OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 3:47 pm

XRAYretired wrote:

So, we have 4 crews on 3 continents over 8 years in similar circumstances who all react initially in pretty much the same way (including all retract flaps). Why do you think that would be?

Ray


All of the crews can be faulted for not applying the Boeing procedure of not retracting Flaps after a stick shaker event.

The NG crew did not have a continuous stick shaker, in their case, it was intermittent. More importantly, they did conduct the "Unreliable Airspeed" procedure and returned to land.

With continuous stick shaker, all the MAX crews elected to continue their missions with continuous stick shaker.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
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litz
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 3:53 pm

planecane wrote:
freakyrat wrote:
Reference the AoA sensor disagree lights and Southwest. Southwest is Boeings best customer and they are not happy campers right now. Neither are the pilots at Southwest. Southwest has even been talking to Airbus about the A220. I just wonder how Boeing is going to regain their trust

Although the AoA disagree warning missing is not a good thing, it is being overblown with respect to these MCAS incidents, especially Lion Air. Since MCAS wasn't described to pilots, they would have had no idea what an AoA disagree could cause. Plus, the stick shaker on one side only would indicate a disagree anyway.


Neither airplane involved in the two crashes had the option installed that included the AoA disagree light.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 4:01 pm

litz wrote:
planecane wrote:
freakyrat wrote:
Reference the AoA sensor disagree lights and Southwest. Southwest is Boeings best customer and they are not happy campers right now. Neither are the pilots at Southwest. Southwest has even been talking to Airbus about the A220. I just wonder how Boeing is going to regain their trust

Although the AoA disagree warning missing is not a good thing, it is being overblown with respect to these MCAS incidents, especially Lion Air. Since MCAS wasn't described to pilots, they would have had no idea what an AoA disagree could cause. Plus, the stick shaker on one side only would indicate a disagree anyway.


Neither airplane involved in the two crashes had the option installed that included the AoA disagree light.

My point was that even if they did, it wouldn't have made any difference. The lion air crew wouldn't have known anything about MCAS. The ET crew seemed to know what they were dealing with, they just misunderstood or weren't properly trained on the recovery procedure. In either case, an AoA disagree indicator wouldn't have changed the outcome.
 
freakyrat
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 4:07 pm

litz wrote:
planecane wrote:
freakyrat wrote:
Reference the AoA sensor disagree lights and Southwest. Southwest is Boeings best customer and they are not happy campers right now. Neither are the pilots at Southwest. Southwest has even been talking to Airbus about the A220. I just wonder how Boeing is going to regain their trust

Although the AoA disagree warning missing is not a good thing, it is being overblown with respect to these MCAS incidents, especially Lion Air. Since MCAS wasn't described to pilots, they would have had no idea what an AoA disagree could cause. Plus, the stick shaker on one side only would indicate a disagree anyway.


Neither airplane involved in the two crashes had the option installed that included the AoA disagree light.


That is right. The Ethiopian Crew did not exactly follow the correct procedure for the overspeed event by leaving the flaps down, lpwering the nose to 10% above the horizon and slowing the aircraft with reduced power 80% of N1 and rasing the speed brakes. They followed the runaway trim event caused by MCAS which happened after the overspeed. This is all accoerding to a B737 Captain and covered in the above posts. This would have saved the airplane and MCAS would have never triggered.

Leaving the flaps down is why the Boeing Test Pilots could make that hammerhead takeoff with the MAX at the Paris Air Show with MCAS not being triggered.
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 4:09 pm

OldAeroGuy wrote:
kalvado wrote:
I am sorry, but you're cheating by making damning assumptions before analysis. Lets try talking without prejudice.
Regardless of further plans, ET302 crew would need to (1)climb out, (2)stabilize flight, (3)contact regional ATC. Whether vectors back to airport or to destination will be requested is another question, I don't believe they requested on or the other.
So lets consider first two steps - climb out, stabilize flight - as immediate tasks.
People blame the crew for not going to fail safe mode. Fail safe at altitude is not fail safe just above the ground. Am I right?


If we examine the ET302 behavior, we find they did not do what you are suggesting.

They did not stabilize the flight. Instead, they accelerated in level flight to Vmo before initiating a climb. Vmo is well beyond normal climb speed of around 280 KIAS. While this is may be understandable as they were dealing with inappropriate MCAS activity, allowing speed to increase to Vmo was a fundamental mistake. and 1500 AGL is not "just above the ground".

Once again, you are wrong.

I can provide you a bigger picture, but then you again would jump into "they are wrong". No, sir, YOU are wrong. But I am not saying that, instead I am trying to go baby steps to bring you to that conclusion yourself
You may refuse the walk, but I think it would be an interesting one for both of us - if you drop prejudice.
Again, no MCAS yet, just a normal takeoff roll, V1... Rotate.... posi Stick shaker, airspeed disagree. Captain? Your immediate action?

What I hear - reduce thrust, control pitch, fly nice and level to the nearest tree. Any other options?
 
FluidFlow
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 4:20 pm

Chemist wrote:
FluidFlow wrote:

They definitely wanted to make it more efficient, the complete product seems to be worse than the NG as it is less safe.

They unfortunately did not make it handle the same Boeing only augmented it, on an aircraft that is grandfathered from a sixty-year-old concept.

In my opinion, the aircraft was too old for that step.


Please explain how the age of the aircraft design had anything to do with whether you can augment handling on a new revision.


Say you have an aircraft A that has 60 year old design and for example hydraulic controls and the amount of force to move the elevator is 20N.
Aircraft B is built after the design of aircraft B but has different aerodynamic forces due to new engines and it needs 40N to move the elevator.
To make them feel the same you need a tool to make both need 20N input force even a/c B actually needs 40N. You would build in an additional servo to help you (like a powersteering).

This complicates things and if it has to apply in certain situations only you need to also figure out when this help is needed and rely on sensors for functions you have not before. This leads to a long trail of possible error sources, as observed with MCAS.

If Boeing will build a 787 MAX in the future with new engines that are placed differently and generate different forces you only have to change the code that converts stick input into elevator movement.
 
DenverTed
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 4:22 pm

Boeing may indeed be correct that they followed certification rules. But that just points to the fact that the certification rules failed. Either Boeing failed to follow the rules, or the FAA rules allowed MCAS 1.0 as a legal single sensor complete command of the range of stab. There definitely is a problem that needs fixing. Who is it? Boeing or the FAA? It seems to me the question of who was in error should be determined before returning the aircraft to flight. Otherwise, there is no collateral to answer this important question. The overall safety system, system of checks and balances, and constant improvement of that system is the paramount duty. This can't be ignored.
 
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7BOEING7
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 4:26 pm

litz wrote:
planecane wrote:
freakyrat wrote:
Reference the AoA sensor disagree lights and Southwest. Southwest is Boeings best customer and they are not happy campers right now. Neither are the pilots at Southwest. Southwest has even been talking to Airbus about the A220. I just wonder how Boeing is going to regain their trust

Although the AoA disagree warning missing is not a good thing, it is being overblown with respect to these MCAS incidents, especially Lion Air. Since MCAS wasn't described to pilots, they would have had no idea what an AoA disagree could cause. Plus, the stick shaker on one side only would indicate a disagree anyway.


Neither airplane involved in the two crashes had the option installed that included the AoA disagree light.


First, it' not a light, it's an amber message down in the lower righthand corner of the PFD (Primary Flight Display) and on the HUD. When you look up AOA DISAGREE in the QRH (its not a memory item) all it says and probably will say in the future is that you may also have an airspeed and/or altitude errors/disagreements. The flight crews on both airplanes knew that already -- they were looking at it. Even if MCAS had been mentioned in the FCOM it probably would have been only one or two sentences of description like STS with no procedures. Having the message and the description would have saved neither of the flights -- a more robust system and better piloting would have.
 
XRAYretired
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:02 pm

OldAeroGuy wrote:
XRAYretired wrote:

So, we have 4 crews on 3 continents over 8 years in similar circumstances who all react initially in pretty much the same way (including all retract flaps). Why do you think that would be?

Ray


All of the crews can be faulted for not applying the Boeing procedure of not retracting Flaps after a stick shaker event.

The NG crew did not have a continuous stick shaker, in their case, it was intermittent. More importantly, they did conduct the "Unreliable Airspeed" procedure and returned to land.

With continuous stick shaker, all the MAX crews elected to continue their missions with continuous stick shaker.


OK. So what do you think the causes are that they all acted incorrectly, why wuld they have done so?

Ray
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:05 pm

FluidFlow wrote:
nikeherc wrote:
FluidFlow wrote:

I think the biggest mistake was the goal from boeing that MAX=NG.

I am no Pilot, i am no engineer but I know quiet alot about fluiddynamics and in that regard MAX=NG is by no means right. They are two different aircraft.

To try to make them equal lead to the death of 350 people.

Traing the pilots for the NEW aircraft would have helped alot as it seems their training was good enough for the OLD NG as there are statistically way less accidents witj that aircraft so the pilots are good enough but the training was not enough to change to the new one.


I don't think that the goal was to make the MAX=NG. Clearly the goal was to make the Max better than the NG. A subsidiary goal was to make the Max fly and handle like the NG. There is nothing wrong with this. The problem was in the execution.


They definitely wanted to make it more efficient, the complete product seems to be worse than the NG as it is less safe.

They unfortunately did not make it handle the same Boeing only augmented it, on an aircraft that is grandfathered from a sixty-year-old concept.

In my opinion, the aircraft was too old for that step.

Morrisond listed nicely that incidents on the FBW aircrafts from Airbus only happened with elevator inputs and it was no problem to recover from it. MCAS does change trim significantly and that can crash aircrafts rather fast. In my opinion, the mixture of FBW feature on an ancient non FBW aircraft does not work and the MAX seems to prove that.

The fault must have happened during the design. (I don’t know how the design with Boeing went but here would be the chain on the stuff I worked on)

The designers improved the aerodynamics of the NG at the drawing board. Then they put the new engines in the only position that allowed enough clearing. A model (1:3 or 1:4) was built and cramped with sensors and put into the wind tunnel.
The collected data was used in a computer simulation and that gave the result that the aircraft was not certifiable under current regulations.

There were now two options:
1) Back to the drawing board, redesign the H-stab, or the nacelles, or the main landing gear, etc.), build another model and test it again in the wind tunnel. Then another simulation and see if the result is certifiable. This would have cost a lot and would have probably taken 6 to 24 months depending on the changes necessary and if the step hat to be repeated.
2) Use a software solution to compensate for the change in aerodynamics. Cheap and fast. That is also were the first deflection in the MCAS came from. Simulations are not perfect and during flight tests it seems that more trim was needed. Instead of making a proper risk analysis at this point and return to step 1) as the input was extreme they went with it and just hoped it will all be fine. Now in the new version they want to go back to the pre-flight-testing settings but that was not enough in the first place. Will be fun to see how they justify that.

We know now which route was taken. Long story short, it would have been cheaper to delay the aircraft by the time it would have taken to redesign.


The only thing inherently wrong with MCAS is that it was poorly implemented, first relying on a single sensor, second for having essentially unlimited authority and third for not stopping when a pilot does something to directly counteract it (trimming opposite).

There is nothing wrong with the concept or unsafe when the sensor is working.

All this garbage about the 737 being too old to be updated is just agenda driven. If Boeing had made a 757MAX and required an MCAS-like system but designed it as poorly the same issues would have happened and the 757 design isn't much older than the A320. I used the 757 hypothetical because it is non-FBW.
 
XRAYretired
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:12 pm

7BOEING7 wrote:
litz wrote:
planecane wrote:
Although the AoA disagree warning missing is not a good thing, it is being overblown with respect to these MCAS incidents, especially Lion Air. Since MCAS wasn't described to pilots, they would have had no idea what an AoA disagree could cause. Plus, the stick shaker on one side only would indicate a disagree anyway.


Neither airplane involved in the two crashes had the option installed that included the AoA disagree light.


First, it' not a light, it's an amber message down in the lower righthand corner of the PFD (Primary Flight Display) and on the HUD. When you look up AOA DISAGREE in the QRH (its not a memory item) all it says and probably will say in the future is that you may also have an airspeed and/or altitude errors/disagreements. The flight crews on both airplanes knew that already -- they were looking at it. Even if MCAS had been mentioned in the FCOM it probably would have been only one or two sentences of description like STS with no procedures. Having the message and the description would have saved neither of the flights -- a more robust system and better piloting would have.


Again, I think you dismiss the situation too easily. I would suspect had AOA DISAGREE been displayed on JT043, it is likely the pilot would have recorded it, as well as IAS and Altitude, such that MX would have to address it prior to JT610 getting into the air and may well have resulted in MX taking the correct action. If AOA DISAGREE had been displayed in ET302, it might have coloured their appreciation of the situation and what subsequent actions they took.

Ray
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:19 pm

planecane wrote:
FluidFlow wrote:
nikeherc wrote:

I don't think that the goal was to make the MAX=NG. Clearly the goal was to make the Max better than the NG. A subsidiary goal was to make the Max fly and handle like the NG. There is nothing wrong with this. The problem was in the execution.


They definitely wanted to make it more efficient, the complete product seems to be worse than the NG as it is less safe.

They unfortunately did not make it handle the same Boeing only augmented it, on an aircraft that is grandfathered from a sixty-year-old concept.

In my opinion, the aircraft was too old for that step.

Morrisond listed nicely that incidents on the FBW aircrafts from Airbus only happened with elevator inputs and it was no problem to recover from it. MCAS does change trim significantly and that can crash aircrafts rather fast. In my opinion, the mixture of FBW feature on an ancient non FBW aircraft does not work and the MAX seems to prove that.

The fault must have happened during the design. (I don’t know how the design with Boeing went but here would be the chain on the stuff I worked on)

The designers improved the aerodynamics of the NG at the drawing board. Then they put the new engines in the only position that allowed enough clearing. A model (1:3 or 1:4) was built and cramped with sensors and put into the wind tunnel.
The collected data was used in a computer simulation and that gave the result that the aircraft was not certifiable under current regulations.

There were now two options:
1) Back to the drawing board, redesign the H-stab, or the nacelles, or the main landing gear, etc.), build another model and test it again in the wind tunnel. Then another simulation and see if the result is certifiable. This would have cost a lot and would have probably taken 6 to 24 months depending on the changes necessary and if the step hat to be repeated.
2) Use a software solution to compensate for the change in aerodynamics. Cheap and fast. That is also were the first deflection in the MCAS came from. Simulations are not perfect and during flight tests it seems that more trim was needed. Instead of making a proper risk analysis at this point and return to step 1) as the input was extreme they went with it and just hoped it will all be fine. Now in the new version they want to go back to the pre-flight-testing settings but that was not enough in the first place. Will be fun to see how they justify that.

We know now which route was taken. Long story short, it would have been cheaper to delay the aircraft by the time it would have taken to redesign.


The only thing inherently wrong with MCAS is that it was poorly implemented, first relying on a single sensor, second for having essentially unlimited authority and third for not stopping when a pilot does something to directly counteract it (trimming opposite).

There is nothing wrong with the concept or unsafe when the sensor is working.

All this garbage about the 737 being too old to be updated is just agenda driven. If Boeing had made a 757MAX and required an MCAS-like system but designed it as poorly the same issues would have happened and the 757 design isn't much older than the A320. I used the 757 hypothetical because it is non-FBW.

My big concern here is that program leadership lost track of what is going on. Problem of complex project is that seemingly innocent changes may bring unexpected consequencies, and everything must be done according to reluctant rules, with many signatures for a small change. Boeing seemingly failed to follow.
They implemented a system so-so, then changed parameter without clear justification. Certain indication was removed - and seemingly not communicated within the team, only to sales. WTF?
Would we also learn that 7075 was replaced with 6061 somewhere in pylon and nobody realized that? Or hose material was changed? or... there are many possibilities to screw up.

As for me, this is the main reason why I want Boeing to recognize the problem as theirs, to own it, and aim at proper plane - not at return to flight ASAP.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:39 pm

kalvado wrote:
planecane wrote:
FluidFlow wrote:

They definitely wanted to make it more efficient, the complete product seems to be worse than the NG as it is less safe.

They unfortunately did not make it handle the same Boeing only augmented it, on an aircraft that is grandfathered from a sixty-year-old concept.

In my opinion, the aircraft was too old for that step.

Morrisond listed nicely that incidents on the FBW aircrafts from Airbus only happened with elevator inputs and it was no problem to recover from it. MCAS does change trim significantly and that can crash aircrafts rather fast. In my opinion, the mixture of FBW feature on an ancient non FBW aircraft does not work and the MAX seems to prove that.

The fault must have happened during the design. (I don’t know how the design with Boeing went but here would be the chain on the stuff I worked on)

The designers improved the aerodynamics of the NG at the drawing board. Then they put the new engines in the only position that allowed enough clearing. A model (1:3 or 1:4) was built and cramped with sensors and put into the wind tunnel.
The collected data was used in a computer simulation and that gave the result that the aircraft was not certifiable under current regulations.

There were now two options:
1) Back to the drawing board, redesign the H-stab, or the nacelles, or the main landing gear, etc.), build another model and test it again in the wind tunnel. Then another simulation and see if the result is certifiable. This would have cost a lot and would have probably taken 6 to 24 months depending on the changes necessary and if the step hat to be repeated.
2) Use a software solution to compensate for the change in aerodynamics. Cheap and fast. That is also were the first deflection in the MCAS came from. Simulations are not perfect and during flight tests it seems that more trim was needed. Instead of making a proper risk analysis at this point and return to step 1) as the input was extreme they went with it and just hoped it will all be fine. Now in the new version they want to go back to the pre-flight-testing settings but that was not enough in the first place. Will be fun to see how they justify that.

We know now which route was taken. Long story short, it would have been cheaper to delay the aircraft by the time it would have taken to redesign.


The only thing inherently wrong with MCAS is that it was poorly implemented, first relying on a single sensor, second for having essentially unlimited authority and third for not stopping when a pilot does something to directly counteract it (trimming opposite).

There is nothing wrong with the concept or unsafe when the sensor is working.

All this garbage about the 737 being too old to be updated is just agenda driven. If Boeing had made a 757MAX and required an MCAS-like system but designed it as poorly the same issues would have happened and the 757 design isn't much older than the A320. I used the 757 hypothetical because it is non-FBW.

My big concern here is that program leadership lost track of what is going on. Problem of complex project is that seemingly innocent changes may bring unexpected consequencies, and everything must be done according to reluctant rules, with many signatures for a small change. Boeing seemingly failed to follow.
They implemented a system so-so, then changed parameter without clear justification. Certain indication was removed - and seemingly not communicated within the team, only to sales. WTF?
Would we also learn that 7075 was replaced with 6061 somewhere in pylon and nobody realized that? Or hose material was changed? or... there are many possibilities to screw up.

As for me, this is the main reason why I want Boeing to recognize the problem as theirs, to own it, and aim at proper plane - not at return to flight ASAP.

I agree with you that program/engineering Management screwed up royally. I also agree that ALL changes made from NG to MAX should be reviewed by regulators before return to flight. This will get "another set of eyes" on the design/implementation.

If the program was properly managed there is nothing inherently wrong or unsafe about updating the "ancient" 737 to the MAX.
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:47 pm

kalvado wrote:
You may refuse the walk, but I think it would be an interesting one for both of us - if you drop prejudice.
Again, no MCAS yet, just a normal takeoff roll, V1... Rotate.... posi Stick shaker, airspeed disagree. Captain? Your immediate action?

What I hear - reduce thrust, control pitch, fly nice and level to the nearest tree. Any other options?


Yes, Pitch, Power and Monitor Performance.

At no time was ET302 in danger of flying into any tree or terrain prior to Flaps retraction.

And if they had followed the Boeing procedures for "Stick Shaker/Buffet" and "Unreliable Airspeed", they also would not have been in danger either.

You are making things up.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:52 pm

XRAYretired wrote:

OK. So what do you think the causes are that they all acted incorrectly, why wuld they have done so?

Ray


Good question. I suspect its lack of training/awareness for scenario.

For me, a nagging question is the erroneous AoA vane signal rate. Maybe one in 8 years and two/three in five months? Why so many recently?
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
lexiion
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Joined: Sun Nov 29, 2015 5:54 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:56 pm

OldAeroGuy wrote:
XRAYretired wrote:

OK. So what do you think the causes are that they all acted incorrectly, why wuld they have done so?

Ray


Good question. I suspect its lack of training/awareness for scenario.

For me, a nagging question is the erroneous AoA vane signal rate. Maybe one in 8 years and two/three in five months? Why so many recently?


The suspicion here is not the AoA sensor itself, but rather the wiring, ADIRU, etc. That has been mentioned a couple of times in the previous thread.

LEXiiON
 
GalaxyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 5:59 pm

OldAeroGuy wrote:
kalvado wrote:
I am sorry, but you're cheating by making damning assumptions before analysis. Lets try talking without prejudice.
Regardless of further plans, ET302 crew would need to (1)climb out, (2)stabilize flight, (3)contact regional ATC. Whether vectors back to airport or to destination will be requested is another question, I don't believe they requested on or the other.
So lets consider first two steps - climb out, stabilize flight - as immediate tasks.
People blame the crew for not going to fail safe mode. Fail safe at altitude is not fail safe just above the ground. Am I right?


If we examine the ET302 behavior, we find they did not do what you are suggesting.

They did not stabilize the flight. Instead, they accelerated in level flight to Vmo before initiating a climb. Vmo is well beyond normal climb speed of around 280 KIAS. While this is may be understandable as they were dealing with inappropriate MCAS activity, allowing speed to increase to Vmo was a fundamental mistake. and 1500 AGL is not "just above the ground".

Once again, you are wrong.


To add, the first priority to maintain aircraft control, BEFORE any QRH or SOP. The crew failed. Lots of reasons but they did not maintain aircraft control. Despite the failings of MCAS, which wasn’t a factor until flap retraction, they didn’t set power to control airspeed, slower is better here; they apparently tried to use the autopilot, wrong idea with a stall shaker. Even with the flaps retracted, they could have used the electric trim switch to trim out the MCAS inputs until the got the plane at some semblance of trim and turned off the trim motor power. Once off, and speed contained at something around 229-250 knots, a return flown visually.

I think the instinct to engage the autopilot reveals a tendency to rely on it and might show a degradation of manual flight skills. Or a lack of confidence in same.

GF
 
morrisond
Posts: 1398
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 6:25 pm

Jamie514 wrote:
morrisond wrote:
Jamie514 wrote:

It seems they told the truth.



It may be a fantastic source of reporting, but any new information must be independently verified. It is impossible to do so with undisclosed sources. And it turns out it may not be accurate.



Thank you very much for this.


You've got it backwards - the AVHerald report came after the official Pre-lim report - they are basically saying the pre-lim report is full of s**t.

Nice partial quoting btw.


Please. You are now not only choosing to believe Boeing over Ethiopian. You are now choosing to believe unverifiable data from an unaccredited website over findings of the official investigation.

I will only grant that at some future time it may turn out that the training document AVHerald cites is real, but until that time, it is unproven conspiracy theory you are touting as a smoking gun here.

In post 97, I asked you:
Has AVHerald actually concluded that Pilot training provided by Ethiopian was the primary cause of the crash? Far as I could see, he only sees it as a POSSIBLE contributing factor, which I would agree with.


And instead of offering his conclusion, you offered unverifiable evidence.

Speaking of partial quoting, 5 paragraphs below what you think is the smoking gun training documents revelation, AVHerald did reach this conclusion,

Primary cause of the accident:
- MCAS activation based on a single faulty AoA sensor input without cross check or plausibility check of the incoming AoA value, which caused the stabilizer to reach a position that could no longer be compensated by elevator inputs

Primary contributing factors int the accident:

- A false AoA value, probably produced by the Air Data Reference unit rather than a mechanical fault, which activated the stick shaker and MCAS.
- aircraft systems not adhering to principles of Cockpit Resource Management CRM (MCAS, Stick Shaker, Air Data Reference Unit, AoA, Trim CUTOUT switches)

Possibly contributing factors into the accident:
- Corporate Culture within Boeing in designing aircraft
- Corporate Culture within FAA in certifying aircraft
- Corporate Culture in Ethiopian Airlines, which did not ensure their flight crew were fully aware of the implications of the LionAir Crash and the related EAD as well as Boeing and FAA approved emergency procedures
- Less than optimal crew performance, e.g. loss of situational awareness with respect to speed and thrust


You are using AVHerald to support your argument as if he was crusading it as the primary cause. It is in reality, the very bottom of his list. At the very top are MCAS, Boeing, FAA, Aircraft Systems.


I never said Pilot training was the primary cause of the crash. There were multiple causes.

Who knows who is right - however the ET document does show a revision date of Feb .21 - it took them almost 4 months to revise it and then did they actually distribute it? Taking 4 months to revise something is not indicative of a strong safety environment.
 
kalvado
Posts: 2022
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 6:28 pm

OldAeroGuy wrote:
kalvado wrote:
You may refuse the walk, but I think it would be an interesting one for both of us - if you drop prejudice.
Again, no MCAS yet, just a normal takeoff roll, V1... Rotate.... posi Stick shaker, airspeed disagree. Captain? Your immediate action?

What I hear - reduce thrust, control pitch, fly nice and level to the nearest tree. Any other options?


Yes, Pitch, Power and Monitor Performance.

At no time was ET302 in danger of flying into any tree or terrain prior to Flaps retraction.

And if they had followed the Boeing procedures for "Stick Shaker/Buffet" and "Unreliable Airspeed", they also would not have been in danger either.

You are making things up.

So what kind of climb gradient would they get?
 
XRAYretired
Posts: 632
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 6:46 pm

lexiion wrote:
OldAeroGuy wrote:
XRAYretired wrote:

OK. So what do you think the causes are that they all acted incorrectly, why wuld they have done so?

Ray


Good question. I suspect its lack of training/awareness for scenario.

For me, a nagging question is the erroneous AoA vane signal rate. Maybe one in 8 years and two/three in five months? Why so many recently?


The suspicion here is not the AoA sensor itself, but rather the wiring, ADIRU, etc. That has been mentioned a couple of times in the previous thread.

LEXiiON


Also mentioned that no one has come up with a sceanario that works for ADIRU or wiring, but AOA problem fits the data we have comfortably.


Ray
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 6:50 pm

morrisond wrote:
Jamie514 wrote:
morrisond wrote:

You've got it backwards - the AVHerald report came after the official Pre-lim report - they are basically saying the pre-lim report is full of s**t.

Nice partial quoting btw.


Please. You are now not only choosing to believe Boeing over Ethiopian. You are now choosing to believe unverifiable data from an unaccredited website over findings of the official investigation.

I will only grant that at some future time it may turn out that the training document AVHerald cites is real, but until that time, it is unproven conspiracy theory you are touting as a smoking gun here.

In post 97, I asked you:
Has AVHerald actually concluded that Pilot training provided by Ethiopian was the primary cause of the crash? Far as I could see, he only sees it as a POSSIBLE contributing factor, which I would agree with.


And instead of offering his conclusion, you offered unverifiable evidence.

Speaking of partial quoting, 5 paragraphs below what you think is the smoking gun training documents revelation, AVHerald did reach this conclusion,

Primary cause of the accident:
- MCAS activation based on a single faulty AoA sensor input without cross check or plausibility check of the incoming AoA value, which caused the stabilizer to reach a position that could no longer be compensated by elevator inputs

Primary contributing factors int the accident:

- A false AoA value, probably produced by the Air Data Reference unit rather than a mechanical fault, which activated the stick shaker and MCAS.
- aircraft systems not adhering to principles of Cockpit Resource Management CRM (MCAS, Stick Shaker, Air Data Reference Unit, AoA, Trim CUTOUT switches)

Possibly contributing factors into the accident:
- Corporate Culture within Boeing in designing aircraft
- Corporate Culture within FAA in certifying aircraft
- Corporate Culture in Ethiopian Airlines, which did not ensure their flight crew were fully aware of the implications of the LionAir Crash and the related EAD as well as Boeing and FAA approved emergency procedures
- Less than optimal crew performance, e.g. loss of situational awareness with respect to speed and thrust


You are using AVHerald to support your argument as if he was crusading it as the primary cause. It is in reality, the very bottom of his list. At the very top are MCAS, Boeing, FAA, Aircraft Systems.


I never said Pilot training was the primary cause of the crash. There were multiple causes.

Who knows who is right - however the ET document does show a revision date of Feb .21 - it took them almost 4 months to revise it and then did they actually distribute it? Taking 4 months to revise something is not indicative of a strong safety environment.


You must be extremely lucking with coin tossing, comes down on the same one side every time. Latest revision does not mean only!


Ray
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 6:52 pm

kalvado wrote:

I am sorry, but you're cheating by making damning assumptions before analysis. Lets try talking without prejudice.
Regardless of further plans, ET302 crew would need to (1)climb out, (2)stabilize flight, (3)contact regional ATC. Whether vectors back to airport or to destination will be requested is another question, I don't believe they requested on or the other.
So lets consider first two steps - climb out, stabilize flight - as immediate tasks.
People blame the crew for not going to fail safe mode. Fail safe at altitude is not fail safe just above the ground. Am I right?


What OAG is saying is correct and backed up by published QRH/Memory items.


XRAYretired wrote:
So, we have 4 crews on 3 continents over 8 years in similar circumstances who all react initially in pretty much the same way (including all retract flaps). Why do you think that would be?

Ray


That is the million dollar question, why didn’t the crew follow the published procedures for stick shaker. That was the first thing that presented itself, then followed by airspeed and altitude problems.

By not dealing with the issues that presented first correctly they only then got into MCAS.

The JT flight from SUB to CGK actually ran some of the checklists and they lived to tell about it. I still do not understand why anyone would think it is ok to do an entire flight with the stick shaker activated.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:00 pm

XRAYretired wrote:
lexiion wrote:
OldAeroGuy wrote:

Good question. I suspect its lack of training/awareness for scenario.

For me, a nagging question is the erroneous AoA vane signal rate. Maybe one in 8 years and two/three in five months? Why so many recently?


The suspicion here is not the AoA sensor itself, but rather the wiring, ADIRU, etc. That has been mentioned a couple of times in the previous thread.

LEXiiON


Also mentioned that no one has come up with a sceanario that works for ADIRU or wiring, but AOA problem fits the data we have comfortably.


Ray


From AVherald:

....Prior to flight JT-43 the left AoA sensor (which was still the one mounted by Boeing during aircraft assembly) was replaced by LionAir maintenance due to repetitive similiar malfunctions on the flights before JT-43, the new AoA sensor on flights JT-43 and JT-610 however showed repetitive malfunctions again, on JT-43 the crew was able to correct, on JT-610 the crew however was not able to correct and crashed....
....On Apr 27th 2019 it became known, that four independent whistleblowers, current and former Boeing employees, had called the FAA hotline for whistleblowers regarding aviation safety concerns on Apr 5th 2019. The concerns reported were wiring damage to the AoA related wiring as result of foreign object damage as well as concerns with the TRIM CUTOUT switches. The FAA believes these reports may open completely new investigative angles into the causes of the two crashes in Indonesia and Ethiopia.......

I still believe the incorrect AoA data did not come from a faulty sensor. But we'll know when we have the final reports, I guess.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:01 pm

zeke wrote:
kalvado wrote:

I am sorry, but you're cheating by making damning assumptions before analysis. Lets try talking without prejudice.
Regardless of further plans, ET302 crew would need to (1)climb out, (2)stabilize flight, (3)contact regional ATC. Whether vectors back to airport or to destination will be requested is another question, I don't believe they requested on or the other.
So lets consider first two steps - climb out, stabilize flight - as immediate tasks.
People blame the crew for not going to fail safe mode. Fail safe at altitude is not fail safe just above the ground. Am I right?


What OAG is saying is correct and backed up by published QRH/Memory items.

Yes, that was mentioned many times. But again - what is the climb gradient achieved by these procedures?
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:03 pm

kalvado wrote:
[
Yes, that was mentioned many times. But again - what is the climb gradient achieved by these procedures?


Probably in excess of 10%, not relevant to the discussion.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:06 pm

zeke wrote:
kalvado wrote:

I am sorry, but you're cheating by making damning assumptions before analysis. Lets try talking without prejudice.
Regardless of further plans, ET302 crew would need to (1)climb out, (2)stabilize flight, (3)contact regional ATC. Whether vectors back to airport or to destination will be requested is another question, I don't believe they requested on or the other.
So lets consider first two steps - climb out, stabilize flight - as immediate tasks.
People blame the crew for not going to fail safe mode. Fail safe at altitude is not fail safe just above the ground. Am I right?


What OAG is saying is correct and backed up by published QRH/Memory items.


XRAYretired wrote:
So, we have 4 crews on 3 continents over 8 years in similar circumstances who all react initially in pretty much the same way (including all retract flaps). Why do you think that would be?

Ray


That is the million dollar question, why didn’t the crew follow the published procedures for stick shaker. That was the first thing that presented itself, then followed by airspeed and altitude problems.

By not dealing with the issues that presented first correctly they only then got into MCAS.

The JT flight from SUB to CGK actually ran some of the checklists and they lived to tell about it. I still do not understand why anyone would think it is ok to do an entire flight with the stick shaker activated.


Hardly, the plane trimmed itself into the ground. That's the million dollar question.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:13 pm

kalvado wrote:
zeke wrote:
kalvado wrote:

I am sorry, but you're cheating by making damning assumptions before analysis. Lets try talking without prejudice.
Regardless of further plans, ET302 crew would need to (1)climb out, (2)stabilize flight, (3)contact regional ATC. Whether vectors back to airport or to destination will be requested is another question, I don't believe they requested on or the other.
So lets consider first two steps - climb out, stabilize flight - as immediate tasks.
People blame the crew for not going to fail safe mode. Fail safe at altitude is not fail safe just above the ground. Am I right?


What OAG is saying is correct and backed up by published QRH/Memory items.

Yes, that was mentioned many times. But again - what is the climb gradient achieved by these procedures?


According to Boeing - Procedure is Flaps up Set N1 75% and 4 Degrees Pitch Up and Flaps Down 80% N1 and 10 Degrees Pitch Up

In Boeing's words

"These pitch and power settings provide a simple reference setting for the crew to use for a short period of time while the initial steps of the checklist are accomplished. These settings do not ensure a level flight or constant airspeed at any particular altitude/airspeed/weight combination. However, they do ensure that at any and all weight/altitude combinations, the aircraft will accelerate from low speeds, and slow from a high speeds, as we cannot assume the aircraft is in stable flight when the NNC is run. It is more likely that the crew or the autopilot has destabilized the airplane as a result of erroneous airspeed indications prior to identification of the need to run the NNC. These memory item pitch and power settings often result in a significant climb (from lower altitudes) and can also result in a gradual descent (from higher altitudes)."

It sounds like the procedure would have really helped ET.

The only possible terrain they had was just off the nose at 2,500 AGL.

If you look at this Topographic Tool they would have also had an additional 5,000' below the plane in elevation if they veered slightly right as the Great Rift Valley opened up in front of them - giving them 12,000+' to deal with any consequences of reducing thrust and the nose possibly dropping.

http://en-gb.topographic-map.com/places ... a-8976505/
Last edited by morrisond on Thu May 02, 2019 7:15 pm, edited 1 time in total.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:14 pm

SEU wrote:

Hardly, the plane trimmed itself into the ground. That's the million dollar question.


If they had followed the procedures for stick shaker, MCAS would never have activated.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:27 pm

morrisond wrote:
People aren't disagreeing on the proper procedures they should have taken - as we learn more about the accident we realize how many things they missed on ET302.

Some realize that - as we learn more about the accident - the Boeing instructions were not very clear, ambigious at best, or just poor at worst.


morrisond wrote:
No one has proven that at least ET properly provided or trained there pilots with the information they needed to save the plane either and it's been reported they made almost no effort - how is that Boeing's fault?

It could be argued (heck, it's been going on for over 100 thread pages) that the Boeing instructions were not clear, and not suited for MCAS failures. Sure, there were instructions for runaway trim, but MCAS failure has different characteristics as what the 737 world has been trained for the last 40 years.


morrisond wrote:
Lionair continued to use a bad system 22 times - how is that symbolic of good airmanship or training - how is that Boeing's fault?

Well, they had a lot of warnings and failures. They knew electric trimming worked for them. Why limit your controllability options when your having control issues? It did certainly not work for ET.


morrisond wrote:
Yes in retrospect MCAS could have been more robust but it was not required to be so (assuming Boeing isn't lying which might be a stretch) and what basic level of airmanship should they be required to design too?

To the same level as 737 NG would be a good start, as the "poorly trianed (third world) pilot comunity" have no apparent issues with that.


morrisond wrote:
Should the pilots only be required to press a big green button that says start and a red one that says stop and the plane should do the rest including account for any parts failures? Yes that would be nice but we are not there yet in terms of automation and probably won't be until we get robust AI and have well trained pilots in the cockpit to train the AI for a good ten years or so.

Nobody is asking for that. I don't understand why you would bring the discussion into such ridiculous extremes, when it is for everyone clearly not needed.
BTW, I do wonder how much AI (if at all) would be needed for autonomous flight to be more safe than human operated flights.


morrisond wrote:
The only reason we are seeing the deficiencies in training is because the planes are so reliable and safe these days that they are never apparent.

And as 737NG, A320, A350, 787 etc safety numbers learns, that seems to be focussed on the MAX specifically. How is that not Boeing's fault?


morrisond wrote:
However almost all the major tragedies in the world in the past 10-15 years have largely been a result of bad training and failure to respond properly to failures in critical systems.

It has been listed previously, none of the new designs or derivatives in this century have had fatal crashes. Not one. Only the MAX, and not just one, even two fatal accidents. And that in just two years.


Now I'm not saying, nor claiming, that there are no training issues. But putting so much emphasize on that as you do, is closing the eyes to the real issues wiht the MAX, IMHO.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:29 pm

morrisond wrote:
Jamie514 wrote:
morrisond wrote:
No one has proven that at least ET properly provided or trained there pilots with the information they needed to save the plane either and it's been reported they made almost no effort - how is that Boeing's fault?


Proper training has been claimed publicly on the airlines official twitter on March 21.

It appears you are choosing to believe the unproven claims made by one organization over another.


I believe AVherald (Which has a fantastic reputation) a lot more than I believe the Airline who was possibly responsible for not training there pilots properly.

Of course ET is going to say that - what do you expect them to publicly admit they never taught there pilots the proper procedures to deal with a runaway MCAS failure?


What training did the pilots not get? Did Boeing define any MCAS related training/instructions?
It is my impression that only after the groundung Boeing started working on MCAS instructions and training. The last official message from Boeing prior to the grounding, was reminder (!) to use Trim Cut Out Switches. Which was followed by the ET crew. Which strongly suggests that they did get this message . . .
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:35 pm

morrisond wrote:
What Pilot competency standard should Airbus and Boeing have to design too?

If Boeing is not lying they designed to the existing standard. The crew are allowed as a back up system in all modern designs by all Manufacturers.


Which was apparently the case before the MCAS parameters were drastically changed during the flight test program. However MCAS authority and speed was increased to such levels, that using pilots as back-up system was no longer valid as your average airline pilot is not expected to observe, trouble shoot and understand the safety critical effects of MCAS failure in timely fashion.

So Boeing perhaps did design to the existing standard, but that was not how the final product was delivered.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:44 pm

PW100 wrote:
morrisond wrote:
Jamie514 wrote:

Proper training has been claimed publicly on the airlines official twitter on March 21.

It appears you are choosing to believe the unproven claims made by one organization over another.


I believe AVherald (Which has a fantastic reputation) a lot more than I believe the Airline who was possibly responsible for not training there pilots properly.

Of course ET is going to say that - what do you expect them to publicly admit they never taught there pilots the proper procedures to deal with a runaway MCAS failure?


What training did the pilots not get? Did Boeing define any MCAS related training/instructions?
It is my impression that only after the groundung Boeing started working on MCAS instructions and training. The last official message from Boeing prior to the grounding, was reminder (!) to use Trim Cut Out Switches. Which was followed by the ET crew. Which strongly suggests that they did get this message . . .


I miss wrote this statement up thread and corrected it.

Boeing published the procedures that would have saved the crew if they had followed them Correctly on Nov 9.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:48 pm

PW100 wrote:
morrisond wrote:
People aren't disagreeing on the proper procedures they should have taken - as we learn more about the accident we realize how many things they missed on ET302.

Some realize that - as we learn more about the accident - the Boeing instructions were not very clear, ambigious at best, or just poor at worst.


morrisond wrote:
No one has proven that at least ET properly provided or trained there pilots with the information they needed to save the plane either and it's been reported they made almost no effort - how is that Boeing's fault?

It could be argued (heck, it's been going on for over 100 thread pages) that the Boeing instructions were not clear, and not suited for MCAS failures. Sure, there were instructions for runaway trim, but MCAS failure has different characteristics as what the 737 world has been trained for the last 40 years.


morrisond wrote:
Lionair continued to use a bad system 22 times - how is that symbolic of good airmanship or training - how is that Boeing's fault?

Well, they had a lot of warnings and failures. They knew electric trimming worked for them. Why limit your controllability options when your having control issues? It did certainly not work for ET.


morrisond wrote:
Yes in retrospect MCAS could have been more robust but it was not required to be so (assuming Boeing isn't lying which might be a stretch) and what basic level of airmanship should they be required to design too?

To the same level as 737 NG would be a good start, as the "poorly trianed (third world) pilot comunity" have no apparent issues with that.


morrisond wrote:
Should the pilots only be required to press a big green button that says start and a red one that says stop and the plane should do the rest including account for any parts failures? Yes that would be nice but we are not there yet in terms of automation and probably won't be until we get robust AI and have well trained pilots in the cockpit to train the AI for a good ten years or so.

Nobody is asking for that. I don't understand why you would bring the discussion into such ridiculous extremes, when it is for everyone clearly not needed.
BTW, I do wonder how much AI (if at all) would be needed for autonomous flight to be more safe than human operated flights.


morrisond wrote:
The only reason we are seeing the deficiencies in training is because the planes are so reliable and safe these days that they are never apparent.

And as 737NG, A320, A350, 787 etc safety numbers learns, that seems to be focussed on the MAX specifically. How is that not Boeing's fault?


morrisond wrote:
However almost all the major tragedies in the world in the past 10-15 years have largely been a result of bad training and failure to respond properly to failures in critical systems.

It has been listed previously, none of the new designs or derivatives in this century have had fatal crashes. Not one. Only the MAX, and not just one, even two fatal accidents. And that in just two years.


Now I'm not saying, nor claiming, that there are no training issues. But putting so much emphasize on that as you do, is closing the eyes to the real issues wiht the MAX, IMHO.


The instructions weren't unclear - I'm not going to find it for you as it's in the other thread but apparently the instructions that the crew would have seen - had return the plane to In-Trim using Electric right at the top of the page.

I've asked it a few times - what type of Emergencies should crew have to deal with then?
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:52 pm

XRAYretired wrote:
7BOEING7 wrote:
litz wrote:

Neither airplane involved in the two crashes had the option installed that included the AoA disagree light.


First, it' not a light, it's an amber message down in the lower righthand corner of the PFD (Primary Flight Display) and on the HUD. When you look up AOA DISAGREE in the QRH (its not a memory item) all it says and probably will say in the future is that you may also have an airspeed and/or altitude errors/disagreements. The flight crews on both airplanes knew that already -- they were looking at it. Even if MCAS had been mentioned in the FCOM it probably would have been only one or two sentences of description like STS with no procedures. Having the message and the description would have saved neither of the flights -- a more robust system and better piloting would have.


Again, I think you dismiss the situation too easily. I would suspect had AOA DISAGREE been displayed on JT043, it is likely the pilot would have recorded it, as well as IAS and Altitude, such that MX would have to address it prior to JT610 getting into the air and may well have resulted in MX taking the correct action. If AOA DISAGREE had been displayed in ET302, it might have coloured their appreciation of the situation and what subsequent actions they took.

Ray


The pilot may or may not have recorded it had it been available, but I would imagine all that information would have been available to maintenance while troubleshooting the issues -- the black boxes (not the orange "black boxes") tell all these days -- pilots have never been good at providing all the information that shows up in front of them.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:52 pm

morrisond wrote:
"These pitch and power settings provide a simple reference setting for the crew to use for a short period of time while the initial steps of the checklist are accomplished. These settings do not ensure a level flight or constant airspeed at any particular altitude/airspeed/weight combination. However, they do ensure that at any and all weight/altitude combinations, the aircraft will accelerate from low speeds, and slow from a high speeds, as we cannot assume the aircraft is in stable flight when the NNC is run. It is more likely that the crew or the autopilot has destabilized the airplane as a result of erroneous airspeed indications prior to identification of the need to run the NNC. These memory item pitch and power settings often result in a significant climb (from lower altitudes) and can also result in a gradual descent (from higher altitudes).

zeke wrote:
kalvado wrote:
[
Yes, that was mentioned many times. But again - what is the climb gradient achieved by these procedures?


Probably in excess of 10%, not relevant to the discussion.


Honestly speaking, things don't quite add up.
Boeing doesn't guarantee climb, while Zeke talks about 200-2500 fpm; and that is for a heavy plane right after takeoff.
I suspect it is "climb not guaranteed" is the core reason to hesitate.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 7:58 pm

PW100 wrote:
morrisond wrote:
People aren't disagreeing on the proper procedures they should have taken - as we learn more about the accident we realize how many things they missed on ET302.

Some realize that - as we learn more about the accident - the Boeing instructions were not very clear, ambigious at best, or just poor at worst.


morrisond wrote:
No one has proven that at least ET properly provided or trained there pilots with the information they needed to save the plane either and it's been reported they made almost no effort - how is that Boeing's fault?

It could be argued (heck, it's been going on for over 100 thread pages) that the Boeing instructions were not clear, and not suited for MCAS failures. Sure, there were instructions for runaway trim, but MCAS failure has different characteristics as what the 737 world has been trained for the last 40 years.


morrisond wrote:
Lionair continued to use a bad system 22 times - how is that symbolic of good airmanship or training - how is that Boeing's fault?

Well, they had a lot of warnings and failures. They knew electric trimming worked for them. Why limit your controllability options when your having control issues? It did certainly not work for ET.


morrisond wrote:
Yes in retrospect MCAS could have been more robust but it was not required to be so (assuming Boeing isn't lying which might be a stretch) and what basic level of airmanship should they be required to design too?

To the same level as 737 NG would be a good start, as the "poorly trianed (third world) pilot comunity" have no apparent issues with that.


morrisond wrote:
Should the pilots only be required to press a big green button that says start and a red one that says stop and the plane should do the rest including account for any parts failures? Yes that would be nice but we are not there yet in terms of automation and probably won't be until we get robust AI and have well trained pilots in the cockpit to train the AI for a good ten years or so.

Nobody is asking for that. I don't understand why you would bring the discussion into such ridiculous extremes, when it is for everyone clearly not needed.
BTW, I do wonder how much AI (if at all) would be needed for autonomous flight to be more safe than human operated flights.


morrisond wrote:
The only reason we are seeing the deficiencies in training is because the planes are so reliable and safe these days that they are never apparent.

And as 737NG, A320, A350, 787 etc safety numbers learns, that seems to be focussed on the MAX specifically. How is that not Boeing's fault?


morrisond wrote:
However almost all the major tragedies in the world in the past 10-15 years have largely been a result of bad training and failure to respond properly to failures in critical systems.

It has been listed previously, none of the new designs or derivatives in this century have had fatal crashes. Not one. Only the MAX, and not just one, even two fatal accidents. And that in just two years.


Now I'm not saying, nor claiming, that there are no training issues. But putting so much emphasize on that as you do, is closing the eyes to the real issues wiht the MAX, IMHO.


Would a MCAS failure not have presented materially different to the crew than an bad Electric Trim Switch that defaulted to the down position internally when released on an intermittent basis? Is this not a failure they should have been able to handle?
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:00 pm

kalvado wrote:
Honestly speaking, things don't quite add up.
Boeing doesn't guarantee climb, while Zeke talks about 200-2500 fpm; and that is for a heavy plane right after takeoff.
I suspect it is "climb not guaranteed" is the core reason to hesitate.


I said at least 10%, that at leat 700 fpm, probably would be able to achieve at least 1000 or 15%.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:00 pm

kalvado wrote:
morrisond wrote:
"These pitch and power settings provide a simple reference setting for the crew to use for a short period of time while the initial steps of the checklist are accomplished. These settings do not ensure a level flight or constant airspeed at any particular altitude/airspeed/weight combination. However, they do ensure that at any and all weight/altitude combinations, the aircraft will accelerate from low speeds, and slow from a high speeds, as we cannot assume the aircraft is in stable flight when the NNC is run. It is more likely that the crew or the autopilot has destabilized the airplane as a result of erroneous airspeed indications prior to identification of the need to run the NNC. These memory item pitch and power settings often result in a significant climb (from lower altitudes) and can also result in a gradual descent (from higher altitudes).

zeke wrote:
kalvado wrote:
[
Yes, that was mentioned many times. But again - what is the climb gradient achieved by these procedures?


Probably in excess of 10%, not relevant to the discussion.


Honestly speaking, things don't quite add up.
Boeing doesn't guarantee climb, while Zeke talks about 200-2500 fpm; and that is for a heavy plane right after takeoff.
I suspect it is "climb not guaranteed" is the core reason to hesitate.


Flaps down 10 Degree Pitch up and 80% N1 would have produced a significant climb at Airfield elevation to where they got too. 94% was TOGA thrust not climb thrust.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:01 pm

7BOEING7 wrote:
XRAYretired wrote:
7BOEING7 wrote:

First, it' not a light, it's an amber message down in the lower righthand corner of the PFD (Primary Flight Display) and on the HUD. When you look up AOA DISAGREE in the QRH (its not a memory item) all it says and probably will say in the future is that you may also have an airspeed and/or altitude errors/disagreements. The flight crews on both airplanes knew that already -- they were looking at it. Even if MCAS had been mentioned in the FCOM it probably would have been only one or two sentences of description like STS with no procedures. Having the message and the description would have saved neither of the flights -- a more robust system and better piloting would have.


Again, I think you dismiss the situation too easily. I would suspect had AOA DISAGREE been displayed on JT043, it is likely the pilot would have recorded it, as well as IAS and Altitude, such that MX would have to address it prior to JT610 getting into the air and may well have resulted in MX taking the correct action. If AOA DISAGREE had been displayed in ET302, it might have coloured their appreciation of the situation and what subsequent actions they took.

Ray


The pilot may or may not have recorded it had it been available, but I would imagine all that information would have been available to maintenance while troubleshooting the issues -- the black boxes (not the orange "black boxes") tell all these days -- pilots have never been good at providing all the information that shows up in front of them.


Did'nt get the chance did they.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:01 pm

nikeherc wrote:
As I understand it, the symptoms of MCAS failure and runaway trim are pretty much identical. Also as I understand it, solution for both is to deactivate the automatic trim and manually trim. Additionally, as I understand it, although there was not specific simulator training for MCAS failure, there is simulator training for runaway trim. Further, as I understand it, the Lion Air plane had experienced multiple failures immediately prior to its final flight, with no resolution. Additionally, as I have read, the Ethiopian pilots raised the flaps when the procedures in the QRH called for not changing aircraft configuration. It has been reported that had the Ethiopian pilots not raised the flaps, MCAS would not have activated. Every airplane has failure modes and procedures to deal with them. It seems to me that we are dealing both human and design problems. The pilots would have been better served by a more robust software design, better absorption of their training and better maintenance actions. There is plenty of blame to go around

Boeing deserves its share of the blame, the airlines must share some of the blame and the pilots are not without flaw either. Many people commenting on this site, whether predisposed to prejudice or not are describing these events in absolute terms. The pilots were absolutely incompetent, Boeing knowing designed and built an absolutely unsafe plane, if Boeing did not deliberately build an unsafe airplane then they must be criminally negligent or worse.

Some of us are defending Boeing absolutely, some of us are condemning Boeing unconditionally. Some of us blame the pilots or airlines totally. Very few folks take a balanced view of this situation. I beg of you think before you type and then think again several times before you hit submit. Don't over simplify or over complicate.

Thank you for your consideration.


Great post!

Just one thing I would like to add: your wrote that "there is plenty of blame to go around". Totally agree. But just keep in mind that it is an attractive trap to put blame on pilots, which no longer live to tell and can not defend themselves. Who is going to step up for them? Whereas it is apparently very difficult to blame a big company thanks to their huge legal departments. So in that respect, it is by no means a level playing field, if one can use those kind of words. Therefore it would be appropriate for the former (blame crew) to carry a bit more evidence, than for the latter (blame Boeing).
Also, the manufacturer should take crew faults deeply into consideration. Which luckily has been the case for the last 30 - 40 years. And which is why aviation has become so safe these days. And which was the reason for introducing MCAS in the first place . . .
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kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:02 pm

morrisond wrote:
PW100 wrote:
morrisond wrote:
People aren't disagreeing on the proper procedures they should have taken - as we learn more about the accident we realize how many things they missed on ET302.

Some realize that - as we learn more about the accident - the Boeing instructions were not very clear, ambigious at best, or just poor at worst.


morrisond wrote:
No one has proven that at least ET properly provided or trained there pilots with the information they needed to save the plane either and it's been reported they made almost no effort - how is that Boeing's fault?

It could be argued (heck, it's been going on for over 100 thread pages) that the Boeing instructions were not clear, and not suited for MCAS failures. Sure, there were instructions for runaway trim, but MCAS failure has different characteristics as what the 737 world has been trained for the last 40 years.


morrisond wrote:
Lionair continued to use a bad system 22 times - how is that symbolic of good airmanship or training - how is that Boeing's fault?

Well, they had a lot of warnings and failures. They knew electric trimming worked for them. Why limit your controllability options when your having control issues? It did certainly not work for ET.


morrisond wrote:
Yes in retrospect MCAS could have been more robust but it was not required to be so (assuming Boeing isn't lying which might be a stretch) and what basic level of airmanship should they be required to design too?

To the same level as 737 NG would be a good start, as the "poorly trianed (third world) pilot comunity" have no apparent issues with that.


morrisond wrote:
Should the pilots only be required to press a big green button that says start and a red one that says stop and the plane should do the rest including account for any parts failures? Yes that would be nice but we are not there yet in terms of automation and probably won't be until we get robust AI and have well trained pilots in the cockpit to train the AI for a good ten years or so.

Nobody is asking for that. I don't understand why you would bring the discussion into such ridiculous extremes, when it is for everyone clearly not needed.
BTW, I do wonder how much AI (if at all) would be needed for autonomous flight to be more safe than human operated flights.


morrisond wrote:
The only reason we are seeing the deficiencies in training is because the planes are so reliable and safe these days that they are never apparent.

And as 737NG, A320, A350, 787 etc safety numbers learns, that seems to be focussed on the MAX specifically. How is that not Boeing's fault?


morrisond wrote:
However almost all the major tragedies in the world in the past 10-15 years have largely been a result of bad training and failure to respond properly to failures in critical systems.

It has been listed previously, none of the new designs or derivatives in this century have had fatal crashes. Not one. Only the MAX, and not just one, even two fatal accidents. And that in just two years.


Now I'm not saying, nor claiming, that there are no training issues. But putting so much emphasize on that as you do, is closing the eyes to the real issues wiht the MAX, IMHO.


Would a MCAS failure not have presented materially different to the crew than an bad Electric Trim Switch that defaulted to the down position internally when released on an intermittent basis? Is this not a failure they should have been able to handle?

And this is exactly why electric trim up is unfeasible in this emergency. You don't know if problem observed is logical, or loose contact; if electric trim can safely be used or it will make things worse as wires touch in unknown fascion. Until, of course, an extensive troubleshooting can be performed in 10 second MCAS off window.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:08 pm

kalvado wrote:
Armodeen wrote:
Except we don’t do we? The road casualty rate has plummeted in modern times, levelling off at what is probably near the minimum possible without greater automation. This has been made possible by massive public campaigns (seatbelts, drinking and driving etc) and ever tighter legislation on safety features. Accident prone roads have been redesigned even.

Life is very safe these days, we live in lucky times.

PW100 wrote:

And yet, aviation, transportation, infrastructure, construction, you name it, has never been more safe than today. We tend to lose sight on how safe these things are. Really.

Side-step: we want government to protect us against a handfull of aviations accidents (or terrorist related deaths), but without even blinking an eye readily accept thousands and thousands of road deaths as normal practice. Go figure.

The best way to reduce road casualties is reinstate the Prohibition. We know how that turned out the first time, though.


Perhaps in your country, but not here in the Netherlands.
No.1 would be disable smart phones while driving.
No.2 would be black box and car video system showing how drivers disrespected road laws and regulations, and using that to hold them repsonsible for their own actions in case of accident.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:17 pm

morrisond wrote:
It turned out, that only very cursory knowledge about the stab trim runaway procedure exists amongst the flight crew of Ethiopian Airlines even 5 months after the EAD was distributed. In particular, none of the conditions suggesting an MCAS related stab trim runaway was known with any degree of certainty. In that context the recommendation by the accident flight's first officer to use the TRIM CUTOUT switches suggests, that he was partially aware of the contents of the EAD and reproduced some but not all of the provisions and not all of the procedure, which may or may not explain some of the obvious omissions in following the procedure in full."


There is no evidence the crew had "only very cursory knowledge about the stab trim runaway procedure".

Also, that is not what the EAD was about. The AD was just a reminder to use that procedure at certain conditions.

And thirdly, the ET crew DID use the Trim Cut Out Switches. Which strongly suggests that they DID receive the EAD message.
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:18 pm

morrisond wrote:
kalvado wrote:
morrisond wrote:
"These pitch and power settings provide a simple reference setting for the crew to use for a short period of time while the initial steps of the checklist are accomplished. These settings do not ensure a level flight or constant airspeed at any particular altitude/airspeed/weight combination. However, they do ensure that at any and all weight/altitude combinations, the aircraft will accelerate from low speeds, and slow from a high speeds, as we cannot assume the aircraft is in stable flight when the NNC is run. It is more likely that the crew or the autopilot has destabilized the airplane as a result of erroneous airspeed indications prior to identification of the need to run the NNC. These memory item pitch and power settings often result in a significant climb (from lower altitudes) and can also result in a gradual descent (from higher altitudes).

zeke wrote:

Probably in excess of 10%, not relevant to the discussion.


Honestly speaking, things don't quite add up.
Boeing doesn't guarantee climb, while Zeke talks about 200-2500 fpm; and that is for a heavy plane right after takeoff.
I suspect it is "climb not guaranteed" is the core reason to hesitate.


Flaps down 10 Degree Pitch up and 80% N1 would have produced a significant climb at Airfield elevation to where they got too. 94% was TOGA thrust not climb thrust.

What I have in mind is that plane was not destabilised at that point as BOeing assumed; so completing takeoff sequence should be reasonably safe. But by the time they should be reducing from takeoff thrust, things became too busy, and they never got that done.
Procedure we're discussing does not guarantee climb, although probably provides climb. From the topo map, there is some mild rise in terrain for the first minute or 2 of runway heading flight, and a bit of distance before they clear off the plateau.
So I can imagine that completing climb out in a planned fashion and switching to fail safe mode could work in NG, without taking a sink chance .
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:24 pm

PW100 wrote:
morrisond wrote:
It turned out, that only very cursory knowledge about the stab trim runaway procedure exists amongst the flight crew of Ethiopian Airlines even 5 months after the EAD was distributed. In particular, none of the conditions suggesting an MCAS related stab trim runaway was known with any degree of certainty. In that context the recommendation by the accident flight's first officer to use the TRIM CUTOUT switches suggests, that he was partially aware of the contents of the EAD and reproduced some but not all of the provisions and not all of the procedure, which may or may not explain some of the obvious omissions in following the procedure in full."


There is no evidence the crew had "only very cursory knowledge about the stab trim runaway procedure".

Also, that is not what the EAD was about. The AD was just a reminder to use that procedure at certain conditions.

And thirdly, the ET crew DID use the Trim Cut Out Switches. Which strongly suggests that they DID receive the EAD message.


Those were AVHeralds words - not mine.

I know the ET crew did use the Trim cut out switches and suggested that as the Co-pilot had just gone through the SIM that is why he might have known about it. The pilot sure didn't seem to know anything about it.

However if MCAS was taught in the SIM - he for sure forgot about putting the plane back in trim before hitting the swtiches to turn it of.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:24 pm

PW100 wrote:
kalvado wrote:
Armodeen wrote:
Except we don’t do we? The road casualty rate has plummeted in modern times, levelling off at what is probably near the minimum possible without greater automation. This has been made possible by massive public campaigns (seatbelts, drinking and driving etc) and ever tighter legislation on safety features. Accident prone roads have been redesigned even.

Life is very safe these days, we live in lucky times.


The best way to reduce road casualties is reinstate the Prohibition. We know how that turned out the first time, though.


Perhaps in your country, but not here in the Netherlands.
No.1 would be disable smart phones while driving.
No.2 would be black box and car video system showing how drivers disrespected road laws and regulations, and using that to hold them repsonsible for their own actions in case of accident.

It drifts off-topic, but in US about 1/3 of accidents are alcohol related. Things get even worse with pedestrian accidents - like half of adult male accidents are alcohol. That is with higher alcohol threshold than in most of europe. But US also has generally higher traffic accident rate.
 
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:29 pm

morrisond wrote:
PixelFlight wrote:
morrisond wrote:

Yes - but it was an Airbus 330 with a FBW system where it tried to put the plane in the ground.

ADIRU fault generating unbelievable, still unexplained, repetitive spike data without triggering any integrity test + FC algorithm design error that was never catch before because nobody was able to think that a such repetitive spike data could be possible in reality. The algorithm was corrected. This ADIRU was analyzed but never sent such repetitive spike data anymore, nobody known why. Safety assessment was evaluated and found ok.


Yes a systems problem put the A330 into a dive and the crew was able to save it - Good crew.


Yes, the crew was able to save it by pulling back on the yoke (and other things).

Which (pulling back on the yoke) does not work for the MAX - Bad Plane. Must be one the most scrariest things that can happen to a pilot.
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Planetalk
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:32 pm

sgrow787 wrote:
PW100 wrote:
And yet, aviation, transportation, infrastructure, construction, you name it, has never been more safe than today. We tend to lose sight on how safe these things are. Really.

Side-step: we want government to protect us against a handfull of aviations accidents (or terrorist related deaths), but without even blinking an eye readily accept thousands and thousands of road deaths as normal practice. Go figure.


I get so tired of hearing people compare commercial air miles to miles in cars on busy multi-lane mult-connected roadways. Why don't we compare using the time spent (ie hours)?

Car passengers
Car owners in 2018: 276,100,000
Avg miles per passenger per year: 10,000 miles
Avg speed: 30 mph
Hours driving per year per passenger: 333 hours
Total hours driving per year: 92,033,333,333 hours
Deaths per year (not including alcohol related): 40000 - 10000 = 30000
# driving hours per death: 3,067,778

Plane passengers
Airplane deaths per trillion revenue passenger kilometers in 2018: 60
(from https://en.wikipedia.org/wiki/Aviation_ ... t_(cropped).png)
Airplane deaths per trillion revenue passenger miles in 2018: 60 * 1.60934 = 97
Avg # passengers per flight: 100
Avg flight time: 2 hours
Avg flight cruise speed: 475 kts
Avg flight cruise time: 1.67 hours
Avg flight cruise distance: 793 miles
Avg descent and approach speed: 200 kts
Avg descent and approach time: 0.33 hours (20 minutes)
Avg descent and approach distance: 66 miles
Avg flight speed: 430 kts
Avg # flights per day: 43000 (from https://www.faa.gov/air_traffic/by_the_numbers)
Total # flights per year: 15,695,000
Total flight miles per year: 13,485,928,750
Total Revenue Passenger Miles: 1,348,592,875,000
Total Expected Passenger Deaths: 130
Total Revenue Passenger Hours: 3,139,000,000
# passenger flying hours per death: 24,105,237

Summary: Airplane travel is safer than automobile travel by a factor of 8 to 1.


Which means on a per journey basis they're not far apart at all, as some academics have already shown (statistics you won't hear much from the industry). It's generally a complete nonsense about the drive to the airport being the most dangerous part of your trip. Given the choice most people would probably choose being in a car crash over watching the ground hurtling towards them as well ....

I believe train travel is by some margin the actual safest form.
 
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:35 pm

OldAeroGuy wrote:
XRAYretired wrote:

So, we have 4 crews on 3 continents over 8 years in similar circumstances who all react initially in pretty much the same way (including all retract flaps). Why do you think that would be?

Ray


All of the crews can be faulted for not applying the Boeing procedure of not retracting Flaps after a stick shaker event.

The NG crew did not have a continuous stick shaker, in their case, it was intermittent. More importantly, they did conduct the "Unreliable Airspeed" procedure and returned to land.

With continuous stick shaker, all the MAX crews elected to continue their missions with continuous stick shaker.


Didn't we've had a rather hefty discussion with respect to "continuous and intermittent" earlier in this thread . . . . ?
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kayik
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 02, 2019 8:35 pm

Seems to be the common practice...

A metals manufacturer faked test results and provided faulty materials to NASA, causing more than $700 million (roughly Rs. 4,900 crores) in losses and two failed satellite launch missions, according to an investigation by the US space agency.

The fraud involved an Oregon company called Sapa Profiles, which falsified thousands of certifications for aluminium parts over 19 years for hundreds of customers, including NASA.


https://gadgets.ndtv.com/science/news/n ... re-2031938

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