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SheikhDjibouti
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 8:57 am

SomebodyInTLS wrote:
SheikhDjibouti wrote:
However, in this case I also see the possibility that "grandfathering" will be put under the microscope, and if that happens things will get really interesting.

Probably not all that interesting... It's not like they'll retrospectively un-certify a bunch of aircraft, but they might tighten up the rules and make it harder to grandfather things without recertification where changes have been made.

I'm sure you're right except I thought grandfathering was already invalidated where "changes have been made"

Is that not precisely why Boeing instigated MCAS, to make the MAX appear to handle just like an NG (i.e. disguising any change)?

Is that not why MCAS was initially proposed with a 0.6deg nose down trim, because the change in aerodynamic performance was only minimal - except that isn't actually true.?

Is that not why minimal extra training was mandated, to persuade the world that the MAX was barely any different from what came before it?

Is that not why a third AoA sensor and additional software to manage the situation was only offered as an option, because fitting it as standard would be equivalent to admitting there were significant changes?

Is that not why Boeing obscured so many details because drawing attention to them could have prejudiced automatic grandfathering?

Each item in itself is possibly trivial, but taken as a package it obviously scared Boeing enough to want to hide it.

I don't have the relevant experience in this field to make a definitive judgement, but I've seen plenty of others on these forums who think they know the answer.
Ultimately lawyers will decide whether these changes constitute enough to invalidate grandfathering for the MAX.
And that is why it will never go to court.

In the absence of proper legal consideration. I predict grandfathering will be relaxed just enough to permit the MAX to fly again (because the world needs it....), and then it will tightened up for all future designs because it is "the right thing to do". The cognitive dissonance caused by such regulatory gymnastics will become an object lesson for future generations to laugh at. Meanwhile those of us alive today will have to hang our heads in shame.
Nothing to see here; move along please.
 
XRAYretired
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 9:05 am

-[url]http://boeing.com/commercial/737max/737-max-update.page#/current
[/url]

Statement Boeing CEO. Nothing unexpected.
 
asdf
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 9:07 am

chicawgo wrote:
...Are car manufacturers "murderers" (as others have suggested) because they don't make them standard? Price makes a difference and customers have the ability to choose between cost and features. If they aren't willing to take the additional risk by saving money, then don't buy a car at all.


well
they told us that they dont build in such features (...wich safed thousands of live ...) because "the pilot should fly the plane not the computer".

but this obviously was not the reason

they simply wanted to increase profit
probably at the expense of the passengers and the crews
 
Pluto707
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 9:22 am

https://www.seattletimes.com/business/b ... 0Usl53CXMA

When i look at the picture, obviously some budgetary cuts at B ? Is this how professional test are effectuated ? My tubes for my goldfish aquarium are better then these, some collection of different lengths and diameters fixed together, no tension rings, some leakage...not important to determine pressures at sensors ?
 
rideforever
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 9:46 am

XRAYretired wrote:

I was feeling better before I heard this.
Why are they rushing out a software fix from the aftermath of LionAir ? They are not changing their plans in respect of the 2nd crash ?
That is brazen.
I find this guy quite fake and plastic, the lights are on but sincerity is not home.
 
dougbr2006
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 10:45 am

Typical initial white wash by Boeing CEO. Easy to say all that and I'm sure everyone is feeling bad at what happened, but some stones that have recently been turned over regarding the MAX certification process and the MCAS system will surely not allow the aircraft to fly again until its more fully investigated (Post ET crash) and all is understood with hopefully new procedures being implemented and possibly a new more rigorous certification of the MAX, other than grandfathering, well I hope that is the case.

Boeing continuing to state that a software fix will sort things out without fully understanding what happened in the ET crash is a bit arrogant to say the least.

They should have said that ongoing development of a software update can resolve the issue should no further steps need to be taken as a result of the ET crash or findings from the investigation of the certification and reported MCAS flaws ( Addition of an additional AOA probe for example has been suggested as a safety backup)

I'm pretty sure the MAX will be on the ground for a longer time than the end of this month. I can't see the authorities of other countries accepting the FAA /Boeing word especially after the certification procedures exposure without there being a full review after the ET initial results are in. These will ultimately result in a much deeper look at what is necessary to fully implement a fix that is 100% safe for the authorities, airlines and flying public.

Seems that some kind of aerodynamic design change may also be needed after those engines were slung further forward and upward, perhaps a larger horizontal stab or elevator area.
 
RickNRoll
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 11:08 am

sgrow787 wrote:
According to a story in the Seattle Times, Boeing really can't fingerpoint to the FAA, since ODA has put the majority of the certification process in the hands of manufacturers:

https://www.seattletimes.com/business/d ... r-the-faa/

"... But in 2005, the power shift accelerated.

That year, the George W. Bush administration changed the certification process to allow Boeing and other companies the authority to appoint their own designees.

The FAA also moved more of the oversight function out of the agency and into the companies themselves. Under a process known as Organization Designation Authorization, or ODA, companies that had received special approval by the FAA could create in-house bodies that oversee the designees who were working on certification."
Many times in other industries self regulation has been found to fail. It costs money to do quality right. People just have to accept that.
 
namezero111111
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 11:34 am

Boeing should burn for their arrogance and ignorance.
And yes, if Airbus or Bombardier or some other manufacturer got caught cheating the certification process like this they should burn, too.
 
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giosue61
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 1:19 pm

rideforever wrote:
XRAYretired wrote:

I was feeling better before I heard this.
Why are they rushing out a software fix from the aftermath of LionAir ? They are not changing their plans in respect of the 2nd crash ?
That is brazen.
I find this guy quite fake and plastic, the lights are on but sincerity is not home.


I totally agree. An imbarassing speech. Wander why they did it.
 
frmrCapCadet
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 1:48 pm

zippy wrote:
SheikhDjibouti wrote:
Anti-lock brakes and side impact airbags "make a safe car safer"™

Despite Boeing's incredibly crass statement, MCAS does not "make a safe plane safer" in quite the same way.


Sure, ABS is considered an "active safety" technology and airbags are typically considered "passive safety" technology. Neither will do you much good if the car is otherwise unsafe. A car that has poor tires won't benefit much from ABS much like car with a weak unibody won't benefit from airbags.

SheikhDjibouti wrote:
The correct analogy is a car maker fitting anti-lock brakes because totally unknown to you they installed a system whereby if the speedometer fails, the car immediately enters a skid.
So to remedy this, they fitted anti-lock brakes to control said skid.
Firstly, that is a long way from "making a safe car safer"
Secondly, offering it as an option in such circumstances counts as criminally negligent.

The phrase "an accident waiting to happen" springs to mind.... :roll:


Said technology already exists in the automotive space and it's typically called something like 'stability control'. Essentially a car can be quite safe under normal driving conditions but once you reach the limits of traction it may be unpredictable. While failure modes are typically of the fail-safe variety, a bad sensor can indeed cause dangerous problems. Thanks for the reminder, this is something I actually need to fix on my car. There are a variety of inputs for the stability control system including: wheel speed of each wheel, yaw rate, steering wheel position, and vehicle speed. The yaw sensor on this car has a finite lifetime but is also in an area prone to water ingress. After a few hours of driving in warm weather the yaw sensor (there's no redundancy) will provide invalid readings that aren't interpreted as "car is in a skid" instead of "yaw sensor is sending invalid values". The computer, of course, engages the brakes in something of a panic stop — trust me, it's unpleasant when you're driving down I-5 and this happens.

Is the auto manufacturer behaving in a criminal manner in this case? IMO, no, because the car itself is nearly twenty years old and it's reasonable to expect that things will fail with age. Am I criminally negligent for continuing to drive this car? Sure, if I were to take it on long trips where I know the behavior will be triggered. The problem is that in the case of the 737 MAX this failure isn't due to the age of the equipment, and it's not something that any of the involved parties (outside of Boeing) knew about. That's where the questions of liability come from.


And a further parallel: in a car with ABS and traction control you often cannot drive at slow speeds in the snow, particularly in driveways backing up until you turn off 'traction control'. And peculiarly they almost always put the alerting light and the button is widely separated places. grrrrrr And the average driver does not know this.
Buffet: the airline business...has eaten up capital...like..no other (business)
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 2:23 pm

You know, the link(video) is spanish and all, but its really good https://www.youtube.com/watch?v=I8waFUbqanw

I personally didnt know where the stab cutoff switches were but now i see.
 
PixelPilot
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 2:42 pm

hivue wrote:
PixelPilot wrote:
So if AOA is the similarity between the accidents then what could be the issue?

https://www.reuters.com/article/us-ethi ... SKCN1QZ1R9


I wonder if the ET crew thought they were approaching stall -- when they really weren't, the airplane was just going on bad AoA information -- and tried to power out of it, accounting for the low altitude and very high airspeed?


I'm not sure if I understand the whole thing but maybe there's a much deeper problem with Max software than MCAS or just the AOA sensors.
Boeing said they are working on software fix just after Lion crash, question is are they working on the MCAS part or a lot more.
I'm quite happy that the Euros will take a look at it.
I'm still not blaming B for deliberate action but I am interested of what will the separate findings show.
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 2:50 pm

rideforever wrote:
XRAYretired wrote:

I was feeling better before I heard this.
Why are they rushing out a software fix from the aftermath of LionAir ? They are not changing their plans in respect of the 2nd crash ?
That is brazen.

I find this guy quite fake and plastic, the lights are on but sincerity is not home.

Not again ... there's not enough data from the second crash to see what was even the reason, geez.
 
BHM
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:06 pm

Etheereal wrote:
You know, the link(video) is spanish and all, but its really good https://www.youtube.com/watch?v=I8waFUbqanw

I personally didnt know where the stab cutoff switches were but now i see.



Nice video... I would love to hear it in English.
 
mm320cap
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:26 pm

WIederling wrote:
mm320cap wrote:
It’s horribly sad that it took a massive loss of life to uncover the issue (or issues). But when people say that modern airplanes have become too complex to fly, they should probably ask the people that do the flying.


I think this is a terrible statement.

The crash was premeditated murder.
It was not about uncovering hidden issues.
The crashes happened because a massive issue has been covered up, carefully hidden from view.
Think about it: when embedding the cert authority does not deliver enough advantage and easement!


Congratulations. This is the most ridiculous statement on this thread.

There would be NO reason for Boeing to “carefully hide from view” an MCAS system. They blundered badly by not making airlines and pilots aware of the system and how it works. As a MAX pilot, I was shocked to hear about it after the Lion crash. I actually went back through differences training to see if I had just missed it somehow. This was a serious screwup. But to suggest Boeing didn’t include it as some dastardly trick to cut corners is just daft. There would be no reason to. There are already systems on the airplane that act in a similar way (Speed Trim) and nobody bats an eye.

Boeing simply didn’t think the possibilities all the way through. It was a failure of imagination. Im guessing they figured that an MCAS fault would present in the same way as a runaway trim, and that they had a procedure for that already. They didn’t consider the possibilities of how the system would react to an AOA fault and that some pilots in the world might struggle to identity and correct an MCAS event caused by such. A collosal lack of judgement to be sure. But pre-meditated murder? Yeah, sure. If I believed that, I would quit my job right now.

I will agree with at least one part of the original premise: modern planes like the MAX ARE too complex..... for 350 hour pilots. That’s just shocking to me.
 
namezero111111
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:27 pm

PixelPilot wrote:
I'm still not blaming B for deliberate action but I am interested of what will the separate findings show.


No, deliberate action is of course ludicrous. I hope though some gutsy federal attorney can assert jurisdiction for a case of depraved-indifference murder.
 
PixelPilot
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:30 pm

namezero111111 wrote:
PixelPilot wrote:
I'm still not blaming B for deliberate action but I am interested of what will the separate findings show.


No, deliberate action is of course ludicrous. I hope though some gutsy federal attorney can assert jurisdiction for a case of depraved-indifference murder.


On what basis?
What if its a batch of AOA sensors that is bad and the whole thing has NOTHING to do with MCAS implementation. We still don't really know what exactly is boeing trying to patch with the software fix. All we know they went ahead with it after the Lion crash.
Last edited by PixelPilot on Tue Mar 19, 2019 3:37 pm, edited 1 time in total.
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:37 pm

BHM wrote:
Etheereal wrote:
You know, the link(video) is spanish and all, but its really good https://www.youtube.com/watch?v=I8waFUbqanw

I personally didnt know where the stab cutoff switches were but now i see.



Nice video... I would love to hear it in English.

I can translate the video for you (i dont think i can do CC since i have no idea how to captions) later at night; but im sure there must be videos somewhere about 737 pilot instructors that must know how simple the stab runaway is.
 
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PW100
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:37 pm

rheinwaldner wrote:
PW100 wrote:
There are around 7000 737NG in service worldwide, each doing on average 6 hrs per day. That's a total of 42000 hrs per day. They reach 140K every 10 days.

Isn't it every 3.3 days?

YES. I should stop posting after bed time . . .
Even makes my point much stronger: the limited hours accumulated by US 737MAX operators is not useful to demonstrate claimed safety.

Thanks for pointing out.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
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TWA302
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:38 pm

I have skimmed through the past 5 or so pages and don't see anything listed to date. Back in the original pages, there were claims that the flight crew reported unreliable airspeed. According to avherald.com, it is now said "there had been no indication of unreliable airspeed by the flight crew" which is strange to me. It doesn't say anything about being from the CVR.

http://avherald.com/h?article=4c534c4a&opt=0
 
Shansgonefishin
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:44 pm

I work in the building controls world (BMS), there’s obviously a lot of sensors and software types etc. It’s not very comforting knowing how much reliance there is on software and sensors etc - especially sensors. I am sure the quality is far superior than what I see.... but they are ALL prone to misreading and failure.

If the MCAS is looking at just one sensor for data, from a life safety perspective alone - that is just insane. Yet I see comments in here stating it’s an upgrade to look at more than one - an up sell??

If that’s true, that is ethically just scary. I highly doubt they did, that’s basic 101 stuff to look at more than one sensor, from an implementation perspective alone, the cost of material and programming would cost next to nothing to have that redundancy.

It’s really hard to believe that is the case.
Last edited by Shansgonefishin on Tue Mar 19, 2019 3:51 pm, edited 4 times in total.
 
felipekk
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:45 pm

TWA302 wrote:
I have skimmed through the past 5 or so pages and don't see anything listed to date. Back in the original pages, there were claims that the flight crew reported unreliable airspeed. According to avherald.com, it is now said "there had been no indication of unreliable airspeed by the flight crew" which is strange to me. It doesn't say anything about being from the CVR.

http://avherald.com/h?article=4c534c4a&opt=0


Yes I believe it was a misquote. I've looked at the articles that TheGuardian posted and they only mention flight control problems not airspeed problems / airspeed indicator problems.

https://www.theguardian.com/world/2019/ ... fore-crash
 
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PW100
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:54 pm

namezero111111 wrote:
PixelPilot wrote:
I'm still not blaming B for deliberate action but I am interested of what will the separate findings show.


No, deliberate action is of course ludicrous. I hope though some gutsy federal attorney can assert jurisdiction for a case of depraved-indifference murder.


Yes, the deliberate action claim is ludicrous.
However a case could probably be made on deliberate non-action when they were aware of the issue. No idea how that relates in legal terms though.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
XRAYretired
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 3:57 pm

SheikhDjibouti wrote:
SomebodyInTLS wrote:
SheikhDjibouti wrote:
However, in this case I also see the possibility that "grandfathering" will be put under the microscope, and if that happens things will get really interesting.

Probably not all that interesting... It's not like they'll retrospectively un-certify a bunch of aircraft, but they might tighten up the rules and make it harder to grandfather things without recertification where changes have been made.

I'm sure you're right except I thought grandfathering was already invalidated where "changes have been made"

Is that not precisely why Boeing instigated MCAS, to make the MAX appear to handle just like an NG (i.e. disguising any change)?

Is that not why MCAS was initially proposed with a 0.6deg nose down trim, because the change in aerodynamic performance was only minimal - except that isn't actually true.?

Is that not why minimal extra training was mandated, to persuade the world that the MAX was barely any different from what came before it?

Is that not why a third AoA sensor and additional software to manage the situation was only offered as an option, because fitting it as standard would be equivalent to admitting there were significant changes?

Is that not why Boeing obscured so many details because drawing attention to them could have prejudiced automatic grandfathering?

Each item in itself is possibly trivial, but taken as a package it obviously scared Boeing enough to want to hide it.

I don't have the relevant experience in this field to make a definitive judgement, but I've seen plenty of others on these forums who think they know the answer.
Ultimately lawyers will decide whether these changes constitute enough to invalidate grandfathering for the MAX.
And that is why it will never go to court.

In the absence of proper legal consideration. I predict grandfathering will be relaxed just enough to permit the MAX to fly again (because the world needs it....), and then it will tightened up for all future designs because it is "the right thing to do". The cognitive dissonance caused by such regulatory gymnastics will become an object lesson for future generations to laugh at. Meanwhile those of us alive today will have to hang our heads in shame.



I can give an analogous situation (at LRU level from many years ago) that fortunately did not result in any serious occurrences but demonstrates the unintended consequences of actions taken to minimise change time/cost. No names, no pack drill but real.

Following EIS, it was found that the reliability of a particular component was so poor as to erode the system safety margins. The 'fix' was to replace the component with one from a different supplier with identicle function and performance but sufficiently different to require a new part number. New part number ostensibly required it to be classified as a modification and therefore a revised type number, level of recertfication and impact on higher level assemblies etc. I.e. lots of time money.

With the cognisance of the DER, the parties agreed to implement the change by adding the new component as a 'preferred alternative' and so the change could be classified as an Ammendment with limited recertification etc and implemented quickly. And so it was.

However, the original component remains on the parts list as the non preferred component and since an amendment did not require any mandatory action by the LRU production facility, they continued to fit the original component since orders were in place and filled on time.

It was further two years and evident continued poor reliability with, what should have been,the new part, before the error was discovered and corrected.

The easy path is rarely the correct one.

Ray
 
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PW100
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 4:04 pm

giosue61 wrote:
rideforever wrote:
XRAYretired wrote:

I was feeling better before I heard this.
Why are they rushing out a software fix from the aftermath of LionAir ? They are not changing their plans in respect of the 2nd crash ?
That is brazen.
I find this guy quite fake and plastic, the lights are on but sincerity is not home.


I totally agree. An imbarassing speech. Wander why they did it.


Did Muilenburg confirm in his speech that both crashes are closely related in terms of root-cause and associated fixes?

Muilenburg wrote:
We’ve been working in full cooperation with the FAA, the DoT and the NTSB on all issues relating to both the Lion Air and the Ethiopian Airlines accidents since the Lion Air accident occurred in October last year.


The good thing is that they have been working on this since the Lion Air accident in October last year, therefore it is not a rush job.

The bad thing is that they have been working on this since the Lion Air accident in October last year, but did not inform the industry sufficiently, allowing a major second accident to happen on their watch. Even worse, after that they maintained in their position that the plane was safe and did not see reason to ground it . . .
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
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PW100
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 4:20 pm

Shansgonefishin wrote:
I work in the building controls world (BMS), there’s obviously a lot of sensors and software types etc. It’s not very comforting knowing how much reliance there is on software and sensors etc - especially sensors. I am sure the quality is far superior than what I see.... but they are ALL prone to misreading and failure.

If the MCAS is looking at just one sensor for data, from a life safety perspective alone - that is just insane. Yet I see comments in here stating it’s an upgrade to look at more than one - an up sell??

If that’s true, that is ethically just scary. I highly doubt they did, that’s basic 101 stuff to look at more than one sensor, from an implementation perspective alone, the cost of material and programming would cost next to nothing to have that redundancy.

It’s really hard to believe that is the case.


The certification thought on the single sensor thing was that Pilot Flying was the second sensor, and Pilot Monitoring was the third sensor. Thus still reaching the required levels of redundancy and safety margins.

Apart from whether that line of thinking is acceptable to provide the desired level of safety on such critical flight control system, the problem is that pilots were not told nor trained on this system, thereby significantly reducing effectively of the redundancy in said task.

To make things even worse, the formal description of when the Trim Cut Out Switches should be applied by pilots, did not fit the characteristics of the MCAS system going berserk.
Trim Cut Out Switch is a pilot memory item, not checklist item as quick reaction is needed. Not fitting the formal description then does not help either.

Many holes in a single layer of the Swiss Cheese model . . .
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
dakota123
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 5:02 pm

mm320cap wrote:
WIederling wrote:
mm320cap wrote:
It’s horribly sad that it took a massive loss of life to uncover the issue (or issues). But when people say that modern airplanes have become too complex to fly, they should probably ask the people that do the flying.


I think this is a terrible statement.

The crash was premeditated murder.
It was not about uncovering hidden issues.
The crashes happened because a massive issue has been covered up, carefully hidden from view.
Think about it: when embedding the cert authority does not deliver enough advantage and easement!


Congratulations. This is the most ridiculous statement on this thread.

There would be NO reason for Boeing to “carefully hide from view” an MCAS system. They blundered badly by not making airlines and pilots aware of the system and how it works. As a MAX pilot, I was shocked to hear about it after the Lion crash. I actually went back through differences training to see if I had just missed it somehow. This was a serious screwup. But to suggest Boeing didn’t include it as some dastardly trick to cut corners is just daft. There would be no reason to. There are already systems on the airplane that act in a similar way (Speed Trim) and nobody bats an eye.

Boeing simply didn’t think the possibilities all the way through. It was a failure of imagination. Im guessing they figured that an MCAS fault would present in the same way as a runaway trim, and that they had a procedure for that already. They didn’t consider the possibilities of how the system would react to an AOA fault and that some pilots in the world might struggle to identity and correct an MCAS event caused by such. A collosal lack of judgement to be sure. But pre-meditated murder? Yeah, sure. If I believed that, I would quit my job right now.

I will agree with at least one part of the original premise: modern planes like the MAX ARE too complex..... for 350 hour pilots. That’s just shocking to me.


:checkmark: :checkmark: :checkmark:

MCAS is discussed in the maintenance manual. Of course, our German friend will next claim that Boeing couldn’t even get the cover-up right. (And he maybe might want to look up the word pre-meditated. I.e. PLANNED to kill? Sheesh.)

Agree, shocking failure of imagination. I’ve had to coach more than one industrial controls engineer to re-consider the implications of a proposed control action. Sounds like the job was handed off to someone very junior and never reviewed.

General note, if folks on here are intellectually honest they’ll spend some time reading NASA ASRS reports from other manufacturers. There’s a few serious control and software blunders by YOUR favorite team as well.
“And If I claim to be a wise man, well surely it means that I don’t know”
 
flybucky
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 5:04 pm

TWA302 wrote:
I have skimmed through the past 5 or so pages and don't see anything listed to date. Back in the original pages, there were claims that the flight crew reported unreliable airspeed. According to avherald.com, it is now said "there had been no indication of unreliable airspeed by the flight crew" which is strange to me. It doesn't say anything about being from the CVR.

felipekk wrote:
Yes I believe it was a misquote. I've looked at the articles that TheGuardian posted and they only mention flight control problems not airspeed problems / airspeed indicator problems.

It's still there in the same AV Herald article that you linked: "On Mar 11th 2019 two listeners on frequency reported independently the crew declared emergency shortly after normal departure, while in the initial climb, reporting they had unreliable airspeed indications and had difficulties to control the aircraft."

There are some interesting updates in the Mar 19th update in the AV Herald article with new info: "According to ground observers the departure was uneventful... later the crew requested to return to Addis Ababa (in a routine like voice), departure cleared the flight to turn right heading 260, the crew replied "stand by, stand by". The "standby" reply by the crew proved to be the last transmission from the aircraft... The source stressed, that there had been no PAN PAN or MAYDAY call, there was also no change in transponder code away from the assigned code 2000, there had been no indication of unreliable airspeed by the flight crew, there had been no distress in the voices or abnormal background noises during transmissions from the aircraft that would have alerted air traffic control to assume a serious problem on board of the aircraft."

This contradicts the previous info from earlier in the AV Herald, as well as many quotes in the NYT article about the tower communications.

The NYT article said: "The captain of a doomed Ethiopian Airlines jetliner faced an emergency almost immediately after takeoff from Addis Ababa, requesting permission in a panicky voice to return after three minutes as the aircraft accelerated to abnormal speed, a person who reviewed air traffic communications said Thursday... The controllers, the person said, “started wondering out loud what the flight was doing.” ... the controllers, sensing an emergency on Flight 302, ordered [other flights] to remain at higher altitudes. It was during that exchange with the other planes, the person said, that Captain Getachew, with panic in his voice, interrupted with his request to turn back.
 
PixelPilot
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 5:10 pm

flybucky wrote:
TWA302 wrote:
I have skimmed through the past 5 or so pages and don't see anything listed to date. Back in the original pages, there were claims that the flight crew reported unreliable airspeed. According to avherald.com, it is now said "there had been no indication of unreliable airspeed by the flight crew" which is strange to me. It doesn't say anything about being from the CVR.

felipekk wrote:
Yes I believe it was a misquote. I've looked at the articles that TheGuardian posted and they only mention flight control problems not airspeed problems / airspeed indicator problems.

It's still there in the same AV Herald article that you linked: "On Mar 11th 2019 two listeners on frequency reported independently the crew declared emergency shortly after normal departure, while in the initial climb, reporting they had unreliable airspeed indications and had difficulties to control the aircraft."

There are some interesting updates in the Mar 19th update in the AV Herald article with new info: "According to ground observers the departure was uneventful... later the crew requested to return to Addis Ababa (in a routine like voice), departure cleared the flight to turn right heading 260, the crew replied "stand by, stand by". The "standby" reply by the crew proved to be the last transmission from the aircraft... The source stressed, that there had been no PAN PAN or MAYDAY call, there was also no change in transponder code away from the assigned code 2000, there had been no indication of unreliable airspeed by the flight crew, there had been no distress in the voices or abnormal background noises during transmissions from the aircraft that would have alerted air traffic control to assume a serious problem on board of the aircraft."

This contradicts the previous info from earlier in the AV Herald, as well as many quotes in the NYT article about the tower communications.

The NYT article said: "The captain of a doomed Ethiopian Airlines jetliner faced an emergency almost immediately after takeoff from Addis Ababa, requesting permission in a panicky voice to return after three minutes as the aircraft accelerated to abnormal speed, a person who reviewed air traffic communications said Thursday... The controllers, the person said, “started wondering out loud what the flight was doing.” ... the controllers, sensing an emergency on Flight 302, ordered [other flights] to remain at higher altitudes. It was during that exchange with the other planes, the person said, that Captain Getachew, with panic in his voice, interrupted with his request to turn back.


This just proves that the only way to be sure is to wait for all the information and final report yet we have murder charges being thrown around already.
Social media will be the doom of humanity.
 
osiris30
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 5:27 pm

namezero111111 wrote:
Boeing should burn for their arrogance and ignorance.
And yes, if Airbus or Bombardier or some other manufacturer got caught cheating the certification process like this they should burn, too.


The same certification rules apply to ALL parties. So ya.. burn them all because they were all FORCED to do it because the FAA said "you have to because we aren't going to.". You are mad at the wrong people.
I don't care what you think of my opinion. It's my opinion, so have a nice day :)
 
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scbriml
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 5:51 pm

PixelPilot wrote:
What if its a batch of AOA sensors that is bad and the whole thing has NOTHING to do with MCAS implementation.


That still has everything to do with the horribly flawed implementation of MCAS since its input is based on a single AOA sensor. Boeing wouldn't be fixing it if it wasn't (badly) broken.

PixelPilot wrote:
We still don't really know what exactly is boeing trying to patch with the software fix. All we know they went ahead with it after the Lion crash.


We do know, because Boeing has already outlined what they're implementing.

https://www.seattletimes.com/business/b ... air-crash/
On Monday, before the grounding of the 737 MAX, Boeing outlined “a flight control software enhancement for the 737 MAX,” that it’s been developing since soon after the Lion Air crash.

According to a detailed FAA briefing to legislators, Boeing will change the MCAS software to give the system input from both angle-of-attack sensors.

It will also limit how much MCAS can move the horizontal tail in response to an erroneous signal. And when activated, the system will kick in only for one cycle, rather than multiple times.

Boeing also plans to update pilot training requirements and flight crew manuals to include MCAS.
Time flies like an arrow. Fruit flies like a banana!
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PixelPilot
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 5:59 pm

scbriml wrote:
PixelPilot wrote:
What if its a batch of AOA sensors that is bad and the whole thing has NOTHING to do with MCAS implementation.


That still has everything to do with the horribly flawed implementation of MCAS since its input is based on a single AOA sensor. Boeing wouldn't be fixing it if it wasn't (badly) broken.

PixelPilot wrote:
We still don't really know what exactly is boeing trying to patch with the software fix. All we know they went ahead with it after the Lion crash.


We do know, because Boeing has already outlined what they're implementing.

https://www.seattletimes.com/business/b ... air-crash/
On Monday, before the grounding of the 737 MAX, Boeing outlined “a flight control software enhancement for the 737 MAX,” that it’s been developing since soon after the Lion Air crash.

According to a detailed FAA briefing to legislators, Boeing will change the MCAS software to give the system input from both angle-of-attack sensors.

It will also limit how much MCAS can move the horizontal tail in response to an erroneous signal. And when activated, the system will kick in only for one cycle, rather than multiple times.

Boeing also plans to update pilot training requirements and flight crew manuals to include MCAS.


But wasn't the second sensor optional and if so not every max is equipped with it?
And unless I'm missing something in this case it would mean A. Boeing is going to equip all maxes with the "optional" sensor or B. they can activate it by patching software?? :?: :?:
 
flybucky
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:03 pm

TWA302 wrote:
Back in the original pages, there were claims that the flight crew reported unreliable airspeed. According to avherald.com, it is now said "there had been no indication of unreliable airspeed by the flight crew" which is strange to me. It doesn't say anything about being from the CVR.

I thought more about why there could contradictory accounts (assuming the sources are being truthful). I looked closer at the Mar 11th quote:

"On Mar 11th 2019 two listeners on frequency reported independently the crew declared emergency shortly after normal departure, while in the initial climb, reporting they had unreliable airspeed indications and had difficulties to control the aircraft. The listeners could not hear later transmissions due to frequency changes."

It could be that the source from the Mar 18th update only heard the recording from the second frequency, so that's why they didn't hear the "unreliable airspeed indications" part from the first frequency.
 
flybucky
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:09 pm

PixelPilot wrote:
But wasn't the second sensor optional and if so not every max is equipped with it?
And unless I'm missing something in this case it would mean A. Boeing is going to equip all maxes with the "optional" sensor or B. they can activate it by patching software??

All 737 MAX already had 2 AoA sensors, but only input from 1 AoA sensor was being fed to MCAS at a time. It was the 3rd AoA sensor that was optional.
 
PixelPilot
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:12 pm

flybucky wrote:
PixelPilot wrote:
But wasn't the second sensor optional and if so not every max is equipped with it?
And unless I'm missing something in this case it would mean A. Boeing is going to equip all maxes with the "optional" sensor or B. they can activate it by patching software??

All 737 MAX already had 2 AoA sensors, but only input from 1 AoA sensor was being fed to MCAS at a time. It was the 3rd AoA sensor that was optional.


Thx.
SO let me ask this...
IF only one sensor was feeding the MCAS, what was the 3rd sensor for considering boeing has to update the software for 2 sensor feed in the "standard" configuration?
 
seat64k
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:25 pm



I'm wondering if we're making too much hay out of the FAA offloading some of the work to Boeing, or at least the causal relationship. In my work we do deal with certification a lot, and it's not uncommon for the the vendor to do some of the grunt work of proving that things are compliant, and the assessor to only look at the evidence presented. And yes, some of these are in areas where lives could be risked. It really depends on the context, and what the risks are of giving an outsider access to the product at hand. To that end, I can imagine that letting a couple of external pilots, who may be 737 type rated but have never set foot in a 783 MAX, loose with instructions to somehow corrupt the sensor data, stall the aircraft and see how the new systems behave, may not be an acceptable risk to either party. (This doesn't excuse the lack of documentation and related issues).

Another question this raises: let's assume the reports in the article about FAA management pressuring engineers to delegate more of the grunt work to Boeing is accurate. That either Boeing has this much influence over the FAA, or that the FAA is this invested in an American manufacturer being able to compete with the Europeans (or some other motivation?). Let's assume this pressure and delegation is what led to the FAA failing to identify the issues with the MCAS system. What does this suggest about certification with the European authorities? Why did they also fail to identify the risks? I doubt fast-tracking Boeing's program is a motivation for EASA, so are they similarly under Boeing's influence?
 
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Finn350
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:26 pm

flybucky wrote:
PixelPilot wrote:
But wasn't the second sensor optional and if so not every max is equipped with it?
And unless I'm missing something in this case it would mean A. Boeing is going to equip all maxes with the "optional" sensor or B. they can activate it by patching software??

All 737 MAX already had 2 AoA sensors, but only input from 1 AoA sensor was being fed to MCAS at a time. It was the 3rd AoA sensor that was optional.


There is no 3rd optional AoA sensor. That misinformation is based on a tweeter who didn't really know the configuration of the 737 MAX.
 
hivue
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:38 pm

scbriml wrote:
It will also limit how much MCAS can move the horizontal tail in response to an erroneous signal. And when activated, the system will kick in only for one cycle, rather than multiple times.


These are fairly significant changes. I wonder if the airplane would be able to retain its certification after they are implemented... Oh, silly me. Boeing will be deciding on the certification. :duck:
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
afriwing
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:41 pm

XRAYretired wrote:


I can give an analogous situation (at LRU level from many years ago) that fortunately did not result in any serious occurrences but demonstrates the unintended consequences of actions taken to minimise change time/cost. No names, no pack drill but real.

Following EIS, it was found that the reliability of a particular component was so poor as to erode the system safety margins. The 'fix' was to replace the component with one from a different supplier with identicle function and performance but sufficiently different to require a new part number. New part number ostensibly required it to be classified as a modification and therefore a revised type number, level of recertfication and impact on higher level assemblies etc. I.e. lots of time money.

With the cognisance of the DER, the parties agreed to implement the change by adding the new component as a 'preferred alternative' and so the change could be classified as an Ammendment with limited recertification etc and implemented quickly. And so it was.

However, the original component remains on the parts list as the non preferred component and since an amendment did not require any mandatory action by the LRU production facility, they continued to fit the original component since orders were in place and filled on time.

It was further two years and evident continued poor reliability with, what should have been,the new part, before the error was discovered and corrected.

The easy path is rarely the correct one.

Ray


That's quite interesting. Seems likely that's why Boeing offered the 3rd AoA sensor as an alternative option only.
Having it as standard would've lengthened the certification? and/or made the grandfathering argument more difficult.

Edit: Seems the 3rd sensor was fake news afterall
Last edited by afriwing on Tue Mar 19, 2019 6:46 pm, edited 1 time in total.
Afriwings
 
afriwing
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:44 pm

Finn350 wrote:
flybucky wrote:
PixelPilot wrote:
But wasn't the second sensor optional and if so not every max is equipped with it?
And unless I'm missing something in this case it would mean A. Boeing is going to equip all maxes with the "optional" sensor or B. they can activate it by patching software??

All 737 MAX already had 2 AoA sensors, but only input from 1 AoA sensor was being fed to MCAS at a time. It was the 3rd AoA sensor that was optional.


There is no 3rd optional AoA sensor. That misinformation is based on a tweeter who didn't really know the configuration of the 737 MAX.


Oh, social media is treacherous grounds.
Afriwings
 
jollo
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:47 pm

1 sensor --> no mission-critical automation that I know of was ever based on a single sensor, MCAS is a first AFAIK (even if is has nothing to do with this tragic accident). BTW cycling the active AOA sensor (Captain-side vs. FO-side) between flights would appear to be borderline criminal, as it makes problem determination and corrective maintenance so much harder.

2 sensors --> fault detection: if sensors disagree the automation disables itself (thus avoiding a catastrophic control runaway WITHOUT requiring human operators - i.e. pilots - to disable it manually) AND the system initiates an emergency shutdown (e.g. a nuclear reactor would SCRAM, a train would brake to a stop, etc.). Obviously not a viable option for an airborne airliner (no automated emergency auto-land feature was designed yet).

3 sensors --> fail safe: if sensors disagree the offending sensor is down-voted (excluded from control logic), the automation keeps working with the remaining 2 agreeing sensors AND the system screams to humans operators (i.e. pilots) to execute a safe shutdown (i.e. landing) ASAP. This is the likely fix Boeing can (and will) implement.
 
LDRA
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 6:51 pm

jollo wrote:
1 sensor --> no mission-critical automation that I know of was ever based on a single sensor, MCAS is a first AFAIK (even if is has nothing to do with this tragic accident). BTW cycling the active AOA sensor (Captain-side vs. FO-side) between flights would appear to be borderline criminal, as it makes problem determination and corrective maintenance so much harder.

2 sensors --> fault detection: if sensors disagree the automation disables itself (thus avoiding a catastrophic control runaway WITHOUT requiring human operators - i.e. pilots - to disable it manually) AND the system initiates an emergency shutdown (e.g. a nuclear reactor would SCRAM, a train would brake to a stop, etc.). Obviously not a viable option for an airborne airliner (no automated emergency auto-land feature was designed yet).

3 sensors --> fail safe: if sensors disagree the offending sensor is down-voted (excluded from control logic), the automation keeps working with the remaining 2 agreeing sensors AND the system screams to humans operators (i.e. pilots) to execute a safe shutdown (i.e. landing) ASAP. This is the likely fix Boeing can (and will) implement.


MCAS is not mission critical, it is there to satisfy cert requirements, some what similar to STS. STS also uses single sensor, its output is bounded so there is no controllability issue even if input sensor failed

Cycling between two sensors is bad design, it allows failures to go latent and undetected
 
jollo
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 7:03 pm

LDRA wrote:
MCAS is not mission critical, it is there to satisfy cert requirements


Semantics. Without MCAS the MAX would not have been certified and if MCAS is not functional a MAX cannot - legally - take off: this sounds to me like a mission-critical component. Mission-critical = the mission must be aborted if not functional <> critical = you are dead if not functional.
 
Backseater
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 7:12 pm

I understand the need for protecting against the risk of the AoA progressing towards a stall condition.
I think I can correctly guess some parts of the algorithm implemented by the current MCAS software, but I do not understand it well enough to build a replica that what could not be distinguished by an external observer.

As for the updated MCAS software supposed to be delivered to regulators next Monday, I only read about some but maybe not all of the changes it entails. Getting input from two AoA sensors sounds better, but what will MCAS do if they disagree as the a/c can still stall while AoA sensors are faulty! No unlimited authority on the stab trim but apply the fix only once! Why only once? Because if they demonstrate the protection during re-certification, they will only test increasing AoA only once? (Or maybe because an electric shock in the pilot seats will teach the pilots not to let that condition happen a second time during the same flight!!!)

Now let me try to be constructive. I do not want to look at the actual code. But I would like to see two, very simple documents, no more than 3 pages each:
1. A pseudocode description of the current MCAS algorithm sufficient to correctly model the current behavior of MCAS;
2. A pseudocode description of the new MCAS algorithm sufficient to correctly model the future behavior of MCAS;

For those not familiar with pseudocode, it is a technique developed over 50 years ago to help software design by promoting the description of algorithms in a manner that all those concerned can understand: the software designer himself/herself, his/her colleagues, managers, coders, testers, maintainers . Pseudocode is used before actual coding because a change at the pseudocode level is very cheap and therefore doable, whereas once it is painfully translated into executable code it is usually very expensive to change and therefore often accepted as cast in concrete.

In practice, pseudocode is “pidgin” English. It consists of simply writing an English descriptions of the steps to be taken in sequence (“The algorithm”) but with structured constructs to make understanding unambiguous for all concerned. For example, the current MCAS algorithm might look a bit like this:
DO FOREVER
|...IF (AP OFF) AND (FLAPS=0) THEN
|...|...READ AoA FROM left seat sensor
|...|...IF AoA is not valid THEN
|...|...| (I don’t know what they do???)
|...|...ELSE
|...|...|...READ Mach_nr FROM ADIRU(?)
|...|...|...IF Mach_nr is valid THEN
|...|...|...|...LOOKUP TABLE to get AoA_threshold given MACH_nr
|...|...|...|...IF AoA > AoA_theshold THEN
|...|...|...|...|...DO FOR UP TO 10 times OR UNTIL ((STAB_TRIM manually moved) OR (AP ON) OR (FLAPS > 0))
|...|...|...|...|...|...IF AoA > AoA_threshold THEN
|...|...|...|...|...|...|...MOVE STAB_TRIM by -0.25 degree
|...|...|...|...|...|...ENDIF
|...|...|...|...|...|...WAIT for 1 second
|...|...|...|...|...ENDDO FOR
|...|...|...|...|...Wait for 5 seconds
|...|...|...|...ENDIF
|...|...|...ELSE
|...|...|...|... (I don’t know what they do???)
|...|...|...ENDIF
|...|... ENDIF
|...ENDIF
ENDDO FOREVER
I am not claiming that is what MCAS did so far. Only Boeing engineers know for sure what their algorithm truly does.

Such documents, being quickly understandable by almost everybody, would help all interested parties:
- Boeing managers if any do not yet to understand what their operational software does
- Certifiers (FAA, EASA, …)
- Pilots
- and the rest of us who wish to quickly rebuild their confidence in aviation.

With all due respect, may I suggest that FAA engineers request those two, simple documents next Monday, if they do not have them already.

Worst case would be if Boeing were to answer that they do not have them, that it would be too complicated and would take too long to produce, but that they can offer instead hundreds of pages of software analysis and testing documentation.

Then I would be truly worried.
 
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PixelFlight
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 7:26 pm

jollo wrote:
1 sensor --> no mission-critical automation that I know of was ever based on a single sensor, MCAS is a first AFAIK (even if is has nothing to do with this tragic accident). BTW cycling the active AOA sensor (Captain-side vs. FO-side) between flights would appear to be borderline criminal, as it makes problem determination and corrective maintenance so much harder.

2 sensors --> fault detection: if sensors disagree the automation disables itself (thus avoiding a catastrophic control runaway WITHOUT requiring human operators - i.e. pilots - to disable it manually) AND the system initiates an emergency shutdown (e.g. a nuclear reactor would SCRAM, a train would brake to a stop, etc.). Obviously not a viable option for an airborne airliner (no automated emergency auto-land feature was designed yet).

3 sensors --> fail safe: if sensors disagree the offending sensor is down-voted (excluded from control logic), the automation keeps working with the remaining 2 agreeing sensors AND the system screams to humans operators (i.e. pilots) to execute a safe shutdown (i.e. landing) ASAP. This is the likely fix Boeing can (and will) implement.


Other solution: sensors filtering with flight dynamic predictors -> allow the best possible estimation regardless of the sensors failures. Feed the flight dynamic model with all the available variables you can get and filter each of them with the probability domain corresponding to the accuracy of the prediction. For example for the JT610, the energy state, control surfaces positions, IR and GPS delta would have correctly feed the flight dynamic predictor to match the next set of data, while the +20° offset on the AoA value would have failed to match the prediction so that it would have get a very low probability in the filter. A good flight dynamic predictor is able to estimate an usable AoA value from the others variables but with a lower probability that require a bigger margin to keep in flight in the safe domain. This is basically the estimation that a pilot will be forced to make if it have no AoA indicator in manual flight. All the required tech already exists and will fit nicely in a AFDX network avionic. I hope this will be someday mandatory for all commercial aircraft.
:stirthepot: 737-8 MAX: "For all speeds higher than 220 Kts and trim set at a value of 2.5 units, the difficulity level of turning the manual trim wheel was level A (trim wheel not movable)." :stirthepot:
 
PlanesNTrains
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 7:36 pm

dakota123 wrote:
Agree, shocking failure of imagination. I’ve had to coach more than one industrial controls engineer to re-consider the implications of a proposed control action. Sounds like the job was handed off to someone very junior and never reviewed.


That can be intentional for nefarious purposes, even if the person delegating doesn't expect there to be any negative outcomes. Someone at the top feels the heat and puts pressure on an underling. That person feels the heat and puts pressure on an underling. And on down the line until the heat finally lands on someone who can't just pass it along (or doesn't know well enough to not accept). Dub it "desperate times call for desperate measures'. Dub it 'plausible deniability' for those smart enough to plan for it. Dub it [peer] pressure. Dub it greed. Ultimately, the poor guy at the bottom and maybe a few up the chain are left holding the bag.

I've not encountered that much in my life, but remember a time in a rail environment where I was instructed by the GM to do something that was against federal regulations without my knowledge. But he knew. It wasn't a big deal type of thing but when you circumvent people who are responsible for safety (including their own) by sending someone else in to do your dirty work just to save a few minutes -- well, it's just wrong. But some people don't care.
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
rideforever
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 8:00 pm

MCAS will kick in only once.
Once .... per flight ? Once .... per minute ? Once what once ?!!!
So now you have 2 AoA. Is that better ?
If one is faulty ... then what ? You still don't know which one. And I assume both are identical equipment types.
Better is you change the equipment so on each side of the cockpit you have a pair. 2 left, 2 right.
And in each pair, one is aspirated, one not ... i.e. of different designs. Then you have 4 total, 2 of each type.
If one blows then you have 3 left.
If two blow then you have 2 working 2 not and you give the pilots the option of which to use.
Plus I believe there are some other AoA type sensors on the back of the aircraft not visible to the pilot.

Boeings plan is to update 5 lines of code and do some printouts ? Wow, big expense there.
Why not just put it on Twitter and go back to sleep.
 
osiris30
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 8:36 pm

seat64k wrote:


I'm wondering if we're making too much hay out of the FAA offloading some of the work to Boeing, or at least the causal relationship. In my work we do deal with certification a lot, and it's not uncommon for the the vendor to do some of the grunt work of proving that things are compliant, and the assessor to only look at the evidence presented. And yes, some of these are in areas where lives could be risked. It really depends on the context, and what the risks are of giving an outsider access to the product at hand. To that end, I can imagine that letting a couple of external pilots, who may be 737 type rated but have never set foot in a 783 MAX, loose with instructions to somehow corrupt the sensor data, stall the aircraft and see how the new systems behave, may not be an acceptable risk to either party. (This doesn't excuse the lack of documentation and related issues).

Another question this raises: let's assume the reports in the article about FAA management pressuring engineers to delegate more of the grunt work to Boeing is accurate. That either Boeing has this much influence over the FAA, or that the FAA is this invested in an American manufacturer being able to compete with the Europeans (or some other motivation?). Let's assume this pressure and delegation is what led to the FAA failing to identify the issues with the MCAS system. What does this suggest about certification with the European authorities? Why did they also fail to identify the risks? I doubt fast-tracking Boeing's program is a motivation for EASA, so are they similarly under Boeing's influence?


People are attributing a bunch of conspiracy and malice to what is the result of budget cuts (or lack of budget growth to account for relation, aka cuts) for federal agencies. Agencies are forever being asked to do more with less, because 'muh taxes'. People constantly want cheaper everything. I want cheaper taxes, I want cheaper flights, I want cheaper vacations, then they respond with shock and terror when the service is crap, the food is crap and the safety suffers.

Good, fast, cheap... pick 2 of the 3. You cannot have all 3. Today's world revolved around fast and cheap. That is why places like China dominate manufacturing. They had cheap because of labor rates and lax regulations.

We can blame Boeing, the FAA and whoever else, but at the end of the day, a lot of the root culpability lies in what the consumer is demanding of the industry and government. The complexity of modern aircraft has continued to grow. We have more systems on an aircraft than ever before. We are closer and closer to aerodynamic margins than ever before. Certification should be harder than ever before and require more effort. Not less. But no one is willing to pay for it.

Of course I am sure a bunch of people will claim I am being apologetic and making excuses for Boeing or the FAA, but I am not. I don't believe either did anything intentionally malicious. I believe mistakes may have been made that will be corrected (as they have throughout the history of aviation). I do believe the safety net designed to prevent such accidents has been weakened and I don't believe it is entirely 'industry pressure' responsible for it. Rather I believe it is ideological beliefs driving a lot of it.
I don't care what you think of my opinion. It's my opinion, so have a nice day :)
 
dragon6172
Posts: 1127
Joined: Sat Jul 14, 2007 9:56 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 8:48 pm

rideforever wrote:
MCAS will kick in only once.
Once .... per flight ? Once .... per minute ? Once what once ?!!!.

My guess would be once until reset. Pilot input to trim or AoA reduction below threshold constitutes a resetting of the system.
Phrogs Phorever
 
planecane
Posts: 1558
Joined: Thu Feb 09, 2017 4:58 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Tue Mar 19, 2019 9:07 pm

What will happen happen with AoA disagree is mcas will be disabled. Pilots will get an indication and divert. They will also be trained to fly without MCAS in the situations where it is normally activated. The plane is flyable without it, it's just different than the NG.

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