BravoOne
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 3:35 pm

Seattle newspapers are quite critical of just about anything Boeing does. Certainly not a warm relationship.
 
WIederling
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 4:05 pm

BravoOne wrote:
Seattle newspapers are quite critical of just about anything Boeing does. Certainly not a warm relationship.

Dominic Gates is a very objective and careful reporter producing articles of substance. Rare.
Seattle Times also had a mealy mouthed less than competent guy writing aero stuff.
( ok some cannot dissociate themselves from a "not with us you must be against us" stance.)

contrast with "Der Spiegel" in Germany insightlessly bashing Airbus on every occasion.
Murphy is an optimist
 
BEG2IAH
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 4:46 pm

N212R wrote:
If you're referring to the informative and well-placed Mr. Mandala, not to worry. His posts can no longer be found in search engine.


I had no idea mandala499 left.
Flying at the cruising altitude is (mostly) boring. I wish all flights were nothing but endless take offs and landings every 10 minutes or so.
 
mjoelnir
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 4:55 pm

BravoOne wrote:
Seattle newspapers are quite critical of just about anything Boeing does. Certainly not a warm relationship.



A very warm relationship. You do not seem to be used to a newspaper that is critical.
 
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SheikhDjibouti
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 5:06 pm

BEG2IAH wrote:
N212R wrote:
If you're referring to the informative and well-placed Mr. Mandala, not to worry. His posts can no longer be found in search engine.


I had no idea mandala499 left.

No, not actually left.
But you will find he has declined to post anything since Jan 1st.
Maybe he got a quiet tap on the shoulder after supplying too much inside information? :scratchchin:

I suspect he's watching us now from the wings (so to speak) and patiently waiting for the final report to be published.

That could be a very smart move by him. :D

:wave:
Nothing to see here; move along please.
 
WIederling
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 5:23 pm

BEG2IAH wrote:
N212R wrote:
If you're referring to the informative and well-placed Mr. Mandala, not to worry. His posts can no longer be found in search engine.


I had no idea mandala499 left.


He did not leave. he stopped posting ( on the Lion Air Crash)
Posts are available:
search.php?author_id=6531&sr=posts
( no idea if there were more OT posts that have been removed for some reason or other)

Going by what he wrote he is in some way involved in the investigation.
So there is a chance that information posted clashed with his professional activity.
Murphy is an optimist
 
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7BOEING7
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 5:35 pm

mjoelnir wrote:

They would not republish it, if they would not agree with it.


They “republished” it because it’s news. If they published articles based whether they agreed with them or not and whether they wanted to bash somebody or not they would have been out of business long ago in this city.
 
BravoOne
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 5:40 pm

mjoelnir wrote:
BravoOne wrote:
Seattle newspapers are quite critical of just about anything Boeing does. Certainly not a warm relationship.



A very warm relationship. You do not seem to be used to a newspaper that is critical.


Delete
 
dragon6172
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 5:52 pm

aljrooney wrote:
My own humble thoughts on this and apologies if I have stated something erroneous or badly put.
For me, the issues really started while in the climb out.
MCAS is disabled with the flaps extended so the AoA issue would be masked until the crew went Flaps 0.
So is it possible that when the aircraft nose dropped after retraction that they assumed it was the IAS disagree from the previous flight? A bit of confirmation bias?
That they assumed the IAS was not showing the correct speed for flaps 0 retraction so put the flaps back to Flaps 1, (the last known good), trimmed up and increased thrust after the initial drop of a few hundred feet. Flying pitch and thrust
They then retracted flaps once more and this time with the increased thrust found just some nose trim was required to fly pitch and thrust and still thinking it was an IAS issue and with an eye on not overspeeding, never thinking another system (they allegedly knew nothing about) was misbehaving?
This would also explain the requests to the tower?
As the situation continued, there was a discussion that the Captain's IAS display was at fault (again maybe confirmation bias from what happened to the previous flight) and the CoPilot became PF. However he was less active on the trim, which let the MCAS increase the nose down trim to the point of no return?

I am not a pilot but have been reading all the excellent posts on here and just trying to go through the steps in my head without bringing the runaway trim NNC into it.
It just struck me that the supposed IAS disagree (whether real or not) seems to me more important than thought.

The radio communication transcripts in the preliminary report show that the crew reported to ATC that they were experiencing a flight control problem. It will be interesting from CVR transcripts whether they were working IAS problems or flight control problems.
Phrogs Phorever
 
BEG2IAH
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Feb 05, 2019 6:11 pm

WIederling wrote:
He did not leave. he stopped posting ( on the Lion Air Crash)


OK good. :) Thanks.
Flying at the cruising altitude is (mostly) boring. I wish all flights were nothing but endless take offs and landings every 10 minutes or so.
 
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GEUltraFan9XGTF
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 07, 2019 8:44 pm

Boeing being sued by Seattle firm over Lion Air crash:
https://q13fox.com/2019/03/07/seattle-l ... air-crash/
© 2019. All statements are my own. The use of my statements, including by journalists, YouTube vloggers like "DJ's Aviation", etc. without my written consent is strictly prohibited.
 
jakubz
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Tue Mar 12, 2019 8:13 pm

KORD>RJAA>KORD day trip? Why not! The beauty of non-reving.
Yes, I use ICAO codes
Flown: PA-28, PA-38
Passenger on: A319/A320 737, 747-400, 757, 767, 777, 787-8/9
Finally got on a 747!

I work for United Airlines, but I don't speak for the company.
 
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keesje
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 9:33 am

https://www.bloomberg.com/news/articles/2018-12-11/lion-air-stands-firm-on-canceling-22-billion-boeing-jet-orders

Rusdi Kirana, Co-founder of Lionair says Boeing tried to divert the attention to LionAir aircraft maintenance, away from the MCAS system.

Image

He has also sent a letter to the Chicago-based company outlining his objections to the way the aircraft maker handled the fallout from the first fatal crash of a 737 Max jet, Kirana said in Jakarta.

“It was very cunning and very inappropriate, which I think is without any ethics,” Kirana said, explaining his plan to scrap the orders. “They did it to one of their biggest customers. They created an opinion that we did not maintain our aircraft properly.”
...
Boeing responded with a lengthy statement that, like the report, alluded to but didn’t mention by name a new system on the 737 Max that was activated by erroneous data from a sensor. The software repeatedly tilted the plane’s nose downward as pilots battled for control amid a cacophony of alarms.


I think the handling of the LionAir crash will be reviewed more closely now.

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mandala499
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 5:11 pm

SomebodyinTLS wrote:
mandala499 (who is qualified to answer this, given his position) stated the mechanic was there for routine type-proving purposes.

I think I've explained it enough. Some, refuse to believe or accept that answer, and for them, there's not much else I can do. It is what it is.

SomebodyinTLS wrote:
Thanks - I did find that option, but only after the first search had made me post (incorrectly) that mandala499's posts had been removed.

I am still here. :)

SomebodyinTLS wrote:
I believe we have yet to find any evidence that the AOA sensor was not fixed correctly... mandala499 and others have suggested the very plausible scenario that the problem lies not with the sensor itself but further into the avionics - in which case maintenance are not really at fault since it was not an abvious failure mode.

I still stand by the view that the abovementioned remains a possibility.

BEG2IAH wrote:
I had no idea mandala499 left.

I am still here from time to time. There were not much development since my last post in this topic (Post 2303), except for the CVR being found... much to the relief of everyone.

SheikhDjibouti wrote:
No, not actually left.
But you will find he has declined to post anything since Jan 1st.
Maybe he got a quiet tap on the shoulder after supplying too much inside information? :scratchchin:

I suspect he's watching us now from the wings (so to speak) and patiently waiting for the final report to be published.

That could be a very smart move by him

1. Correct. I did not leave.
2. No, I didn't get a quiet/hard tap on the shoulder for supplying too much inside information. All information written here are either publicly known (either locally, or globally), or are deemed "safe enough to publish".
3. I actually haven't logged in here for a while for various reasons. My computer crashed at one stage, busy at work (which isn't accident investigation), busy with media inquiries on the JT610 crash and other issues in Indonesian aviation (which is a LOT), busy with advising or in my activities in local aviation industry groups, and the lack of developments (except for the CVR being found) that is worth raising discussions on, and last but not least, had a new baby son while I was away from here. So yes, I have a real life outside A.net forums. :) Sometimes, I stepaway from here to focus on that.

BEG2IAH wrote:
He did not leave. he stopped posting ( on the Lion Air Crash)
Posts are available:
search.php?author_id=6531&sr=posts
( no idea if there were more OT posts that have been removed for some reason or other)

Going by what he wrote he is in some way involved in the investigation.
So there is a chance that information posted clashed with his professional activity.

Correct... My last post on this topic was Post 2303... I can still see it. :)

Let me state this:
1. I am NOT involved in the official accident investigation, with the exception of providing raw ADS-B data to the NTSC (done by my colleague, but I have to sign off for permission to surrender that data to the NTSC), and that data has been barred from publication in accordance with the Indonesian Aviation Law articles on "Investigation Data" (yes, received the "lock up order") and I had to use data from other ADS-B sites such as FR24, and several others (including the less obvious) for talking to the media which is painful to me because once I see my own ADS-B data set, I am legally barred from divulging the contents to anyone outside the official investigation.
2. I have some involvement in unofficial investigations, and no confidential information is published. I am not barred in any way from divulging what is not confidential (at the given time).
3. My posts here on the accident has not clashed with my professional activity so far.

The funniest thing so far is for me to be accused publicly (not in this forum) for being a "paid publicity agent paid by Boeing to conduct a cover up"... LOL

Anyway, I logged in to check on the discussions here in light of the ET302 crash... (I'll read that topic after I finish this reply)
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SomebodyInTLS
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 5:21 pm

mandala499 wrote:
and last but not least, had a new baby son while I was away from here.


Congratulations! Genuinely glad to hear you're still around...

Anyway, I logged in to check on the discussions here in light of the ET302 crash... (I'll read that topic after I finish this reply)


Ha ha ha - better pour yourself a stiff drink and be ready for about 24 hours of wading through the cowpoop...
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BirdBrain
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 5:23 pm

mandala499 wrote:
.


Congrats on the baby!
 
WIederling
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 5:40 pm

mandala499 wrote:
SomebodyinTLS wrote:
I believe we have yet to find any evidence that the AOA sensor was not fixed correctly... mandala499 and others have suggested the very plausible scenario that the problem lies not with the sensor itself but further into the avionics - in which case maintenance are not really at fault since it was not an abvious failure mode.

I still stand by the view that the abovementioned remains a possibility.

hey! :-)

Have you seen the info on other pilots ( US and PRC ) having a run in with sensor issues on the MAX?
At least the US ones are said to have gone to the FAA where they seem to have been "composted".
( posted in the Ethiopian Airlines ...crash" and/or I think in the "ground MAX" thread.)
Last edited by WIederling on Wed Mar 13, 2019 5:44 pm, edited 1 time in total.
Murphy is an optimist
 
avier
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 5:43 pm

keesje wrote:

Rusdi Kirana, Co-founder of Lionair says Boeing tried to divert the attention to LionAir aircraft maintenance, away from the MCAS system.



And now Boeing is facing its own Karma...ouch.

They thought they could get away with it. But no, things will get back to them.
 
Curiousflyer
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 6:27 pm

So the CVR data is still a secret???
 
32andBelow
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 6:28 pm

avier wrote:
keesje wrote:

Rusdi Kirana, Co-founder of Lionair says Boeing tried to divert the attention to LionAir aircraft maintenance, away from the MCAS system.



And now Boeing is facing its own Karma...ouch.

They thought they could get away with it. But no, things will get back to them.

How does lion air have any credibility? They crashed NGs just fine.
 
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scbriml
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 6:33 pm

Curiousflyer wrote:
So the CVR data is still a secret???


Yes, it's still being edited. Are you not on the distribution list for daily updates?
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Curiousflyer
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 6:56 pm

The CVR data should be available by now, or at least there should be an explanation for why it is not.
 
StTim
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 7:22 pm

Why must the investigation be conducted in the open.
Initial views may change under analysis.
The important parties will be informed. We, the interested public, have no need to be informed.
 
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PixelFlight
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Wed Mar 13, 2019 9:26 pm

StTim wrote:
Why must the investigation be conducted in the open.
Initial views may change under analysis.
The important parties will be informed. We, the interested public, have no need to be informed.

It used to be so normal: closed investigation. But the interconnected social media world has now reach a point where this might be not appropriate to continue that way in order to maximize credibility. Forum like this has clearly show the trend. Peoples love to understand and/or to speculate on any subjects and there no limitation to ask any question. Not feeding this big demand could be perceived as suspicious, especially regarding raw data like the CVR. The interpretation of the data might change over time, but not the raw data itself. I don't see how closed investigation benefit the professionals of aircraft industry anyway.
 
arfbool
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 7:20 am

SomebodyInTLS wrote:
ikramerica wrote:
3. When something break you fix it

Lion Air attempted 3. After many tries they didn’t get it right.


Woah! Hold it right there...

That is a massive (and AFAIK false) assumption you're making!

I believe we have yet to find any evidence that the AOA sensor was not fixed correctly... mandala499 and others have suggested the very plausible scenario that the problem lies not with the sensor itself but further into the avionics - in which case maintenance are not really at fault since it was not an abvious failure mode.


This. Sorry I'm late coming to this thread and it's practically impossible I can catch up on thousands of posts. But I've tried reading the preliminary accident report (https://reports.aviation-safety.net/201 ... MINARY.pdf) and this FDR data is provided from the accident flight:

Image

You will notice that the altitude, airspeed, and AoA all disagree. The AoA disagrees significantly, by about 20 degrees according to the report, but notice both left and right curves track each other. This seems to indicate both AoA sensors are functioning and providing correct data, but the problem is somewhere downstream in the avionics. This would explain why replacing the AoA sensor did not solve any problem.
 
Armadillo1
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 7:28 am

its about AoA or airspeed sensors (pitot tubes)?
 
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keesje
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 7:43 am

arfbool wrote:
Image


Yeah must be maintenance again :shakehead:

The trimming fight with the unknown(for pilots) MCAS is shocking. And than to realize nothing is mentioned in preliminairy reports (no hard proof) & public opinion was steered towards LionAir maintence and operations track record. I can see why LionAir Management is angry. An independent, seperate ethics investigation into handling and communication on this crash seems in place IMO.
"Never mistake motion for action." Ernest Hemingway
 
StTim
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 8:05 am

As far as I am aware the mechanic who worked it was a passenger on the fatal flight. He was there to provide support for a new frame at the outstation.
 
arfbool
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 8:18 am

keesje wrote:
arfbool wrote:
Image


Yeah must be maintenance again :shakehead:

The trimming fight with the unknown(for pilots) MCAS is shocking. And than to realize nothing is mentioned in preliminairy reports (no hard proof) & public opinion was steered towards LionAir maintence and operations track record. I can see why LionAir Management is angry. An independent, seperate ethics investigation into handling and communication on this crash seems in place IMO.


But what maintenance exactly? According to the report, the AoA sensor was replaced and tested, and based on the FDR, it was working, but with a huge offset. How to fix that, and was that covered in the maintenance manual?

The data shows the MCAS response is so slow, it's possible to fly the plane in spite of its malfunction. The repeating cycle, despite the obvious nuisance, is periodically stable, until suddenly it's not. Why? What changed? The preliminary report also does not state if the trim lock out feature was attempted. Maybe it was, but it didn't work. And in the case of Ethiopian, it seems inconceivable that they would not have been aware how to use the trim lock out, yet their flight took a similar course.
 
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Revelation
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 8:19 am

arfbool wrote:
You will notice that the altitude, airspeed, and AoA all disagree. The AoA disagrees significantly, by about 20 degrees according to the report, but notice both left and right curves track each other. This seems to indicate both AoA sensors are functioning and providing correct data, but the problem is somewhere downstream in the avionics. This would explain why replacing the AoA sensor did not solve any problem.

Take us through this.

We have two sensor readings that differ by a constant value.

How can we say this suggests this is not an issue with one of the two sensors and a "downstream" problem instead?

In either case the disagreement was indicated at zero altitude i.e. while taxiing, and the aircraft had write ups from the earlier flights.

Doesn't this support the idea that the aircraft was not airworthy and should not have flown?
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arfbool
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 8:28 am

I don't know where the problem truly lies. But given that both sensors were responding to changes in angle of attack in the same way throughout the flight (the instantaneous slopes match), the sensor was probably functioning. It was not stuck or producing random or erratic garbage data. Maybe the mechanics missed a simple, crucial calibration or autozero step. Maybe the plane is supposed to cal itself on powerup, but didn't for some reason. For the other sensors, I have no idea what mismatch tolerances are allowed.
 
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Francoflier
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 8:39 am

Revelation wrote:
Doesn't this support the idea that the aircraft was not airworthy and should not have flown?


It's possible, but we would need to know what maintenance procedure was followed, how it was followed, and whether it was the proper maintenance procedure.

What is interesting from this data is that there seems to be fairly constant offset between left and right airspeed and altitude as well...
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juliuswong
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 9:41 am

avier wrote:
keesje wrote:

Rusdi Kirana, Co-founder of Lionair says Boeing tried to divert the attention to LionAir aircraft maintenance, away from the MCAS system.



And now Boeing is facing its own Karma...ouch.

They thought they could get away with it. But no, things will get back to them.

Rusdi Kirana must be sticking his middle fingers at Boeing now. Lolx
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asdf
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 9:45 am

arfbool wrote:
I don't know where the problem truly lies. But given that both sensors were responding to changes in angle of attack in the same way throughout the flight (the instantaneous slopes match), the sensor was probably functioning. It was not stuck or producing random or erratic garbage data. Maybe the mechanics missed a simple, crucial calibration or autozero step. Maybe the plane is supposed to cal itself on powerup, but didn't for some reason. For the other sensors, I have no idea what mismatch tolerances are allowed.


way up the thread someone posted that there is no on-site calibration of the AoA venes
its done in the shop

no idea if that is true
 
RickNRoll
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 10:54 am

Revelation wrote:
arfbool wrote:
You will notice that the altitude, airspeed, and AoA all disagree. The AoA disagrees significantly, by about 20 degrees according to the report, but notice both left and right curves track each other. This seems to indicate both AoA sensors are functioning and providing correct data, but the problem is somewhere downstream in the avionics. This would explain why replacing the AoA sensor did not solve any problem.

Take us through this.

We have two sensor readings that differ by a constant value.

How can we say this suggests this is not an issue with one of the two sensors and a "downstream" problem instead?

In either case the disagreement was indicated at zero altitude i.e. while taxiing, and the aircraft had write ups from the earlier flights.

Doesn't this support the idea that the aircraft was not airworthy and should not have flown?


What is the MEL for AoA sensors?
 
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mfranjic
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 11:00 am


Related to .Lion Air Flight 610

….Image

mandala499 wrote:

… and last but not least, had a new baby son while I was away from here…



I congratulate Your wife (or girlfriend) and You for having become parents and got the God's thrust to raise and nurtur that little creature.
I wish this child to be, as long as You are together in this world, Your joy and the comfort!
God bless You and look out for all of You!


Image.With regard to the noticed similarities and analogy in those two accidents of the Boeing 737 MAX 8 aircraft, I find the grounding of the Boeing 737 MAX aircraft family to be absolutely moral, honest and logical step, regardless of the real validity of the doubt in the safety and reliability of the aircraft. Human lives are more valuable and precious than anything else! People often do not think this way all until accidents happen to someone else and somewhere far away from their homes.
The life is so unpredictable and vulnerable. Today someone's other life story tomorrow can easily become yours.

If the investigation after the crash of the first aircraft was obstructed and pulled in the wrong direction, now, after the accident with the .Ethiopian Airlines Flight 409, it will be maximally hurried and taken in the right one. I do really hope the right solution to any deficiencies in the Image.737 MAX aircraft's system(s) in question will be found soon and applied quickly and correctly.

For those who lost their lives in those tragedies it will be too late. This aircraft took their lives, but I strongly believe it brough their souls to Heaven.
For those who left behind them, it will be a poor consolation. They will continue to live with their pain and endless void in themselves.
For all those who will continue to fly on this aircraft it will mean safety.
Unfortunately, that's the life; for somebody it will always be just too late...

As a human I deeply empathize with all those who lost their close and loved persons in those tragedies. As a devotee and the loyalist of the aviation, I would feel very sad and disapointed to see Boeing 737 ending its lifetime this way. And that will not happen…

Mario
"Only a life lived for others is a life worthwhile" - Albert Einstein
 
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Revelation
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 11:20 am

mfranjic wrote:
Image.With regard to the noticed similarities and analogy in those two accidents of the Boeing 737 MAX 8 aircraft, I find the grounding of the Boeing 737 MAX aircraft family to be absolutely moral, honest and logical step, regardless of the real validity of the doubt in the safety and reliability of the aircraft. Human lives are more valuable and precious than anything else! People often do not think this way all until accidents happen to someone else and somewhere far away from their homes.
The life is so unpredictable and vulnerable. Today someone's other life story tomorrow can easily become yours.

If the investigation after the crash of the first aircraft was obstructed and pulled in the wrong direction, now, after the accident with the .Ethiopian Airlines Flight 409, it will be maximally hurried and taken in the right one. I do really hope the right solution to any deficiencies in the Image.737 MAX aircraft's system(s) in question will be found soon and applied quickly and correctly.

For those who lost their lives in those tragedies it will be too late. This aircraft took their lives, but I strongly believe it brough their souls to Heaven.
For those who left behind them, it will be a poor consolation. They will continue to live with their pain and endless void in themselves.
For all those who will continue to fly on this aircraft it will mean safety.
Unfortunately, that's the life; for somebody it will always be just too late...

As a human I deeply empathize with all those who lost their close and loved persons in those tragedies. As a devotee and the loyalist of the aviation, I would feel very sad and disapointed to see Boeing 737 ending its lifetime this way. And that will not happen…

Mario

Thank you as always for your excellent post. It is hard to find the right balance between the concern for the victims and those who loved them, and the desire/need to know what happened and why. You've done an excellent job of striking the right balance.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
RickNRoll
Posts: 1620
Joined: Fri Jan 06, 2012 9:30 am

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 11:31 am

There is a warning system on the 737Max that warns if the AoA sensors disagree. It's an Optional Extra.
 
dragon6172
Posts: 1068
Joined: Sat Jul 14, 2007 9:56 am

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 12:51 pm

arfbool wrote:

But what maintenance exactly? According to the report, the AoA sensor was replaced and tested, and based on the FDR, it was working, but with a huge offset. How to fix that, and was that covered in the maintenance manual?

The data shows the MCAS response is so slow, it's possible to fly the plane in spite of its malfunction. The repeating cycle, despite the obvious nuisance, is periodically stable, until suddenly it's not. Why? What changed? The preliminary report also does not state if the trim lock out feature was attempted. Maybe it was, but it didn't work. And in the case of Ethiopian, it seems inconceivable that they would not have been aware how to use the trim lock out, yet their flight took a similar course.

It would be nice to see the FDR traces for the flights before the AoA sensor change. I have maintained that the AoA sensor change is part of that swiss cheese. The three flights prior to the AoA change had different discrepancies... similar, but different. They also didn't have any erroneous MCAS inputs, at least none reported. So was the AoA change done properly? Was the installed part bad? Was there enough info provided in the maintenance manuals for the AoA replacement?
Phrogs Phorever
 
buzzard302
Posts: 149
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 12:58 pm

Generally speaking, the two AOA sensors were likely in the same physical positions on the exterior of the plane, and according to the curves, physically reacting in the same manner. There is an obvious offset in the two curves, meaning the sensor output or interpretation likely differed electronically. This could be manufacturing tolerances in the two sensors themselves. I somewhat doubt there would be this much tolerance in the sensors themselves. They would have to be made to very strict tolerances and pass a stringent QC process. It could be programming issues with the system that receives data from the AOA. It could be a calibration procedure during maintenance change out. Only Boeing and the maintenance departments would likely know about a specific calibration procedure.
 
dragon6172
Posts: 1068
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Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 1:16 pm

Image
Image
Image

Better FDR traces with scales marked
Phrogs Phorever
 
User avatar
keesje
Posts: 12807
Joined: Thu Apr 12, 2001 2:08 am

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 2:12 pm

dragon6172 wrote:
Better FDR traces with scales marked


I think it is good these read outs are publicly available now
"Never mistake motion for action." Ernest Hemingway
 
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SomebodyInTLS
Posts: 1633
Joined: Wed Jun 15, 2016 12:31 pm

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 2:42 pm

buzzard302 wrote:
Generally speaking, the two AOA sensors were likely in the same physical positions on the exterior of the plane, and according to the curves, physically reacting in the same manner. There is an obvious offset in the two curves, meaning the sensor output or interpretation likely differed electronically. This could be manufacturing tolerances in the two sensors themselves. I somewhat doubt there would be this much tolerance in the sensors themselves. They would have to be made to very strict tolerances and pass a stringent QC process. It could be programming issues with the system that receives data from the AOA. It could be a calibration procedure during maintenance change out. Only Boeing and the maintenance departments would likely know about a specific calibration procedure.


From memory, the offset appears *after* the start of FDR recording. That means it is *not* a physical calibration error.
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
buzzard302
Posts: 149
Joined: Sat Jun 06, 2015 12:06 pm

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 3:06 pm

SomebodyInTLS wrote:
buzzard302 wrote:
Generally speaking, the two AOA sensors were likely in the same physical positions on the exterior of the plane, and according to the curves, physically reacting in the same manner. There is an obvious offset in the two curves, meaning the sensor output or interpretation likely differed electronically. This could be manufacturing tolerances in the two sensors themselves. I somewhat doubt there would be this much tolerance in the sensors themselves. They would have to be made to very strict tolerances and pass a stringent QC process. It could be programming issues with the system that receives data from the AOA. It could be a calibration procedure during maintenance change out. Only Boeing and the maintenance departments would likely know about a specific calibration procedure.


From memory, the offset appears *after* the start of FDR recording. That means it is *not* a physical calibration error.


Can you clarify what you mean? If I recall correctly, I have seen mention that FDR stores many hours of data, including that of previous flights. Are you saying the offset was 0 up until some point later after take off of the ill fated flight?

If it is not a physical calibration error, it would lend itself to be an electronic issue. Perhaps a specific set of circumstances induces a digital offset for some reason. Circumstances that were unpredictable during the design phase of the control system. All speculation and just talking out loud on my part.
 
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SomebodyInTLS
Posts: 1633
Joined: Wed Jun 15, 2016 12:31 pm

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 3:44 pm

buzzard302 wrote:
Can you clarify what you mean? If I recall correctly, I have seen mention that FDR stores many hours of data, including that of previous flights. Are you saying the offset was 0 up until some point later after take off of the ill fated flight?

If it is not a physical calibration error, it would lend itself to be an electronic issue. Perhaps a specific set of circumstances induces a digital offset for some reason. Circumstances that were unpredictable during the design phase of the control system. All speculation and just talking out loud on my part.


That's what I'm saying, yes. I could be wrong - I'm not as knowledgeable as others on here and I'm not in a position to look at the charts at the moment (firewall means that e.g. dragon6172's charts are blocked for me), but IIRC (it's been a few months) the discrepancy was minimal while airspeed was building up then jumped soon after or during take off.

Assuming the calibration is such that it can't slip once set, that would seem to indicate a physical problem with the AoA instrument (a bit coincidental if original and replacement both had such issues, and IIRC both had checked out OK on the ground) or something happening to the signal/data further down the line.
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
WIederling
Posts: 8357
Joined: Sun Sep 13, 2015 2:15 pm

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 4:00 pm

dragon6172 wrote:
arfbool wrote:

But what maintenance exactly? According to the report, the AoA sensor was replaced and tested, and based on the FDR, it was working, but with a huge offset. How to fix that, and was that covered in the maintenance manual?

The data shows the MCAS response is so slow, it's possible to fly the plane in spite of its malfunction. The repeating cycle, despite the obvious nuisance, is periodically stable, until suddenly it's not. Why? What changed? The preliminary report also does not state if the trim lock out feature was attempted. Maybe it was, but it didn't work. And in the case of Ethiopian, it seems inconceivable that they would not have been aware how to use the trim lock out, yet their flight took a similar course.

It would be nice to see the FDR traces for the flights before the AoA sensor change. I have maintained that the AoA sensor change is part of that swiss cheese. The three flights prior to the AoA change had different discrepancies... similar, but different. They also didn't have any erroneous MCAS inputs, at least none reported. So was the AoA change done properly? Was the installed part bad? Was there enough info provided in the maintenance manuals for the AoA replacement?


The data values that are handed down stream appears to be a computed synthetic value.
( AoA, airspeed, barometric height ) if they show different divergence from cold start to cold start
there is an initialization problem in the software that does the synthesizing heuristics.
i.e. some intermediate value used programatically is not initialized and inserts random but constant
offsets into the data passed downstream. No idea if this value is always positive or +- .
If MCAS sees the compromised synthetic AoA it will do nothing on too low and jump into action on too high input.
( open if both path ( left right ) are hit by the same problem. But only one (the current active ) sensor and only a + signed error are dangerous.
Murphy is an optimist
 
smartplane
Posts: 905
Joined: Fri Aug 03, 2018 9:23 pm

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 5:57 pm

RickNRoll wrote:
There is a warning system on the 737Max that warns if the AoA sensors disagree. It's an Optional Extra.

Certification loophole. Optional extras are discounted from grandfathering formula. If standard, questions would be asked why, whats changed from earlier models.....................
 
SteinarN
Posts: 150
Joined: Mon Dec 29, 2014 1:26 pm

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 6:13 pm

mfranjic wrote:

Related to .Lion Air Flight 610

….Image

mandala499 wrote:

… and last but not least, had a new baby son while I was away from here…



I congratulate Your wife (or girlfriend) and You for having become parents and got the God's thrust to raise and nurtur that little creature.
I wish this child to be, as long as You are together in this world, Your joy and the comfort!
God bless You and look out for all of You!


Image.With regard to the noticed similarities and analogy in those two accidents of the Boeing 737 MAX 8 aircraft, I find the grounding of the Boeing 737 MAX aircraft family to be absolutely moral, honest and logical step, regardless of the real validity of the doubt in the safety and reliability of the aircraft. Human lives are more valuable and precious than anything else! People often do not think this way all until accidents happen to someone else and somewhere far away from their homes.
The life is so unpredictable and vulnerable. Today someone's other life story tomorrow can easily become yours.

If the investigation after the crash of the first aircraft was obstructed and pulled in the wrong direction, now, after the accident with the .Ethiopian Airlines Flight 409, it will be maximally hurried and taken in the right one. I do really hope the right solution to any deficiencies in the Image.737 MAX aircraft's system(s) in question will be found soon and applied quickly and correctly.

For those who lost their lives in those tragedies it will be too late. This aircraft took their lives, but I strongly believe it brough their souls to Heaven.
For those who left behind them, it will be a poor consolation. They will continue to live with their pain and endless void in themselves.
For all those who will continue to fly on this aircraft it will mean safety.
Unfortunately, that's the life; for somebody it will always be just too late...

As a human I deeply empathize with all those who lost their close and loved persons in those tragedies. As a devotee and the loyalist of the aviation, I would feel very sad and disapointed to see Boeing 737 ending its lifetime this way. And that will not happen…

Mario


Thanks for a very thoughtfull post!

I remember you well from several years ago when you was posting in the A380 production tread. It was always (and still is) such a joy reading you. Your style of writing- and your personality which your writing reveals - has such a calming and soothing effect in a stressfull world.

I hope to see you here regularly in the future :)

Almost forgot, so nice to learn you have got a son. Congratulations! I truly wish you and your wife and son a very happy life in the coming years.

Steinar
 
WIederling
Posts: 8357
Joined: Sun Sep 13, 2015 2:15 pm

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 6:45 pm

smartplane wrote:
RickNRoll wrote:
There is a warning system on the 737Max that warns if the AoA sensors disagree. It's an Optional Extra.

Certification loophole. Optional extras are discounted from grandfathering formula. If standard, questions would be asked why, whats changed from earlier models.....................


Interesting to know. ( who ordered the option and did they get a hint to better order that too ? )
Murphy is an optimist
 
RickNRoll
Posts: 1620
Joined: Fri Jan 06, 2012 9:30 am

Re: Lion Air 737MAX8 Crashed Jakarta to Pangkal Pinang

Thu Mar 14, 2019 6:46 pm

smartplane wrote:
RickNRoll wrote:
There is a warning system on the 737Max that warns if the AoA sensors disagree. It's an Optional Extra.

Certification loophole. Optional extras are discounted from grandfathering formula. If standard, questions would be asked why, whats changed from earlier models.....................


That is bizarre. MCAS depends on them being accurate yet there is no mention of the requirement for them to be functioning correctly for MCAS to work correctly. A massive hole in the cheese right there which any normal safety analysis should have picked up.

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