mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 8:40 pm

American Airlines Extends Boeing 737 Max Flight Cancellations

https://www.huffpost.com/entry/boeing-7 ... e34778d327

AA is removing the MAX out of their flight plan through the 3rd of September.

For those who do not like Huffpost

The same news on the Seattle times
https://www.seattletimes.com/business/b ... gh-sept-3/
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 8:43 pm

planecane wrote:
aerolimani wrote:
XRAYretired wrote:

Why dispute what he is quoted as saying and then get it wrong when the quote is readily available?
https://www.bbc.co.uk/news/business-48461110

This is the Chris Brady Quote-
Chris Brady, a pilot and author of The Boeing 737 Technical Guide said: "I'm fairly confident that the Ethiopian Airlines flight probably would not have crashed if they had had the AOA disagree alert" on the aircraft.

This is the reporters appreciation of his interview-
Mr Brady believes that if there had been an alert warning light showing that the AOA sensors were giving different readings, then the pilots might have followed an emergency procedure at an earlier point in the doomed flight.

These are a few possibilities I posted earlier, perhaps you missed them-
AOA DISAGREE would have been displayed from 05:39:00 (a full minute before MCAS activation), at the latest, and in presence of single side stick shaker may have helped conclude that stick shaker was erroneous more quickly. With IAS and ALT DISGREE also probably present, the crew may have been alerted to the possibility of the MCAS problem, looking out for it and acting more quickly when it engaged. They may even have elected to CUT-OUT stab trim prior to MCAS engaging, at a push. They may have elected to keep flaps extended and pulled back the thrust. (Although may they still have retracted flaps because it was still not communicated as a condition of MCAS activation in the documents).

The point is that they were not given the chance because the display was not available.

Ray

Short version: they might have hit stab trim cutout before MCAS activated, and before the aircraft was out of trim.


Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.


So what is your opinion about what causes the MCAS failure mode other that an defect AoA sensor?

There is no NNC procedure about the AoA warning on the MAX, because Boeing was hiding MCAS and its deadly failure mode.
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 8:46 pm

14ccKemiskt wrote:
Of course the disagree light fuss is a Red Herring.

You have to ask yourself why Boeing is so quick to accept blame for the non-functioning AoA disagree light. They know that they easily can prove that the light would have made little difference in the two crashes and hence they'd rather have people talking about that than the real problem.

And they kind of succed, both the media along with a big part of this thread is now focusing on that instead of what should really be focused on: Why they released MCAS only connected to a single AoA sensor. Why they did that might be the single most important part of this story and if the paper trail shows that it was because what the whistleblower in 60 minutes Australia claims, then Boeing could be in really big trouble.


Boeing are so quick to accept blame for the disagree light because they are entirely to blame for it not working??

They've got zero choice on that
 
StTim
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 8:48 pm

STT757 wrote:
StTim wrote:
STT757 wrote:

I don’t think it would be beneficial to anyone to deviate now from past practices of the FAA and EASA accepting each other’s certifications. Not with Captain tariffs in the White House. Airbus depends heavily on the US market.


This seriously sounds like a threat - Do as the US says or we will cause problems. Not the way to resolve this situation.


That was my point. Look at how this administration deals with diplomacy.


Sent from my iPhone using Tapatalk Pro


Well I for one hope EASA do the right thing which is to lift the grounding if, and only if, they are completely satisfied with the fixes.

I think it will fly again and in the interests of safety it must be done correctly. Stand up to the bullies if necessary.
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 8:49 pm

mjoelnir wrote:
planecane wrote:
aerolimani wrote:
Short version: they might have hit stab trim cutout before MCAS activated, and before the aircraft was out of trim.


Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.


So what is your opinion about what causes the MCAS failure mode other that an defect AoA sensor?

There is no NNC procedure about the AoA warning on the MAX, because Boeing was hiding MCAS and its deadly failure mode.


That's how ridiculous this actually all is
 
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:13 pm

ArgentoSystems wrote:
zippy wrote:
OldAeroGuy wrote:
Even CNN's Richard Quest has described not having the "AOA DISAGREE" Alert issue as a red herring.


The problem isn't so much that not having a working annunciator is a catastrophic problem.

+1. The problem is that it is yet another thing that Boeing did that defies reason.

-1.
Without the accident(s), this would probably not even be an AD.
It is a oversight of small proportions, that became was made huge because of other, rather unrelated issues.
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:19 pm

mjoelnir wrote:
The alarm that points out a failure in the sensor that triggers MCAS, is to be completely disregarded? It does not matter if this alarm is active or not? Tell more of this jokes.


Yet, the alarm is basically useless without crews having sufficient insight into MCAS and it deeper workings.

The problem is not this AoA disagree thing missing. The problem is a) Boeing not implementing MCAS first time right, and b) not telling/training pilots how it works and how to deal with its failure scenarios.
Only when a) and b) have been taking care of, only then c) AoA disagree message becomes relevant in terms of the accident(s). But since a) and b) were not available to the crews, c) is pretty much irrelevant in terms of these accident(s).
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:22 pm

sillystrings wrote:
Wouldn't it be logical to look for AOA DISAGREE if one suspects MCAS is misfiring?

OInly when one has sufficient understanding of MCAS and its deeper workings. Neither of which was not available nor trained to the accident crews.
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:30 pm

aerolimani wrote:
Short version: they might have hit stab trim cutout before MCAS activated, and before the aircraft was out of trim.

Would a pilot take away an important control function (i.e. manual electric trimming) if he/she does not yet know if MCAS will fail, especially when he/she does not understand the inner working of MCAS? This really is bordering, if not crossing into hindsight knowledge territory.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:34 pm

Interested wrote:
mjoelnir wrote:
planecane wrote:

Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.


So what is your opinion about what causes the MCAS failure mode other that an defect AoA sensor?

There is no NNC procedure about the AoA warning on the MAX, because Boeing was hiding MCAS and its deadly failure mode.


That's how ridiculous this actually all is

Indeed. With an AOA disagree, MCAS should have been prevented from operating in the first place.

Or, post-Lion Air, should pilots at least have been directed to run the runaway stab NNC upon observing AOA disagree warning? Oh, right. That wouldn’t have worked, because Boeing already knew the warning didn’t show in all the Max aircraft.

Apparently, it was better to let a known system put the plane out of trim, and force the pilots to deal with it, than to design a plane correctly in the first place.
 
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par13del
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:39 pm

Dieuwer wrote:
The recertification seem to drag on forever. So much for this magical "quick fix".

What recertification?
We know Boeing came up with their software fix, tested it and finally submitted to the FAA for review and approval.

Ok, maybe I need clarity, when you say recertification, are you talking about the initial certification of the MAX a few years ago or the certification of the fix to allow the a/c to return to flight?
 
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aerolimani
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:41 pm

PW100 wrote:
aerolimani wrote:
Short version: they might have hit stab trim cutout before MCAS activated, and before the aircraft was out of trim.

Would a pilot take away an important control function (i.e. manual electric trimming) if he/she does not yet know if MCAS will fail, especially when he/she does not understand the inner working of MCAS? This really is bordering, if not crossing into hindsight knowledge territory.

It probably is crossing into hindsight territory. Rather, it highlights the problems with Boeing not explaining MCAS properly, in its avoidance of properly training pilots. People can harp on all they want about “worldwide training deficiencies,” but the biggest training deficiency seems to originate at Boeing.
 
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par13del
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:53 pm

StTim wrote:
Well I for one hope EASA do the right thing which is to lift the grounding if, and only if, they are completely satisfied with the fixes.

How do you suggest they do that, have a MAX shipped to Europe by barge so that EASA personnel can verify and test everything?
In this environment, it makes no sense to have EASA personnel in the USA since Boeing is in charge of everything, tells the FAA what to do and hides information that is damaging to Boeing. EASA does not have the local law enforcement authority to issue demands for info or compel testimony.
Since EASA will not work with the FAA who will they work with, if they do not have the resources will they use Airbus personnel?

On the other hand, if we throw the rhetoric out the window and accept reality, EASA and other international authorities will have to work with the USA authorities to get the issue resolved. It is interesting that we are getting all this information out here of what Boeing did and did not do yet we still cannot get all the information about the two fatal crashes so more informed decisions can be made by the public, has the media already moved on and decided we know all we need to know?
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 9:58 pm

mjoelnir wrote:
planecane wrote:
aerolimani wrote:
Short version: they might have hit stab trim cutout before MCAS activated, and before the aircraft was out of trim.


Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.


So what is your opinion about what causes the MCAS failure mode other that an defect AoA sensor?

There is no NNC procedure about the AoA warning on the MAX, because Boeing was hiding MCAS and its deadly failure mode.


My point was that all AoA disagree situations would not have led to an MCAS runaway. Either the failed sensor could still read an AoA less than the activation trigger or the failed sensor could be on the non-active side for MCAS.
 
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aerolimani
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 10:50 pm

par13del wrote:
StTim wrote:
Well I for one hope EASA do the right thing which is to lift the grounding if, and only if, they are completely satisfied with the fixes.

How do you suggest they do that, have a MAX shipped to Europe by barge so that EASA personnel can verify and test everything?
In this environment, it makes no sense to have EASA personnel in the USA since Boeing is in charge of everything, tells the FAA what to do and hides information that is damaging to Boeing. EASA does not have the local law enforcement authority to issue demands for info or compel testimony.
Since EASA will not work with the FAA who will they work with, if they do not have the resources will they use Airbus personnel?

On the other hand, if we throw the rhetoric out the window and accept reality, EASA and other international authorities will have to work with the USA authorities to get the issue resolved. It is interesting that we are getting all this information out here of what Boeing did and did not do yet we still cannot get all the information about the two fatal crashes so more informed decisions can be made by the public, has the media already moved on and decided we know all we need to know?

If the EASA wants to test the 737MAX on their own it’s pretty easy. They can issue ferry permits, for one. But, since we’re talking about a software fix, the update can be sent electronically, and then the EASA can use any of the planes already parked in the EU.

Does EASA doing some of their own certification work preclude them from also working with the FAA?
 
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7BOEING7
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun Jun 09, 2019 11:52 pm

aerolimani wrote:
par13del wrote:
StTim wrote:
Well I for one hope EASA do the right thing which is to lift the grounding if, and only if, they are completely satisfied with the fixes.

How do you suggest they do that, have a MAX shipped to Europe by barge so that EASA personnel can verify and test everything?
In this environment, it makes no sense to have EASA personnel in the USA since Boeing is in charge of everything, tells the FAA what to do and hides information that is damaging to Boeing. EASA does not have the local law enforcement authority to issue demands for info or compel testimony.
Since EASA will not work with the FAA who will they work with, if they do not have the resources will they use Airbus personnel?

On the other hand, if we throw the rhetoric out the window and accept reality, EASA and other international authorities will have to work with the USA authorities to get the issue resolved. It is interesting that we are getting all this information out here of what Boeing did and did not do yet we still cannot get all the information about the two fatal crashes so more informed decisions can be made by the public, has the media already moved on and decided we know all we need to know?

If the EASA wants to test the 737MAX on their own it’s pretty easy. They can issue ferry permits, for one. But, since we’re talking about a software fix, the update can be sent electronically, and then the EASA can use any of the planes already parked in the EU.

Does EASA doing some of their own certification work preclude them from also working with the FAA?


Or has been done previously, they can just send their pilots to Seattle if they need an inflight demonstration. Same with other regulatory bodies that have a flight crew. Don’t have to worry about doing stalls on a non- instrumented airframe that way also.
 
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par13del
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 12:17 am

aerolimani wrote:
Does EASA doing some of their own certification work preclude them from also working with the FAA?

Well StTim wants EASA to do it right, so what do you think?
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 12:54 am

planecane wrote:
aerolimani wrote:
XRAYretired wrote:

Why dispute what he is quoted as saying and then get it wrong when the quote is readily available?
https://www.bbc.co.uk/news/business-48461110

This is the Chris Brady Quote-
Chris Brady, a pilot and author of The Boeing 737 Technical Guide said: "I'm fairly confident that the Ethiopian Airlines flight probably would not have crashed if they had had the AOA disagree alert" on the aircraft.

This is the reporters appreciation of his interview-
Mr Brady believes that if there had been an alert warning light showing that the AOA sensors were giving different readings, then the pilots might have followed an emergency procedure at an earlier point in the doomed flight.

These are a few possibilities I posted earlier, perhaps you missed them-
AOA DISAGREE would have been displayed from 05:39:00 (a full minute before MCAS activation), at the latest, and in presence of single side stick shaker may have helped conclude that stick shaker was erroneous more quickly. With IAS and ALT DISGREE also probably present, the crew may have been alerted to the possibility of the MCAS problem, looking out for it and acting more quickly when it engaged. They may even have elected to CUT-OUT stab trim prior to MCAS engaging, at a push. They may have elected to keep flaps extended and pulled back the thrust. (Although may they still have retracted flaps because it was still not communicated as a condition of MCAS activation in the documents).

The point is that they were not given the chance because the display was not available.

Ray

Short version: they might have hit stab trim cutout before MCAS activated, and before the aircraft was out of trim.


Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.

Actually looking at it as a system... Just poor design all over.
An indicator for event trigger is deemed uniportant. It should send to tw other checklists, none of them covering critical aspect of a problem. Problem diagnostics is reduced to guessing..
I know Boeing had been great few decades ago, but overall seems engineering avalanching downhill. Following footsteps of IBM?...
 
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7BOEING7
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 1:03 am

kalvado wrote:
planecane wrote:
aerolimani wrote:
Short version: they might have hit stab trim cutout before MCAS activated, and before the aircraft was out of trim.


Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.

Actually looking at it as a system... Just poor design all over.
An indicator for event trigger is deemed uniportant. It should send to tw other checklists, none of them covering critical aspect of a problem. Problem diagnostics is reduced to guessing..
I know Boeing had been great few decades ago, but overall seems engineering avalanching downhill. Following footsteps of IBM?...


An IAS DISAGREE amber alert is staring you in the face — you do the Airspeed Unreliable NNC which is memory items, very simple.
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 1:06 am

planecane wrote:
mjoelnir wrote:
planecane wrote:

Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.


So what is your opinion about what causes the MCAS failure mode other that an defect AoA sensor?

There is no NNC procedure about the AoA warning on the MAX, because Boeing was hiding MCAS and its deadly failure mode.


My point was that all AoA disagree situations would not have led to an MCAS runaway. Either the failed sensor could still read an AoA less than the activation trigger or the failed sensor could be on the non-active side for MCAS.


So you would trust the likelihood of it not going active? Is your hobby walking through a minefield or playing Russian roulette?
 
ArgentoSystems
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 2:44 am

PW100 wrote:
Without the accident(s), this would probably not even be an AD.

True that. Without the accidents Boeing would've quietly fixed it in 2020 and no one would've even known there was a defect in the first place.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 2:53 am

7BOEING7 wrote:
kalvado wrote:
planecane wrote:

Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.

Actually looking at it as a system... Just poor design all over.
An indicator for event trigger is deemed uniportant. It should send to tw other checklists, none of them covering critical aspect of a problem. Problem diagnostics is reduced to guessing..
I know Boeing had been great few decades ago, but overall seems engineering avalanching downhill. Following footsteps of IBM?...


An IAS DISAGREE amber alert is staring you in the face — you do the Airspeed Unreliable NNC which is memory items, very simple.

It’s interesting that this idea is found only in forums, and has never been reported in any media I can find. Why is that, do you suppose?

The most damning article I have ever found is this one: https://www.forbes.com/sites/jeremyboga ... rocedures/
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 6:13 am

ArgentoSystems wrote:
PW100 wrote:
Without the accident(s), this would probably not even be an AD.

True that. Without the accidents Boeing would've quietly fixed it in 2020 and no one would've even known there was a defect in the first place.


And isn't that exactly what Boeing were hoping they could get away with?
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 9:45 am

aerolimani wrote:
7BOEING7 wrote:
kalvado wrote:
Actually looking at it as a system... Just poor design all over.
An indicator for event trigger is deemed uniportant. It should send to tw other checklists, none of them covering critical aspect of a problem. Problem diagnostics is reduced to guessing..
I know Boeing had been great few decades ago, but overall seems engineering avalanching downhill. Following footsteps of IBM?...


An IAS DISAGREE amber alert is staring you in the face — you do the Airspeed Unreliable NNC which is memory items, very simple.

It’s interesting that this idea is found only in forums, and has never been reported in any media I can find. Why is that, do you suppose?

The most damning article I have ever found is this one: https://www.forbes.com/sites/jeremyboga ... rocedures/

Media tries to filter out acute idiocy. Not that they do a good job, and certainly not when they are paid for it, but we can give them done credit for trying.
 
AIRT0M
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 10:52 am

mjoelnir wrote:
American Airlines Extends Boeing 737 Max Flight Cancellations

https://www.huffpost.com/entry/boeing-7 ... e34778d327

AA is removing the MAX out of their flight plan through the 3rd of September.

For those who do not like Huffpost

The same news on the Seattle times
https://www.seattletimes.com/business/b ... gh-sept-3/



Ridiculous. According to our a.net experts, the Max will be back in the air by the end of the week/in April/in May/in July for sure ...
 
sillystrings
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 11:09 am

PW100 wrote:
sillystrings wrote:
Wouldn't it be logical to look for AOA DISAGREE if one suspects MCAS is misfiring?

OInly when one has sufficient understanding of MCAS and its deeper workings. Neither of which was not available nor trained to the accident crews.

Once again. The subject line of the pertinent NNC bulletin states: "Uncommanded Nose Down Stabilizer Trim Due to Erroneous Angle of Attack (AOA) During Manual Flight Only".
Additionally the background info states :"The Indonesian National Transportation Safety Committee has indicated that Lion Air flight 610 experienced erroneous AOA data. Boeing would like to call attention to an AOA failure condition that can occur during manual flight only. This bulletin directs flight crews to existing procedures to address this condition.In the event of erroneous AOA data, the pitch trim system can trim the stabilizer nose down in increments lasting up to 10 seconds."
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 11:24 am

ArgentoSystems wrote:
PW100 wrote:
Without the accident(s), this would probably not even be an AD.

True that. Without the accidents Boeing would've quietly fixed it in 2020 and no one would've even known there was a defect in the first place.

Not so certain. My understanding is that the 2020 planed fix was for the AoA disagree indicator only. The MCAS nose down from a single erratic high AoA value would have stay. This would be different if there planned to use to AoA disagree indicator to disable the MCAS, but I did not read something like that. The MCASv2 most probably use his own intern algorithm to compare the AoA values and don't directly rely on the AoA disagree indicator as an input.
 
RickNRoll
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 12:03 pm

aerolimani wrote:
7BOEING7 wrote:
kalvado wrote:
Actually looking at it as a system... Just poor design all over.
An indicator for event trigger is deemed uniportant. It should send to tw other checklists, none of them covering critical aspect of a problem. Problem diagnostics is reduced to guessing..
I know Boeing had been great few decades ago, but overall seems engineering avalanching downhill. Following footsteps of IBM?...


An IAS DISAGREE amber alert is staring you in the face — you do the Airspeed Unreliable NNC which is memory items, very simple.

It’s interesting that this idea is found only in forums, and has never been reported in any media I can find. Why is that, do you suppose?

The most damning article I have ever found is this one: https://www.forbes.com/sites/jeremyboga ... rocedures/
I have wondered by Boeing didn't put it in the EAD. Perhaps they felt they couldn't since the AoA disagree warning wasn't active. Since the lion air incident happened right after take off it would have been much safer to tell pilots to make sure they follow UAS procedure which would have had the huge advantage of not waiting for MCAS to kick in.
 
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SomebodyInTLS
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 12:31 pm

par13del wrote:
StTim wrote:
Well I for one hope EASA do the right thing which is to lift the grounding if, and only if, they are completely satisfied with the fixes.

How do you suggest they do that, have a MAX shipped to Europe by barge so that EASA personnel can verify and test everything?
In this environment, it makes no sense to have EASA personnel in the USA since Boeing is in charge of everything, tells the FAA what to do and hides information that is damaging to Boeing. EASA does not have the local law enforcement authority to issue demands for info or compel testimony.
Since EASA will not work with the FAA who will they work with, if they do not have the resources will they use Airbus personnel?

On the other hand, if we throw the rhetoric out the window and accept reality, EASA and other international authorities will have to work with the USA authorities to get the issue resolved. It is interesting that we are getting all this information out here of what Boeing did and did not do yet we still cannot get all the information about the two fatal crashes so more informed decisions can be made by the public, has the media already moved on and decided we know all we need to know?


I expect all the authorities have delegates who frequently visit manufacturers all round the world... Don't know why you'd think otherwise...
"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."
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 12:43 pm

RickNRoll wrote:
I have wondered by Boeing didn't put it in the EAD.


It is in the EAD, along with a list of other symptoms.

Here's a portion of the EAD along with indications that would have been present shortly after liftoff for ET302 are shown in BOLD.
AOA DISAGREE is shown in italic.

737 MAX EAD 2018-23-51 lists these symptoms for potential erroneous MCAS operation:

Continuous or intermittent stick shaker on the affected side only
Minimum speed bar (red and black) on the affected side only
Increasing nose down control forces
IAS DISAGREE alert
ALT DISAGREE alert

AOA DISAGREE alert (if the option is installed)
FEEL DIFF PRESS light
Auto pilot may disengage
Inability to engage the autopilot

In terms of criticality, stick shaker and IAS DISAGREE would have had a higher pilot action priority than AOA DISAGREE.

There has been no evidence that NNC's were performed for either condition.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 12:44 pm

PixelFlight wrote:
ArgentoSystems wrote:
PW100 wrote:
Without the accident(s), this would probably not even be an AD.

True that. Without the accidents Boeing would've quietly fixed it in 2020 and no one would've even known there was a defect in the first place.

Not so certain. My understanding is that the 2020 planed fix was for the AoA disagree indicator only.

Yes. I was referring to fixing missing AoA indicator only.
 
XRAYretired
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 12:52 pm

RickNRoll wrote:
aerolimani wrote:
7BOEING7 wrote:

An IAS DISAGREE amber alert is staring you in the face — you do the Airspeed Unreliable NNC which is memory items, very simple.

It’s interesting that this idea is found only in forums, and has never been reported in any media I can find. Why is that, do you suppose?

The most damning article I have ever found is this one: https://www.forbes.com/sites/jeremyboga ... rocedures/
I have wondered by Boeing didn't put it in the EAD. Perhaps they felt they couldn't since the AoA disagree warning wasn't active. Since the lion air incident happened right after take off it would have been much safer to tell pilots to make sure they follow UAS procedure which would have had the huge advantage of not waiting for MCAS to kick in.

There is no reason to presume that AIRSPEED UNRELIABLE NNC was not attempted in any of the three flights. This presumption is the position of the 'blame the pilots' mob.

Ray
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 2:13 pm

OldAeroGuy wrote:
RickNRoll wrote:
I have wondered by Boeing didn't put it in the EAD.


It is in the EAD, along with a list of other symptoms.

Here's a portion of the EAD along with indications that would have been present shortly after liftoff for ET302 are shown in BOLD.
AOA DISAGREE is shown in italic.

737 MAX EAD 2018-23-51 lists these symptoms for potential erroneous MCAS operation:

Continuous or intermittent stick shaker on the affected side only
Minimum speed bar (red and black) on the affected side only
Increasing nose down control forces
IAS DISAGREE alert
ALT DISAGREE alert

AOA DISAGREE alert (if the option is installed)
FEEL DIFF PRESS light
Auto pilot may disengage
Inability to engage the autopilot

In terms of criticality, stick shaker and IAS DISAGREE would have had a higher pilot action priority than AOA DISAGREE.

There has been no evidence that NNC's were performed for either condition.


Behind AoA disagree you write, "if option is installed" is that so written somewhere in the manuals?

Because AoA disagree is not an option. It is standard and declared so in the manuals The thing is only that it is missing and Boeing knowing that, did not tell either the FAA or the customers.

If Boeing were suddenly talking about an option, they had been lying before that, selling something as a standard without any thought about providing it.
I also assume the MAX was certified with AoA disagree as a standard. We have to assume that most MAX delivered to customers, were not equipped to the certified standard.
 
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 4:10 pm

7BOEING7 wrote:
kalvado wrote:
planecane wrote:

Except there is no NNC procedure that said to do that on AoA disagree warning. Just an AoA disagree doesn't mean MCAS would cause runaway.

Actually looking at it as a system... Just poor design all over.
An indicator for event trigger is deemed uniportant. It should send to tw other checklists, none of them covering critical aspect of a problem. Problem diagnostics is reduced to guessing..
I know Boeing had been great few decades ago, but overall seems engineering avalanching downhill. Following footsteps of IBM?...


An IAS DISAGREE amber alert is staring you in the face — you do the Airspeed Unreliable NNC which is memory items, very simple.

If it was that simple, we wouldn't have this thread.

It would be that simple if the IAS DISAGREE was the only thing staring in their face. However at the same time they also had stick shaker going off, stall warning, anti-ice master caution, and probably several other warnings, cautions and alert messages as well. How do you arrive at the conclusion that this is a simple thing and Airspeed Unreliable NNC would be top priority? (IINM, we have been told in this thread that this NNC includes reducing N1 to around 83%, which sound like really bad idea just after lift off with stick shaker and stall warning going off).
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 4:14 pm

Interested wrote:
ArgentoSystems wrote:
PW100 wrote:
Without the accident(s), this would probably not even be an AD.

True that. Without the accidents Boeing would've quietly fixed it in 2020 and no one would've even known there was a defect in the first place.


And isn't that exactly what Boeing were hoping they could get away with?


It has nothing to do with getting away with, as every change Boeing initiates is validated through FAA. This is just part of every day life and continous improvements.

While Boeing has lots of xplainings to do on so many levels, this one is fairly low at their list. But I guess some see a bear behind every tree . . .
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7BOEING7
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 4:32 pm

PW100 wrote:
7BOEING7 wrote:
kalvado wrote:
Actually looking at it as a system... Just poor design all over.
An indicator for event trigger is deemed uniportant. It should send to tw other checklists, none of them covering critical aspect of a problem. Problem diagnostics is reduced to guessing..
I know Boeing had been great few decades ago, but overall seems engineering avalanching downhill. Following footsteps of IBM?...


An IAS DISAGREE amber alert is staring you in the face — you do the Airspeed Unreliable NNC which is memory items, very simple.

If it was that simple, we wouldn't have this thread.

It would be that simple if the IAS DISAGREE was the only thing staring in their face. However at the same time they also had stick shaker going off, stall warning, anti-ice master caution, and probably several other warnings, cautions and alert messages as well. How do you arrive at the conclusion that this is a simple thing and Airspeed Unreliable NNC would be top priority? (IINM, we have been told in this thread that this NNC includes reducing N1 to around 83%, which sound like really bad idea just after lift off with stick shaker and stall warning going off).


Leaving the N1 at takeoff thrust until you're 40 to 60 kts +\- above VMO is a worse idea. With the third memory item (10 seconds maybe) you've determined which airspeed indicator is accurate, can them realize the stick shaker is bogus and proceed from there. The LIon Air crew with the same issues +/- had control of the airplane for several minutes until they stopped trimming.
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 4:37 pm

PW100 wrote:
Interested wrote:
ArgentoSystems wrote:
True that. Without the accidents Boeing would've quietly fixed it in 2020 and no one would've even known there was a defect in the first place.


And isn't that exactly what Boeing were hoping they could get away with?


It has nothing to do with getting away with, as every change Boeing initiates is validated through FAA. This is just part of every day life and continous improvements.

While Boeing has lots of xplainings to do on so many levels, this one is fairly low at their list. But I guess some see a bear behind every tree . . .


Big words, that is why Boeing did not declare to the FAA that a warning message, part of the standard on the MAX, was inoperative. I would say that Boeing is that arrogant, that they feel above the need to ask for validation by the FAA.

It has definitely everything to do with Boeing believing to get away with it.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 4:44 pm

PW100 wrote:
Interested wrote:
ArgentoSystems wrote:
True that. Without the accidents Boeing would've quietly fixed it in 2020 and no one would've even known there was a defect in the first place.


And isn't that exactly what Boeing were hoping they could get away with?


It has nothing to do with getting away with, as every change Boeing initiates is validated through FAA. This is just part of every day life and continous improvements.

While Boeing has lots of xplainings to do on so many levels, this one is fairly low at their list. But I guess some see a bear behind every tree . . .


I didn't think FAA or the airlines were aware of the faulty sensor?

Boeing chose not to tell them!!

That's how bad this all is

Not exactly a bear behind a tree

Shocking stuff really
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 4:47 pm

mjoelnir wrote:
PW100 wrote:
Interested wrote:

And isn't that exactly what Boeing were hoping they could get away with?


It has nothing to do with getting away with, as every change Boeing initiates is validated through FAA. This is just part of every day life and continous improvements.

While Boeing has lots of xplainings to do on so many levels, this one is fairly low at their list. But I guess some see a bear behind every tree . . .


Big words, that is why Boeing did not declare to the FAA that a warning message, part of the standard on the MAX, was inoperative. I would say that Boeing is that arrogant, that they feel above the need to ask for validation by the FAA.

It has definitely everything to do with Boeing believing to get away with it.


Spot on

The Boeing defenders explain stuff so well and simply at times - only for Boeing to have let them down badly when the facts slowly but surely come out

And the difficult stuff they just ignore or walk away from as it comes out

The sensor not working initially came out with everyone assuming it was just a bad error that nobody noticed. Incompetent enough in its own right.

Then a few weeks later it comes out Boeing did notice - they just chose not to tell anybody and planned for it to be fixed in 2020.
 
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keesje
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 5:01 pm

If the goal of putting everything MAX into one mega thread, where nobody can find back anything & 10 sub topics come & come back, to suppress usefull exchange of information, that seems successful. It has become a useless monsterthread. Pitty..
"Never mistake motion for action." Ernest Hemingway
 
LDRA
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 5:03 pm

mjoelnir wrote:
OldAeroGuy wrote:
RickNRoll wrote:
I have wondered by Boeing didn't put it in the EAD.


It is in the EAD, along with a list of other symptoms.

Here's a portion of the EAD along with indications that would have been present shortly after liftoff for ET302 are shown in BOLD.
AOA DISAGREE is shown in italic.

737 MAX EAD 2018-23-51 lists these symptoms for potential erroneous MCAS operation:

Continuous or intermittent stick shaker on the affected side only
Minimum speed bar (red and black) on the affected side only
Increasing nose down control forces
IAS DISAGREE alert
ALT DISAGREE alert

AOA DISAGREE alert (if the option is installed)
FEEL DIFF PRESS light
Auto pilot may disengage
Inability to engage the autopilot

In terms of criticality, stick shaker and IAS DISAGREE would have had a higher pilot action priority than AOA DISAGREE.

There has been no evidence that NNC's were performed for either condition.


Behind AoA disagree you write, "if option is installed" is that so written somewhere in the manuals?

Because AoA disagree is not an option. It is standard and declared so in the manuals The thing is only that it is missing and Boeing knowing that, did not tell either the FAA or the customers.

If Boeing were suddenly talking about an option, they had been lying before that, selling something as a standard without any thought about providing it.
I also assume the MAX was certified with AoA disagree as a standard. We have to assume that most MAX delivered to customers, were not equipped to the certified standard.


Spot on! The fact Boeing was not forthcoming regarding AoA disagree warning in the MCAS AD is extremely damning
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 5:34 pm

PW100 wrote:
Interested wrote:
ArgentoSystems wrote:
True that. Without the accidents Boeing would've quietly fixed it in 2020 and no one would've even known there was a defect in the first place.


And isn't that exactly what Boeing were hoping they could get away with?


It has nothing to do with getting away with, as every change Boeing initiates is validated through FAA. This is just part of every day life and continous improvements.

While Boeing has lots of xplainings to do on so many levels, this one is fairly low at their list. But I guess some see a bear behind every tree . . .


https://www.rt.com/usa/461371-boeing-alert-fix-2020/

Would you like to re-consider your point of view now?
 
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aerolimani
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 5:57 pm

keesje wrote:
If the goal of putting everything MAX into one mega thread, where nobody can find back anything & 10 sub topics come & come back, to suppress usefull exchange of information, that seems successful. It has become a useless monsterthread. Pitty..

However, when things are split up in different threads, you get people copy-and-pasting their own comments across multiple threads, and especially when some posters appear to have very strong agendas. Either way you go, it seems there are some people determined to swing the conversation in one particular direction. So… damned if you do, damned if you don't.

Bring back paid memberships, I say. Perhaps pay-to-play would filter out some junk.
 
morrisond
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 6:09 pm

Interested wrote:
PW100 wrote:
Interested wrote:

And isn't that exactly what Boeing were hoping they could get away with?


It has nothing to do with getting away with, as every change Boeing initiates is validated through FAA. This is just part of every day life and continous improvements.

While Boeing has lots of xplainings to do on so many levels, this one is fairly low at their list. But I guess some see a bear behind every tree . . .


https://www.rt.com/usa/461371-boeing-alert-fix-2020/

Would you like to re-consider your point of view now?


I might be wrong but I don't think Lionair or ET paid for the optional sensors so it would never had worked anyways.

From the RT article

"Pilots were supposed to be alerted about possible problems with the sensors by an AoA Disagree alert, which should light up when data coming from two AoA sensors does not match. But the alert required an optional set of indicators to be installed to actually work, and only 20 percent of the aircraft sold had them."
 
StTim
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 6:09 pm

I wonder if there was any thought process in the ET flight wondering if it was an AoA discrepancy (like the AD warned of) but the pilots noticed that the AoA disagree indicator was not illuminated?
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 6:36 pm

morrisond wrote:
Interested wrote:
PW100 wrote:

It has nothing to do with getting away with, as every change Boeing initiates is validated through FAA. This is just part of every day life and continous improvements.

While Boeing has lots of xplainings to do on so many levels, this one is fairly low at their list. But I guess some see a bear behind every tree . . .


https://www.rt.com/usa/461371-boeing-alert-fix-2020/

Would you like to re-consider your point of view now?


I might be wrong but I don't think Lionair or ET paid for the optional sensors so it would never had worked anyways.

From the RT article

"Pilots were supposed to be alerted about possible problems with the sensors by an AoA Disagree alert, which should light up when data coming from two AoA sensors does not match. But the alert required an optional set of indicators to be installed to actually work, and only 20 percent of the aircraft sold had them."


The AoA disagree should have worked according to the information and manual for the MAX. Boeing was hiding the fact, that it was not working in the standard configuration. So it could well be pilots were expecting the warning to come in case there problems with the AoA sensors.

So was the standard version of the MAX even certified with the AoA disagree not active? Because according to certification it should have been active.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 7:20 pm

morrisond wrote:
Interested wrote:
PW100 wrote:

It has nothing to do with getting away with, as every change Boeing initiates is validated through FAA. This is just part of every day life and continous improvements.

While Boeing has lots of xplainings to do on so many levels, this one is fairly low at their list. But I guess some see a bear behind every tree . . .


https://www.rt.com/usa/461371-boeing-alert-fix-2020/

Would you like to re-consider your point of view now?


I might be wrong but I don't think Lionair or ET paid for the optional sensors so it would never had worked anyways.

From the RT article

"Pilots were supposed to be alerted about possible problems with the sensors by an AoA Disagree alert, which should light up when data coming from two AoA sensors does not match. But the alert required an optional set of indicators to be installed to actually work, and only 20 percent of the aircraft sold had them."


Basically the AoA disagree alert should have worked as standard on every plane. With or without the extra optional indicators (which by the way will be standard now as well!)

However, in 2017 Boeing discovered a flaw which meant they realised the standard indicator only actually worked when airlines had paid for the extra optional indicators you could add. This was an error/ defect and not the intention of course. Damn what do we do now?

Boeing chose not to inform FAA OR the airlines (Something the FAA and airlines have complained about since).

Boeing chose to delay fixing the flaw until 2020

13 months later (after the first crash) Boeing were finally forced to let the FAA and airlines know about their defect and to bring forward fixing it ahead of 2020. Backed into this situation they couldn't get away with hiding it anymore. Let's be honest.

It makes horrible reading for Boeing management

A poster above already tried to defend Boeing as you can see (clearly assuming they delayed fixing the flaw they discovered with the full knowledge and approval of FAA) .

NOT CORRECT

They hid their flaw and didn't communicate it to anyone. They made a conscious decision not to let anyone know about the defect they had discovered.

Good luck defending that

This is one of the facts you just have to put your hand up and say that's awful. And it's one that the CEO has had to admit was a mistake. That's very good of him to admit. He had no choice did he?

It's only come out in recent weeks into the public domain. Of course had 350 people not died the general public would have never known

Even now on here it appears many don't realise how bad this is?
 
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aerolimani
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 9:08 pm

mjoelnir wrote:
OldAeroGuy wrote:
RickNRoll wrote:
I have wondered by Boeing didn't put it in the EAD.


It is in the EAD, along with a list of other symptoms.

Here's a portion of the EAD along with indications that would have been present shortly after liftoff for ET302 are shown in BOLD.
AOA DISAGREE is shown in italic.

737 MAX EAD 2018-23-51 lists these symptoms for potential erroneous MCAS operation:

Continuous or intermittent stick shaker on the affected side only
Minimum speed bar (red and black) on the affected side only
Increasing nose down control forces
IAS DISAGREE alert
ALT DISAGREE alert

AOA DISAGREE alert (if the option is installed)
FEEL DIFF PRESS light
Auto pilot may disengage
Inability to engage the autopilot

In terms of criticality, stick shaker and IAS DISAGREE would have had a higher pilot action priority than AOA DISAGREE.

There has been no evidence that NNC's were performed for either condition.


Behind AoA disagree you write, "if option is installed" is that so written somewhere in the manuals?

Because AoA disagree is not an option. It is standard and declared so in the manuals The thing is only that it is missing and Boeing knowing that, did not tell either the FAA or the customers.

If Boeing were suddenly talking about an option, they had been lying before that, selling something as a standard without any thought about providing it.
I also assume the MAX was certified with AoA disagree as a standard. We have to assume that most MAX delivered to customers, were not equipped to the certified standard.


From the article linked below:

Since just after the Lion Air accident, Boeing has described the AOA Disagree as an available option on the MAX, which was accurate. It was not until Apr. 29 that it explained the AOA Disagree’s status as an option was a mistake—it was supposed to be standard, as it is on the NG. Six days later, it acknowledged that it has known about this problem since mid-2017.

https://aviationweek.com/commercial-avi ... found-2017
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 9:17 pm

And this is an organisation that claims to put safety first

Im staggered that senior management haven't resigned yet tbh

It's embarrassing as the truth slowly but surely emerges

It's the kind of thing you just don't expect from an organisation like Boeing

(At least I would never have expected it)

What organisations can you actually trust to do the right things any more?
 
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon Jun 10, 2019 9:38 pm

7BOEING7 wrote:
PW100 wrote:
7BOEING7 wrote:

An IAS DISAGREE amber alert is staring you in the face — you do the Airspeed Unreliable NNC which is memory items, very simple.

If it was that simple, we wouldn't have this thread.

It would be that simple if the IAS DISAGREE was the only thing staring in their face. However at the same time they also had stick shaker going off, stall warning, anti-ice master caution, and probably several other warnings, cautions and alert messages as well. How do you arrive at the conclusion that this is a simple thing and Airspeed Unreliable NNC would be top priority? (IINM, we have been told in this thread that this NNC includes reducing N1 to around 83%, which sound like really bad idea just after lift off with stick shaker and stall warning going off).


Leaving the N1 at takeoff thrust until you're 40 to 60 kts +\- above VMO is a worse idea. With the third memory item (10 seconds maybe) you've determined which airspeed indicator is accurate, can them realize the stick shaker is bogus and proceed from there. The LIon Air crew with the same issues +/- had control of the airplane for several minutes until they stopped trimming.


ET were nowhere near Vmo when MCAS first kicked in.

Right upto MCAS first cycle, things seemed to be reasonably under control. From first MCAS though, things went down hill and never recovered.

From lift off to first MCAS cycle was 75 seconds. We have no idea what went on during that 75 seconds, what NNCs were (or were not) performed. We do not know what the crew discussed during that 75 seconds. Therefore I'm not in a position to claim that the crew did not make any (basic) mistakes, and I have not done so in any of my posts. The same should also apply to the opposite.
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