Nils75cz
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 5:50 pm

Is this thread about the grounding or pilot skills? There is a reason for the grounding. Are there lots of incompetent pilots flying passenger aircraft out there? I don't think so. None of them are flawless, no matter their education. There are education standards out there, some stricter, some less. That is why a plane has to be designed to be flyable to the smallest possible denominator, the pilot. With human flaws and possible education deficits. And that is why the 737 MAX is grounded. Because Boeing produced a fail prone product.
 
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7BOEING7
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 5:56 pm

planecane wrote:
mjoelnir wrote:
Your valid procedure, I assume the runaway trim procedure, seems to be a simple joke. Auto throttle off, electrical trim off gives you an unflyable frame, because manual trim will not work without the roller coaster maneuver and for that you need plenty of height above ground.

Failure with training for MCAS is all about Boeing and Boeing only. Boeing hid MCAS and made sure that a MAX simulator would not be able to show it.

You will not get away from that Boeing killed 189 people with their negligent design of MCAS and 157 more with their callous decision to not ground the MAX well knowing what happened to Lion Air.


It is not a joke. As I posted above, the procedure was used (including flying for hours with the manual trim wheel) on Lion Air 043 to recover from an MCAS-induced runawy stabilizer.

Here are the facts as I see them:

1) The design of the MCAS algorithm was horrible and incompentent.
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.
4) An MCAS-induced runaway stabilizer is relatively easily recoverable using the runaway stabilzer NNC as evidenced by Lion Air 043.
5) Boeing didn't orignally document the slightly different symptoms of MCAS-induced runaway stabilizer vs. prior causes of it. This was added after Lion Air 610 by the EAD.
6) Neither the crew of Lion Air 610 or ET 302 correctly ran the runaway stabilizer NNC.



I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.
 
AABusDrvr
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 5:58 pm

PixelFlight wrote:
planecane wrote:
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.

The 737-8/9 MAX introduce a new unsafe condition compared to the 737-800/900 NG: this is Boeing own description in the EAD-2018-23-51:

(e) Unsafe Condition
This AD was prompted by analysis performed by the manufacturer showing that if an
erroneously high single angle of attack (AOA) sensor input is received by the flight control system,
there is a potential for repeated nose-down trim commands of the horizontal stabilizer. We are issuing
this AD to address this potential resulting nose-down trim, which could cause the flight crew to have
difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss,
and possible impact with terrain.


The fact the this unsafe condition is "repeated" is a new failure mode no possible on any 737 before. This is why the MCAS v2 will only generate a single AND command per high AoA cycle. I challenge anyone to find a training for that "repeated" failure condition. Still, no 737 pilot have yet described in details here what a simulator runaway stabilizer training session on his airline.



I'm fairly certain we did a runaway stab during my initial conversion training on the 737. But honestly, I don't remember anything about the setup. Recognizing the problem is the hardest part of the whole scenario. Once you identify whats going on, and apply the QRH procedures, the whole thing is pretty much a non event.
 
xmp125a
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 6:08 pm

par13del wrote:
If MCAS is such a botched design making the MAX so deadly, why would one crew have a jump seater disable the function then rather than return to base they continued their flight?


How many pilots 737MAX needs to be safely flown then? Three?
 
Agrajag
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 6:34 pm

Half of all 737 pilots are below average. I do not think it unreasonable to expect Boeing to produce a plane that can be flown safely by them as well.
The plural of anecdote is anecdotes, not data.
Slartibartfast had a point
 
xmp125a
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 6:39 pm

planecane wrote:
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.


MCAS-sourced runaway stabilizer presents much different symptoms. It is strictly periodical, and relentless. It is a failure mode no well trained pilot without MCAS knowledge would anticipate. Some would recognize it as runaway stabilizer, some would not. Because some didn't, 350 people were killed. And, for the cherry on top, MAX branded simulators actually did not include MCAS-induced variant of runaway stabilizer for the pilots to get familiar with the MCAS-variant of it.

The outcry of AA pilots after LionAir crash which has only now become public knowledge had a reason. Probably many of well trained pilots had their "oh (beep)" moment, realizing that what happened to LionAir **could** potentially hapen to them, experience and training notwithstanding.
 
Agrajag
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 6:43 pm

xmp125a wrote:
planecane wrote:
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.


MCAS-sourced runaway stabilizer presents much different symptoms. It is strictly periodical, and relentless. It is a failure mode no well trained pilot without MCAS knowledge would anticipate. Some would recognize it as runaway stabilizer, some would not. Because some didn't, 350 people were killed. And, for the cherry on top, MAX branded simulators actually did not include MCAS-induced variant of runaway stabilizer for the pilots to get familiar with the MCAS-variant of it.

The outcry of AA pilots after LionAir crash which has only now become public knowledge had a reason. Probably many of well trained pilots had their "oh (beep)" moment, realizing that what happened to LionAir **could** potentially hapen to them, experience and training notwithstanding.


Spot on!
The plural of anecdote is anecdotes, not data.
Slartibartfast had a point
 
xmp125a
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 6:46 pm

MrBretz wrote:
Some more bad news: 737 MAX simulators don't properly simulate all the force needed to turn the trim wheels....

https://www.nytimes.com/2019/05/17/busi ... ators.html


Yes. (sarcasm on) NOW we know, why Boeing insist sim training is not needed - simulators don't replicate either faulty MCAS or trim wheel force. (sarcasm off) Indeed, sim training would not help, but due to the different reason.

“Every day, there is new news about something not being disclosed or something was done in error or was not complete,” said Dennis Tajer, a spokesman for the American Airlines pilots union and a 737 pilot.


Indeed. This is what I was saying about the certification process and whole Boeing safety culture that is apparently in tatters. Digging deeper and deeper, more gremlins are found. At this pace, it should take some time before MAX is in air again. If FAA & world agencies are serious, no way in June.
 
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par13del
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 6:58 pm

xmp125a wrote:
par13del wrote:
If MCAS is such a botched design making the MAX so deadly, why would one crew have a jump seater disable the function then rather than return to base they continued their flight?


How many pilots 737MAX needs to be safely flown then? Three?

I am still not sure if the jump seater knew about MCAS, however, we are all sure that MCAS did activate during that flight and they were able to not only disable it but fly the a/c to its destination.
I still question why they did not return to base, unless in their opinion, once they got the a/c under control, they were able to fly manually with no problem, so as another poster says, a non-event?
So, does that flight indicate that MCAS was a recoverable event even by third world pilots? I would say yes.
 
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 7:03 pm

planecane wrote:
Here are the facts as I see them:

1) The design of the MCAS algorithm was horrible and incompentent.
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.
4) An MCAS-induced runaway stabilizer is relatively easily recoverable using the runaway stabilzer NNC as evidenced by Lion Air 043.
5) Boeing didn't orignally document the slightly different symptoms of MCAS-induced runaway stabilizer vs. prior causes of it. This was added after Lion Air 610 by the EAD.
6) Neither the crew of Lion Air 610 or ET 302 correctly ran the runaway stabilizer NNC.

These facts lead me to the opinion that the drastically increased incidence of runaway stabilizer caused by MCAS (Boeing's fault), combined with inadequately trained (or incapable) crews led to the two crashes. I do not believe that either crew would have successfully responded to a runaway stabilizer caused by something other than MCAS. I believe that this statement applies to many other crews that fly the 737 (all series). Luckily, the other systems that can cause runaway stabilizer are designed correctly with an extremely low failure rate so very few crews have had to deal with it, and, again luckily, any that did were properly trained and capable.

Both Boeing and the pilots (especially the ET crew) were at fault for these crashes. If Boeing had designed MCAS properly (logically) then the crashes would not have happened. However, if the crews were properly trained and capable, the crashes still wouldn't have happened.

7BOEING7 wrote:
I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

I was about to post that people weren't remembering the sequence of events nor their significance very well and were letting their own interpretations take over, till I saw these posts.

Thanks for writing them.

My main concern is that fears of liability from negligence law suits has created the strong impetus for Boeing to treat this as a case of technological misjudgement rather than do a full exploration with regard to negligence, and from what I see so far, we may never get an open and honest exploration with regard to negligence.

I hope I'm wrong, but it seems pretty clear to me that odds are strong we will not, much like we never did with regards to the GFC of 2008, which also involved "too big to fail" institutions.

We see that Boeing is moving forward with the plausible deniability approach, exactly because what they are saying is plausible and so far no one has evidence that would eliminate the deniability.

I'm also reading about the meeting in Dallas on the 23rd of May to bless the fix, but not hearing of a meeting that will really address exactly how MCAS happened and how it can be avoided in the future, and that's a concern.
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
 
Aptivaboy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 7:28 pm

Revelation,

I think we will eventually get a full accounting. Between plaintiff's lawyers and legal discovery, and the two criminal investigations that are currently with Boeing insiders acting as whistleblowers, we'll find out the true extent of the MCAS issues in due course. The only real question is, how long will that take? It wouldn't shock me to see criminal indictments at least concerning the Ethiopian crash. Boeing reportedly knew that MCAS was troublesome, especially after the Lion Air crash but didn't do anything about it, certainly not publicly. They were probably trying to force a quick software patch downstream, hoping that would solve the problem before another crash. They gambled with lives, and lost. Even if they claim that the Lion Air crash was a fluke, they can't with the Ethiopian crash, and that's where the real criminal liability enters the picture.
 
morrisond
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 7:37 pm

xmp125a wrote:
planecane wrote:
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.


MCAS-sourced runaway stabilizer presents much different symptoms. It is strictly periodical, and relentless. It is a failure mode no well trained pilot without MCAS knowledge would anticipate. Some would recognize it as runaway stabilizer, some would not. Because some didn't, 350 people were killed. And, for the cherry on top, MAX branded simulators actually did not include MCAS-induced variant of runaway stabilizer for the pilots to get familiar with the MCAS-variant of it.

The outcry of AA pilots after LionAir crash which has only now become public knowledge had a reason. Probably many of well trained pilots had their "oh (beep)" moment, realizing that what happened to LionAir **could** potentially hapen to them, experience and training notwithstanding.


So what is ETs excuse then - they knew all about it - Supposedly - I don't believe there airline actually told them so I hold the Pilots blameless if they were never told about it - however you think they would have done some independent research after Lionair
 
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 7:49 pm

Aptivaboy wrote:
I think we will eventually get a full accounting. Between plaintiff's lawyers and legal discovery, and the two criminal investigations that are currently with Boeing insiders acting as whistleblowers, we'll find out the true extent of the MCAS issues in due course. The only real question is, how long will that take? It wouldn't shock me to see criminal indictments at least concerning the Ethiopian crash. Boeing reportedly knew that MCAS was troublesome, especially after the Lion Air crash but didn't do anything about it, certainly not publicly. They were probably trying to force a quick software patch downstream, hoping that would solve the problem before another crash. They gambled with lives, and lost. Even if they claim that the Lion Air crash was a fluke, they can't with the Ethiopian crash, and that's where the real criminal liability enters the picture.

Sure but it seems Boeing is doing its darndest to avoid such an accounting because so many have already decided there is negligence and won't provide the presumption of innocence that they are entitled to.

I used the words "plausible deniability" with much consideration because in my mind it is plausible that this all is a technological miscalculation, and so far, I can't see that anyone has provided the kind of evidence that would destroy the deniability.

As you say, we do know of at least two criminal investigations, along with the discovery process that I'm sure the victim's lawyers will be granted much latitude to use, so God help Boeing if a smoking gun is found.

Yet the more time that passes, the less likely it is that such a smoking gun will appear.
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
 
Aptivaboy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 7:52 pm

Boeing is doubtless under court orders to not destroy any internal correspondence relating to MCAS. All it would take is one whistleblower, one email relating to something now missing, to completely destroy them. The DOJ may already have such a smoking gun given that Boeing employees are cooperating. I think it will happen.
 
smartplane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 7:59 pm

Buffalomatt1027 wrote:
Even with the AA pilots complaints ...... the American airlines pilots like AA WN UA all had pilots that could handle the MAX and the current issues. ET and Lion could not.

AA pilots had the opportunity to prepare for the simulation, presumably sent their best (inter-company rivalry), had a Boeing briefing, observed Boeing test pilots first, and even they were 'surprised' by what they experienced. And was it even a 'real' simulation, or softened, for example like now emerges has been the case for years with simulated manual trim.
 
xmp125a
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 8:41 pm

par13del wrote:
xmp125a wrote:
par13del wrote:
If MCAS is such a botched design making the MAX so deadly, why would one crew have a jump seater disable the function then rather than return to base they continued their flight?


How many pilots 737MAX needs to be safely flown then? Three?

I am still not sure if the jump seater knew about MCAS, however, we are all sure that MCAS did activate during that flight and they were able to not only disable it but fly the a/c to its destination.
I still question why they did not return to base, unless in their opinion, once they got the a/c under control, they were able to fly manually with no problem, so as another poster says, a non-event?
So, does that flight indicate that MCAS was a recoverable event even by third world pilots? I would say yes.


I perhaps overloaded my reply with sarcasm ... the point is, when MCAS hell breaks loose, pilots are under immense workload, in the situation where one wrong decision means irrecoverable way to becoming a huge lawn dart. It is very telling that it needed a THIRD pilot (which DID NOT FLY A PLANE) to diagnose the symptoms. Because, primary job of pilots is flying a plane, not debugging faulty safety-critical software. And as a third pilot, he had the possibility of thinking "let us try this, hmmm...." and got it right. We don't even know how many "let's try this"he tried until he got the jackpot. Two pilot crew does not have latitude to do this when fighting suicidal plane systems.

So, the fact that in 3 known faulty MCAS activations the only time it was recognized properly was when there was additional help in the cockpit is especially damning for Boeing. To tell it differently: Both two pilot crews that encounter MCAS malfunction were killed, along with their passengers. Great job, Boeing! Who needs those 3rd world customers anyway!
 
xmp125a
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 8:44 pm

smartplane wrote:
Buffalomatt1027 wrote:
Even with the AA pilots complaints ...... the American airlines pilots like AA WN UA all had pilots that could handle the MAX and the current issues. ET and Lion could not.

AA pilots had the opportunity to prepare for the simulation, presumably sent their best (inter-company rivalry), had a Boeing briefing, observed Boeing test pilots first, and even they were 'surprised' by what they experienced. And was it even a 'real' simulation, or softened, for example like now emerges has been the case for years with simulated manual trim.


They were higher as ET pilots as well, and yet the "rollercoaster" procedure resulted in 2000 ft AGL. Why didnt they put them at ET pilots' altitude? To prevent hell breaking loose when AA's best crash a plane?
 
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PixelFlight
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 8:57 pm

planecane wrote:
PixelFlight wrote:
The fact the this unsafe condition is "repeated" is a new failure mode no possible on any 737 before. This is why the MCAS v2 will only generate a single AND command per high AoA cycle. I challenge anyone to find a training for that "repeated" failure condition. Still, no 737 pilot have yet described in details here what a simulator runaway stabilizer training session on his airline.

You are nitpicking semantics. What is the PRACTICAL difference between a continuous uncommanded stabilizer movement and a repeated uncommanded stabilizer movement? They are both a runaway stabilizer and the same NNC is used to recover.

The practical difference is 346 peoples killed. All the crews corrected the first runaway.
 
slcdeltarumd11
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 9:07 pm

https://www.businessinsider.com/boeing- ... rts-2019-5

We live in a bubble here. I think there is going to be huge coverage and concern when this plane flys again. Talking to normal people they are terrified to get on a MAX. I genuinely think we are very far from seeing this plane return to scheduled service, the patch is only a first hurdle. Not a so go day goes by where someone asks me if they are booked on a MAX when they see 737 on a schedule.
 
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PixelFlight
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 9:13 pm

AABusDrvr wrote:
I'm fairly certain we did a runaway stab during my initial conversion training on the 737. But honestly, I don't remember anything about the setup. Recognizing the problem is the hardest part of the whole scenario. Once you identify whats going on, and apply the QRH procedures, the whole thing is pretty much a non event.

Many thanks for your message. It's interesting to know that "Recognizing the problem is the hardest part of the whole scenario." (I agree with that). Sade that your can't remember anything about the setup (alarms, speed, altitude), this give the impression that this training is not done often. Did you know if there is specific a document that define the setup for that training ?
 
xmp125a
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 9:14 pm

planecane wrote:
PixelFlight wrote:
planecane wrote:
I guess I can see what you are saying. The way I read it, it is part of step 2. I think it is just treated kind of like common sense basically saying "fly the airplane."

The common sens will not guess that the pilot have only maximum 5 seconds to go from the second indented (could be misinterpreted as only if AP engaged) point 2 to the first indented (could be misinterpreted due to MCAS discontinue action) point 5, and that all the next points can't be done at high speed. Under stress and without appropriate specific training, this procedure as redacted could easily be error prone.


Don't focus on MCAS in this case. If the training isn't adequate for runaway stabilizer then it is an issue for ALL causes of runaway stabilizer. If they (specifically the ET crew) didn't run the NNC properly for an MCAS induced runaway stabilizer, they wouldn't have run it properly for runaway stabilizer caused by something else.


Oh yes, we need to focus on this. Because when airplanes crash with technical problem, which has not been properly handled by a crew, it is mostly the fact that they did not properly diagnose the problem. After you know the diagnosis (and is not terminal) then basically every pilot will recover.

Boeing ASSUMED that pilots will diagnose MCAS failure as runaway stabilizer - and what tests did they do to ground their assumption in? Even after Lion Air crash, the EAD does actually describe the symptoms of MCAS failure, if I remember correctly. So it is of no help if pilots waste precious seconds by trying to establish what is wrong and end up with unflyable plane.
 
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Asturias
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 9:19 pm

MSPNWA wrote:


Agrajag wrote:
It is also clear that they are not getting value for money.

Wow. I have my suspicions about some posters in this forum. You're heightening those suspicions.


Suspicions that they're on to you?

Your agenda is evident for anyone to see, you may deny it, but you don't hide it. I've been a member here for more than a decade and you've always been a known shill for Boeing.

This is not personal, and I'm a big Boeing fan, but there you go.
Tonight we fly
 
xmp125a
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 9:20 pm

slcdeltarumd11 wrote:
https://www.businessinsider.com/boeing-737-max-crisis-response-confusing-hard-to-trust-experts-2019-5

We live in a bubble here. I think there is going to be huge coverage and concern when this plane flys again. Talking to normal people they are terrified to get on a MAX. I genuinely think we are very far from seeing this plane return to scheduled service, the patch is only a first hurdle. Not a so go day goes by where someone asks me if they are booked on a MAX when they see 737 on a schedule.


It also depends whether someone wants to profit of this. There is a air ticket website that promised "ignore all flights with 737MAX" checkmark for search before MAX is grounded. Imagine if the publicity is bad enough that the big internet ticket searches add this option. Imagine that they figure that the checkmark should be on by default.

Imagine that the airlines who don't have MAX in their fleet start advertising "Rest assured, we don't fly 737 MAX".

Imagine that the ones who have MAX in their fleet stop supplying aircraft data to the search engines. Imagine that the checkmark mutates in "ignore all airlines with 737MAX in their fleet."

Oh yes, this COULD go as ugly as possible in this age of social media. Nothing is impossible.
 
art
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 9:36 pm

morrisond wrote:
On ET if they had followed the Memory procedure for unreliable airspeed and they had not retracted the flaps they would never have gotten to MCAS..


Getting to MCAS meant triggering activation of a safety feature, did it not? Problem that led to activation therefore solved! Hence no Lion Air crash.

In practice MCAS was an undisclosed danger feature that would wrest pitch control from the pilot flying, pushing the aircraft's nose down for 10 seconds. After 5 more seconds it would wrest pitch control from the pilot flying, pushing the aircraft's nose down for 10 seconds. After 5 more seconds it would wrest pitch control from the pilot flying, pushing the aircraft's nose down for 10 seconds... until the aircraft hit terra firma.

Existence of this system that would take pitch control away from pilots for 10 seconds, hand it back for 5 seconds, take it away, hand it back ad infinitum had been deliberately concealed by Boeing so that no pilot could explain the pitch behaviour of the aircraft when this unknown danger feature started then reiterated, reiterated, reiterated... until all on board would be killed.

MAX should have been grounded once the FDR data had been observed IMO

@morrisond, I do not understand how you seem to fail to grasp that any safety feature based on using a single sensor data source, a safety feature capable of forcing an aircraft into a dive should NEVER have been passed by the FAA so should NEVER have been installed on the 737 MAX. It was a heinous design. Whether or not the crew could have prevented MCAS activation is hardly of relevance, is it?
 
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par13del
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 9:44 pm

xmp125a wrote:
So, the fact that in 3 known faulty MCAS activations the only time it was recognized properly was when there was additional help in the cockpit is especially damning for Boeing.

The point here and the basis of my post was that the procedure to recover from MCAS does work, if you read post in this thread, the thought is that the processes does not work and would never work, and that was for version I.
I note that you now say two pilots may not be enough, that may go towards what, more training in fault recognition?
As I posted before, pilots are there for when the automation goes wrong, until we fully automate, that is our reality.
 
speedbird52
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 9:57 pm

7BOEING7 wrote:
planecane wrote:
mjoelnir wrote:
Your valid procedure, I assume the runaway trim procedure, seems to be a simple joke. Auto throttle off, electrical trim off gives you an unflyable frame, because manual trim will not work without the roller coaster maneuver and for that you need plenty of height above ground.

Failure with training for MCAS is all about Boeing and Boeing only. Boeing hid MCAS and made sure that a MAX simulator would not be able to show it.

You will not get away from that Boeing killed 189 people with their negligent design of MCAS and 157 more with their callous decision to not ground the MAX well knowing what happened to Lion Air.


It is not a joke. As I posted above, the procedure was used (including flying for hours with the manual trim wheel) on Lion Air 043 to recover from an MCAS-induced runawy stabilizer.

Here are the facts as I see them:

1) The design of the MCAS algorithm was horrible and incompentent.
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.
4) An MCAS-induced runaway stabilizer is relatively easily recoverable using the runaway stabilzer NNC as evidenced by Lion Air 043.
5) Boeing didn't orignally document the slightly different symptoms of MCAS-induced runaway stabilizer vs. prior causes of it. This was added after Lion Air 610 by the EAD.
6) Neither the crew of Lion Air 610 or ET 302 correctly ran the runaway stabilizer NNC.



I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.
 
PixelPilot
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 10:05 pm

speedbird52 wrote:
7BOEING7 wrote:
planecane wrote:

It is not a joke. As I posted above, the procedure was used (including flying for hours with the manual trim wheel) on Lion Air 043 to recover from an MCAS-induced runawy stabilizer.

Here are the facts as I see them:

1) The design of the MCAS algorithm was horrible and incompentent.
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.
4) An MCAS-induced runaway stabilizer is relatively easily recoverable using the runaway stabilzer NNC as evidenced by Lion Air 043.
5) Boeing didn't orignally document the slightly different symptoms of MCAS-induced runaway stabilizer vs. prior causes of it. This was added after Lion Air 610 by the EAD.
6) Neither the crew of Lion Air 610 or ET 302 correctly ran the runaway stabilizer NNC.



I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


What are the pilots there for??
I mean seriously.
All you boeing haters somehow believe that pilots are there for smiles or something?
 
speedbird52
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 10:09 pm

PixelPilot wrote:
speedbird52 wrote:
7BOEING7 wrote:

I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


What are the pilots there for??
I mean seriously.
All you boeing haters somehow believe that pilots are there for smiles or something?

Technically the Lauda Air 767 that crashed because the thrust reverser unlocked was also caused by the pilots not following proper procedure if you want to go with this logic
 
mysfit
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 10:35 pm

It's lousy engineering and safety practice to EXPECT pilots to successfully counteract emergency which is caused by a single point failure resulting in a software fix for a mechanical issue going haywire during a heavy workload portion of flight.

Argue all you want about how pilots, with all hell breaking loose, should have responded. That really isn't even the point.

Crappy engineering of an issue handed pilots an accident waiting to happen. Single point failure. Non disclosure of a system which took control from them. The decision to make sure nothing more than an hour on an IPAD was needed. The reports by American pilots that the training manual was criminally negligent and lacking information on items unrelated to MCAS.

I don't hate Boeing but as an engineer, this was poorly executed and poorly designed. Engineers are responsible for limiting points for human error. Not to count on humans to overcome an intentionally introduced weak point. And then hide it.
 
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 10:47 pm

speedbird52 wrote:
Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist.

Ah yes when a meter or two off the ground and the stick shaker goes off the first thing you will think about is all those memory items you should have memorized back in training but never really did. Hmm, there was a reason you should have memorized those memory items, but don't dare to ask the co-pilot if he remembers, one must not lose face... Hmm, punch the auto throttles and auto pilot and hope it sorts it all out... Stick shaker going off, but hmm, drop the flaps cuz that's what you normally do, let's see what happens...
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
 
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7BOEING7
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 11:00 pm

speedbird52 wrote:
7BOEING7 wrote:
planecane wrote:

It is not a joke. As I posted above, the procedure was used (including flying for hours with the manual trim wheel) on Lion Air 043 to recover from an MCAS-induced runawy stabilizer.

Here are the facts as I see them:

1) The design of the MCAS algorithm was horrible and incompentent.
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.
4) An MCAS-induced runaway stabilizer is relatively easily recoverable using the runaway stabilzer NNC as evidenced by Lion Air 043.
5) Boeing didn't orignally document the slightly different symptoms of MCAS-induced runaway stabilizer vs. prior causes of it. This was added after Lion Air 610 by the EAD.
6) Neither the crew of Lion Air 610 or ET 302 correctly ran the runaway stabilizer NNC.



I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


What do you think he should have been doing for the minute and 15 seconds (until MCAS became active) while stick shaker was going off and the IAS DISAGREE alert was displayed at the bottom of his speed tape? I guess he could of gone thru his stall recovery procedures but didn't do that either. Instead he did what he always did and engaged the autopilot -- which didn't engage. The only thing I can think of is that he was going to clean up and them worry about all the issues he had but that just added one more -- which was one to many.
 
RickNRoll
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 11:27 pm

planecane wrote:
mysfit wrote:
morrisond wrote:

You missed the part that after the first crash ET had a valid procedure that would have saved the aircraft and ET proceeded to do little or maybe none at all training with their pilots on how to implement it if faced with the same situation.



A valid procedure based on exactly what data? What live tests? Because the smoking crater would contradict the notion of a valid procedure. If it were a legitimate. Tested. Valid procedure why was the plane grounded and remains so?

The plane was sold as only an iPads worth of training needed when that clearly was not the case. But yet the 2nd crash was entirely the result of a lack of training? Boeing screwed up. The FAA was complicit. The bulk of the problem rests with them and their abandonment of safety in the pursuit of money.


The valid procedure was to run the runaway stabilizer NNC. The live test was Lion Air 043 when they had the exact MCAS induced issue but recovered and continued to the destination. They also used the manual trim wheel to trim the aircraft for the remainder of the flight so this is not the impossible task that some make it out to be. From the preliminary report on Lion Air 610, describing Lion Air 043 (emphasis added to show the use of the manual trim wheel):

The PIC then moved the STAB TRIM switches back to CUT OUT and continued with manual trim without auto-pilot until the end of the flight.

The pilot performed three Non-Normal Checklists (NNCs) consisting of Airspeed Unreliable, ALT DISAGREE, and Runaway Stabilizer


The plane was grounded and remains grounded because the original implementation of MCAS increased the likelihood of runaway stabilizer by what seems to be a few orders of magnitude. ET 302 demonstrated that there are likely training issues with crews dealing with a runaway stabilizer, even after the post Lion Air 610 EAD. Therefore, worldwide authorities don't want an aircraft in the air that has a relatively high incidence of a failure mode that crews have had extreme difficulty dealing with.
I have mentioned MCAS failure at takeoff leading to pilot overload. The third pilot in the first failure indicated exactly that. He was able to focus on the problem and just trying to keep the plane in the air. It is not a simple situation no matter how many times morrisond portrays it as such.
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 11:35 pm

7BOEING7 wrote:
speedbird52 wrote:
7BOEING7 wrote:

I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


What do you think he should have been doing for the minute and 15 seconds (until MCAS became active) while stick shaker was going off and the IAS DISAGREE alert was displayed at the bottom of his speed tape? I guess he could of gone thru his stall recovery procedures but didn't do that either. Instead he did what he always did and engaged the autopilot -- which didn't engage. The only thing I can think of is that he was going to clean up and them worry about all the issues he had but that just added one more -- which was one to many.

Lets expand a little bit
A single failure in a set of sensors designed to WWII standards, a failure which should be a non-event by XXI century standards, causes (by design) a high workload situation. Then, due to a deviation from procedure written for completely different scenarios, a 21st-century style function duck taped to antiquated sensor suit causes a runaway which can be corrected by procedure removed from the manual somewhere in 80s.
 
GalaxyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 11:56 pm

It's lousy engineering and safety practice to EXPECT pilots to successfully counteract emergency which is caused by a single point failure resulting in a software fix for a mechanical issue going haywire during a heavy workload portion of flight.


Hate to break the news but, we do that in many scenarios—engine failure on take-off, on go around from a CAT II for two instances that are considerably more demanding than this one. Then there’s, wait for it, runaway trim in darned every jet since the 707. It was a failure mode in the C-5 and the 727.

Do you really think either crew would have done any better with a trim runaway on take-off?


gf
 
GalaxyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 12:00 am

kalvado wrote:
7BOEING7 wrote:
speedbird52 wrote:
Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


What do you think he should have been doing for the minute and 15 seconds (until MCAS became active) while stick shaker was going off and the IAS DISAGREE alert was displayed at the bottom of his speed tape? I guess he could of gone thru his stall recovery procedures but didn't do that either. Instead he did what he always did and engaged the autopilot -- which didn't engage. The only thing I can think of is that he was going to clean up and them worry about all the issues he had but that just added one more -- which was one to many.

Lets expand a little bit
A single failure in a set of sensors designed to WWII standards, a failure which should be a non-event by XXI century standards, causes (by design) a high workload situation. Then, due to a deviation from procedure written for completely different scenarios, a 21st-century style function duck taped to antiquated sensor suit causes a runaway which can be corrected by procedure removed from the manual somewhere in 80s.


Stop making stuff up—the AOA vanes and standards therefor weren’t WW II designs. Do you really believe Boeing is just rewarming the B-17?
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 12:02 am

GalaxyFlyer wrote:
It's lousy engineering and safety practice to EXPECT pilots to successfully counteract emergency which is caused by a single point failure resulting in a software fix for a mechanical issue going haywire during a heavy workload portion of flight.


Hate to break the news but, we do that in many scenarios—engine failure on take-off, on go around from a CAT II for two instances that are considerably more demanding than this one. Then there’s, wait for it, runaway trim in darned every jet since the 707. It was a failure mode in the C-5 and the 727.

Do you really think either crew would have done any better with a trim runaway on take-off?


gf

How often engine failure on take-off, or a go around from a CAT II is practiced? I had an impression engine-out is a mandatory part for periodic sim session, as well as some complex go-around. That is a part of the answer.
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 12:08 am

GalaxyFlyer wrote:
kalvado wrote:
7BOEING7 wrote:

What do you think he should have been doing for the minute and 15 seconds (until MCAS became active) while stick shaker was going off and the IAS DISAGREE alert was displayed at the bottom of his speed tape? I guess he could of gone thru his stall recovery procedures but didn't do that either. Instead he did what he always did and engaged the autopilot -- which didn't engage. The only thing I can think of is that he was going to clean up and them worry about all the issues he had but that just added one more -- which was one to many.

Lets expand a little bit
A single failure in a set of sensors designed to WWII standards, a failure which should be a non-event by XXI century standards, causes (by design) a high workload situation. Then, due to a deviation from procedure written for completely different scenarios, a 21st-century style function duck taped to antiquated sensor suit causes a runaway which can be corrected by procedure removed from the manual somewhere in 80s.


Stop making stuff up—the AOA vanes and standards therefor weren’t WW II designs. Do you really believe Boeing is just rewarming the B-17?

Were they standard on Me-262 or Meteor?
And I am talking about the general approach to the concept of redundancy, though. COncept of independent instrument suits as backup dates to 40s, I believe.
 
GalaxyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 12:30 am

I have no idea about the Me-262, but you a “set of sensors designed to WW II standards” and that isn’t correct by a long way. Yes, engine is a standard sim check event, but pilots are expected to be proficient at all procedures, even the ones not checked. Which is, IMO, a big hole in training and checking, too much time spent of a set of maneuvers, V1 cut for one and not enough on all the more subtle emergencies and NNC events. Another thread.

GF
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 12:54 am

GalaxyFlyer wrote:
I have no idea about the Me-262, but you a “set of sensors designed to WW II standards” and that isn’t correct by a long way.

post-WWII development, in particular spaceflight, brought up new level of redundancy - single failure should not cause a catastrophic outcome. It became especially important as emergency landing is not a true option for spaceflight, and single failure of should be a non-event for most components.
Very tangential, you can look at Richard Feynman books, where he describes his "inspection" of Manhattan project enrichment plant. A beginning of redundancy planning during WWII.
GalaxyFlyer wrote:
Yes, engine is a standard sim check event, but pilots are expected to be proficient at all procedures, even the ones not checked. Which is, IMO, a big hole in training and checking, too much time spent of a set of maneuvers, V1 cut for one and not enough on all the more subtle emergencies and NNC events. Another thread.

Maybe proficiency in all procedures comes with 10" airmanship - but most people live in a world where person graduating from medical school with lowest passing grade is still called a "Doctor", and full SAT grade is achieved by single digit number of students out of millions taking the test. In fact, I don't know any single test where 100% score is the passing requirement. Astronauts, maybe? In many cases, human is the weakest link in an emergency.
For most people there is a strong correlation between the probability of successful outcome and practice of appropriate action. Then there are risk estimates and practice focused on high (probability*consequencies) product, and we just pray for the best for lower value ones. Fault-tolerant (including human error) design is another part of it.
 
RickNRoll
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 12:58 am

GalaxyFlyer wrote:
It's lousy engineering and safety practice to EXPECT pilots to successfully counteract emergency which is caused by a single point failure resulting in a software fix for a mechanical issue going haywire during a heavy workload portion of flight.


Hate to break the news but, we do that in many scenarios—engine failure on take-off, on go around from a CAT II for two instances that are considerably more demanding than this one. Then there’s, wait for it, runaway trim in darned every jet since the 707. It was a failure mode in the C-5 and the 727.

Do you really think either crew would have done any better with a trim runaway on take-off?


gf

You are confusing the case of designed to fail and designed to not fail.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 1:53 am

xmp125a wrote:
planecane wrote:
PixelFlight wrote:
The common sens will not guess that the pilot have only maximum 5 seconds to go from the second indented (could be misinterpreted as only if AP engaged) point 2 to the first indented (could be misinterpreted due to MCAS discontinue action) point 5, and that all the next points can't be done at high speed. Under stress and without appropriate specific training, this procedure as redacted could easily be error prone.


Don't focus on MCAS in this case. If the training isn't adequate for runaway stabilizer then it is an issue for ALL causes of runaway stabilizer. If they (specifically the ET crew) didn't run the NNC properly for an MCAS induced runaway stabilizer, they wouldn't have run it properly for runaway stabilizer caused by something else.


Oh yes, we need to focus on this. Because when airplanes crash with technical problem, which has not been properly handled by a crew, it is mostly the fact that they did not properly diagnose the problem. After you know the diagnosis (and is not terminal) then basically every pilot will recover.

Boeing ASSUMED that pilots will diagnose MCAS failure as runaway stabilizer - and what tests did they do to ground their assumption in? Even after Lion Air crash, the EAD does actually describe the symptoms of MCAS failure, if I remember correctly. So it is of no help if pilots waste precious seconds by trying to establish what is wrong and end up with unflyable plane.

It seems the ET crew did diagnose it. They just cut off electric trim too soon.

The EAD says there can be uncommanded nose down trim on the MAX and if there is, the runaway stabilizer NNC should be performed.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 2:00 am

speedbird52 wrote:
7BOEING7 wrote:
planecane wrote:

It is not a joke. As I posted above, the procedure was used (including flying for hours with the manual trim wheel) on Lion Air 043 to recover from an MCAS-induced runawy stabilizer.

Here are the facts as I see them:

1) The design of the MCAS algorithm was horrible and incompentent.
2) MCAS does not introduce a new failure mode, it adds another source of runaway stabilizer.
3) MCAS appears to increase the likelihood of runaway stabilzer on a 737 by a few orders of magnitude.
4) An MCAS-induced runaway stabilizer is relatively easily recoverable using the runaway stabilzer NNC as evidenced by Lion Air 043.
5) Boeing didn't orignally document the slightly different symptoms of MCAS-induced runaway stabilizer vs. prior causes of it. This was added after Lion Air 610 by the EAD.
6) Neither the crew of Lion Air 610 or ET 302 correctly ran the runaway stabilizer NNC.



I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


The discussion was speciation that the NG trim wheel was more difficult to use than the classic. It was based on the wheel being smaller but nobody knew if the gearing was changed to compensate.

The wheel was used for over an hour by Lion Air 043 after cutting off electric trim.
 
zoom321
Posts: 38
Joined: Sat Mar 09, 2019 3:05 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 2:14 am

xmp125a wrote:
planecane wrote:
PixelFlight wrote:
The common sens will not guess that the pilot have only maximum 5 seconds to go from the second indented (could be misinterpreted as only if AP engaged) point 2 to the first indented (could be misinterpreted due to MCAS discontinue action) point 5, and that all the next points can't be done at high speed. Under stress and without appropriate specific training, this procedure as redacted could easily be error prone.


Don't focus on MCAS in this case. If the training isn't adequate for runaway stabilizer then it is an issue for ALL causes of runaway stabilizer. If they (specifically the ET crew) didn't run the NNC properly for an MCAS induced runaway stabilizer, they wouldn't have run it properly for runaway stabilizer caused by something else.


Oh yes, we need to focus on this. Because when airplanes crash with technical problem, which has not been properly handled by a crew, it is mostly the fact that they did not properly diagnose the problem. After you know the diagnosis (and is not terminal) then basically every pilot will recover.

Boeing ASSUMED that pilots will diagnose MCAS failure as runaway stabilizer - and what tests did they do to ground their assumption in? Even after Lion Air crash, the EAD does actually describe the symptoms of MCAS failure, if I remember correctly. So it is of no help if pilots waste precious seconds by trying to establish what is wrong and end up with unflyable plane.

To be precise, B wanted to assume that pilots will diagnose MCAS failure as runaway stabilizer & wanted the world to think it was just at worst an honest wrong assumption if anything goes wrong which it did in the most tragic ways.
Most likely someone in B did highlight the need to amend the procedure to remove any doubts. It's after all a simple change of words that can save lives.
But in the end B decided against it due to the strong desire to hide mcas or portray that it's not a big change even if it's found out.
B is rotten to the core.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 2:27 am

mysfit wrote:
It's lousy engineering and safety practice to EXPECT pilots to successfully counteract emergency which is caused by a single point failure resulting in a software fix for a mechanical issue going haywire during a heavy workload portion of flight.

Argue all you want about how pilots, with all hell breaking loose, should have responded. That really isn't even the point.

Crappy engineering of an issue handed pilots an accident waiting to happen. Single point failure. Non disclosure of a system which took control from them. The decision to make sure nothing more than an hour on an IPAD was needed. The reports by American pilots that the training manual was criminally negligent and lacking information on items unrelated to MCAS.

I don't hate Boeing but as an engineer, this was poorly executed and poorly designed. Engineers are responsible for limiting points for human error. Not to count on humans to overcome an intentionally introduced weak point. And then hide it.


Nobody can argue against the fact that MCAS 1.0 was a horrifically bad design. That said, the key reason for pilots to exist is to get the aircraft on the ground when things go wrong. It doesn't matter if the emergency is caused by a single failure or a chain of 65 events. The job of the pilots is to respond to the emergency.

The old "two wrongs don't make a right" saying cones into play here. The bad design of MCAS by Boeing doesn't excuse the crews from being capable of recovering.

Especially when they were able to do things that counteracted MCAS. Even if there was no checklist, if the trim goes nose down uncommanded but you can get back in trim with the thumb switch every time, why stop using the trim switch? I would like to think that pilots have some level of logic. If the Lion Air crew just kept trimming nose up they would have accidentally fixed the problem when they deployed flaps on approach.

Based on the preliminary report on the ET crash, it seems like they got tunnel vision about the cutoff switches which caused them to disable electric trim too soon. When they turned it back on, they didn't even try to counteract MCAS which they had done earlier.

I will reiterate, if Boeing had designed MCAS properly, neither crash would have happened. However, despite the bad design, the crews should have been able to recover. The fact that they didn't leads me to fear training deficiencies quite possibly on many aircraft and it has just been luck that the improperly trained crews have been lucky not to face emergency situations since the failure rates are so low.
 
speedbird52
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 2:29 am

planecane wrote:
speedbird52 wrote:
7BOEING7 wrote:

I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


The discussion was speciation that the NG trim wheel was more difficult to use than the classic. It was based on the wheel being smaller but nobody knew if the gearing was changed to compensate.

The wheel was used for over an hour by Lion Air 043 after cutting off electric trim.

Then the ET crew not using it doesn't make sense
 
kalvado
Posts: 1710
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 2:43 am

speedbird52 wrote:
planecane wrote:
speedbird52 wrote:
Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


The discussion was speciation that the NG trim wheel was more difficult to use than the classic. It was based on the wheel being smaller but nobody knew if the gearing was changed to compensate.

The wheel was used for over an hour by Lion Air 043 after cutting off electric trim.

Then the ET crew not using it doesn't make sense

In case you missed it: Trim wheel is usable when the airplane is close to proper trim. When trim goes way off and significant yoke input is required to keep flight more or less level, the force on a trim wheel increases to the point when a normal person cannot move the wheel anymore. In early 737 days, Boeing had a specific procedure to trim from a way out-of-trim condition, but it was removed from regular training curriculum as design improvements rendered severe out-of-trim runaways almost non-existent.
Quick problem diagnostics as MCAS - as opposed to "normal" trim runaway; and very specific response - significantly different from vanilla "stuck switch trim runaway" are the key for survival.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 2:44 am

speedbird52 wrote:
planecane wrote:
speedbird52 wrote:
Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


The discussion was speciation that the NG trim wheel was more difficult to use than the classic. It was based on the wheel being smaller but nobody knew if the gearing was changed to compensate.

The wheel was used for over an hour by Lion Air 043 after cutting off electric trim.

Then the ET crew not using it doesn't make sense

Lion Air 043 wasn't over speed and I don't believe they were as far out of trim when they cut off electric trim.

Until the final report with (I'd assume) the full CVR transcript we won't know if the ET crew tried the wheel or not.
 
zoom321
Posts: 38
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 3:04 am

planecane wrote:
mysfit wrote:
It's lousy engineering and safety practice to EXPECT pilots to successfully counteract emergency which is caused by a single point failure resulting in a software fix for a mechanical issue going haywire during a heavy workload portion of flight.

Argue all you want about how pilots, with all hell breaking loose, should have responded. That really isn't even the point.

Crappy engineering of an issue handed pilots an accident waiting to happen. Single point failure. Non disclosure of a system which took control from them. The decision to make sure nothing more than an hour on an IPAD was needed. The reports by American pilots that the training manual was criminally negligent and lacking information on items unrelated to MCAS.

I don't hate Boeing but as an engineer, this was poorly executed and poorly designed. Engineers are responsible for limiting points for human error. Not to count on humans to overcome an intentionally introduced weak point. And then hide it.


Nobody can argue against the fact that MCAS 1.0 was a horrifically bad design. That said, the key reason for pilots to exist is to get the aircraft on the ground when things go wrong. It doesn't matter if the emergency is caused by a single failure or a chain of 65 events. The job of the pilots is to respond to the emergency.

The old "two wrongs don't make a right" saying cones into play here. The bad design of MCAS by Boeing doesn't excuse the crews from being capable of recovering.

Especially when they were able to do things that counteracted MCAS. Even if there was no checklist, if the trim goes nose down uncommanded but you can get back in trim with the thumb switch every time, why stop using the trim switch? I would like to think that pilots have some level of logic. If the Lion Air crew just kept trimming nose up they would have accidentally fixed the problem when they deployed flaps on approach.

Based on the preliminary report on the ET crash, it seems like they got tunnel vision about the cutoff switches which caused them to disable electric trim too soon. When they turned it back on, they didn't even try to counteract MCAS which they had done earlier.

I will reiterate, if Boeing had designed MCAS properly, neither crash would have happened. However, despite the bad design, the crews should have been able to recover. The fact that they didn't leads me to fear training deficiencies quite possibly on many aircraft and it has just been luck that the improperly trained crews have been lucky not to face emergency situations since the failure rates are so low.

Simulations have shown the ET coud not have recovered, so to say they should have been able to recover is based largely just on wishful thinking. Especially given the pilots were just following B procedures.
Training can/should be improved, but the most important steps to achieve this is B has to provide full disclosure on mcas, correct procedures to follow, working simulators & fix the manual trim so that pilots can be trained correctly, instead of continuing to provide half baked procedures whose main aim is to portray the steps as 'simple' & 'existing' over providing as much info as possible to ensure safety.
 
RickNRoll
Posts: 1611
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 3:14 am

planecane wrote:
speedbird52 wrote:
7BOEING7 wrote:

I'd like to add one more:

7) The crew of ET302 failed to run the AIRSPEED UNRELIABLE NNC.

Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


The discussion was speciation that the NG trim wheel was more difficult to use than the classic. It was based on the wheel being smaller but nobody knew if the gearing was changed to compensate.

The wheel was used for over an hour by Lion Air 043 after cutting off electric trim.


They also had to add a damper to the NG, which added to the force required to operate it.
 
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7BOEING7
Posts: 2990
Joined: Fri Oct 12, 2012 5:28 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 3:46 am

RickNRoll wrote:
planecane wrote:
speedbird52 wrote:
Ah yes when a plane is trying to pitch itself into the ground and kill you the first thing you will think about is running the airspeed unreliable checklist. On another note, wasn't there a discussion about the 737 MAXs trim wheel being more difficult to use than the NG, and that's why they kept electric trim on? Or was that disproven.


The discussion was speciation that the NG trim wheel was more difficult to use than the classic. It was based on the wheel being smaller but nobody knew if the gearing was changed to compensate.

The wheel was used for over an hour by Lion Air 043 after cutting off electric trim.


They also had to add a damper to the NG, which added to the force required to operate it.


Which is not an issue during normal operations.

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