Author Topic: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'  (Read 64439 times)

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Offline Nusa

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #350 on: March 15, 2019, 02:12:19 am »
A software workaround is when your software is changed to handle a failure in some other system.

So when hardware fails, whatever the software does to compensate is, by definition, a workaround -- something designed to work as well as possible until the failing system can be repaired. There are many other workarounds designed into avionics software, as there are many systems that have the potential to fail. This is one that just wasn't done right the first time around. And got through testing and review.
 

Offline raptor1956

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #351 on: March 15, 2019, 02:17:41 am »
News reports suggest that part of the reason they were able to tie the two crashes together and point towards both crashes having a similar/same cause and before they had the FDR or CVR was the position of the horizontal stabilizer jack screw.  If the plane was forced down by MCAS or similar the jack screw would be wound up towards one end of travel -- the end forcing the plane down.  That, on top of the refined GPS altitude data pointing to a bucking bronco ride into the ground is pretty clear evidence that Lionair and this crash have a common cause.

The French now have the recorders and hopefully we'll get a preliminary readout on them tomorrow or soon and I would be very interested to know what the AOA, altitude and airspeed indications were and what differences, if any, one side had versus the other.


Brian
 
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Online Brumby

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #352 on: March 15, 2019, 03:26:56 am »
That, on top of the refined GPS altitude data pointing to a bucking bronco ride into the ground is pretty clear evidence that Lionair and this crash have a common cause.

That is absolutely incorrect.

At this point, you cannot say they have a common cause.  What you can say is that they have an apparently similar symptom.

This is one of the specific areas of objectivity of crash analysts that cannot be understated ... and it is why only the Media are making such a big noise with hypotheses.  You can never allow previous incidents to influence a current investigation or you could end up with "scenario fulfillment" instead of an accurate, unbiased report on what actually happened.

"Feel good" answers don't stop planes falling out of the sky in the future.  Only ones derived from meticulous scrutiny by objective, trained staff following a rigorous process will.


This is the reason why I will not speculate on events such as these.
 
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Offline floobydust

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #353 on: March 15, 2019, 04:33:01 am »
The similar time-constant apparently correlates to the anti-stall automation at work.

Even to a layman, Boeing's MCAS implementation is shit, even if it's not a factor in the ET 302 crash.
I can't see why we defend the mighty Boeing and blame the pilots for not executing some manual sequence from hell.

People say Boeing's product-development cycle cannot move this fast (to compete with Airbus) and continue to make safe aircraft. Using undocumented automation to cover up a handling problem, then sneak it through FAA approvals is terrible. There is huge money at stake here, Boeing's stock losing $28B in market cap and there are $600B of orders in the books.

Kudos to Ethiopian Airlines for not giving the black boxes over to US authorities, and instead having France's BEA do the investigation. I have no confidence in the FAA after insisting the aircraft is airworthy despite the rest of the world grounding the aircraft, and how MCAS made it through certification in the first place.
 
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Offline raptor1956

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #354 on: March 15, 2019, 04:54:14 am »
That, on top of the refined GPS altitude data pointing to a bucking bronco ride into the ground is pretty clear evidence that Lionair and this crash have a common cause.

That is absolutely incorrect.

At this point, you cannot say they have a common cause.  What you can say is that they have an apparently similar symptom.

This is one of the specific areas of objectivity of crash analysts that cannot be understated ... and it is why only the Media are making such a big noise with hypotheses.  You can never allow previous incidents to influence a current investigation or you could end up with "scenario fulfillment" instead of an accurate, unbiased report on what actually happened.

"Feel good" answers don't stop planes falling out of the sky in the future.  Only ones derived from meticulous scrutiny by objective, trained staff following a rigorous process will.


This is the reason why I will not speculate on events such as these.


Oh please, while there is more to learn from the FDR and CVR and it is possible the cause will point elsewhere, the idea that the forensic data from the crashed plane and the data from the broadcast GPS data are meaningless is, well, laughable.  The fact is, the results of those aforementioned two datapoints are that dozens of airlines and aviation agencies including the FAA grounded the 737 Max, before the data from the FDR and CVR were even downloaded, and even the manufacturer, Boeing, was compelled to call for the grounding, prior to the analysis of the CVR and FDR, makes it crystal clear that the consensus view of the experts is that the similarities are sufficient to call for grounding.  And, while it is possible that analysis of the recorders will clear this 737 Max from a MCAS or similar automation problem, the data they have already was enough to make a call that will cost billions to numerous airline and quite possibly many billions for Boeing.  Not to mention the unavoidable impact that this grounding will have on millions of airline passengers and quite possibly for months or longer.  Perhaps try and be a bit less sanctimonious!


Brian
 

Online Brumby

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #355 on: March 15, 2019, 06:09:41 am »
Really?

I never said that the fallout for Boeing wouldn't be significant - no matter what the outcome.  So don't try throwing that in my face.

All I AM saying is that ANYBODY who has "determined" the cause of this accident at this point in time is not basing it on all the facts.

You MAY be right - and if it does turn out that you are, that still does not give you any right to be sanctimonious about your guessing at this stage.


Just pile on with the Media circus.  You'll enjoy their company.

I'll wait.
 
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Offline GeorgeOfTheJungle

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #356 on: March 15, 2019, 07:41:33 am »
But Brumby, the data we already have is very telling, isn't it?
Even when the experts all agree, they may well be mistaken.
 

Offline Kjelt

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #357 on: March 15, 2019, 07:53:19 am »
I agree with Brumby, if you do not have all the information it becomes speculation.

The grounding of the plane AFAIK is foremost taken because it is a new plane AND two brand new planes crashed within a half year.
 
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Offline GeorgeOfTheJungle

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #358 on: March 15, 2019, 08:08:38 am »
The grounding of the plane AFAIK is foremost taken because it is a new plane AND two brand new planes crashed within a half year.

... apparently in the same way and for the same reason. No?
Even when the experts all agree, they may well be mistaken.
 

Online Brumby

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #359 on: March 15, 2019, 11:11:15 am »
But Brumby, the data we already have is very telling, isn't it?

It does lend itself to the conclusions the Media is jumping to with great haste.  As I said, it may be that those conclusions could be close to the truth - but the information available is by no means sufficient to start drawing definitive conclusions at this time.


... apparently in the same way and for the same reason. No?

Even that is a little too far for my liking - but it does acknowledge an element of uncertainty, which is appropriate.
 
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Offline langwadt

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #360 on: March 15, 2019, 11:39:34 am »
That, on top of the refined GPS altitude data pointing to a bucking bronco ride into the ground is pretty clear evidence that Lionair and this crash have a common cause.

That is absolutely incorrect.

At this point, you cannot say they have a common cause.  What you can say is that they have an apparently similar symptom.

This is one of the specific areas of objectivity of crash analysts that cannot be understated ... and it is why only the Media are making such a big noise with hypotheses.  You can never allow previous incidents to influence a current investigation or you could end up with "scenario fulfillment" instead of an accurate, unbiased report on what actually happened.

In one of the "Air Crash Investigation" episodes one of the investigators said they internationally do not watch any kind of news
before examining the crash site

 
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Offline Kjelt

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #361 on: March 15, 2019, 11:44:25 am »
The grounding of the plane AFAIK is foremost taken because it is a new plane AND two brand new planes crashed within a half year.
... apparently in the same way and for the same reason. No? 
You can not talke about "The same reason" while the cause is not 100% determined and investigation is not completed IMO.

I would go as far as that two new planes crash within a limited timeframe without obvious external cause.

(If there was a second plane involved that crashed into the plane or that there was extreme weather like a tornado etc. that would IMO be an external cause)
 
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Offline tooki

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #362 on: March 15, 2019, 11:50:55 am »
That, on top of the refined GPS altitude data pointing to a bucking bronco ride into the ground is pretty clear evidence that Lionair and this crash have a common cause.

That is absolutely incorrect.

At this point, you cannot say they have a common cause.  What you can say is that they have an apparently similar symptom.

This is one of the specific areas of objectivity of crash analysts that cannot be understated ... and it is why only the Media are making such a big noise with hypotheses.  You can never allow previous incidents to influence a current investigation or you could end up with "scenario fulfillment" instead of an accurate, unbiased report on what actually happened.

In one of the "Air Crash Investigation" episodes one of the investigators said they internationally do not watch any kind of news
before examining the crash site
Yep.

And also, there have been cases where crash investigators announced the cause prematurely, and it turned out that their initial suspicion was wrong.
 
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Offline tooki

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #363 on: March 15, 2019, 11:54:15 am »
Kudos to Ethiopian Airlines for not giving the black boxes over to US authorities, and instead having France's BEA do the investigation. I have no confidence in the FAA after insisting the aircraft is airworthy despite the rest of the world grounding the aircraft, and how MCAS made it through certification in the first place.
Your mistrust is misplaced, then, because the FAA isn't responsible for crash investigations at all. Black boxes are sent to the NTSB, a completely different arm of government that is independent from the FAA. (It doesn't make rules, it produces crash reports and recommendations, which regulatory agencies like the FAA, as well as manufacturers, can choose to follow, or not.)
 
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Offline TheNewLab

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #364 on: March 15, 2019, 12:13:52 pm »
Kudos to Ethiopian Airlines for not giving the black boxes over to US authorities, and instead having France's BEA do the investigation. I have no confidence in the FAA after insisting the aircraft is airworthy despite the rest of the world grounding the aircraft, and how MCAS made it through certification in the first place.
Your mistrust is misplaced, then, because the FAA isn't responsible for crash investigations at all. Black boxes are sent to the NTSB, a completely different arm of government that is independent from the FAA. (It doesn't make rules, it produces crash reports and recommendations, which regulatory agencies like the FAA, as well as manufacturers, can choose to follow, or not.)

Correct.
Grew up around airline and aviation people.  The NTSB is world-class. Their labs and investigative abilities set the standard
 
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Online MasterTech

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #365 on: March 15, 2019, 12:46:35 pm »

Correct.
Grew up around airline and aviation people.  The NTSB is world-class. Their labs and investigative abilities set the standard

Agreed, but Nasa is also world-class and political/administrative pressures made the Columbia accident happen.

So given this is not a cessna or learjet accident investigation, and given the interests are extremely high due to uncalculable economic losses a bit of caution regarding who investigates this is understandable

Also, the plane was configured to crash dive, https://www.bloomberg.com/news/articles/2019-03-15/piece-found-in-crash-wreckage-said-to-show-jet-was-set-to-dive
 
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Offline GeorgeOfTheJungle

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #366 on: March 15, 2019, 02:44:32 pm »
Grew up around airline and aviation people.  The NTSB is world-class. Their labs and investigative abilities set the standard

All NTSB investigations go like this: if the pilot died in the accident, it was a pilot error ~ 100% of the times, if he's alive, 50/50 chance of he being the culprit. Just watch the "Mayday" series and do the math.

Another example: we've been flying in 747 Jumbos with faulty cargo door lock mechanisms for decades... and they knew that. It was the father of a victim who had to demonstrate that, because the NTSB was hiding the truth:

https://en.wikipedia.org/wiki/United_Airlines_Flight_811#Personal_investigation_and_later_developments

I for one am glad the ET 302 black box wasn't sent to the USA, it's not a good thing when the judge is a part.
« Last Edit: March 15, 2019, 03:04:23 pm by GeorgeOfTheJungle »
Even when the experts all agree, they may well be mistaken.
 

Offline GeorgeOfTheJungle

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #367 on: March 15, 2019, 03:20:45 pm »
https://www.sapromo.com/737-max-crash-a-jackscrew-screwed-up/47577

Quote
MyBroadband.co.za reports that the US’s Federal Aviation Administration chief Daniel Elwell earlier this week cited unspecified evidence found at the crash scene as part of the justification for the agency to reverse course and temporarily halt flights of Boeing’s largest selling aircraft. Up until then, American regulators had held off as nation after nation had grounded the plane, Boeing’s best-selling jet model.

The piece of evidence was a so-called jackscrew, used to set the trim that raises and lowers the plane’s nose, according to the person, who requested anonymity to discuss the inquiry.

A preliminary review of the device and how it was configured at the time of the crash indicated that it was set to push down the nose, according to the person, who wasn’t authorized to speak publicly about the investigation.

The jackscrew, combined with a newly obtained satellite flight track of the plane, convinced the FAA that there were similarities to the Oct. 29 crash of the same Max model off the coast of Indonesia. In the earlier accident, a safety feature on the Boeing aircraft was repeatedly trying to put the plane into a dive as a result of a malfunction.

All 157 people aboard Ethiopian Airlines Flight 302 died early Sunday shortly after the plane took off. The pilot reported an unspecified problem and was trying to return to the airport. The plane crashed near Addis Ababa, Ethiopia’s capital. The plane’s crash-proof recorders have been sent to France to be analyzed.

The discovery of the jackscrew was earlier reported by NBC News.

One plus one...
Even when the experts all agree, they may well be mistaken.
 

Offline floobydust

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #368 on: March 15, 2019, 05:40:37 pm »
Kudos to Ethiopian Airlines for not giving the black boxes over to US authorities, and instead having France's BEA do the investigation. I have no confidence in the FAA after insisting the aircraft is airworthy despite the rest of the world grounding the aircraft, and how MCAS made it through certification in the first place.
Your mistrust is misplaced, then, because the FAA isn't responsible for crash investigations at all. Black boxes are sent to the NTSB, a completely different arm of government that is independent from the FAA. (It doesn't make rules, it produces crash reports and recommendations, which regulatory agencies like the FAA, as well as manufacturers, can choose to follow, or not.)

I'm not clear then on what US agency Ethiopian Airlines is blowing off, by getting France's BEA to do the crash investigation.
The NTSB can make recommendations to the FAA, who may or may not choose to adopt them.

Who is driving the software update to the MCAS? It should not be Boeing, as their processes already failed implementing it, and not the FAA for wrongly certifying it.
As an outcome of the Lion Air crash investigation, I assume some agency recommended MCAS changes- which were not rolled out and of course they would make Boeing liable.
 

Offline Nusa

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #369 on: March 15, 2019, 06:33:48 pm »
As an outcome of the Lion Air crash investigation, I assume some agency recommended MCAS changes- which were not rolled out and of course they would make Boeing liable.
What outcome? The accident happened last October, one black box was found in November and the other one in January. Plus both the FAA and NTSB mostly stopped working for a month because Trump shut down the government. NTSB is thorough and professional and doesn't jump to conclusions like most of us, but the price is time. Expect their report and recommendations in a year or so.
It'll show up here: https://www.ntsb.gov/investigations/AccidentReports/Pages/aviation.aspx
All we have so far is some data releases. And we've yet to hear what the cockpit recorder said at all.

The FAA, on the other hand, can choose to react much more quickly with Airworthiness Directives, based on events or on recommendations from aircraft manufacturers.

As for the software process, I already mentioned that earlier in the thread. It's not quick, even if you want it to be, testing is required, and the FAA does have to certify it. A few months is really fast turnaround.
 

Offline raptor1956

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #370 on: March 15, 2019, 07:40:42 pm »
Really?

I never said that the fallout for Boeing wouldn't be significant - no matter what the outcome.  So don't try throwing that in my face.

All I AM saying is that ANYBODY who has "determined" the cause of this accident at this point in time is not basing it on all the facts.

You MAY be right - and if it does turn out that you are, that still does not give you any right to be sanctimonious about your guessing at this stage.


Just pile on with the Media circus.  You'll enjoy their company.

I'll wait.


Again with the sanctimonious nonsense -- at no time did I declare the the accident was definitely this that or anything else -- you really should pull your head out of you anally retentive a$$!

The investigators, not me, have reviewed the crash scene and in combination with the broadcast GPS data have determined the crash is sufficiently similar to the Lionair crash that it warranted grounding the 737 Max.  IT WAS NOT I THAT DID THAT DIP SH!T!


Brian
 

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Offline Simon

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #372 on: March 15, 2019, 09:45:57 pm »
Really?

I never said that the fallout for Boeing wouldn't be significant - no matter what the outcome.  So don't try throwing that in my face.

All I AM saying is that ANYBODY who has "determined" the cause of this accident at this point in time is not basing it on all the facts.

You MAY be right - and if it does turn out that you are, that still does not give you any right to be sanctimonious about your guessing at this stage.


Just pile on with the Media circus.  You'll enjoy their company.

I'll wait.


Again with the sanctimonious nonsense -- at no time did I declare the the accident was definitely this that or anything else -- you really should pull your head out of you anally retentive a$$!

The investigators, not me, have reviewed the crash scene and in combination with the broadcast GPS data have determined the crash is sufficiently similar to the Lionair crash that it warranted grounding the 737 Max.  IT WAS NOT I THAT DID THAT DIP SH!T!


Brian

Calm down.
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Offline GeorgeOfTheJungle

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Even when the experts all agree, they may well be mistaken.
 

Online KL27x

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #374 on: March 15, 2019, 11:12:42 pm »
Raptor1956:
Just wanted to say that I came to this thread, seemingly only the other day. I had read some of the recent revelations about the MCAS and the trim/elevator and the elevation graph, and I found this paints one very clear picture of what likely happened in both of these crashes.

So when I saw this megathread, I was curious to see what the EEV hive mind thought, and I read more or less every single post from the beginning, seemingly for the first time. Curiously, though, I found I had thanked one of your earlier posts, lol. So I had visited this thread, at least once, before. And I recognized your early posts to be among the most rational and logical and comprehensive... without any innate bias. And as it turns out, I would say that hindsight will more than likely show that you were the right horse to bet on.

I just wanted you to know your input to this thread has been appreciated by me and surely by others. I hope you don't get caught up in semantic BS from latecomers to the thread. It is obvious from the thread history that you are not making assumptions at any stage in the thread. Even prior to the more recent relevations, your thought process and conjecture was unimpeachable and insightful, IMO, as a non-pilot.
« Last Edit: March 15, 2019, 11:24:26 pm by KL27x »
 
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