DenverTed
Posts: 161
Joined: Wed Mar 27, 2019 11:12 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:10 am

Free the MAX. Is it definitively known if MCAS was needed for certification? Or was it just optional to decrease training from the NG. Is there a definitive statement on this from Boeing or the FAA?

Seems like the most basic question for Boeing or the FAA to answer to regain credibility with other agencies, and the flying public like myself.
 
morrisond
Posts: 1103
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:17 am

kalvado wrote:
morrisond wrote:
kalvado wrote:
Thanks for proving my point. There shouldn't be twenty different versions describing same procedure. Hire qualified document control professionals, good technical writers, qualified engineers. This is not rocket science after all, this is a catastrophic lack of training among Boeing workforce!


So the pilots are going to ignore what is in there manuals and go by the AD? That's really weak.

I am not acquitting pilots of all blame, I am just bringing up the topic of Boeing workforce qualification. Everyone pretends MCAS is a mistake - no, it has to be a systematic failure due to poor training!


You are quite possibly right on this - it's probably not a great idea to keep firing and rehiring engineers all the time - you lose tribal knowledge.
 
morrisond
Posts: 1103
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:18 am

RickNRoll wrote:
morrisond wrote:
mjoelnir wrote:

Yes victims first of Boeing's negligent design and than the callous disregard in taking no action after the Lion Air accident.


Umm - they published procedures that if they had been followed we would not be having this discussion.


Umm - they published a procedure that waited for MCAS to try to plant the plane in the ground when there was another procedure available that would have prevented it ever activating. Going for the minimal response to safety was what got us here in the first place.


You mean the non-normal airspeed procedure where they never would have got to MCAS procedure anyways if they had never retracted the flaps?
 
User avatar
JerseyFlyer
Posts: 1325
Joined: Fri May 25, 2007 7:24 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 7:12 am

1. Additional taining is "not needed" to transfer from NG to MAX
2. Flying NG is "safe"
3. Flying MAX is "unsafe" due to poor training

Please resolve!
 
FluidFlow
Posts: 128
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 7:39 am

For some on topic information, Boeing is getting hit with more lawsuits and compensation demands:

https://www.bbc.com/news/business-48362283

https://edition.cnn.com/2019/05/21/europe/french-widow-sues-boeing-intl/index.html
 
mjoelnir
Posts: 8361
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 9:56 am

morrisond wrote:
RickNRoll wrote:
morrisond wrote:

Umm - they published procedures that if they had been followed we would not be having this discussion.


Umm - they published a procedure that waited for MCAS to try to plant the plane in the ground when there was another procedure available that would have prevented it ever activating. Going for the minimal response to safety was what got us here in the first place.


You mean the non-normal airspeed procedure where they never would have got to MCAS procedure anyways if they had never retracted the flaps?


The non normal airspeed hit them after MCAS pushed the nose down. If Boeing would have explained MCAS, how it works, what the failure modes would be, offered serious training and so on, before and when the first 737MAX were delivered, Boeing would not have killed over 300 people with a dangerous design.
After Lion Air Boeing had a second chance to stop killing people with there dangerous frames.
 
mjoelnir
Posts: 8361
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 11:00 am

planecane wrote:
mjoelnir wrote:
planecane wrote:

Please post links to the sources of these simulator sessions. I have not seen one where they simulated recovery from the beginning of the MCAS-induced runaway stabilizer. I have seen the aviation week simulator session where they started with the electric trim cut off and recovered using the manual trim wheel and roller coaster procedure from higher altitude.


Read the thread, was posted here, why should I do that work for you?


Because none of the simulations I've seen posted have attempted to simulate recovery starting from the beginning of the MCAS runaway. If you know of one, then I'd like you to point me to it since you are using them as part of your argument that they "just managed to avoid crash." That is only relevant if they are simulating starting from the point of failure.


The information about pilots doing it on a simulator was posted here no video. Sometimes it is necessary to read information instead of watching it.
 
bcg
Posts: 2
Joined: Sat Apr 27, 2019 9:35 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 11:08 am

https://www.ft.com/content/f66729d2-7be ... 85092ab560

European agency’s demands on Boeing signal rift among regulators
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 11:13 am

mjoelnir wrote:
planecane wrote:
mjoelnir wrote:

Read the thread, was posted here, why should I do that work for you?


Because none of the simulations I've seen posted have attempted to simulate recovery starting from the beginning of the MCAS runaway. If you know of one, then I'd like you to point me to it since you are using them as part of your argument that they "just managed to avoid crash." That is only relevant if they are simulating starting from the point of failure.


The information about pilots doing it on a simulator was posted here no video. Sometimes it is necessary to read information instead of watching it.


Assuming you are referring to the aviation week simulation, that was simulating trying to recover after the electric trim was cut off, not recover from the start of the emergency.
 
FluidFlow
Posts: 128
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 11:22 am

bcg wrote:
https://www.ft.com/content/f66729d2-7bee-11e9-81d2-f785092ab560

European agency’s demands on Boeing signal rift among regulators


Here a free to read version if you cant access the FT article:

https://www.irishtimes.com/business/manufacturing/european-agency-s-demands-on-boeing-signal-rift-among-regulators-1.3900462

The three demands of the EASA:

The conditions are: that any design changes by Boeing are EASA approved and mandated; that an additional independent design review being conducted by the agency is completed; and that Max flight crews “have been adequately trained”.
 
User avatar
PW100
Posts: 3559
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 11:22 am

morrisond wrote:
mjoelnir wrote:
Revelation wrote:
OK then, I'll take it at face value that your newly voiced sympathy for accident victims is more genuine than your emnity for so many things you've repeated so many times on this forum.


Yes victims first of Boeing's negligent design and than the callous disregard in taking no action after the Lion Air accident.


Umm - they published procedures that if they had been followed we would not be having this discussion.


We don't know they did not follow procedures. In fact we know very little of their actions and motivations. We certainly know the result, but we don't know why the crew did what and what not and why not. We don't even have a full CVR transcript.
Way too early to conclude they did not follow published procedures. Perhaps the published procedures were not appropriate for the issues they faced.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
User avatar
PW100
Posts: 3559
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 11:27 am

planecane wrote:
mjoelnir wrote:
planecane wrote:

Please post links to the sources of these simulator sessions. I have not seen one where they simulated recovery from the beginning of the MCAS-induced runaway stabilizer. I have seen the aviation week simulator session where they started with the electric trim cut off and recovered using the manual trim wheel and roller coaster procedure from higher altitude.


Read the thread, was posted here, why should I do that work for you?


Because none of the simulations I've seen posted have attempted to simulate recovery starting from the beginning of the MCAS runaway. If you know of one, then I'd like you to point me to it since you are using them as part of your argument that they "just managed to avoid crash." That is only relevant if they are simulating starting from the point of failure.


The metourpilot video closely resembles the air speed conditions of ET first MCAS cycle:
https://www.youtube.com/watch?v=aoNOVlxJmow
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 11:36 am

PW100 wrote:
planecane wrote:
mjoelnir wrote:

Read the thread, was posted here, why should I do that work for you?


Because none of the simulations I've seen posted have attempted to simulate recovery starting from the beginning of the MCAS runaway. If you know of one, then I'd like you to point me to it since you are using them as part of your argument that they "just managed to avoid crash." That is only relevant if they are simulating starting from the point of failure.


The metourpilot video closely resembles the air speed conditions of ET first MCAS cycle:
https://www.youtube.com/watch?v=aoNOVlxJmow


Yes but this is demonstrating using the manual trim wheel. mjoelnir's implication is that American pilots in simulators, knowing all about the crashes, barely recovered from an MCAS runaway stabilizer. I have not seen any simulation it read a report of one that simulates if running the NNC makes for an easy recovery or not. It has been established that if the aircraft is significantly mistrimmed and the pilot is pulling back on the control column with a lot of force, using the manual trim wheel is extremely difficult.

However, that fact is being used (both here and by media) to imply that recovery using the published procedure is very difficult but they are two completely different things.
 
User avatar
PixelFlight
Posts: 426
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 11:40 am

FluidFlow wrote:
bcg wrote:
https://www.ft.com/content/f66729d2-7bee-11e9-81d2-f785092ab560

European agency’s demands on Boeing signal rift among regulators


Here a free to read version if you cant access the FT article:

https://www.irishtimes.com/business/manufacturing/european-agency-s-demands-on-boeing-signal-rift-among-regulators-1.3900462

The three demands of the EASA:

The conditions are: that any design changes by Boeing are EASA approved and mandated; that an additional independent design review being conducted by the agency is completed; and that Max flight crews “have been adequately trained”.

Thanks for the quote.

I found the wording no precise enough. "any design changes" could be from the 737-800/900 NG or could be from the initial 737-8/9 MAX.
The news is that the training is now officially on the target, hitting the initial Boeing promise for the 737-8/9 MAX. It must be noted that this "adequate" training will be specific to the 737-8/9 MAX, otherwise others models must logically be grounded as well. This additional specific training was not available to the pilots that was killed.

For the public, I don't see how an aircraft that need additional specific training could be perceived as safe as all the others aircrafts.
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 12:57 pm

PixelFlight wrote:
FluidFlow wrote:
bcg wrote:
https://www.ft.com/content/f66729d2-7bee-11e9-81d2-f785092ab560

European agency’s demands on Boeing signal rift among regulators


Here a free to read version if you cant access the FT article:

https://www.irishtimes.com/business/manufacturing/european-agency-s-demands-on-boeing-signal-rift-among-regulators-1.3900462

The three demands of the EASA:

The conditions are: that any design changes by Boeing are EASA approved and mandated; that an additional independent design review being conducted by the agency is completed; and that Max flight crews “have been adequately trained”.

Thanks for the quote.

I found the wording no precise enough. "any design changes" could be from the 737-800/900 NG or could be from the initial 737-8/9 MAX.
The news is that the training is now officially on the target, hitting the initial Boeing promise for the 737-8/9 MAX. It must be noted that this "adequate" training will be specific to the 737-8/9 MAX, otherwise others models must logically be grounded as well. This additional specific training was not available to the pilots that was killed.

For the public, I don't see how an aircraft that need additional specific training could be perceived as safe as all the others aircrafts.


The wording could be better but it seems clear from the context that the are talking about changes from the original MAX.
 
User avatar
PW100
Posts: 3559
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 12:57 pm

planecane wrote:
mjoelnir wrote:
Saintor wrote:

Wrong. It is the result of a crew in an horrible situation who didn't monitor their speed, care or know to turn off the auto-throttle. Boeing can thrive on this gross negligence.


Thrust has far less influence on speed than pitch, reducing thrust pitches the nose further down. Again a red herring in the relentless attacks on the crew. Boeing is responsible for MCAS and the sudden aggressive nose down pitch commands.


This post is exactly what I mean about people with an anti-Boeing agenda posting authoritative sounding things that are not correct. There is a difference between PITCH and PITCH TRIM. If you look at the FDR traces, the PITCH TRIM was positioned nose down by MCAS. The pilots were fighting this with the control column (and some electric trim). The PITCH remained at or above the angle that it was prior to MCAS kicking in for just about the entire time until the final MCAS nose down PITCH TRIM command about 20 seconds before impact.

Therefore you are wrong about MCAS causing the evolution of the airspeed, which continued to increase while the PITCH was neutral or even 5-10 degrees nose up.

Your post is essentially making things up in order to absolve the crew of any possible mistakes.


The pitch and air speed profile upto first MCAS failure was (if I understand correctly) fairly in line with what other crews did with AoA disagree and stick shaker. IAS around 250 kts.
Upto the first MCAS cycle, FDR graph suggests that things were pretty much under control. It is from first MCAS cycle that things started to get away from the crew.

Look not only at PITCH and PITCH TRIM, also pay attention to CTRL COLUMN POS. to understand the struggle from the first MCAS cycle on. The struggle which only started on first MCAS cycle, and did not stop until there was crater in the ground.

Therefore it does not seem far-fetched to see a correlation between "evolution of air speed" (not my term btw) and MCAS.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
User avatar
PW100
Posts: 3559
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 1:01 pm

planecane wrote:
On the training front, you are missing the big picture. In my opinion, the training issues that exist are not specific to the 737MAX. We can't know for sure until the final reports on both crashes, but I do not believe, based on available evidence, that either crew would have recovered from a runaway stabilizer in a 737NG given all other factors being the same at the time of the runaway. The runaway stabilizer NNC is supposed to be a memory item. If my belief is proven by the final reports with full CVR transcripts, it is highly concerning that there are issues with an NNC that is a memory item.


How often did an actual stabilizer runaway happen on NG series? Is there any data available on that?
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
User avatar
PW100
Posts: 3559
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 1:07 pm

morrisond wrote:
kalvado wrote:
morrisond wrote:

You are thinking of the AD and not what was actually in the FCOM that the pilots rely on which has return the trim to neutral in the first paragraph - not much ambiguity in that.

Thanks for proving my point. There shouldn't be twenty different versions describing same procedure. Hire qualified document control professionals, good technical writers, qualified engineers. This is not rocket science after all, this is a catastrophic lack of training among Boeing workforce!


So the pilots are going to ignore what is in there manuals and go by the AD? That's really weak.


AD overrules any manual section it may apply to. That is exactly its intention and authority.

How is that weak (other than on the document writer's end)???
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
User avatar
PW100
Posts: 3559
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 1:21 pm

planecane wrote:
PW100 wrote:
planecane wrote:

Because none of the simulations I've seen posted have attempted to simulate recovery starting from the beginning of the MCAS runaway. If you know of one, then I'd like you to point me to it since you are using them as part of your argument that they "just managed to avoid crash." That is only relevant if they are simulating starting from the point of failure.


The metourpilot video closely resembles the air speed conditions of ET first MCAS cycle:
https://www.youtube.com/watch?v=aoNOVlxJmow


Yes but this is demonstrating using the manual trim wheel. mjoelnir's implication is that American pilots in simulators, knowing all about the crashes, barely recovered from an MCAS runaway stabilizer. I have not seen any simulation it read a report of one that simulates if running the NNC makes for an easy recovery or not. It has been established that if the aircraft is significantly mistrimmed and the pilot is pulling back on the control column with a lot of force, using the manual trim wheel is extremely difficult.


Well, you wrote ". . . simulate recovery starting from the beginning of the MCAS runaway . . .".
In terms of flight characteristics, the referenced video is fairly close to the ET situation from the beginning of MCAS runaway.

I will not dispute that better trained pilots (and I'll ignore type specifics here), would/could/should have done a better job in in the 75 seconds before MCAS became alive. However once MCAS activated, I'm not convinced that most other crews would have done a better job than the ET crew.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
morrisond
Posts: 1103
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 2:32 pm

PW100 wrote:
morrisond wrote:
kalvado wrote:
Thanks for proving my point. There shouldn't be twenty different versions describing same procedure. Hire qualified document control professionals, good technical writers, qualified engineers. This is not rocket science after all, this is a catastrophic lack of training among Boeing workforce!


So the pilots are going to ignore what is in there manuals and go by the AD? That's really weak.


AD overrules any manual section it may apply to. That is exactly its intention and authority.

How is that weak (other than on the document writer's end)???


Yes and when the AD is released the FCOM needs to be updated as per the AD and it is the FCOM that they follow.
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 2:44 pm

PW100 wrote:
planecane wrote:
On the training front, you are missing the big picture. In my opinion, the training issues that exist are not specific to the 737MAX. We can't know for sure until the final reports on both crashes, but I do not believe, based on available evidence, that either crew would have recovered from a runaway stabilizer in a 737NG given all other factors being the same at the time of the runaway. The runaway stabilizer NNC is supposed to be a memory item. If my belief is proven by the final reports with full CVR transcripts, it is highly concerning that there are issues with an NNC that is a memory item.


How often did an actual stabilizer runaway happen on NG series? Is there any data available on that?


I have been able to find any data which leads to my assumption is that it extremely rare. That is why I think the training issue may not be specific to the MAX. It is very possible that the reason that there have been no runaway stabilizer crashes on the NG is because it has either never happened or only happened a handful of times with luckily well-trained crews. I think that there could very well be an issue in general with recognition of runaway stabilizer and executing the memory item NNC.

The reason I am very interested to see the transcript of the Lion Air CVR, is that I want to know if runaway stabilizer was discussed at all. I just can't imagine that they discussed the possibility and concluded not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous.

My opinion on this whole MCAS debacle is that MCAS caused the rate of occurance of runaway stabilizer to increase by several orders of magnitude over prior 737 models but that there are probably a large percentage of 737 pilots that don't have the training or understanding to recognize and respond to any runaway stabilizer.
 
FluidFlow
Posts: 128
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 2:46 pm

I just came across this: https://riskandinsurance.com/grounding-of-the-boeing-737-max-8/

Now it is a bit older but I guess the essential part still stands:

He said Boeing has $500 million in coverage for grounding liability and that underwriters began setting aside reserves before the grounding was even announced.


So the first 500Mio will be covered. Interesting will be what the premium is, especially after considering there was already a grounding not so long ago with the 787. Chances are, that the premiums for Boeing will increase sharply for the next few years, and Boeing might decide to ditch insurance for grounding. This is a risky strategy because if there is then another grounding, Boeing will have to carry the full costs and class action lawsuits will have it easier to succeed.

Also mentioned:

Catastrophic disasters like this only strengthen the resolve of aviation underwriters aiming to increase rates and premiums. It’s an already expensive business with attritional losses — like scrapes and abrasions, wingtips hitting each other or fire suppression systems going off and ruining jet engines.

“Just the daily grind runs between $500 million and $750 million per year,” said Meinhardt.


If underwriters will see the MAX as a higher risk in the future and increase premiums for MAX operators, the business case for Boeing will get harder, especially if also additional training will be mandated.
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 2:48 pm

PW100 wrote:
planecane wrote:
mjoelnir wrote:

Thrust has far less influence on speed than pitch, reducing thrust pitches the nose further down. Again a red herring in the relentless attacks on the crew. Boeing is responsible for MCAS and the sudden aggressive nose down pitch commands.


This post is exactly what I mean about people with an anti-Boeing agenda posting authoritative sounding things that are not correct. There is a difference between PITCH and PITCH TRIM. If you look at the FDR traces, the PITCH TRIM was positioned nose down by MCAS. The pilots were fighting this with the control column (and some electric trim). The PITCH remained at or above the angle that it was prior to MCAS kicking in for just about the entire time until the final MCAS nose down PITCH TRIM command about 20 seconds before impact.

Therefore you are wrong about MCAS causing the evolution of the airspeed, which continued to increase while the PITCH was neutral or even 5-10 degrees nose up.

Your post is essentially making things up in order to absolve the crew of any possible mistakes.


The pitch and air speed profile upto first MCAS failure was (if I understand correctly) fairly in line with what other crews did with AoA disagree and stick shaker. IAS around 250 kts.
Upto the first MCAS cycle, FDR graph suggests that things were pretty much under control. It is from first MCAS cycle that things started to get away from the crew.

Look not only at PITCH and PITCH TRIM, also pay attention to CTRL COLUMN POS. to understand the struggle from the first MCAS cycle on. The struggle which only started on first MCAS cycle, and did not stop until there was crater in the ground.

Therefore it does not seem far-fetched to see a correlation between "evolution of air speed" (not my term btw) and MCAS.


I don't disagree with what you are saying but mjoelnir is saying that the "evolution of air speed" as he coined it was caused by MCAS forcing the nose down. That is not the case as the crew was able to keep the pitch nose up by exerting the force on the control column. The "evolution of air speed" occurred because they left the engines at takeoff thrust, not because the pitch angle was negative. That same speed increase made it more difficult to maintain the pitch and also helped to make it nearly impossible (if they tried) to move the stabilizer with the manual trim wheel.
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:01 pm

PW100 wrote:
planecane wrote:
PW100 wrote:

The metourpilot video closely resembles the air speed conditions of ET first MCAS cycle:
https://www.youtube.com/watch?v=aoNOVlxJmow


Yes but this is demonstrating using the manual trim wheel. mjoelnir's implication is that American pilots in simulators, knowing all about the crashes, barely recovered from an MCAS runaway stabilizer. I have not seen any simulation it read a report of one that simulates if running the NNC makes for an easy recovery or not. It has been established that if the aircraft is significantly mistrimmed and the pilot is pulling back on the control column with a lot of force, using the manual trim wheel is extremely difficult.


Well, you wrote ". . . simulate recovery starting from the beginning of the MCAS runaway . . .".
In terms of flight characteristics, the referenced video is fairly close to the ET situation from the beginning of MCAS runaway.

I will not dispute that better trained pilots (and I'll ignore type specifics here), would/could/should have done a better job in in the 75 seconds before MCAS became alive. However once MCAS activated, I'm not convinced that most other crews would have done a better job than the ET crew.


That video is about using the manual trim wheel. The correct simulation to determine how easily recoverable an MCAS-induced runaway stabilizer (if using an NG simulator) would be to set the trim to full nose down and then have the pilots run the NNC. After they have stopped trimming wait 9 seconds and have somebody start moving the trim nose down again (because the NNC says that if the runaway continues to move the switches to cutout) and see how long it takes for them to move the switches to cutout and how far out of trim was reached by that time. THEN use the manual wheel to recover from that point.
 
kalvado
Posts: 1729
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:07 pm

planecane wrote:
PW100 wrote:
planecane wrote:
On the training front, you are missing the big picture. In my opinion, the training issues that exist are not specific to the 737MAX. We can't know for sure until the final reports on both crashes, but I do not believe, based on available evidence, that either crew would have recovered from a runaway stabilizer in a 737NG given all other factors being the same at the time of the runaway. The runaway stabilizer NNC is supposed to be a memory item. If my belief is proven by the final reports with full CVR transcripts, it is highly concerning that there are issues with an NNC that is a memory item.


How often did an actual stabilizer runaway happen on NG series? Is there any data available on that?


I have been able to find any data which leads to my assumption is that it extremely rare. That is why I think the training issue may not be specific to the MAX. It is very possible that the reason that there have been no runaway stabilizer crashes on the NG is because it has either never happened or only happened a handful of times with luckily well-trained crews. I think that there could very well be an issue in general with recognition of runaway stabilizer and executing the memory item NNC.

The reason I am very interested to see the transcript of the Lion Air CVR, is that I want to know if runaway stabilizer was discussed at all. I just can't imagine that they discussed the possibility and concluded not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous.

My opinion on this whole MCAS debacle is that MCAS caused the rate of occurance of runaway stabilizer to increase by several orders of magnitude over prior 737 models but that there are probably a large percentage of 737 pilots that don't have the training or understanding to recognize and respond to any runaway stabilizer.

As far as I understand, trim runaway was one of teething problems. There was a comment upstream that Boeing replaced switches used in early 737 with a more reliable model (double contacts, so double failure is required for runaway - probability drops like a rock); and I assume wiring and relay quality improved. So major sources of problem are eliminated and problem description hangs around as part of legacy. Time spent on trim runaway training can now be dedicated to some more pressing issues (e.g. runway overruns). Single mention of procedure is as much as you can justify.
Same as with MCAS: probability of further problems is all but totally eliminated; but it will be a (useless) part of training cirriculum for decades to come.
Not realizing that is... well, probably understandable if system integrators were hired off the street and never were in 737 cockpit either before or during the project.
 
User avatar
PixelFlight
Posts: 426
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:16 pm

morrisond wrote:
PW100 wrote:
morrisond wrote:

So the pilots are going to ignore what is in there manuals and go by the AD? That's really weak.


AD overrules any manual section it may apply to. That is exactly its intention and authority.

How is that weak (other than on the document writer's end)???


Yes and when the AD is released the FCOM needs to be updated as per the AD and it is the FCOM that they follow.

So if the FCOM is per AD, then the information in the FCOM are the same as in the AD. Two possibilities:
1) The FCOM contain the same information than in the AD, no point in ignoring the FCOM and go to the AD.
2) The FCOM did not contain the same information than in the AD, the FCOM was not maintained as required by the AD. Fixing this go to point 1).
 
XRAYretired
Posts: 367
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:30 pm

PixelFlight wrote:
morrisond wrote:
PW100 wrote:

AD overrules any manual section it may apply to. That is exactly its intention and authority.

How is that weak (other than on the document writer's end)???


Yes and when the AD is released the FCOM needs to be updated as per the AD and it is the FCOM that they follow.

So if the FCOM is per AD, then the information in the FCOM are the same as in the AD. Two possibilities:
1) The FCOM contain the same information than in the AD, no point in ignoring the FCOM and go to the AD.
2) The FCOM did not contain the same information than in the AD, the FCOM was not maintained as required by the AD. Fixing this go to point 1).

The relevant parts of the ETH FCOM are copierd in the Preliminary Report. Look the same as the AD to me.

Ray
 
User avatar
PixelFlight
Posts: 426
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:30 pm

planecane wrote:
PW100 wrote:
planecane wrote:
On the training front, you are missing the big picture. In my opinion, the training issues that exist are not specific to the 737MAX. We can't know for sure until the final reports on both crashes, but I do not believe, based on available evidence, that either crew would have recovered from a runaway stabilizer in a 737NG given all other factors being the same at the time of the runaway. The runaway stabilizer NNC is supposed to be a memory item. If my belief is proven by the final reports with full CVR transcripts, it is highly concerning that there are issues with an NNC that is a memory item.


How often did an actual stabilizer runaway happen on NG series? Is there any data available on that?


I have been able to find any data which leads to my assumption is that it extremely rare. That is why I think the training issue may not be specific to the MAX. It is very possible that the reason that there have been no runaway stabilizer crashes on the NG is because it has either never happened or only happened a handful of times with luckily well-trained crews. I think that there could very well be an issue in general with recognition of runaway stabilizer and executing the memory item NNC.

The reason I am very interested to see the transcript of the Lion Air CVR, is that I want to know if runaway stabilizer was discussed at all. I just can't imagine that they discussed the possibility and concluded not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous.

My opinion on this whole MCAS debacle is that MCAS caused the rate of occurance of runaway stabilizer to increase by several orders of magnitude over prior 737 models but that there are probably a large percentage of 737 pilots that don't have the training or understanding to recognize and respond to any runaway stabilizer.

Great. You make a good step forward today! :thumbsup:
The "MCAS caused the rate of occurance of runaway stabilizer to increase by several orders of magnitude over prior 737 models" is the fundamental reason why the 737-8/9 MAX is grounded.
The "not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous" is caused by the lack of appropriate procedure and specific training for that situation unique to the 737-8/9 MAX.
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:35 pm

kalvado wrote:
planecane wrote:
PW100 wrote:

How often did an actual stabilizer runaway happen on NG series? Is there any data available on that?


I have been able to find any data which leads to my assumption is that it extremely rare. That is why I think the training issue may not be specific to the MAX. It is very possible that the reason that there have been no runaway stabilizer crashes on the NG is because it has either never happened or only happened a handful of times with luckily well-trained crews. I think that there could very well be an issue in general with recognition of runaway stabilizer and executing the memory item NNC.

The reason I am very interested to see the transcript of the Lion Air CVR, is that I want to know if runaway stabilizer was discussed at all. I just can't imagine that they discussed the possibility and concluded not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous.

My opinion on this whole MCAS debacle is that MCAS caused the rate of occurance of runaway stabilizer to increase by several orders of magnitude over prior 737 models but that there are probably a large percentage of 737 pilots that don't have the training or understanding to recognize and respond to any runaway stabilizer.

As far as I understand, trim runaway was one of teething problems. There was a comment upstream that Boeing replaced switches used in early 737 with a more reliable model (double contacts, so double failure is required for runaway - probability drops like a rock); and I assume wiring and relay quality improved. So major sources of problem are eliminated and problem description hangs around as part of legacy. Time spent on trim runaway training can now be dedicated to some more pressing issues (e.g. runway overruns). Single mention of procedure is as much as you can justify.
Same as with MCAS: probability of further problems is all but totally eliminated; but it will be a (useless) part of training cirriculum for decades to come.
Not realizing that is... well, probably understandable if system integrators were hired off the street and never were in 737 cockpit either before or during the project.


I'd really like to get more information (if anybody is allowed to divulge) about what, besides MCAS and switch or relay failures can cause a runaway stabilizer. IIRC from a session in a 737-800 simulator, the thumb switch is actually two switches next to each other that you press simultaneously. Both would have to fail to cause a runawy. As you said, I'm sure that relays and things have gotten much more reliable since the 1960's.

I also agree that once MCAS is fixed, this additional training will be essentially a waste of time and take away time from training for much more likely situations. Based on the described fixes, it will be an extremely rare case for MCAS to cause a runaway and if it does, the runaway will be limited to 2.5 degrees nose down and will be easily fixed by simply trimming 2.5 degrees nose up one time.
 
THS214
Posts: 162
Joined: Thu Jul 27, 2017 4:01 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:36 pm

morrisond wrote:
THS214 wrote:
morrisond wrote:


Nice personal attack BTW.

That being said I'll bet you I practised it more (stalls) than either of the ET pilots plus full spins which I doubt they did.

If you think I'm inexperienced just remember both ET pilots had marginally more hours and they were put into the cockpit of a 737. So if you think I'm inexperienced WTH are they doing in the cockpit of a 737.


How many of those stalls and full spins were in a jet and how many in 737 category jets?

In a small cessna you can keep yock full back and that plane keeps on recovering on its own. Spin recovery in an aircraft were spin is allowed are relatively easy. Stall and spin in a training aircraft and in a 737 are very different.


None - and no 737 pilot has done any in an 737 either but the principles are the same - it's too expensive to do it in an actual plane as you could damage a lot of the interior furnishings. That is why the US has mandated Sims that allow full stall training and requires pilot's to complete training on them.

Yes - you can keep Yoke full back and a Cessna will most likely recover on it's own - as the Wing is stalled the nose will drop to the point where gravity will increase the speed of the air over the wing so it is unstalled, and assuming you don't let it develop into a spin by letting a wing drop. You could probably do the same in an 737 as well. They are required to stall like a Cessna by the FAR's.

If you have some evidence that a 737 is death trap in a stall please produce it. As far as I know the only commercial aircraft that have stalled in the last 10 years and the Pilots were unable to recover was an A330 on AF447 and a Dash 8-400 on Colgan 3407 , both were ruled Pilot Error.

However the whole point of this was some were implying that a stall could develop on a 737 in a split second and all bets were off. In reality if you watch the video - even in an 30 Degree Bank corner it takes some time to develop - there are tons of warnings and correcting it simple - before you even get into the stall - and if you do it's really not a death sentence - the people in the back will get banged around but any pilot should be able to recover from a stall and it should never develop into a spin.

Here is the 737 NG Video again - No one commented on it yesterday when it was posted probably because it's pretty evident that you would have to be pretty incompetent to allow a stall to develop with all the warnings in the video https://www.youtube.com/watch?v=zCJco59tqoQ


Your right, but my point is that while the principles are the same, in real situation its different. Stall in a small Cessna is different than in a 737, a lot different. Also if you have done spins in real life, it was a plane that was meant to do that. 737 is not meant to do that.

What I mean is that planes where stalls and spins are OK is not what happens in a 737 cockpit.
 
XRAYretired
Posts: 367
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:36 pm

planecane wrote:
PW100 wrote:
planecane wrote:

Yes but this is demonstrating using the manual trim wheel. mjoelnir's implication is that American pilots in simulators, knowing all about the crashes, barely recovered from an MCAS runaway stabilizer. I have not seen any simulation it read a report of one that simulates if running the NNC makes for an easy recovery or not. It has been established that if the aircraft is significantly mistrimmed and the pilot is pulling back on the control column with a lot of force, using the manual trim wheel is extremely difficult.


Well, you wrote ". . . simulate recovery starting from the beginning of the MCAS runaway . . .".
In terms of flight characteristics, the referenced video is fairly close to the ET situation from the beginning of MCAS runaway.

I will not dispute that better trained pilots (and I'll ignore type specifics here), would/could/should have done a better job in in the 75 seconds before MCAS became alive. However once MCAS activated, I'm not convinced that most other crews would have done a better job than the ET crew.


That video is about using the manual trim wheel. The correct simulation to determine how easily recoverable an MCAS-induced runaway stabilizer (if using an NG simulator) would be to set the trim to full nose down and then have the pilots run the NNC. After they have stopped trimming wait 9 seconds and have somebody start moving the trim nose down again (because the NNC says that if the runaway continues to move the switches to cutout) and see how long it takes for them to move the switches to cutout and how far out of trim was reached by that time. THEN use the manual wheel to recover from that point.


Sine we now know that the Simulator significantly under performs in terms of the forces on the trim wheel, I think all bets are off regarding the accuracy of any of the simulations and their results either way. They will need to be run again with the new setup before any realism can be ascribed. Wonder if anyone will do it?

Ray
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:39 pm

PixelFlight wrote:

The "not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous" is caused by the lack of appropriate procedure and specific training for that situation unique to the 737-8/9 MAX.


We can not conclude this without the full CVR transcript of the Lion Air flight. If they didn't even discuss the possibility of runaway stabilizer, I'd say it is not unique to the MAX that it wouldn't even enter their mind as a possibility given that it is a memory item.
 
THS214
Posts: 162
Joined: Thu Jul 27, 2017 4:01 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:41 pm

XRAYretired wrote:
planecane wrote:
PW100 wrote:

Well, you wrote ". . . simulate recovery starting from the beginning of the MCAS runaway . . .".
In terms of flight characteristics, the referenced video is fairly close to the ET situation from the beginning of MCAS runaway.

I will not dispute that better trained pilots (and I'll ignore type specifics here), would/could/should have done a better job in in the 75 seconds before MCAS became alive. However once MCAS activated, I'm not convinced that most other crews would have done a better job than the ET crew.


That video is about using the manual trim wheel. The correct simulation to determine how easily recoverable an MCAS-induced runaway stabilizer (if using an NG simulator) would be to set the trim to full nose down and then have the pilots run the NNC. After they have stopped trimming wait 9 seconds and have somebody start moving the trim nose down again (because the NNC says that if the runaway continues to move the switches to cutout) and see how long it takes for them to move the switches to cutout and how far out of trim was reached by that time. THEN use the manual wheel to recover from that point.


Sine we now know that the Simulator significantly under performs in terms of the forces on the trim wheel, I think all bets are off regarding the accuracy of any of the simulations and their results either way. They will need to be run again with the new setup before any realism can be ascribed. Wonder if anyone will do it?

Ray


No-one until there is a simulator that can do that. That cannot be based on only Boeing data.

I see a long grounding as FAA and Boeing data will not be trusted by other authorities.
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:52 pm

THS214 wrote:
XRAYretired wrote:
planecane wrote:

That video is about using the manual trim wheel. The correct simulation to determine how easily recoverable an MCAS-induced runaway stabilizer (if using an NG simulator) would be to set the trim to full nose down and then have the pilots run the NNC. After they have stopped trimming wait 9 seconds and have somebody start moving the trim nose down again (because the NNC says that if the runaway continues to move the switches to cutout) and see how long it takes for them to move the switches to cutout and how far out of trim was reached by that time. THEN use the manual wheel to recover from that point.


Sine we now know that the Simulator significantly under performs in terms of the forces on the trim wheel, I think all bets are off regarding the accuracy of any of the simulations and their results either way. They will need to be run again with the new setup before any realism can be ascribed. Wonder if anyone will do it?

Ray


No-one until there is a simulator that can do that. That cannot be based on only Boeing data.

I see a long grounding as FAA and Boeing data will not be trusted by other authorities.


If the grounding length is based on simulation of the manual trim wheel, then the 737NG fleet will also need to be grounded since it is the same.

The grounding will be lifted when authorities are convinced that the software update to MCAS will prevent this situation from happening again.
 
kalvado
Posts: 1729
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:54 pm

planecane wrote:
THS214 wrote:
XRAYretired wrote:

Sine we now know that the Simulator significantly under performs in terms of the forces on the trim wheel, I think all bets are off regarding the accuracy of any of the simulations and their results either way. They will need to be run again with the new setup before any realism can be ascribed. Wonder if anyone will do it?

Ray


No-one until there is a simulator that can do that. That cannot be based on only Boeing data.

I see a long grounding as FAA and Boeing data will not be trusted by other authorities.


If the grounding length is based on simulation of the manual trim wheel, then the 737NG fleet will also need to be grounded since it is the same.

The grounding will be lifted when authorities are convinced that the software update to MCAS will prevent this situation from happening again.

Grounding should be lifted when authorities are convinced that the MAX is safe to fly, which may include way more than MCAS software.
 
User avatar
PW100
Posts: 3559
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 3:55 pm

planecane wrote:
PW100 wrote:
How often did an actual stabilizer runaway happen on NG series? Is there any data available on that?


I have been able to find any data which leads to my assumption is that it extremely rare. That is why I think the training issue may not be specific to the MAX. It is very possible that the reason that there have been no runaway stabilizer crashes on the NG is because it has either never happened or only happened a handful of times with luckily well-trained crews. I think that there could very well be an issue in general with recognition of runaway stabilizer and executing the memory item NNC.

The reason I am very interested to see the transcript of the Lion Air CVR, is that I want to know if runaway stabilizer was discussed at all. I just can't imagine that they discussed the possibility and concluded not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous.

My opinion on this whole MCAS debacle is that MCAS caused the rate of occurance of runaway stabilizer to increase by several orders of magnitude over prior 737 models but that there are probably a large percentage of 737 pilots that don't have the training or understanding to recognize and respond to any runaway stabilizer.


That is my perception as well. One might even arrive at the conclusion that the "lack of training/understanding" of runaway stabilizer for the NG is an acceptable risk, where on the MAX it is not, due to much more frequent event.

If the rate on the NG is less than 10E-9, then it ("lack of training") could be seen as an acceptable situation, requiring no further training. Or in other words, the resources and effort spent on such training might very well be better spent in other areas.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 4:26 pm

PW100 wrote:
planecane wrote:
PW100 wrote:
How often did an actual stabilizer runaway happen on NG series? Is there any data available on that?


I have been able to find any data which leads to my assumption is that it extremely rare. That is why I think the training issue may not be specific to the MAX. It is very possible that the reason that there have been no runaway stabilizer crashes on the NG is because it has either never happened or only happened a handful of times with luckily well-trained crews. I think that there could very well be an issue in general with recognition of runaway stabilizer and executing the memory item NNC.

The reason I am very interested to see the transcript of the Lion Air CVR, is that I want to know if runaway stabilizer was discussed at all. I just can't imagine that they discussed the possibility and concluded not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous.

My opinion on this whole MCAS debacle is that MCAS caused the rate of occurance of runaway stabilizer to increase by several orders of magnitude over prior 737 models but that there are probably a large percentage of 737 pilots that don't have the training or understanding to recognize and respond to any runaway stabilizer.


That is my perception as well. One might even arrive at the conclusion that the "lack of training/understanding" of runaway stabilizer for the NG is an acceptable risk, where on the MAX it is not, due to much more frequent event.

If the rate on the NG is less than 10E-9, then it ("lack of training") could be seen as an acceptable situation, requiring no further training. Or in other words, the resources and effort spent on such training might very well be better spent in other areas.


I agree with your thought process. However, there would be a disconnect between it being an acceptable risk on the NG and the NNC being a memory item. If the failure rate is on the order of a wing falling off, why make it a memory item?

This may have been part of the reason for the bad assumptions by Boeing about what would happen in the event of an MCAS failure. Knowing runaway stabilizer was a memory item could have led them to assume that if MCAS caused a runaway stabilizer there wouldn't be any issues because pilots of 737s would easily recognize it and recover. If, in reality, runaway stabilizer doesn't ever happen for all intents and purposes, training and focus on it may have fallen into the "noise" so pilots didn't have it in the forefront of their minds.

A disconnect between the engineer's assumptions and the reality of the NG would give a "non-criminal" explanation to the decisions made in the design and give a reason why they didn't characterize MCAS worse on the scale of possible outcomes. In other words, the engineers may have thought that an MCAS failure would be handled in the same routine, instinctual manner than an engine failure at rotation would be. It isn't something desireable but pilots handle that scenario all the time without difficulty. Of course, engine failures happen frequently enough that all pilots are well trained and well versed in handling it.
 
User avatar
PixelFlight
Posts: 426
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 5:43 pm

planecane wrote:
PixelFlight wrote:

The "not to run the runaway stabilizer NNC because the movement of the stabilizer was not continuous" is caused by the lack of appropriate procedure and specific training for that situation unique to the 737-8/9 MAX.


We can not conclude this without the full CVR transcript of the Lion Air flight. If they didn't even discuss the possibility of runaway stabilizer, I'd say it is not unique to the MAX that it wouldn't even enter their mind as a possibility given that it is a memory item.

There are dead. No need of the CVR to understand that there was not able to handle the situation with the training there received for this specific event. What there possibly said will not give you a definitive understanding of there mind. There could be stressed, overloaded, on high workload, subject to the tunnel effect, time compression, amygdala hijack, etc..
 
THS214
Posts: 162
Joined: Thu Jul 27, 2017 4:01 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 5:58 pm

kalvado wrote:
planecane wrote:
THS214 wrote:

No-one until there is a simulator that can do that. That cannot be based on only Boeing data.

I see a long grounding as FAA and Boeing data will not be trusted by other authorities.


If the grounding length is based on simulation of the manual trim wheel, then the 737NG fleet will also need to be grounded since it is the same.

The grounding will be lifted when authorities are convinced that the software update to MCAS will prevent this situation from happening again.

Grounding should be lifted when authorities are convinced that the MAX is safe to fly, which may include way more than MCAS software.


Thats what I meant. Thanks for putting it plain english
 
Amexair
Posts: 56
Joined: Tue Sep 08, 2009 8:16 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 6:28 pm

PW100 wrote:
planecane wrote:
PW100 wrote:

I will not dispute that better trained pilots (and I'll ignore type specifics here), would/could/should have done a better job in in the 75 seconds before MCAS became alive. However once MCAS activated, I'm not convinced that most other crews would have done a better job than the ET crew.
:checkmark:

I think you hit it on the nail here with framing this discussion on pilot training etc. THis is the critical aspects that some of our devout pilot error propagators are failing to conceptualize.
 
User avatar
PixelFlight
Posts: 426
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 6:36 pm

planecane wrote:
I agree with your thought process. However, there would be a disconnect between it being an acceptable risk on the NG and the NNC being a memory item. If the failure rate is on the order of a wing falling off, why make it a memory item?

Just a guess: 737 history.
At some point in the past the runaway stabilizer could have been a concern that both contributed to create the runaway stabilizer NCC memory item and to improve the design to decrease the failure rate. The two was constructive to improve safety, not one against the other like your question might imply. I don't know if the training of this runaway stabilizer NCC memory item have decreased over time, but the only response I got about 737 runaway stabilizer training did suggest that it's far from a top concern to deliver pilots licences.
 
cat3appr50
Posts: 155
Joined: Wed Jan 16, 2013 10:44 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 6:48 pm

The Lion Air JT610 accident occurred on Oct. 29, 2018. The KNKT Preliminary Accident Report was issued November 2018. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, and no CVR data. No accident investigation updates (or the final report issued) have occurred for around 6 months.

The Ethiopian Airlines ET302 accident occurred on March 10, 2019. The AIB Preliminary Accident Report was issued March 2019. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, no CVR data, and no data why the (controlling) AoA sensor was dysfunctional. No accident investigation updates (or the final report issued) have occurred for around 2 months.

It would be IMO inappropriate and unacceptable for the FAA (or any other regulatory agency) to allow a return of the Max 8 to service without both of these aviation accidents Final Accident Reports being formally issued with full DFDR, CVR, etc. data. The conversations going on in those cockpits with both flights per the CVR data are particularly, absolutely critical.

So, the question is (in this gaping and ominous silence from the KNKT and AAIB investigating agencies) when specifically are these Final Accident Reports with all of the specific details going to be issued publicly? Is there not a schedule for same? And if not, why not? Should they not update the public on the specific timing (and adherence to same) of their final reports?

Why is there so much discussion about timing of the Max 8 return to service when both Final Accident Reports haven’t even been issued yet? If the agencies want public trust and confidence to be restored, the Final Reports public issuance/public communication is needed and is just as critical as the engineering changes and return to service activities.
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 7:05 pm

PixelFlight wrote:
planecane wrote:
I agree with your thought process. However, there would be a disconnect between it being an acceptable risk on the NG and the NNC being a memory item. If the failure rate is on the order of a wing falling off, why make it a memory item?

Just a guess: 737 history.
At some point in the past the runaway stabilizer could have been a concern that both contributed to create the runaway stabilizer NCC memory item and to improve the design to decrease the failure rate. The two was constructive to improve safety, not one against the other like your question might imply. I don't know if the training of this runaway stabilizer NCC memory item have decreased over time, but the only response I got about 737 runaway stabilizer training did suggest that it's far from a top concern to deliver pilots licences.


Which is why I want to know what was said on the doomed Lion Air flight between the crew members. It is important to know if runaway stabilizer even crossed their mind from the training. This is important because it is possible that decsions were made when designing MCAS that assumed runaway stabilizer was a "no brainer" for crews due to it being a memory item.

Assuming that the training for runaway stabilizer has decreased over time, it would also explain why the ET crew did not execute the NNC exactly as it was intended even though they seemed to recognize that they had a runaway stabilizer.

It is important to understand this not just for the 737 series but for all aircraft. It is no out of the realm of possibility that based on training focus from 1987 which is now glossed over, that Airbus made a design decision on the A320NEO. I'm not saying they did, but it is possible.

If this type of disconnect between documented training and actual training focus exists, a process must be put in place for engineers to be educated on current training practices for a model when they are designing updates to the model.
 
BravoOne
Posts: 3321
Joined: Fri Apr 12, 2013 2:27 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 7:07 pm

DenverTed wrote:
Free the MAX. Is it definitively known if MCAS was needed for certification? Or was it just optional to decrease training from the NG. Is there a definitive statement on this from Boeing or the FAA?

Seems like the most basic question for Boeing or the FAA to answer to regain credibility with other agencies, and the flying public like myself.


Clearly stated on a thread under the Technical banner. It was required per the Part 25 cert. process and nothing to with eliminating additional training.

Noted from the original Boeing CSID document covering flight controls

Maneuver Characteristics Augmentation System (MCAS)

"The larger diameter LEAP-1B engines on the 737 MAX degrade high-speed pitch up
characteristics compared to the 737 NG. The MCAS control law, along with a revised
vortex generator pattern, were added to the MAX to provide approach-to-stall feel forces
consistent with those required in AC 25-7B"
Last edited by BravoOne on Wed May 22, 2019 7:12 pm, edited 1 time in total.
 
planecane
Posts: 754
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 7:09 pm

cat3appr50 wrote:
The Lion Air JT610 accident occurred on Oct. 29, 2018. The KNKT Preliminary Accident Report was issued November 2018. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, and no CVR data. No accident investigation updates (or the final report issued) have occurred for around 6 months.

The Ethiopian Airlines ET302 accident occurred on March 10, 2019. The AIB Preliminary Accident Report was issued March 2019. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, no CVR data, and no data why the (controlling) AoA sensor was dysfunctional. No accident investigation updates (or the final report issued) have occurred for around 2 months.

It would be IMO inappropriate and unacceptable for the FAA (or any other regulatory agency) to allow a return of the Max 8 to service without both of these aviation accidents Final Accident Reports being formally issued with full DFDR, CVR, etc. data. The conversations going on in those cockpits with both flights per the CVR data are particularly, absolutely critical.

So, the question is (in this gaping and ominous silence from the KNKT and AAIB investigating agencies) when specifically are these Final Accident Reports with all of the specific details going to be issued publicly? Is there not a schedule for same? And if not, why not? Should they not update the public on the specific timing (and adherence to same) of their final reports?

Why is there so much discussion about timing of the Max 8 return to service when both Final Accident Reports haven’t even been issued yet? If the agencies want public trust and confidence to be restored, the Final Reports public issuance/public communication is needed and is just as critical as the engineering changes and return to service activities.


Nothing has been released publicly on either investigation since the preliminary reports and won't be until the final reports. However, I can guarantee that the FAA and other worldwide regulators have access to the CVR transcripts (and probably recording as well) and any other evidence which has turned up since the preliminary reports were issued. Boeing most likely has all of this information as well.
 
smartplane
Posts: 903
Joined: Fri Aug 03, 2018 9:23 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 8:10 pm

planecane wrote:
mjoelnir wrote:
planecane wrote:

Please post links to the sources of these simulator sessions. I have not seen one where they simulated recovery from the beginning of the MCAS-induced runaway stabilizer. I have seen the aviation week simulator session where they started with the electric trim cut off and recovered using the manual trim wheel and roller coaster procedure from higher altitude.


Read the thread, was posted here, why should I do that work for you?


Because none of the simulations I've seen posted have attempted to simulate recovery starting from the beginning of the MCAS runaway. If you know of one, then I'd like you to point me to it since you are using them as part of your argument that they "just managed to avoid crash." That is only relevant if they are simulating starting from the point of failure.

What's the point? None of the simulations have been on true MCAS representative simulators. Even the Boeing simulator is claimed not to accurately reflect actual manual trim loads.
 
User avatar
spinotter
Posts: 466
Joined: Wed May 27, 2015 1:37 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 8:22 pm

cat3appr50 wrote:
The Lion Air JT610 accident occurred on Oct. 29, 2018. The KNKT Preliminary Accident Report was issued November 2018. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, and no CVR data. No accident investigation updates (or the final report issued) have occurred for around 6 months.

The Ethiopian Airlines ET302 accident occurred on March 10, 2019. The AIB Preliminary Accident Report was issued March 2019. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, no CVR data, and no data why the (controlling) AoA sensor was dysfunctional. No accident investigation updates (or the final report issued) have occurred for around 2 months.

It would be IMO inappropriate and unacceptable for the FAA (or any other regulatory agency) to allow a return of the Max 8 to service without both of these aviation accidents Final Accident Reports being formally issued with full DFDR, CVR, etc. data. The conversations going on in those cockpits with both flights per the CVR data are particularly, absolutely critical.

So, the question is (in this gaping and ominous silence from the KNKT and AAIB investigating agencies) when specifically are these Final Accident Reports with all of the specific details going to be issued publicly? Is there not a schedule for same? And if not, why not? Should they not update the public on the specific timing (and adherence to same) of their final reports?

Why is there so much discussion about timing of the Max 8 return to service when both Final Accident Reports haven’t even been issued yet? If the agencies want public trust and confidence to be restored, the Final Reports public issuance/public communication is needed and is just as critical as the engineering changes and return to service activities.


Obvious answer why no CVR etc. A coverup.
 
kalvado
Posts: 1729
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 8:27 pm

planecane wrote:
PixelFlight wrote:
planecane wrote:
I agree with your thought process. However, there would be a disconnect between it being an acceptable risk on the NG and the NNC being a memory item. If the failure rate is on the order of a wing falling off, why make it a memory item?

Just a guess: 737 history.
At some point in the past the runaway stabilizer could have been a concern that both contributed to create the runaway stabilizer NCC memory item and to improve the design to decrease the failure rate. The two was constructive to improve safety, not one against the other like your question might imply. I don't know if the training of this runaway stabilizer NCC memory item have decreased over time, but the only response I got about 737 runaway stabilizer training did suggest that it's far from a top concern to deliver pilots licences.


Which is why I want to know what was said on the doomed Lion Air flight between the crew members. It is important to know if runaway stabilizer even crossed their mind from the training. This is important because it is possible that decsions were made when designing MCAS that assumed runaway stabilizer was a "no brainer" for crews due to it being a memory item.

Assuming that the training for runaway stabilizer has decreased over time, it would also explain why the ET crew did not execute the NNC exactly as it was intended even though they seemed to recognize that they had a runaway stabilizer.

It is important to understand this not just for the 737 series but for all aircraft. It is no out of the realm of possibility that based on training focus from 1987 which is now glossed over, that Airbus made a design decision on the A320NEO. I'm not saying they did, but it is possible.

If this type of disconnect between documented training and actual training focus exists, a process must be put in place for engineers to be educated on current training practices for a model when they are designing updates to the model.

It is possible that A320NEO, as well as 777X, 330NEO and even A350 - which some jurisdictions consider same rating as 330 - have these problems. So far, 320NEO keeps accumulating statistics to back up "no surprises" claim.
This is really about keeping a tight control on changes, with honest review of any variations required; and keeping grandfathering with grandfathers - people who actually understand an old system before making changes. That should help avoid drastic changes, and help document them should changes be needed; and follow up on maintenance, training, technical support to keep things under control.
I.e. work should be performed by a well organized and properly qualified team.
Last edited by kalvado on Wed May 22, 2019 8:30 pm, edited 1 time in total.
 
PixelPilot
Posts: 244
Joined: Tue Jan 16, 2018 1:19 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 8:29 pm

spinotter wrote:
cat3appr50 wrote:
The Lion Air JT610 accident occurred on Oct. 29, 2018. The KNKT Preliminary Accident Report was issued November 2018. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, and no CVR data. No accident investigation updates (or the final report issued) have occurred for around 6 months.

The Ethiopian Airlines ET302 accident occurred on March 10, 2019. The AIB Preliminary Accident Report was issued March 2019. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, no CVR data, and no data why the (controlling) AoA sensor was dysfunctional. No accident investigation updates (or the final report issued) have occurred for around 2 months.

It would be IMO inappropriate and unacceptable for the FAA (or any other regulatory agency) to allow a return of the Max 8 to service without both of these aviation accidents Final Accident Reports being formally issued with full DFDR, CVR, etc. data. The conversations going on in those cockpits with both flights per the CVR data are particularly, absolutely critical.

So, the question is (in this gaping and ominous silence from the KNKT and AAIB investigating agencies) when specifically are these Final Accident Reports with all of the specific details going to be issued publicly? Is there not a schedule for same? And if not, why not? Should they not update the public on the specific timing (and adherence to same) of their final reports?

Why is there so much discussion about timing of the Max 8 return to service when both Final Accident Reports haven’t even been issued yet? If the agencies want public trust and confidence to be restored, the Final Reports public issuance/public communication is needed and is just as critical as the engineering changes and return to service activities.


Obvious answer why no CVR etc. A coverup.


I'll bite lol.
By whom?
 
morrisond
Posts: 1103
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 22, 2019 8:34 pm

PixelPilot wrote:
spinotter wrote:
cat3appr50 wrote:
The Lion Air JT610 accident occurred on Oct. 29, 2018. The KNKT Preliminary Accident Report was issued November 2018. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, and no CVR data. No accident investigation updates (or the final report issued) have occurred for around 6 months.

The Ethiopian Airlines ET302 accident occurred on March 10, 2019. The AIB Preliminary Accident Report was issued March 2019. This report contained preliminary DFDR data, minimal ATC to/from cockpit conversations, no CVR data, and no data why the (controlling) AoA sensor was dysfunctional. No accident investigation updates (or the final report issued) have occurred for around 2 months.

It would be IMO inappropriate and unacceptable for the FAA (or any other regulatory agency) to allow a return of the Max 8 to service without both of these aviation accidents Final Accident Reports being formally issued with full DFDR, CVR, etc. data. The conversations going on in those cockpits with both flights per the CVR data are particularly, absolutely critical.

So, the question is (in this gaping and ominous silence from the KNKT and AAIB investigating agencies) when specifically are these Final Accident Reports with all of the specific details going to be issued publicly? Is there not a schedule for same? And if not, why not? Should they not update the public on the specific timing (and adherence to same) of their final reports?

Why is there so much discussion about timing of the Max 8 return to service when both Final Accident Reports haven’t even been issued yet? If the agencies want public trust and confidence to be restored, the Final Reports public issuance/public communication is needed and is just as critical as the engineering changes and return to service activities.


Obvious answer why no CVR etc. A coverup.


I'll bite lol.
By whom?


Let me guess - Ethiopian Airlines and the Ethiopian Civil Aviation Authority to cover up that Ethiopian never even told it's Pilots about MCAS or lack of fundamental training on basic required memory procedures?

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos