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

Tue Feb 05, 2019 2:51 pm

Revelation: OP made it very clear from the very beginning that he was using NYT article as a reinforcement of his own opinion, so there's that. At least he's being honest that he's just gonna dismiss anything else as it doesnt suit his narrative.
 
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SheikhDjibouti
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 4:51 pm

Etheereal wrote:
Revelation: OP made it very clear from the very beginning that he was using NYT article as a reinforcement of his own opinion, so there's that. At least he's being honest that he's just gonna dismiss anything else as it doesnt suit his narrative.

Posters A, B and C make it very clear from their choice of what facts and articles they select, that they are reinforcing their own opinions.
It's what people do.

Posters X,Y and Z are always gonna dismiss anything else as it doesnt suit their narrative.
That is also what people do.

A small minority of people do not have a dog in this fight.
An even smaller minority of people have somehow managed to bring an open-mind to this argument, having somehow not been swayed by decades of propaganda for and against individual parties.
And... a ridiculously pitiful quantity of rare individuals arrive with one idea in their head, read & digest the evidence, and actually consider changing their minds about a subject.
:o

I'm not even sure which category I fit into myself; quite often bias has crept into my subconscious without me even being aware of it.

But I do know this; your post is a sly attack on the OP, thus none-to-subtly undermining both him and the NYT article itself.
You make it appear as if he is the only one here with feet of clay.
Bravo!

Meanwhile, if you can genuinely claim that you are above such influences and bias, you have been truly blessed, and I look forward to your forthcoming beatification.

p.s. I was immediately jarred by your use of the word "narrative", so I checked and this particular word has been used 2852 times on these forums... mostly by Revelation. :rotfl:
Nothing to see here; move along please.
 
ikramerica
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 10:12 pm

SheikhDjibouti wrote:
Etheereal wrote:
Revelation: OP made it very clear from the very beginning that he was using NYT article as a reinforcement of his own opinion, so there's that. At least he's being honest that he's just gonna dismiss anything else as it doesnt suit his narrative.

Posters A, B and C make it very clear from their choice of what facts and articles they select, that they are reinforcing their own opinions.
It's what people do.

Posters X,Y and Z are always gonna dismiss anything else as it doesnt suit their narrative.
That is also what people do.

A small minority of people do not have a dog in this fight.
An even smaller minority of people have somehow managed to bring an open-mind to this argument, having somehow not been swayed by decades of propaganda for and against individual parties.
And... a ridiculously pitiful quantity of rare individuals arrive with one idea in their head, read & digest the evidence, and actually consider changing their minds about a subject.
:o

I'm not even sure which category I fit into myself; quite often bias has crept into my subconscious without me even being aware of it.

But I do know this; your post is a sly attack on the OP, thus none-to-subtly undermining both him and the NYT article itself.
You make it appear as if he is the only one here with feet of clay.
Bravo!

Meanwhile, if you can genuinely claim that you are above such influences and bias, you have been truly blessed, and I look forward to your forthcoming beatification.

p.s. I was immediately jarred by your use of the word "narrative", so I checked and this particular word has been used 2852 times on these forums... mostly by Revelation. :rotfl:

It’s not dismissing.

No matter why the problem is happening, it’s the maintenance departments job not to release an aircraft with a dangerous defect. It’s flight ops job to make sure that pilots are properly briefed.

You can argue bad design all day, but this was the 4th flight with a major flight safety problem and the second flight (that we know of) where the pilots had to intervene to prevent a dive into the ocean.
Of all the things to worry about... the Wookie has no pants.
 
Exeiowa
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Feb 05, 2019 10:47 pm

To only blame maintenace ignores that this failure could have happened in flight and not have occured to a previous crew. Systems should be designed to make it harder for occurancs like this to occur. These pilots for whatever reason did not save this aircraft, if they knew that the switches might be useful they could have probably used them. Boeing did have that information, and these pilots did not recieve it, at the end of the day people lost their lives, we should do things in our power to make this less likely. An aircraft with an unremedied falt was sent out, but a plane could develpope this fault in operation and without informed crew how would they remedy it? This tragic accident will probably not be repeated becasuse of the knowledge that became shared. It just should not happened that way
 
prebennorholm
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 4:39 am

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

:checkmark:

Modern airliners have three AoA sensors. All three are constantly monitored for agreement. In case one disagrees, then it is informed to the crew and written in the MX log.

Under normal ops #1 and #2 are used pretty much as the two on the MAX. #3 is a standby.

In case either #1 or #2 disagrees with the two others, then the disagreeing sensor will be disengaged, and the standby sensor will be used in its place.

If all three sensors disagree, then crew is informed about consequences. For instance Airbus FBW planes will degrade flight control into Alternate Mode, which means manual control on all three axis pretty much like a C172.

During the last fifty years we have been told that airliners are designed always with redundancy in mind. And that a single point failure will never create a new hole in a swiss cheese layer. Obviously we are not there yet.

I am puzzled that I haven't seen anybody compare this accident to TK1951 ten years ago in Amsterdam. One altimeter showed negative 8 feet during all approach, the one displayed on the PNF (left hand) side. Nothing serious, daylight, runway in sight. Except exactly the failing altimeter alone fed the auto throttle computer, which at that faulty indicated altitude was programmed to change to Flare Mode (retard) while at several hundred feet. Runway undershoot, nine dead, 86 injured, some critically.

That is another accident where a plane, equipped with dual sensors, had a single sensor fault which initiated a fatal chain reaction. A chain reaction which hopefully most crews would have broken, but in these two cases they didn't manage to do that in time.
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BoeingGuy
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 4:49 am

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

:checkmark:

Modern airliners have three AoA sensors. All three are constantly monitored for agreement. In case one disagrees, then it is informed to the crew and written in the MX log.

Under normal ops #1 and #2 are used pretty much as the two on the MAX. #3 is a standby.

In case either #1 or #2 disagrees with the two others, then the disagreeing sensor will be disengaged, and the standby sensor will be used in its place.

If all three senors disagree, then crew is informed about consequences. For instance Airbus FBW planes will degrade flight control into Alternate Mode, which means manual control on all three axis pretty much like a C172.

During the last fifty years we have been told that airliners are designed always with redundancy in mind. And that a single point failure will never create a new hole in a swiss cheese layer. Obviously we are not there yet.

I am puzzled that I haven't seen anybody compare this accident to TK1951 ten years ago in Amsterdam. One altimeter showed negative 8 feet during all approach, the one displayed on the PNF (left hand) side. Nothing serious, daylight, runway in sight. Except exactly the failing altimeter alone fed the auto throttle computer, which at that faulty indicated altitude was programmed to change to Flare Mode (retard) while at several hundred feet. Runway undershoot, nine dead, 86 injured, some critically.

That is another accident where a plane, equipped with dual sensors, had a single sensor fault which initiated a fatal chain reaction. A chain reaction which hopefully most crews would have broken, but in these two cases they didn't manage to do that in time.


How about flying the airplane? The autothrottle goes into IDLE mode (not FLARE mode as incorrectly stated - that’s an Autopilot mode) and the airplane starts losing speed at altitude. If a crew was properly monitoring speed and altitude and the PF had his hands on the thrust levers, he would have caught the problem and disconnected the faulty automation. Same with Asiana.

How about pilots flying the airplane instead of sitting back complacent expecting the automation to do everything. If you don’t understand what the automation is doing, there is a very simple solution - click, click and click, click. Maintain control of the airplane.
 
WIederling
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 9:01 am

BoeingGuy wrote:
How about pilots flying the airplane instead of sitting back complacent expecting the automation to do everything. If you don’t understand what the automation is doing, there is a very simple solution - click, click and click, click. Maintain control of the airplane.


This turns into a difficult task when the plane starts to unexpectedly go into "topping from the bottom" mode.
( Boeing at the time was exceptionally lucky/successful to have the cause hung on TK alone.
same for the "We Too Low" crew. That exposed IMHo not only a UI issue but also
a strongly racist attitude from the country of manufacture in general
and we do see comparable work towards character assasination in this Lion Air case.)
Murphy is an optimist
 
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SheikhDjibouti
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 11:58 am

prebennorholm wrote:
I am puzzled that I haven't seen anybody compare this accident to TK1951 ten years ago in Amsterdam.

One altimeter showed negative 8 feet during all approach, the one displayed on the PNF (left hand) side. Nothing serious, daylight, runway in sight. Except exactly the failing altimeter alone fed the auto throttle computer, which at that faulty indicated altitude was programmed to change to Flare Mode (retard) while at several hundred feet. Runway undershoot, nine dead, 86 injured, some critically.

That is another accident where a plane, equipped with dual sensors, had a single sensor fault which initiated a fatal chain reaction. A chain reaction which hopefully most crews would have broken, but in these two cases they didn't manage to do that in time.

Good call!
I searched for TK1951 and discovered something strange; you are the first person to mention it here on a.net. :o
It was never discussed at the time (2009), or since.
WTF?

Fortunately there is a half-decent wikipedia article
https://en.wikipedia.org/wiki/Turkish_A ... light_1951

The Dutch Safety Board wrote:
The initial investigation results indicated that the left radio altimeter system had passed on an erroneous altitude reading of -8 feet to the automatic throttle control system (the autothrottle).
The ‘Dispatch Deviation Guide’ for the Boeing 737800, a manual of additional procedures and warnings for maintenance crews and pilots to consult before the aircraft is flown includes a warning added in 2004, stating that with radio altimeter(s) inoperative, the associated autopilot or autothrottle must not be used for the approach and landing.
Boeing stated that a provision such as this did not lend itself for inclusion in a defects checklist in the Quick Reference Handbook.
On the one hand because a non-normal checklist must be based on a readily identifiable failure that is identified by an alert or a fault-warning, which was not the case with this radio altimeter failure.
On the other hand because of the complexity of the fault, it is not practical to develop a non-normal checklist that would address all possible situations.
Furthermore incorporating the procedure in the Quick Reference Handbook would unnecessarily remove airplane system functionality. This means that as an aircraft has two identical systems, one system is also a back-up for the other system. When one of these systems does not work prior to dispatch no back-up system is available and the flight should not be dispatched or the systems should not be used. If however during the flight one of the systems should fail the other system, the back-up, will take over and that is what it is meant for. Not using a system anymore at that moment should be too big a restriction for the operations.

I confess some of that is a tad too technical for me to fully comprehend without at least two more coffees inside me. :oops:

The aircraft is fitted with two radio altimeter systems, one on the left and one on the right. In principle, the autothrottle uses the altitude measurements provided by the left radio altimeter system. Only if there is an error in the left system that is recognised as such by the system, the autothrottle will use the right-hand radio altimeter system.
The aircraft involved in the accident was being flown by the first officer, who was sitting on the right-hand side. His primary flight display showed the readings measured by the right radio altimeter system.
The first officer’s (right-hand) primary flight display indicated the correct height, as provided by the right-hand system. The lefthand radio altimeter system, however, categorised the erroneous altitude reading as a correct one, and did not record any error. This is why there was no transfer to the right-hand radio altimeter system. In turn, this meant that it was the erroneous altitude reading that was used by various aircraft systems, including the autothrottle.


The crew were unaware of this, and could not have known about it. The manuals for use during the flight did not contain any procedures for errors in the radio altimeter system. In addition, the training that the pilots had undergone did not include any detailed system information that would have allowed them to understand the significance of the problem.


To my untrained eyes, it does indeed seem to parallel this Lion Air incident, albeit with autothrottle being the villain instead of MCAS.
I will probably attract some adverse criticism if I add that Boeing seem to have dodged a bullet on that occasion too. :lol:
But then again, I'm just an amateur here; what do I know....? :duck:

Selected quotes from the Dutch Safety Board report, 2009 (with very minor edits to make it slightly more digestible)
Nothing to see here; move along please.
 
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SomebodyInTLS
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 12:57 pm

SheikhDjibouti wrote:
I searched for TK1951 and discovered something strange; you are the first person to mention it here on a.net. :o
It was never discussed at the time (2009), or since.
WTF?


Then search must be broken or you should try different search strings - there were definitely many many comments at the time.
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
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Revelation
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 1:38 pm

SomebodyInTLS wrote:
SheikhDjibouti wrote:
I searched for TK1951 and discovered something strange; you are the first person to mention it here on a.net. :o
It was never discussed at the time (2009), or since.
WTF?


Then search must be broken or you should try different search strings - there were definitely many many comments at the time.

It seems to have fallen off the Googlesphere ( maybe due to site transition ?) but there's always the Internet Archive:

https://web.archive.org/web/20090228093 ... in/4329329

It kept rolling for at least 10 pages of ~200 posts each:

https://web.archive.org/web/20090314044 ... n/4346357/

Hope y'all enjoy reading this stuff. It gives me a headache to go back a decade in time with just a few clicks...

At least one constant is true across a decade's time: a.net was talking smack about the A380 a decade ago:

https://web.archive.org/web/20090219115 ... in/4318918

Hmm, I didn't find user Revelation in that thread, guess that ruins that narrative...
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LDRA
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 1:52 pm

In addition to MCAS, Single AoA failure also appearantly causes altitude mismatch(How the heck that happens?!), as well as air speed mismatch, plus possibility of false stall warning. That is a lot of critical stuff broken in a cockpit. I think the investigation will focus on cockpit workload/feasibility of failure isolation topic as well
Last edited by LDRA on Wed Feb 06, 2019 2:11 pm, edited 1 time in total.
 
LDRA
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 1:56 pm

Boeing dropped ball on MCAS hazard analysis. Previous auto trim system, STS, Mach trim have bounded output, which means there is limited control-ability issue, which means failure has low severity. That is why Boeing got away with single input feeding STS and mach trim(Still a shitty design never the less).

MCAS can continue to command multiple increments of trim down, which clearly should be considered high severity failure
 
dtw2hyd
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 2:10 pm

On previous threads, there was a lot of discussion on how previous flight landed safely with the same issues.
What did that crew do differently compared to ill-fated last flight?

Did they cut off two switches (vs) one cutoff on the doomed flight?
All posts are just opinions.
 
BoeingGuy
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 2:45 pm

WIederling wrote:
BoeingGuy wrote:
How about pilots flying the airplane instead of sitting back complacent expecting the automation to do everything. If you don’t understand what the automation is doing, there is a very simple solution - click, click and click, click. Maintain control of the airplane.


This turns into a difficult task when the plane starts to unexpectedly go into "topping from the bottom" mode.
( Boeing at the time was exceptionally lucky/successful to have the cause hung on TK alone.
same for the "We Too Low" crew. That exposed IMHo not only a UI issue but also
a strongly racist attitude from the country of manufacture in general
and we do see comparable work towards character assasination in this Lion Air case.)


I have no idea what you are trying to say.

However, I wasn’t commenting on whether the designs were good or not. I was talking about the pilots not taking control of the airplane.

Don’t pull the race card either as an excuse. I said nothing about race. I was talking about pilots maintaining situational awareness and control and not being complacent.

The autothrottle unexpectedly goes to IDLE mode at 1000 feet and airspeed starts decreasing. Then click it off and fly the airplane.
 
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767333ER
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 4:13 pm

The problem with dismissing any blame Boeing gets here is that you can’t simply just point your fingers at the human factors side of things and say that’s the problem. Human factors is far too complicated. Someone else in the same situation might’ve made the same mistake, they might not have, or they might have made a different mistake. What remains constant would be the poor design of the system and the lack of knowledge on it. Sure the pilots could’ve done this different or that different which is asking quite a bit given the confusing situation rogue MCAS would be when you have no idea what it is, but had thing been designed properly in the first place the AOA vane would’ve failed and it would’ve compared it to the other two and shut down that system and it doesn’t take someone with degrees in engineering or much education at all to come up with an idea like that. As well new key systems that change how the plane flies and how it deals with certain flight situations should be considered need to know and should be included in the FCTM so that the benchmark includes that and only airlines decide where to go from there. Solving the problem by using the thinking and actions of the crew in their limited timeframe is far moreover complicated then solving the problem from an engineering standpoint which is an easy engineering problem to fix. This failure and malfunction condition doesn’t need to exist, it’s Boeing that allowed it to.

To point fingers only at the pilots and not at Boeing is almost like saying when you’re driving a car with recalled airbags (before they were recalled) or driving a Ford Pinto it’s up to you to not get into a collision and yes you can control that to some degree, but if these things were designed properly in the first place, the only thing you’d need to worry about is not getting into a collision simply because collisions are dangerous, not because your car will explode or your airbag will fail and not save your life.
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zuckie13
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 4:31 pm

This is one of those cases where multiple parties really did screw up and the blame should go to all where appropriate. I don't care who you are a fan of (full disclosure, I'm generally a Boeing fan - and a fan of the largest operator of the type WN), you have to look at it from an outside perspective.

1) Boeing screwed up. Boeing should have made pilots aware of the MCAS feature, even if the response to a a failure is the same a previous checklists.
2) FAA, EASA and others screwed up. Regulatory bodies should have insisted on the above, not bowed to manufacturer pressure.
3) Lion Air screwed up. If airplane has similar sensor malfunctions on what appears to have been multiple flights in a row then the plan should have been grounded and probably then test flown empty after it was fixed.
4) The pilots probably (need to see what the transcript says) screwed up. There are clear signs the elevator trim is moving to cause the nose down, and they have a way to disable it that they didn't hit (but pilots on previous flights did.

Like most accidents it took more than one failure to cause it. Trying to lean the blame fully one way or the other is just plain wrong.
 
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PW100
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 5:26 pm

BoeingGuy wrote:
How about pilots flying the airplane instead of sitting back complacent expecting the automation to do everything. If you don’t understand what the automation is doing, there is a very simple solution - click, click and click, click. Maintain control of the airplane
. . .
I was talking about pilots maintaining situational awareness and control and not being complacent.

. . .

The autothrottle unexpectedly goes to IDLE mode at 1000 feet and airspeed starts decreasing. Then click it off and fly the airplane.



I understand your point. However the main reason we have automation, is that relying on pilots doing the right thing day hour after hour, day after day, month after month, has proved to produce a *lot* of smoking holes in the ground. Not because they were intentionally making mistakes, but because they are human beings. And human beings are from time to time complacent, tired, poor attitude (resulting in poor CRM), have lack of knowledge etc. etc (I'm sure you are familiar with the dirty dozen). But also human beings can get confused when faced with multiple non-standard issues simultaneously.

Human beings make mistakes. Heck even the simplest repetitive task such as of typing my own name, will produce mistakes from time to time. If we even make mistakes in such a simple task, how can we expect a crew to not make mistakes in much more difficult task, when faced with multiple issues at he same time. Yes, the JT crew may have made errors (please note that the jury is still out . . . . ), but stopping there and not looking deeper into other issues (such as training syllabi, human-automation interface and interaction, system design) would be a gross mistake.

What I find interesting in both the TK and JT "the automation" had sufficient authority to put the aircraft in an unrecoverable condition, where we relying on crew being not-complacent, not-tired, good attitude (resulting in perfect CRM), have excellent level of knowledge (on MCAS) etc. to prevent a bad day in the office. History has proven that's fairly poor way of preventing accidents.
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BoeingGuy
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Re: Solid NYT Article on MCAS and Lion Air Crash

Wed Feb 06, 2019 5:33 pm

PW100 wrote:
BoeingGuy wrote:
How about pilots flying the airplane instead of sitting back complacent expecting the automation to do everything. If you don’t understand what the automation is doing, there is a very simple solution - click, click and click, click. Maintain control of the airplane
. . .
I was talking about pilots maintaining situational awareness and control and not being complacent.

. . .

The autothrottle unexpectedly goes to IDLE mode at 1000 feet and airspeed starts decreasing. Then click it off and fly the airplane.



I understand your point. However the main reason we have automation, is that relying on pilots doing the right thing day hour after hour, day after day, month after month, has proved to produce a *lot* of smoking holes in the ground. Not because they were intentionally making mistakes, but because they are human beings. And human beings are from time to time complacent, tired, poor attitude (resulting in poor CRM), have lack of knowledge etc. etc (I'm sure you are familiar with the dirty dozen). But also human beings can get confused when faced with multiple non-standard issues simultaneously.

Human beings make mistakes. Heck even the simplest repetitive task such as of typing my own name, will produce mistakes from time to time. If we even make mistakes in such a simple task, how can we expect a crew to not make mistakes in much more difficult task, when faced with multiple issues at he same time. Yes, the JT crew may have made errors (please note that the jury is still out . . . . ), but stopping there and not looking deeper into other issues (such as training syllabi, human-automation interface and interaction, system design) would be a gross mistake.

What I find interesting in both the TK and JT "the automation" had sufficient authority to put the aircraft in an unrecoverable condition, where we relying on crew being not-complacent, not-tired, good attitude (resulting in perfect CRM), have excellent level of knowledge (on MCAS) etc. to prevent a bad day in the office. History has proven that's fairly poor way of preventing accidents.


Well written post. Your points are very thorough and valid.

One point though. TK wasn’t remotely close to being unrecoverable. Like OZ, the crews had multiple cues in plenty of time to recover.

Nowhere have I stated whether or not I think the designs were flawed. I’m well familiar with all three incidents, so I won’t comment. I simply said that if the crews had been monitoring airspeed and the automation like a pilot should, TK and OZ would t have happened.
 
Beaver84
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Re: Solid NYT Article on MCAS and Lion Air Crash

Thu Feb 07, 2019 11:23 pm

Let me provide a couple of clarifications about 737 use of AOA and STS/MCAS control.

737 has two AOA vanes. Each is used by the air data and flight computer system on that side of the airplane. Static pressure measurement is adjusted slightly based on AOA to compensate for distortion in pressure at sensor location. L/R AOA mis-compare leads to different static pressure corrections being applied to the L/R measurements. In this way a single AOA error can result in L/R mis-compares of AOA, Altitude, and Airspeed.

737 STS and MCAS are implemented in the Flight Control Computers (FCCs). When autopilot is engaged, the FCC on the side of the airplane from which autopilot is first engaged takes on the role of master and provides commands. Knowing this, flight crew can control which FCC is active for autopilot function. When flying manually (autopilot disconnected) FCCs provide STS and MCAS commands. Pilots do not have control over which FCC is active for these functions. Upon power up L FCC takes on active role for STS and MCAS. Provided power continues to be applied to FCCs, each landings / takeoff cycle causes switch between L/R FCC as active for STS and MCAS. Starting from cold/dark it will be the L FCC that provides STS and MCAS commands for the first segment of the day.

Regards,

Beaver84
 
brons2
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Mar 12, 2019 2:40 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.


Alarming yes, but not really news. The same thing happened with the DC-10 cargo door back in the 70s. They stalled on putting out an AD to fix the thing because they didn't want Douglas to get bad press and 346 people paid with their lives. RIP.
Firings, if well done, are good for employee morale.
 
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Veigar
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Mar 12, 2019 2:56 pm

zkojq wrote:
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...


Wasn't a huge factor of AF447 pilot error?
 
ShamrockBoi330
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Mar 12, 2019 3:00 pm

Veigar wrote:
zkojq wrote:
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...


Wasn't a huge factor of AF447 pilot error?


Yes
 
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Veigar
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Mar 12, 2019 3:07 pm

ShamrockBoi330 wrote:
Veigar wrote:
zkojq wrote:
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...


Wasn't a huge factor of AF447 pilot error?


Yes


Thank you for refreshing my memory. So F-GZCP was 100% airworthy then, unlike the Lion Air plane.
 
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zkojq
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Mar 12, 2019 3:38 pm

Veigar wrote:
ShamrockBoi330 wrote:
Veigar wrote:

Wasn't a huge factor of AF447 pilot error?


Yes


Thank you for refreshing my memory. So F-GZCP was 100% airworthy then, unlike the Lion Air plane.

It was airworthy at the time it left the gate on departure. But during the flight it had an airspeed system error in flight (which was catastrophically mishandled by the crew leading to the crash). Once the airspeed error had occurred it was no longer airworthy/dispatchable.
First to fly the 787-9
 
kipfilet
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Mar 12, 2019 3:42 pm

As someone else pointed out in another thread, the FAA is under the umbrella of the Department of Transportation, whose current secretary (Elaine Chao) has received several contributions from airline and aerospace industry lobbies and interest groups. Seems to me a clear case of regulatory capture.
 
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Jouhou
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Re: Solid NYT Article on MCAS and Lion Air Crash

Tue Mar 12, 2019 4:42 pm

hivue wrote:
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.



#2 is the most upsetting, it seems they were wrong, in a way that cost lives. How extremely shameful. They decided they could pass the blame on the pilots in the event of an accident and thus it was okay.
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