeed. Not shotgunning a part and hope all goes well. You can’t operate critical flight systems with known serious malfunctions, you just can’t. In the US it’s a criminal action. If you can’t reliably verify the corrective action a test flight gets scheduled. At lion air the test flight had people on it. Thats wrong. You can’t spin what they did.

The MCAS did what it was supposed to do, it wasn’t broken, and most likely kicked in on the previous flights, but as the article mentioned the other pilot at least knew to disconnect the runaway stab, it’s been there since the -100. But the MCAS operated only because of the malfunction with airspeed, which lion air knew about, because it was a chronic problem, which is unheard of at airlines that have an iota of safety sense.

No, diagnosing an aircraft isn’t art. It takes work, brains, and the integrity to not shotgun or put broken airplanes back into service. Something those mechanics at lion air didn’t have.
 
TTailedTiger
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 12:47 pm

wjcandee wrote:
B737900ER wrote:
The aircraft was unairworthy. It never should have flown. Blame MCAS all you want, but the system was broken. Any critical system that’s unairworthy is unsafe and if you don’t fix it you’re on the disaster count down.

Imagine the scenario where you have four engine flameouts in a row due to fuel contamination. After each reported flameout the mechanics signed it off as ops check good without even running the engine. Would you then blame the engine manufacturer when it flames out again and crashes? That’s the same thing going on here. Everybody points the finger at Boeing, but Lion air had a known fight safety hazard and ignored it. Four times. And you and the NYT are going to let them get away with it.


So there was a printout somewhere that said, "MCAS is broken" that the maintenance people ignored?

Or is diagnosing a sick aircraft an art? And if the speed trim system checks out normal after an AOA sensor is replaced, I'm trying to understand why maint would have suspected MCAS.

I'm sorry to say that my own belief is that this could quite-readily have happened to WN or AA. Debate all you want whether "as easily" as Lion Air, which is what Boeing wants you to think. But I think the American carriers and Boeing got lucky that this happened overseas first.

And nobody is letting anybody get away with anything, I assure you. To turn it on its head, you're trying to "let Boeing get away with it". And Boeing is doing a very animated tapdance trying to absolve itself from blame, which is pretty-disgraceful. Does anyone there really believe that the design of that system (particularly the one-sensor approach) was in any way adequte? I'm pretty-sure there are some Boeing engineers who are distraught over what happened here, because they have pride in their work and the legacy of their company. Just like the Thiokol guys were about the space shuttle explosion -- they knew immediately what had happened because they were telling their managers over and over not to launch.


That aircraft narrowly escaped catastrophe the day before the accident and Lion Air didn't do anything. Any reputable airline would have hauled it off to a maintenance hangar until a competent maintenance team and perhaps the NTSB could have looked at it. Yes that's right, the NTSB also examine near-fatal events. An Eastwind 737 experienced an uncommanded rudder hardover but the crew managed to save the aircraft. The NTSB was able to finally put the pieces together and figure out what caused two previous accidents. Lion Air shrugged their shoulder and refused to pull the plane out of service after numerous write ups.
 
wjcandee
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 12:58 pm

B737900ER wrote:
The aircraft was unairworthy. It never should have flown.


Okay, swell. Never should have flown.

Now...once we're past that, are you saying that we should just accept that everyone is doomed once that plane gets into the air? Or are there in fact layers of safety, a critical one of which is pilots, who can respond to a situation in an unairworthy aircraft by doing more than saying their prayers? If so, shouldn't they be as well-equipped as we can make them?

What has been the tradition in terms of differences training? Was it followed here? Have manufacturers departed from an altruistic, best-practices, safest-operation-based training paradigm towards one that is designed instead to make the aircraft most-marketable?

Is the influence of Silicon Valley, where vaporware and BS is the norm, tainting what used to be a straight-laced, engineering-first, honest company/industry?
Last edited by wjcandee on Mon Feb 04, 2019 1:13 pm, edited 1 time in total.
 
wjcandee
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:00 pm

TTailedTiger wrote:
Any reputable airline would have hauled it off to a maintenance hangar until a competent maintenance team and perhaps the NTSB could have looked at it. Yes that's right, the NTSB also examine near-fatal events.


In Indonesia?

And yeah, yeah, "Lion Air sucks." "Lion Air's maintenance sucks." Blah-blah. Again: once it is in the air, shouldn't the pilots be given the maximum amount of information that could allow them to diagnose what is causing the aircraft to behave this way and respond to it? That is the focus of this article. Or should we just assume that once it takes off, everybody is dead?
Last edited by wjcandee on Mon Feb 04, 2019 1:04 pm, edited 1 time in total.
 
TTailedTiger
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:02 pm

wjcandee wrote:
TTailedTiger wrote:
Any reputable airline would have hauled it off to a maintenance hangar until a competent maintenance team and perhaps the NTSB could have looked at it. Yes that's right, the NTSB also examine near-fatal events.


In Indonesia?


Yes, it is an aircraft manufactured in the US. It wouldn't be the first time.
 
Aviation737
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:02 pm

Dude, just wait for the official investigation to come out before you start pointing fingers. But, if you still want to continue there's already another thread for you to do so.
 
wjcandee
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:08 pm

Aviation737 wrote:
Dude, just wait for the official investigation to come out before you start pointing fingers. But, if you still want to continue there's already another thread for you to do so.


Well, sadly, the point of the thread was to highlight an interesting summary of facts regarding the aircraft's development, authored by some pretty-good reporters, that was factually-accurate and pretty-well-balanced, which is rare for a mainstream media article on aviation. Some discussion is appropriate.

Unfortunately, people are leaping right in to defend Boeing and say Lion Air is wholly to blame.

That's not really the point -- the point was really to talk about market forces, aircraft development, and how much should pilots know about the complex system they are operating? What's the norm? Was the norm followed here? I think those are interesting topics for discussion arising from this article, and I would like to see and have such a discussion.
 
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GEUltraFan9XGTF
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:14 pm

The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.
© 2020. All statements are my own. The use of my statements, including by journalists, YouTube vloggers like "DJ's Aviation", etc. without my written consent is strictly prohibited.
 
wjcandee
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:18 pm

B777LRF wrote:
Lion Air is a basket case of corruption, poor standards, poor regulatory oversight, understaffing, severe engineering shortfalls and P2F pilots. Throw MCAS in the mix, and you have a lethal cocktail just waiting to go off. It was almost inevitable that an airline such as this would be the first to 'suffer' from an accident involving MCAS, and not e.g. AA or SW.


I love the way you phrased this. Excellent writing. But it does seem that the WN pilots and the AA pilots are massively-pissed about how this was handled nonetheless. It would be interesting to know what their thinking is, to go a little further than the article did.

As to Lion Air, it seems like the question becomes then: Given the fact that the manufacturer is eagerly selling hundreds or even thousands of these aircraft to such carriers, should it take these factors into account when recommending training for pilots? Does this mean the systems themselves should be more redundant/foolproof? Should the aircraft be able to diagnose itself more in line with, say, the A320 as an example?

Looking at the 787, it always struck me that it rolled out in the early days to quite a few developing-world carriers. Obviously ANA was an appropriate launch customer, but I still wondered how the distribution of early aircraft would shake out in terms of issues like this. As it turned out, not too bad. I wonder whether the fact that it was a clean-sheet program helped with this.
Last edited by wjcandee on Mon Feb 04, 2019 1:27 pm, edited 2 times in total.
 
TTailedTiger
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:19 pm

GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.


Sure, because Lion Air is the pinnacle of how an airline should operate. I wouldn't trust them to fly or fix a kite.
 
wjcandee
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:24 pm

TTailedTiger wrote:
GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.


Sure, because Lion Air is the pinnacle of how an airline should operate. I wouldn't trust them to fly or fix a kite.


So do you then think it is ethical for Boeing to sell them aviation products and financing? Should Boeing consider different training/support for such carriers if it does?
 
TTailedTiger
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:24 pm

wjcandee wrote:
B777LRF wrote:
Lion Air is a basket case of corruption, poor standards, poor regulatory oversight, understaffing, severe engineering shortfalls and P2F pilots. Throw MCAS in the mix, and you have a lethal cocktail just waiting to go off. It was almost inevitable that an airline such as this would be the first to 'suffer' from an accident involving MCAS, and not e.g. AA or SW.


So the question becomes then: Given the fact that the manufacturer is eagerly selling hundreds or even thousands of these aircraft to such carriers, should it take these factors into account when recommending training for pilots? Does this mean the systems themselves should be more redundant/foolproof? Should the aircraft be able to diagnose itself more in line with, say, the A320 as an example?

Looking at the 787, it always struck me that it rolled out in the early days to quite a few developing-world carriers. Obviously ANA was an appropriate launch customer, but I still wondered how the distribution of early aircraft would shake out in terms of issues like this. As it turned out, not too bad. I wonder whether the fact that it was a clean-sheet program helped with this.


So then why has the A320 crashed in developing countries too?
 
TTailedTiger
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:25 pm

wjcandee wrote:
TTailedTiger wrote:
GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.


Sure, because Lion Air is the pinnacle of how an airline should operate. I wouldn't trust them to fly or fix a kite.


So do you then think it is ethical for Boeing to sell them aviation products and financing? Should Boeing consider different training/support for such carriers if it does?


I don't think Boeing has a choice in the matter if a bad airline wants to buy planes and can come up with the money. I'd suspect a lawsuit would follow if they refused. As far as I know Boeing can sell anyone an airplane if they have the money and don't have an embargo against them. I could buy a 737 if I had the money. It would be up to the FAA on whether or not I'm allowed to operate it.
 
bob75013
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 1:36 pm

wjcandee wrote:
TTailedTiger wrote:
Any reputable airline would have hauled it off to a maintenance hangar until a competent maintenance team and perhaps the NTSB could have looked at it. Yes that's right, the NTSB also examine near-fatal events.


In Indonesia?

And yeah, yeah, "Lion Air sucks." "Lion Air's maintenance sucks." Blah-blah. Again: once it is in the air, shouldn't the pilots be given the maximum amount of information that could allow them to diagnose what is causing the aircraft to behave this way and respond to it? That is the focus of this article. Or should we just assume that once it takes off, everybody is dead?


Ahhh, pilots are supposed to aviate first. Mechanics are supposed to diagnose and fix first - which they did not do this time.
 
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GEUltraFan9XGTF
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 2:03 pm

Can't a simple software change fix this?

IF "AOA(L)" <> "AOA(R)" THEN MCAS=0 (Disabled)

The article states that the Captain's AOA sensor was faulty, triggering MCAS. The simple line of code would kill MCAS if the two AOA sensors don't agree.
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WIederling
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 2:51 pm

GEUltraFan9XGTF wrote:
Can't a simple software change fix this?


Software changes for safety relevant stuff is never "simple" :-)
Murphy is an optimist
 
kalvado
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 3:20 pm

GEUltraFan9XGTF wrote:
Can't a simple software change fix this?

IF "AOA(L)" <> "AOA(R)" THEN MCAS=0 (Disabled)

The article states that the Captain's AOA sensor was faulty, triggering MCAS. The simple line of code would kill MCAS if the two AOA sensors don't agree.

There are probably millions lines of code running the airplane. It is not about if there are mistakes in that code - it is about severity of those mistakes. And not about how many design issues are there - it is about how those are addressed.
This one was a bad one, both in design and treatment
and for those who blame Lion squarely... I never been in Indonesia, I am not planning to go there, I have no friends or relatives there.
Lion could screw up many times, and it would have little effect on me personally. Absolving Boeing of any blame.. WHo said there are no more surprises in their designs?
 
BravoOne
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 3:50 pm

wjcandee wrote:
TTailedTiger wrote:
GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.


Sure, because Lion Air is the pinnacle of how an airline should operate. I wouldn't trust them to fly or fix a kite.


So do you then think it is ethical for Boeing to sell them aviation products and financing? Should Boeing consider different training/support for such carriers if it does?



Might shock you to learn that Airbus was awarded the contract to train Lion Air crews. Go figure. Doubt if it would have made any difference in the outcome.
 
Okie
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 4:15 pm

GEUltraFan9XGTF wrote:
Can't a simple software change fix this?IF "AOA(L)" <> "AOA(R)" THEN MCAS=0 (Disabled) The article states that the Captain's AOA sensor was faulty, triggering MCAS. The simple line of code would kill MCAS if the two AOA sensors don't agree.


AOA was replaced before the accident flight.
You are making the assumption that AOA sensor that was replaced was faulty and the replacement unit faulty as well.
The replaced AOA unit was set aside for forensic analysis. We will have to see what that reveals. Still probably a year away for that report.

While I agree with your thought going forward, however there is something else going on here.
Obviously we do not have the plane for an analysis only the replaced AOA sensor.
We do not know what other conditions that might cause the same results as in the failure of the power supply feeding the AOA sensor or a hundred other issues.
They will have to back up investigation to the Mx done before the flight of the first incident that could have caused the issue which the previous flight crew handled correctly.

For all we know there could be an issue with a line of code that would give a +20 deg readout to the AOA if light bulb burns out in the strobe.

Okie
 
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GlobalAirways
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 4:25 pm

wjcandee wrote:
Aviation737 wrote:
Dude, just wait for the official investigation to come out before you start pointing fingers. But, if you still want to continue there's already another thread for you to do so.


Well, sadly, the point of the thread was to highlight an interesting summary of facts regarding the aircraft's development, authored by some pretty-good reporters, that was factually-accurate and pretty-well-balanced, which is rare for a mainstream media article on aviation. Some discussion is appropriate.

Unfortunately, people are leaping right in to defend Boeing and say Lion Air is wholly to blame.

That's not really the point -- the point was really to talk about market forces, aircraft development, and how much should pilots know about the complex system they are operating? What's the norm? Was the norm followed here? I think those are interesting topics for discussion arising from this article, and I would like to see and have such a discussion.
 
Unflug
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 4:31 pm

wjcandee wrote:
NY Times wrote a remarkably-thorough article on the MCAS system and the Lion Air crash, giving a good history of the MCAS system's development and the assertions by both sides about the adequacy of its presentation to pilots. https://www.nytimes.com/2019/02/03/worl ... ilots.html


I agree that this is a very well written article. I don't know how many of the participants in this discussion have actually read it, unfortunately. Thanks for posting!
 
dtw2hyd
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 4:37 pm

GEUltraFan9XGTF wrote:
Can't a simple software change fix this?

IF "AOA(L)" <> "AOA(R)" THEN MCAS=0 (Disabled)

The article states that the Captain's AOA sensor was faulty, triggering MCAS. The simple line of code would kill MCAS if the two AOA sensors don't agree.


Depends how on how the redundancy is implemented.

Failure mitigation techniques need not be just based on hardware and software.

It appears, in this design, FO taking over control mitigates the risk of component failure on Captain's side.

Debatable, but probably an acceptable type of failure risk mitigation techniques.
All posts are just opinions.
 
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SheikhDjibouti
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 5:16 pm

B737900ER wrote:
And you and the NYT are going to let them get away with it.

Yes, how utterly disgraceful of the NYT to even consider writing such a "well-written" & "remarkably thorough" article!
Who do they think they are?

Are you suggesting the NYT should think MAGA and bury this piece?
What are you afraid of? What have you got to hide?
If Boeing are not at fault, then that is what the final report will say.
Until then, hushing up the NYT and bullying various posters on these forums looks awfully suspicious.

B737900ER wrote:
The aircraft was unairworthy. It never should have flown. Blame MCAS all you want, but the system was broken. Any critical system that’s unairworthy is unsafe and if you don’t fix it you’re on the disaster count down.
Imagine the scenario...

Imagine the scenario where the failure had not occurred during the previous flight.
Instead it occurs shortly after take-off on flight 610. With the same outcome?

Now who are you going to blame? :scratchchin:

B737900ER wrote:
No, diagnosing an aircraft isn’t art.
It takes work, brains, and the integrity to not shotgun or put broken airplanes back into service.
Something those mechanics at lion air Boeing didn’t have.

Sorry - couldn't resist a couple of minor corrections, just to show you what "balance" looks like.
Or you could actually read the NYT article. :lol:
Nothing to see here; move along please.
 
7673mech
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 5:35 pm

wjcandee wrote:
B737900ER wrote:
The aircraft was unairworthy. It never should have flown. Blame MCAS all you want, but the system was broken. Any critical system that’s unairworthy is unsafe and if you don’t fix it you’re on the disaster count down.

Imagine the scenario where you have four engine flameouts in a row due to fuel contamination. After each reported flameout the mechanics signed it off as ops check good without even running the engine. Would you then blame the engine manufacturer when it flames out again and crashes? That’s the same thing going on here. Everybody points the finger at Boeing, but Lion air had a known fight safety hazard and ignored it. Four times. And you and the NYT are going to let them get away with it.


So there was a printout somewhere that said, "MCAS is broken" that the maintenance people ignored?

Or is diagnosing a sick aircraft an art? And if the speed trim system checks out normal after an AOA sensor is replaced, I'm trying to understand why maint would have suspected MCAS.

I'm sorry to say that my own belief is that this could quite-readily have happened to WN or AA. Debate all you want whether "as easily" as Lion Air, which is what Boeing wants you to think. But I think the American carriers and Boeing got lucky that this happened overseas first.

And nobody is letting anybody get away with anything, I assure you. To turn it on its head, you're trying to "let Boeing get away with it". And Boeing is doing a very animated tapdance trying to absolve itself from blame, which is pretty-disgraceful. Does anyone there really believe that the design of that system (particularly the one-sensor approach) was in any way adequte? I'm pretty-sure there are some Boeing engineers who are distraught over what happened here, because they have pride in their work and the legacy of their company. Just like the Thiokol guys were about the space shuttle explosion -- they knew immediately what had happened because they were telling their managers over and over not to launch.


No but when you have four legs of similar write ups you take an airplane out of service and shake it down.
You get your local Boeing rep and the smart people in Tukwila (actually Long Beach now I guess) involved.

At the end of the day the final report isn't out. Everyone is talking about the pilots, no one had questioned the maintenance done.
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Mon Feb 04, 2019 6:29 pm

Here are two disturbing points I took away from the article --

(1) Boeing included an MCAS description in maintenance documentation but not in documentation flight crew would see. This appears to have been a deliberate strategy and not an oversight, the aim being to reinforce the notion that simulator training was not required for conversion to the MAX.

(2) Boeing (and the FAA) knew that a single point failure could spuriously activate MCAS, but decided that was OK because they predicted flight crew would understand the situation as runaway stab trim (even if it really wasn't) and apply the correct procedure for runaway stab trim.
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 1:21 am

wjcandee wrote:
Well, sadly, the point of the thread was to highlight an interesting summary of facts regarding the aircraft's development, authored by some pretty-good reporters, that was factually-accurate and pretty-well-balanced, which is rare for a mainstream media article on aviation. Some discussion is appropriate.

I read the whole article. Early on it said:

Boeing has taken the position that the pilots of the Lion Air flight should have known how to handle the emergency despite not knowing about the modification. The company has maintained that properly following established emergency procedures — essentially, a checklist — long familiar to pilots from its earlier 737s should have allowed the crew to handle a malfunction of the so-called maneuvering characteristics augmentation system, known as M.C.A.S., whether they knew it was on the plane or not.

... and I read the clear, complete, well-written (etc) article waiting for them to tell me what was wrong with this expectation.

I never found that.

In fact I found:

There is no indication that they tried to flip the stabilizer cutout switches, as the emergency checklist suggests they should have. Findings from the cockpit voice recorder could establish in more detail what culpability, if any, rests with the Lion Air pilots.

So, yeah, the MAX has differences from the NG. The engineer's job is to minimize the impact of such differences. The pilot's job is to do what TFM tells them to do and follow the checklist the engineers wrote. The pilot's job is not to pretend they are test pilots and start reverse engineering the systems in flight with a plane load of pax in the back.
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 2:46 am

So WN retired an entire sub-fleet early to avoid a separate pilot pool, but the article intimates that unions and Boeing were culpable because they did not want to invest money, the WN pilots union were even holding out for an additional pay scale or no MAX8 flying.
Not sure the industrial angle flies, but as with all things, little bit of this and that and you can speculate a full story.
At this rate the actual official results of the investigation may just be a footnote.
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 3:09 am

If pilots knew of M.C.A.S. and that it used only the active-side sensors, the easiest fix would have been to switch control sides. How much more training would disclosing M.C.A.S. have required? This seems such a bizarre decision.

Based on the write-up of the previous crew, could the mechanics have figured out that the root cause was the sensors?
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 3:16 am

VS11 wrote:
If pilots knew of M.C.A.S. and that it used only the active-side sensors, the easiest fix would have been to switch control sides. How much more training would disclosing M.C.A.S. have required? This seems such a bizarre decision.

Based on the write-up of the previous crew, could the mechanics have figured out that the root cause was the sensors?


Can you switch AOA sources on a 737?
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 3:24 am

BoeingGuy wrote:
VS11 wrote:
If pilots knew of M.C.A.S. and that it used only the active-side sensors, the easiest fix would have been to switch control sides. How much more training would disclosing M.C.A.S. have required? This seems such a bizarre decision.

Based on the write-up of the previous crew, could the mechanics have figured out that the root cause was the sensors?


Can you switch AOA sources on a 737?


Per the article, only one sensor at a time was being used:

"In designing the 737 Max, Boeing decided to feed M.C.A.S. with data from only one of the two angle of attack sensors at a time, depending on which of two, redundant flight control computers — one on the captain’s side, one on the first officer’s side — happened to be active on that flight.

That decision kept the system simpler, but also left it vulnerable to a single malfunctioning sensor, or data improperly transferred from it — as appeared to occur on the day of the crash."
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 3:29 am

VS11 wrote:
BoeingGuy wrote:
VS11 wrote:
If pilots knew of M.C.A.S. and that it used only the active-side sensors, the easiest fix would have been to switch control sides. How much more training would disclosing M.C.A.S. have required? This seems such a bizarre decision.

Based on the write-up of the previous crew, could the mechanics have figured out that the root cause was the sensors?


Can you switch AOA sources on a 737?


Per the article, only one sensor at a time was being used:

"In designing the 737 Max, Boeing decided to feed M.C.A.S. with data from only one of the two angle of attack sensors at a time, depending on which of two, redundant flight control computers — one on the captain’s side, one on the first officer’s side — happened to be active on that flight.

That decision kept the system simpler, but also left it vulnerable to a single malfunctioning sensor, or data improperly transferred from it — as appeared to occur on the day of the crash."


You implied that the pilots could have source selected over to the other AOA input. I’m asking if you know whether that kind of switch exists on a 737.
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 3:35 am

BoeingGuy wrote:
VS11 wrote:
BoeingGuy wrote:

Can you switch AOA sources on a 737?


Per the article, only one sensor at a time was being used:

"In designing the 737 Max, Boeing decided to feed M.C.A.S. with data from only one of the two angle of attack sensors at a time, depending on which of two, redundant flight control computers — one on the captain’s side, one on the first officer’s side — happened to be active on that flight.

That decision kept the system simpler, but also left it vulnerable to a single malfunctioning sensor, or data improperly transferred from it — as appeared to occur on the day of the crash."


You implied that the pilots could have source selected over to the other AOA input. I’m asking if you know whether that kind of switch exists on a 737.


I don't know but based on the article I would assume that if the other side of the cockpit took control of the aircraft, the sensor feeding their flight computer would be used. In other words, pilots would not need to select a different sensor, the change over would happen by virtue of using a different flight control computer.
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 3:59 am

Revelation: the sarcasm doesn't suit you. And it's unnecessary. The answer was in fact in the article. First, Boeing did not disclose to anyone that one of the methods of halting a runaway stab trim, which is to pull the Yoke full-back, was inhibited as pertains to the MCAS. So it's complete BS that the normal methods would have solved the problem. Second, the whole point is that if you don't know the system exists and what it does, which is to shove the nose down as quickly as possible using the stabilizer, it could be easy to become confused as to what was happening. Were the elevators not functioning properly? The control cables somehow corrupted? The airplane is fighting you and you don't know why and unless you know that there's a system that might be shoving the nose down on you, you can't understand why the thing is diving. Previous crew guessed that there was something wrong with the stabilizer trim, but they did not identify MCAS, cuz they didn't know about it.

To my own opinion: the proper way to solve this issue with the engine placement and effect on CG would be a clean sheet analysis of the best practice and best system to address it. Instead, Boeing tried to sneak in the weaseliest corrective path, and keep it hush-hush, purely for marketing purposes. That's the bottom line. Nobody putting Safety First would build in a system that would use something as ungainly as the stabilizer to do the function of a stick pusher, or would they allow it to take over the airplane, when it is in what the pilots presume is manual flight mode, based on the input of only one sensor. It's of course not clear here that the sensor was even defective; it could well have been the software, some weird bug or wiring error, or Communications connection. But for one input to be able to take the plane out of the hands of the pilots, without telling them what it was doing or why, is not something that someone with safety as the Paramount Focus would engineer. And when the trial lawyers ultimately take the depositions of the engineers involved in this, I am highly confident that a lot of them would have objected to how this was done.
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 4:21 am

B777LRF wrote:
Lion Air is a basket case of corruption, poor standards, poor regulatory oversight, understaffing, severe engineering shortfalls and P2F pilots. Throw MCAS in the mix, and you have a lethal cocktail just waiting to go off. It was almost inevitable that an airline such as this would be the first to 'suffer' from an accident involving MCAS, and not e.g. AA or SW.



Southwest is not "SW" it's WN.
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 4:22 am

wjcandee wrote:
B737900ER wrote:
The aircraft was unairworthy. It never should have flown.


Okay, swell. Never should have flown.

Now...once we're past that, are you saying that we should just accept that everyone is doomed once that plane gets into the air? Or are there in fact layers of safety, a critical one of which is pilots, who can respond to a situation in an unairworthy aircraft by doing more than saying their prayers? If so, shouldn't they be as well-equipped as we can make them?


Exactly. Saying the aircraft is unairworthy is a red herring. Aircraft 'brake down' all the time and not just at the gate before the flight. F-GZCP was airworthy when it pushed back from the gate, departing to Paris as AF447...

Any situation where a single point of failure can cause an accident is not acceptable.


GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.

Agreed. A lot has to be answered for here.

B777LRF wrote:
Lion Air is a basket case of corruption, poor standards, poor regulatory oversight, understaffing, severe engineering shortfalls and P2F pilots. Throw MCAS in the mix, and you have a lethal cocktail just waiting to go off. It was almost inevitable that an airline such as this would be the first to 'suffer' from an accident involving MCAS, and not e.g. AA or SW.

Well said.
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WN732
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 5:22 am

zkojq wrote:
wjcandee wrote:
B737900ER wrote:
The aircraft was unairworthy. It never should have flown.


Okay, swell. Never should have flown.

Now...once we're past that, are you saying that we should just accept that everyone is doomed once that plane gets into the air? Or are there in fact layers of safety, a critical one of which is pilots, who can respond to a situation in an unairworthy aircraft by doing more than saying their prayers? If so, shouldn't they be as well-equipped as we can make them?


Exactly. Saying the aircraft is unairworthy is a red herring. Aircraft 'brake down' all the time and not just at the gate before the flight. F-GZCP was airworthy when it pushed back from the gate, departing to Paris as AF447...

Any situation where a single point of failure can cause an accident is not acceptable.


GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.

Agreed. A lot has to be answered for here.

B777LRF wrote:
Lion Air is a basket case of corruption, poor standards, poor regulatory oversight, understaffing, severe engineering shortfalls and P2F pilots. Throw MCAS in the mix, and you have a lethal cocktail just waiting to go off. It was almost inevitable that an airline such as this would be the first to 'suffer' from an accident involving MCAS, and not e.g. AA or SW.

Well said.


I don't think AF447 is a good comparison. Even with the pitot tubes frozen that airplane was definitely flyable. Within minutes they would have melted the ice and it would've made it to Paris. That was AF lack of training and slow installation of updated pitot tubes.

This is more of an AS261
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 6:28 am

WN732 -- interesting analysis re AF447, and you are correct in that, in fact, IIRC, the pitot tube issue had resolved itself before the pilots induced all sorts of unnecessary drama. They could have just sat back, switched the autopilot back on, and lived.
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 6:38 am

wjcandee wrote:
Aviation737 wrote:
Dude, just wait for the official investigation to come out before you start pointing fingers. But, if you still want to continue there's already another thread for you to do so.


Well, sadly, the point of the thread was to highlight an interesting summary of facts regarding the aircraft's development, authored by some pretty-good reporters, that was factually-accurate and pretty-well-balanced, which is rare for a mainstream media article on aviation. Some discussion is appropriate.

Unfortunately, people are leaping right in to defend Boeing and say Lion Air is wholly to blame.

That's not really the point -- the point was really to talk about market forces, aircraft development, and how much should pilots know about the complex system they are operating? What's the norm? Was the norm followed here? I think those are interesting topics for discussion arising from this article, and I would like to see and have such a discussion.

No, the point of the thread was to blame Boeing which you did in your OP. You had no intention to be balanced.

The facts are still clear: if Lion had taken the plane out of service to properly repair it the crash would not have happened. And if Lion had at minimum made sure the next pilots knew what the previous pilots did to control the situation the crash wouldn’t have happened. So either Lion failed to properly maintain their aircraft or they failed to properly brief their pilots. Take your pick.

Or just blame a system design you don’t like. That’s easier.
Last edited by ikramerica on Tue Feb 05, 2019 6:41 am, edited 1 time in total.
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ikramerica
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 6:40 am

WN732 wrote:
zkojq wrote:
wjcandee wrote:

Okay, swell. Never should have flown.

Now...once we're past that, are you saying that we should just accept that everyone is doomed once that plane gets into the air? Or are there in fact layers of safety, a critical one of which is pilots, who can respond to a situation in an unairworthy aircraft by doing more than saying their prayers? If so, shouldn't they be as well-equipped as we can make them?


Exactly. Saying the aircraft is unairworthy is a red herring. Aircraft 'brake down' all the time and not just at the gate before the flight. F-GZCP was airworthy when it pushed back from the gate, departing to Paris as AF447...

Any situation where a single point of failure can cause an accident is not acceptable.


GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.

Agreed. A lot has to be answered for here.

B777LRF wrote:
Lion Air is a basket case of corruption, poor standards, poor regulatory oversight, understaffing, severe engineering shortfalls and P2F pilots. Throw MCAS in the mix, and you have a lethal cocktail just waiting to go off. It was almost inevitable that an airline such as this would be the first to 'suffer' from an accident involving MCAS, and not e.g. AA or SW.

Well said.


I don't think AF447 is a good comparison. Even with the pitot tubes frozen that airplane was definitely flyable. Within minutes they would have melted the ice and it would've made it to Paris. That was AF lack of training and slow installation of updated pitot tubes.

This is more of an AS261

No it’s not. If Lion has briefed the pilots correctly on the previous flight they would have landed safely.
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 9:05 am

BoeingGuy wrote:
You implied that the pilots could have source selected over to the other AOA input. I’m asking if you know whether that kind of switch exists on a 737.

to quote the poster directly above your post:

"In designing the 737 Max, Boeing decided to feed M.C.A.S. with data from only one of the two angle of attack sensors at a time, depending on which of two, redundant flight control computers — one on the captain’s side, one on the first officer’s side — happened to be active on that flight."

Now find out what determines which one is active at any moment in time :-)
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 10:52 am

TTailedTiger wrote:
wjcandee wrote:
TTailedTiger wrote:
Any reputable airline would have hauled it off to a maintenance hangar until a competent maintenance team and perhaps the NTSB could have looked at it. Yes that's right, the NTSB also examine near-fatal events.


In Indonesia?


Yes, it is an aircraft manufactured in the US. It wouldn't be the first time.

Only at the request of the airworthiness authority in the country of the crash site, otherwise no.

Gemuser
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 10:55 am

GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.

Exactly. It's called" catch of the regulator by the regulated", it happens in many industries in many countries.

Gemuser
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 12:27 pm

WN732 wrote:
I don't think AF447 is a good comparison. Even with the pitot tubes frozen that airplane was definitely flyable. Within minutes they would have melted the ice and it would've made it to Paris. That was AF lack of training and slow installation of updated pitot tubes.


Oh sure, I'm not trying to blame AF447 on Mechanical failure or anything, my point is that pitot tubes and angle of attack sensors break - that's an operational reality and thus having a single point of failure is unacceptable. MCAS intervention becomes a problem when the AOA sensor or Pitot Tube fails, so it doesn't matter if the failure itself happened on takeoff or on a previous flight.

If like AF447, the AOA sensor or Pitot Tube failure had happened during cruise, the same issue would likely occur as the Lion Air flight once the autopilot was engaged on approach.

ikramerica wrote:
The facts are still clear: if Lion had taken the plane out of service to properly repair it the crash would not have happened. And if Lion had at minimum made sure the next pilots knew what the previous pilots did to control the situation the crash wouldn’t have happened. So either Lion failed to properly maintain their aircraft or they failed to properly brief their pilots. Take your pick.


Noone is defending Lion Air. Failures of airspeed and AOA instruments happen in flight - that is an operational reality. Thanks to MCAS that failure can spiral (literally) into a catastrophically dangerous situation.
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 12:46 pm

par13del wrote:
Not sure the industrial angle flies, but as with all things, little bit of this and that and you can speculate a full story.
At this rate the actual official results of the investigation may just be a footnote.

:checkmark:

wjcandee wrote:
Revelation: the sarcasm doesn't suit you. And it's unnecessary. The answer was in fact in the article. First, Boeing did not disclose to anyone that one of the methods of halting a runaway stab trim, which is to pull the Yoke full-back, was inhibited as pertains to the MCAS. So it's complete BS that the normal methods would have solved the problem. Second, the whole point is that if you don't know the system exists and what it does, which is to shove the nose down as quickly as possible using the stabilizer, it could be easy to become confused as to what was happening. Were the elevators not functioning properly? The control cables somehow corrupted? The airplane is fighting you and you don't know why and unless you know that there's a system that might be shoving the nose down on you, you can't understand why the thing is diving. Previous crew guessed that there was something wrong with the stabilizer trim, but they did not identify MCAS, cuz they didn't know about it.

I re-read what I wrote and I stand by it.

You are now making the argument that the pilots had no way of knowing the root cause of problems they were happening was predictable or unpredictable, due to elements within their control or not within their control, due to intentional design decisions or unintentional mechanical faults, etc.

It suggests even more effort should have been focused on following documented procedures rather than retrying things over and over again that they knew were not resolving the problem.

wjcandee wrote:
To my own opinion: the proper way to solve this issue with the engine placement and effect on CG would be a clean sheet analysis of the best practice and best system to address it. Instead, Boeing tried to sneak in the weaseliest corrective path, and keep it hush-hush, purely for marketing purposes. That's the bottom line. Nobody putting Safety First would build in a system that would use something as ungainly as the stabilizer to do the function of a stick pusher, or would they allow it to take over the airplane, when it is in what the pilots presume is manual flight mode, based on the input of only one sensor. It's of course not clear here that the sensor was even defective; it could well have been the software, some weird bug or wiring error, or Communications connection. But for one input to be able to take the plane out of the hands of the pilots, without telling them what it was doing or why, is not something that someone with safety as the Paramount Focus would engineer. And when the trial lawyers ultimately take the depositions of the engineers involved in this, I am highly confident that a lot of them would have objected to how this was done.

Thank you for labeling this as opinion because it presumes facts that are not in evidence.

It seems you are treating the NYT article as gospel truth when even it admits it is based on off the record interviews of people who may no longer have access to current information.

In my opinion, the evidence we have so far points to a poorly maintained aircraft and a poorly trained crew. I'm looking forward to what we learn from the CVR.
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 2:13 pm

Is it so hard to admit that it may be that contributory factors from both Lion Air and Boeing caused this? Does it have to be a clear-cut case of one or the other? The outcome is hundreds of dead people no matter what, so what can we learn from this? Desperately defending Boeing suggests that they should not have done anything different under any circumstances; they did everything right. I don't agree with that. More info to the pilots could have helped and may have averted this disaster. Desperately defending Lion Air suggests they were not at fault and if only pilots were given this info nothing would have happened. This also seems to be an incorrect standpoint.

In my not too informed opinion, Boeing made a mistake not informing pilots about MCAS and Lion Air made a bunch of mistakes in assessing the situation and clearing a defective aircraft for operations. Air traffic safety is not about making sure one thing at a time cannot go wrong, it's about making sure as few things go wrong as seldom as possible. When the holes in that famous Swiss cheese lines up, it's rarely just one or two holes that line up, it's often quite a few circumstances that interact to facilitate a catastrophic outcome. Despite poor maintenance practices and possible piloting skills (making up quite a few holes in that cheese), if MCAS info had been available to (and understood by) the pilots, this accident would have been averted. That doesn't make Boeing at fault on its own. things had started to go wrong with this flight days earlier, and poor maintenance had lined up holes in that cheese multiple times. Perhaps poor pilot training and CRM contributed too. Boeing aligning that single (?) MCAS hole in the cheese with the others was a contributing factor, not the sole reason, and neither were Lion Air's shortcomings.

When drone incidents are discussed, some say "It's not a dig deal, a modern airliner will smash it and keep going as if nothing happened". Sure, that's probably true in virtually all cases. We haven't seen any serious accidents with drones and have no proof that they can cause a deadly accident or even an engine failure. Should we just ignore them? No, because there may come a moment in time where a twin engined airliner with one engine out just happens to take a drone hit to the working engine, which happens to have a fan blade fatigue crack caused by a recently detected manufacturing problem. The drone hits the defective blade, breaks it and the engine pulverises. Make this happen during long final to LHR or similar with no chance to glide to a safe landing spot, and a few hundred people are doomed. Is the engine manufacturer at fault for the crash because of the fatigue crack? Is the drone operator the one that single-handedly caused this? OK, I admit that the drone operator did something illegal and the analogy is not 100 % correct (apart from those of you that think that Lion Air was criminally negligent with maintenance and such), but I think you get my point. Without the other two contributing factors, no single factor caused the crash. Removing one of the contributing factors leads to a better outcome.

This all bears so much resemblance to the SK751 MD81 crash at Arlanda in 1991 in where the manufacturer only briefly informed the airline that ATR (Automatic Thrust Restoration) was part of the design, and the airline failed to realize the importance of this, not informing the pilots. The pilots and maintenance failed to detect clear ice on parts of the wings, which broke loose during takeoff, causing both engines to pump. The (correct for non-ATR-equipped models) recovery attempts by the pilots were mitigated by ATR, which lead to dual engine failure. There was one serious permanent injury, no deaths luckily.
 
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 2:29 pm

GEUltraFan9XGTF wrote:
The fact that the FAA would intervene on behalf of Boeing is the most alarming news here. Sort of like the ratings agencies before the Great Recession. Fox guarding the hen house. Boeing and the FAA need to burn for this.

This is the most intriguing thing here. FAA sits in the same boat as Boeing, pushing other countries authorities to compromise their normal standards.

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