morrisond
Posts: 1149
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 7:18 pm

DenverTed wrote:
frmrCapCadet wrote:
I have asked before, surely it is possible to have something between an iPad and a $15Million simulator. Flight Simulator with some used 737 hardware could be set up for specific training routines such as Runaway Stabilizer. While the first one could cost a million subsequent versions likely under a $100K. A senior pilot could both set this up, and explain its limitations. Muscle memory for running a memory procedure is a known effective training tool.

Personally I think the more training is theater. They fixed it, there's not much more to it. I'm ready to fly on a MAX no problem.
I just don't understand the resistance to low cost transparent incremental improvement of safety. Boeing's design process for MCAS should be as transparent as the pilot's actions. Where did they error, how will they improve in the future?
How expensive is it to change words? Shouldn't runaway trim now be replaced with malfunctioning trim? Shouldn't "continuous" be replaced with continuous or intermittent? Shouldn't the runaway trim procedure now say "use electric trim to neutralize column forces"

Should Boeing restore the AutoPilot trim cutout switch that was on the NG? What if the Mach trim or speed trim goes haywire?
When they removed it, why not just have one switch? Clean and logical or cluttered and inexplicable design?


The problem with its fixed and the current state of pilot proficiency is okay is that parts fail/maintenance screws up even in perfectly designed airplanes.

How would you feel with an ET crew in instrument conditions if their Autopilots went on the blink due to a parts failure, Lightning strike, or some sort of electrical failure due to something missed in maintenance(which can happen to any airline). Assume they would be forced to hand fly with no Autothrottle either.

Do you think you would make it?
 
User avatar
PixelFlight
Posts: 478
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 7:24 pm

morrisond wrote:
It's highly likely Lionair would have made it if they had run the Runaway Stabilizer Procedure - they were never out of of trim for 22 instances of MCAS they knew how to counter MCAS's (at least the Pilot did) - all they had to do was hit the switches and turn off the wonky system - no matter what was causing it to go bonkers. Yes it didn't present classically - but sometimes you have to think outside the box - you can't write a procedure and make it a memory item for every potential failure or variation of failure.

JT043, JT610 and ET302 proved that a new "potential failure or variation of failure" was not appropriately handled by the existing procedures and training. You perfectly know this, but still repeat yourself over and over again like if your paycheck depend on the number of posts you generate to make this thread debating on pilots instead of Boeing. Never before the Runaway Stabilizer Procedure was about a repetitive discontinuous automatic movement that still allow the manual electric trim to work.

morrisond wrote:
On ET they missed many things and they (supposedly) even had a full explanation of what MCAS can do and how to handle it. I argue they were never trained on it.

So what your conclusion from your own analysis ? That explanation is not enough to avoid training. Thanks, Now please analyze from where the training was supposed to be defined.

morrisond wrote:
It is Boeing's fault that the design was not very robust and MCAS's unlimited authority was really stupid in hindsight - but its use and certification assumed that the Pilots knew the required procedures as part of their type rating. Rightly or wrongly that seems to be what Boeing and the FAA are hanging their hat on and in a strict legal sense they might be right unless someone finds a smoking gun where an internal Engineer or someone from the FAA wrote an email - saying the Single sensor solution was way more risky/more failure consequences than assumed and/or that the current state of pilot training was insufficient to handle an AOA failure that lead to an MCAS activation.

Someone on this thread already provided the certification text that require redundancy for operating important control surface.

morrisond wrote:
However It doesn't seem like I will ever win "Pilot's need more training" argument on here so here is a new one - bring on Autoflight as much as possible and install a Cirrus like CAPS (Airframe Parachute) on all future designs - so when HAL screws up there is human to pull the circuit boards and hit the Big Red Oh Sh*t button to deploy the chute.

Airlines and pilots will pragmatically compare the training requirement for each aircraft to preserve there market. From a personal point of view, I am for even more redundancies and high level algorithms that can still work with rare sensors failure, definitively not for single sensor and stupid code driving main control surface.
 
OldAeroGuy
Posts: 3858
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 7:45 pm

IADFCO wrote:
furthermore, MCAS 2.0 will turn itself off *by design* after activating once. So, after the "protection" is needed once, it will not be available again (not clear for how long).


I think you're incorrect on how MCAS 2.0 will function.

- MCAS 2.0 will activate once when both AoA vanes exceed the trigger AoA. If AoA remains above the trigger AoA, it will not activate again.

- If both AoA's drop below the trigger AoA, MCAS 2.0 will re-activate if trigger AoA is again exceeded.

- If Left/Right AoA disagree by more than X deg, MCAS 2.0 will be shut down.

OAG
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
MSPNWA
Posts: 3250
Joined: Thu Apr 23, 2009 2:48 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 7:51 pm

PixelFlight wrote:
Never before the Runaway Stabilizer Procedure was about a repetitive discontinuous automatic movement that still allow the manual electric trim to work.


How do you know this for a fact?
 
User avatar
RayChuang
Posts: 8136
Joined: Sat Jun 24, 2000 7:43 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 7:56 pm

I am beginning to think that the FAA, EASA and CAAC (China) may not be satisfied with Bosing's MCAS fix for the 737 MAX and there is a small, but not completely zero, chance that the 737 MAX may face a permanent grounding. If that happens, Boeing may have to file for bankruptcy to defray the costs of scrapping several hundred planes already built (and fuselages for planes yet to be assembled). Can Boeing dust off the Yellowstone 1 studies for a true 737 replacement and get the program into production phase by 2025, crazy as it sounds?
 
User avatar
PixelFlight
Posts: 478
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 8:26 pm

MSPNWA wrote:
PixelFlight wrote:
Never before the Runaway Stabilizer Procedure was about a repetitive discontinuous automatic movement that still allow the manual electric trim to work.

How do you know this for a fact?

No airline using 737 ever trained there pilots with a scenario that match all the above terms. Prove me wrong. You only need to find one to win. :checkeredflag:
 
MSPNWA
Posts: 3250
Joined: Thu Apr 23, 2009 2:48 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 8:30 pm

PixelFlight wrote:
No airline using 737 ever trained there pilots with a scenario that match all the above terms.


How do you know this for a fact?
 
morrisond
Posts: 1149
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 8:33 pm

PixelFlight wrote:
morrisond wrote:
It's highly likely Lionair would have made it if they had run the Runaway Stabilizer Procedure - they were never out of of trim for 22 instances of MCAS they knew how to counter MCAS's (at least the Pilot did) - all they had to do was hit the switches and turn off the wonky system - no matter what was causing it to go bonkers. Yes it didn't present classically - but sometimes you have to think outside the box - you can't write a procedure and make it a memory item for every potential failure or variation of failure.

JT043, JT610 and ET302 proved that a new "potential failure or variation of failure" was not appropriately handled by the existing procedures and training. You perfectly know this, but still repeat yourself over and over again like if your paycheck depend on the number of posts you generate to make this thread debating on pilots instead of Boeing. Never before the Runaway Stabilizer Procedure was about a repetitive discontinuous automatic movement that still allow the manual electric trim to work.

morrisond wrote:
On ET they missed many things and they (supposedly) even had a full explanation of what MCAS can do and how to handle it. I argue they were never trained on it.

So what your conclusion from your own analysis ? That explanation is not enough to avoid training. Thanks, Now please analyze from where the training was supposed to be defined.

morrisond wrote:
It is Boeing's fault that the design was not very robust and MCAS's unlimited authority was really stupid in hindsight - but its use and certification assumed that the Pilots knew the required procedures as part of their type rating. Rightly or wrongly that seems to be what Boeing and the FAA are hanging their hat on and in a strict legal sense they might be right unless someone finds a smoking gun where an internal Engineer or someone from the FAA wrote an email - saying the Single sensor solution was way more risky/more failure consequences than assumed and/or that the current state of pilot training was insufficient to handle an AOA failure that lead to an MCAS activation.

Someone on this thread already provided the certification text that require redundancy for operating important control surface.

morrisond wrote:
However It doesn't seem like I will ever win "Pilot's need more training" argument on here so here is a new one - bring on Autoflight as much as possible and install a Cirrus like CAPS (Airframe Parachute) on all future designs - so when HAL screws up there is human to pull the circuit boards and hit the Big Red Oh Sh*t button to deploy the chute.

Airlines and pilots will pragmatically compare the training requirement for each aircraft to preserve there market. From a personal point of view, I am for even more redundancies and high level algorithms that can still work with rare sensors failure, definitively not for single sensor and stupid code driving main control surface.


Your avoiding the question - so what happens if something takes out all the auto-systems? Would you want to be on that flight in instrument conditions with the state of today's training?
 
planecane
Posts: 872
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 8:42 pm

RayChuang wrote:
I am beginning to think that the FAA, EASA and CAAC (China) may not be satisfied with Bosing's MCAS fix for the 737 MAX and there is a small, but not completely zero, chance that the 737 MAX may face a permanent grounding. If that happens, Boeing may have to file for bankruptcy to defray the costs of scrapping several hundred planes already built (and fuselages for planes yet to be assembled). Can Boeing dust off the Yellowstone 1 studies for a true 737 replacement and get the program into production phase by 2025, crazy as it sounds?


What source is making you begin to think this? No airline has extended the removal of the 737MAX from their schedules. I would assume they have more information than you do. I will say that there is an absolute zero chance of a permanent grounding. The worst case would be that they conclude that the MAX must be retrofitted with a 3rd AoA vane and MCAS to be reprogrammed to use triple redundant sensors.

Honestly MCAS 2.0, assuming it operates as designed, removes all of the issues with the system running amok. Therefore, what would the justification be for a permanent grounding? They may require training (which will just be for show) in conjunction with the update which will delay the return to service.

Bankruptcy is used to discharge debt due to the inability to pay the debt. The cost of a few hundred planes will not force them into bankruptcy. The only thing that could is if they have contractual obligations to pay penalties for non-delivered frames.
 
davidjohnson6
Posts: 301
Joined: Mon Jun 20, 2016 10:10 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 9:05 pm

If the US FAA allows the 737 Max to fly but the European or Chinese try to require a permanent grounding of the 737 Max, then one can expect Boeing to call in some favours and for the US Govt to become much more active in helping Boeing through diplomatic means. The US Govt is not shy about protecting its strategic interests when they are under threat
 
2175301
Posts: 1426
Joined: Wed May 16, 2007 11:19 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 9:19 pm

I'd like to post my summary of what I think the key issues are - and to debunk some of what I see as the most common misconceptions presented:

1) Misconception & Outright Not True: Boeing hid the MCAS system, its design functions, etc from anyone. Boeing clearly and fully told both all the regulatory agencies and the Airlines about MCAS. It is fully documented and discussed in the Airline Maintenance Manuals. Boeing presented to the regulatory authorities around the world that they did not believe that the changes that this system produced required any specific pilot training. It is my understanding that all but one isolated regulatory agency in the world agreed. I recall buried in either the Lion Air or Ethiopian tread where someone listed a country where the regulatory agency required its airlines to train the pilots on MCAS. Also, I recall someone posting (with confirmation by others) in one of those threads that there was a major airline in either North America or Europe who decided that its pilots needed to be trained on MCAS - and did so. Boeing did not hide it. There are many (likely thousands) of details about how something operates in a modern commercial aircraft that the pilots are not specifically trained on. The regulatory agencies have criteria for that.

Now perhaps in hind-site you can point out that the lack of training requirement was a factor here... and that standards need to be changed. Point your fingers at the regulatory agencies and perhaps the Airlines on that; and not Boeing. Boeing did tell every Airline and Regulator in the world about the system. It is quite common for upgrades and modifications to be grandfathered in from all aircraft manufacturers in every country of the world. It is also common practice by all aircraft manufactures to minimize (eliminate if possible) additional training for changes - and everyone does so (and many Airlines desire that).

The information presented above was identified early on in the Lion Air crash thread. Why some people continue to claim that Boeing hid this system???

2) Boeing key mistake: Inadequate Failure and Failure Effects Analysis. There can be many discussions about how Boeing made decisions and there are comments coming out by people involved (or clsoe to those involved) about how things could have been done differently in the design and approval process. That always is the case as all final design decisions are always an "what appears adequate at this time". There is never enough time and money to design a perfect product or process. Decisions are always made not to do things that would be better due to cost and timeline. To paraphrase some Military General: "An adequate plan implemented immediately is more successful than a perfect plan implemented too late." That is as true in business as it is in war. All the comments by people that we could have done better... or a different timeline would have been more appropriate: in reality, that always exist for every item and project and do not in and of themselves represent any meaningful legal liability or criminal behavior (although they can have those consequences if you really missed something very obvious or intentionally did something not legal or obviously not safe). Boeing may not have the best safety culture; but, I doubt that anything really decided by them during this process will have any significant legal impact (it will have a financial impact).

The problem with performing a Failure and Failure Effect Analysis is that identifying new modes of failure is not easy. I have done these for modifications in nuclear power plants. For basic mechanicla or electric equipment modifications or component replacements in a nuclear plant you start with what a few years ago was an 8 page list of known failure modes for the equipment or process you are working on. Each section on the checklist has a final question of "Can you imaging any other failure mode, or failure effects not covered above." I assure you that it is difficult to think outside of the box and identify unique and never before occurring failure modes. Interesting enough. The same kind of project files from 20-30 years earlier had only a 4-5 page form. Virtually every additional line added since those shorter forms from days of yore were from actual unanticipated failures or effects more serious than anticipated. Electronic components also had its own similar length form, and things dealing with noticeable radiation and anything related to reactor or spent fuel pool reactivity management had its own multi-page form. Some modifications involved all three forms.

I have no idea if the miss was from a new unanticipated failure, or that the failure consequence was much worse than estimated. Perhaps both.

I also personally doubt that there are more than 2 others on this forum who have actually been involved in doing a comprehensive Failure and Failure Effect Analysis; and I doubt that most people claiming how much fault Boeing has for this could do an adequate one to Nuclear or Aviation standards for something simple like a paper weight, much less a electrical, mechanical, electronics system that could affect flight controls.

Boeing missed here; and Boeing knows that. They will likely have civil liability here. I do not see any chance of criminal liability.

3) Problems with Certification & Regulatory Approval Process. I take both Boeing and the FAA at their word that their were no inherent problems with either the certification or regulatory approval process. They both followed it and did what they were required. Hence no problems with what they did in accordance with the current approved process. Both Boeing and the FAA have made specific statements to that.

However, that is different that asking if there was a problem with the process... something missing. I believe that yes, there is a missing item from the existing process: Adequate review of Failure and Failure Effect Analysis.

Boeing, the FAA, and other regulatory agencies in the world have reviewed the process.... Note that the Europeans are requiring an independent review. Note also that the FAA has set up an independent review. Design review is basic. Getting the Failure and Failure Effect Analysis correct - and designing to eliminate identified concerns above a certain level - are the key to good design. In my opinion and engineering judgement, that has to be what the independent review is doing.

I do not see any true major change worldwide in certification process; as everyone uses essentially the same process. The Manufacturers will still do much of the specific certification work, the regulators will do a high level review and approval. The Regulators do not have and will never have the manpower for anything else than that. But, what I see likely to be added is a requirement for an independent review of the various Failure and Failure Effect Analysis for modified components and systems.

4) Worldwide certification of the "Fix." By all historical patterns and processes the FAA must first approve it as they are the original certifier as the 737-8Max is designed and built in the USA. Then the other countries certify. That is how all new and all modifications are always done.

I expect that the other major countries will quickly follow - and note that the FAA met with many May 23 and I am sure that one of the things they asked was if there was anything they needed to add to their process to answer any concerns the other countries had (note that the FAA is already using an independent reviewer per the European stated requirements). I am sure that the FAA will include any reasonable request from the other countries.

Other countries (especially Brazil, Canada, and Europe, with China as a lessor player) are playing with fire not to provide additional items and then rapidly approve with out any other major work. Otherwise expect that Airbus, Bombardier, and Embraer, etc will find that they can no longer easily certify upgrades, modifications, and new aircraft in the USA; or anywhere else in the world. I think that the regulators actually understand this - and what I think the May 23 meeting was more about was what changes did the US (and other countries) now need in their certification process to be sure things were done right. Expect independent reviews to become part of those regulatory agency requirements as well going forward.

5) Pilot Training. In the Ethiopian thread I recall that I posted after the preliminary report that it appeared that the pilots found themselves in a situation where you would not expect a normal pilot to be able to recover from. I am no longer sure of that. A lot of reading since then has raised to me a question of why would not one of the very basic things to do if the controls are not responding correctly and you were airborne without a major failure (engine or wing) that you would not immediately go to standard pitch and power, and turn off all automatics; and just fly straight until the aircraft stabilized at whatever altitude it would get to with standard pitch and power; unless there is a mountain in the way. Then troubleshoot - or just fly in total manual flight mode until you land. I am beginning to wonder why there is not a requirement that every pilot and copilot fly at least 1 flight every 6 months or year totally manual from takeoff to landing (with allowances for the other pilot to cover for short bathroom breaks, etc), why every pilot has not actually flown their aircraft at pitch and power from both a low altitude and high altitude to experience how the plane will level out at a safe altitude and speed (it will descend from a high, and ascend from a lower altitude to reach a modest altitude). This would be minimal training cost additions and could be done as part of normal flights.

I'm wondering if perhaps we have made it far to complicated for the pilots in expecting them to remember dozens of procedures. How about just a few: Transition to manual at pitch and power for control problems, engine out, etc. This is essentially a training issue; although procedures would have to be modified to emphasize that.

I also note, that what many are calling "pilot error" in this thread is much more likely a procedure or training issue, than actual pilot error.

6) What the final accident reports will likely say: First off in the Lion Air case the fact that the previous flight had the same or similar issue, the pilots handled it; and apparently did not communicate that to the next set of pilots is a biggie: If I were running a root cause investigation in a nuke power plant this failure of communication would likely be the root cause. Equipment gets buggered, it fails, latent design errors and poor procedures do set the operators up for problems (happens a lot more than many realize). For someone to recognize the problem, find a fix, and not communicate it to the next crew.... That is the one thing under immediate control that would have prevented the event. Note that Nuclear Plant Rood Cause investigation is the same process the NTSB uses - I'm trained and certified to the same standard; and have run teams of up to 30 people for up to 6 months investigating issues or equipment failures, plant trips in nuclear power plants (and we study Air Transport Root Causes all the time in training).

Now is that due to Lion Air procedures, training, human factor (pilots sick), or other reason. I don't know. I don't see how Lion Air escapes on this one. At this time and based on the information I have I only see the MCAS as a contributing factor as the prior flight dealt with the issue. Procedures, Training, and other things will also be identified. It would be common for their to be an element of pilot error caused at least by situational overload. It may not even get listed as a contributing factor (being human is not a reportable cause or factor).

I have made no conclusions of any kind on the Ethiopian crash.

7) Finally, until we actually see the final accident reports with full information - we are unlikely to be able to say much more. Speculation may feel good; and is often wrong. Opinions far to often get in the way of facts.

Hope this helps, and have a great day,
 
OldAeroGuy
Posts: 3858
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 9:35 pm

PixelFlight wrote:
JT043, JT610 and ET302 proved that a new "potential failure or variation of failure" was not appropriately handled by the existing procedures and training.


Existing procedures and training seemed to work for JT043.

It did take someone who recognized a "Runaway Stabilizer" and advised applying the appropriate NNC.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
Posts: 3858
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 9:44 pm

2175301 wrote:
I'd like to post my summary of what I think the key issues are - and to debunk some of what I see as the most common misconceptions presented:

1) Misconception & Outright Not True: Boeing hid the MCAS system, its design functions, etc from anyone. Boeing clearly and fully told both all the regulatory agencies and the Airlines about MCAS. It is fully documented and discussed in the Airline Maintenance Manuals. Boeing presented to the regulatory authorities around the world that they did not believe that the changes that this system produced required any specific pilot training. It is my understanding that all but one isolated regulatory agency in the world agreed. I recall buried in either the Lion Air or Ethiopian tread where someone listed a country where the regulatory agency required its airlines to train the pilots on MCAS. Also, I recall someone posting (with confirmation by others) in one of those threads that there was a major airline in either North America or Europe who decided that its pilots needed to be trained on MCAS - and did so. Boeing did not hide it. There are many (likely thousands) of details about how something operates in a modern commercial aircraft that the pilots are not specifically trained on. The regulatory agencies have criteria for that.

Now perhaps in hind-site you can point out that the lack of training requirement was a factor here... and that standards need to be changed. Point your fingers at the regulatory agencies and perhaps the Airlines on that; and not Boeing. Boeing did tell every Airline and Regulator in the world about the system. It is quite common for upgrades and modifications to be grandfathered in from all aircraft manufacturers in every country of the world. It is also common practice by all aircraft manufactures to minimize (eliminate if possible) additional training for changes - and everyone does so (and many Airlines desire that).

The information presented above was identified early on in the Lion Air crash thread. Why some people continue to claim that Boeing hid this system???

2) Boeing key mistake: Inadequate Failure and Failure Effects Analysis. There can be many discussions about how Boeing made decisions and there are comments coming out by people involved (or clsoe to those involved) about how things could have been done differently in the design and approval process. That always is the case as all final design decisions are always an "what appears adequate at this time". There is never enough time and money to design a perfect product or process. Decisions are always made not to do things that would be better due to cost and timeline. To paraphrase some Military General: "An adequate plan implemented immediately is more successful than a perfect plan implemented too late." That is as true in business as it is in war. All the comments by people that we could have done better... or a different timeline would have been more appropriate: in reality, that always exist for every item and project and do not in and of themselves represent any meaningful legal liability or criminal behavior (although they can have those consequences if you really missed something very obvious or intentionally did something not legal or obviously not safe). Boeing may not have the best safety culture; but, I doubt that anything really decided by them during this process will have any significant legal impact (it will have a financial impact).

The problem with performing a Failure and Failure Effect Analysis is that identifying new modes of failure is not easy. I have done these for modifications in nuclear power plants. For basic mechanicla or electric equipment modifications or component replacements in a nuclear plant you start with what a few years ago was an 8 page list of known failure modes for the equipment or process you are working on. Each section on the checklist has a final question of "Can you imaging any other failure mode, or failure effects not covered above." I assure you that it is difficult to think outside of the box and identify unique and never before occurring failure modes. Interesting enough. The same kind of project files from 20-30 years earlier had only a 4-5 page form. Virtually every additional line added since those shorter forms from days of yore were from actual unanticipated failures or effects more serious than anticipated. Electronic components also had its own similar length form, and things dealing with noticeable radiation and anything related to reactor or spent fuel pool reactivity management had its own multi-page form. Some modifications involved all three forms.

I have no idea if the miss was from a new unanticipated failure, or that the failure consequence was much worse than estimated. Perhaps both.

I also personally doubt that there are more than 2 others on this forum who have actually been involved in doing a comprehensive Failure and Failure Effect Analysis; and I doubt that most people claiming how much fault Boeing has for this could do an adequate one to Nuclear or Aviation standards for something simple like a paper weight, much less a electrical, mechanical, electronics system that could affect flight controls.

Boeing missed here; and Boeing knows that. They will likely have civil liability here. I do not see any chance of criminal liability.

3) Problems with Certification & Regulatory Approval Process. I take both Boeing and the FAA at their word that their were no inherent problems with either the certification or regulatory approval process. They both followed it and did what they were required. Hence no problems with what they did in accordance with the current approved process. Both Boeing and the FAA have made specific statements to that.

However, that is different that asking if there was a problem with the process... something missing. I believe that yes, there is a missing item from the existing process: Adequate review of Failure and Failure Effect Analysis.

Boeing, the FAA, and other regulatory agencies in the world have reviewed the process.... Note that the Europeans are requiring an independent review. Note also that the FAA has set up an independent review. Design review is basic. Getting the Failure and Failure Effect Analysis correct - and designing to eliminate identified concerns above a certain level - are the key to good design. In my opinion and engineering judgement, that has to be what the independent review is doing.

I do not see any true major change worldwide in certification process; as everyone uses essentially the same process. The Manufacturers will still do much of the specific certification work, the regulators will do a high level review and approval. The Regulators do not have and will never have the manpower for anything else than that. But, what I see likely to be added is a requirement for an independent review of the various Failure and Failure Effect Analysis for modified components and systems.

4) Worldwide certification of the "Fix." By all historical patterns and processes the FAA must first approve it as they are the original certifier as the 737-8Max is designed and built in the USA. Then the other countries certify. That is how all new and all modifications are always done.

I expect that the other major countries will quickly follow - and note that the FAA met with many May 23 and I am sure that one of the things they asked was if there was anything they needed to add to their process to answer any concerns the other countries had (note that the FAA is already using an independent reviewer per the European stated requirements). I am sure that the FAA will include any reasonable request from the other countries.

Other countries (especially Brazil, Canada, and Europe, with China as a lessor player) are playing with fire not to provide additional items and then rapidly approve with out any other major work. Otherwise expect that Airbus, Bombardier, and Embraer, etc will find that they can no longer easily certify upgrades, modifications, and new aircraft in the USA; or anywhere else in the world. I think that the regulators actually understand this - and what I think the May 23 meeting was more about was what changes did the US (and other countries) now need in their certification process to be sure things were done right. Expect independent reviews to become part of those regulatory agency requirements as well going forward.

5) Pilot Training. In the Ethiopian thread I recall that I posted after the preliminary report that it appeared that the pilots found themselves in a situation where you would not expect a normal pilot to be able to recover from. I am no longer sure of that. A lot of reading since then has raised to me a question of why would not one of the very basic things to do if the controls are not responding correctly and you were airborne without a major failure (engine or wing) that you would not immediately go to standard pitch and power, and turn off all automatics; and just fly straight until the aircraft stabilized at whatever altitude it would get to with standard pitch and power; unless there is a mountain in the way. Then troubleshoot - or just fly in total manual flight mode until you land. I am beginning to wonder why there is not a requirement that every pilot and copilot fly at least 1 flight every 6 months or year totally manual from takeoff to landing (with allowances for the other pilot to cover for short bathroom breaks, etc), why every pilot has not actually flown their aircraft at pitch and power from both a low altitude and high altitude to experience how the plane will level out at a safe altitude and speed (it will descend from a high, and ascend from a lower altitude to reach a modest altitude). This would be minimal training cost additions and could be done as part of normal flights.

I'm wondering if perhaps we have made it far to complicated for the pilots in expecting them to remember dozens of procedures. How about just a few: Transition to manual at pitch and power for control problems, engine out, etc. This is essentially a training issue; although procedures would have to be modified to emphasize that.

I also note, that what many are calling "pilot error" in this thread is much more likely a procedure or training issue, than actual pilot error.

6) What the final accident reports will likely say: First off in the Lion Air case the fact that the previous flight had the same or similar issue, the pilots handled it; and apparently did not communicate that to the next set of pilots is a biggie: If I were running a root cause investigation in a nuke power plant this failure of communication would likely be the root cause. Equipment gets buggered, it fails, latent design errors and poor procedures do set the operators up for problems (happens a lot more than many realize). For someone to recognize the problem, find a fix, and not communicate it to the next crew.... That is the one thing under immediate control that would have prevented the event. Note that Nuclear Plant Rood Cause investigation is the same process the NTSB uses - I'm trained and certified to the same standard; and have run teams of up to 30 people for up to 6 months investigating issues or equipment failures, plant trips in nuclear power plants (and we study Air Transport Root Causes all the time in training).

Now is that due to Lion Air procedures, training, human factor (pilots sick), or other reason. I don't know. I don't see how Lion Air escapes on this one. At this time and based on the information I have I only see the MCAS as a contributing factor as the prior flight dealt with the issue. Procedures, Training, and other things will also be identified. It would be common for their to be an element of pilot error caused at least by situational overload. It may not even get listed as a contributing factor (being human is not a reportable cause or factor).

I have made no conclusions of any kind on the Ethiopian crash.

7) Finally, until we actually see the final accident reports with full information - we are unlikely to be able to say much more. Speculation may feel good; and is often wrong. Opinions far to often get in the way of facts.

Hope this helps, and have a great day,


:checkmark: :checkmark: :checkmark: Well thought out and well written.

OAG
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
User avatar
PW100
Posts: 3641
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 10:00 pm

GalaxyFlyer wrote:
zoom321 wrote:
GalaxyFlyer wrote:
Trimming is about second or third one learns during pilot training. It shouldn’t require an AD to tell pilots to put the plane in trim. Trim is like managing thrust. In UPT, if you weren’t “in trim” they’d just reach under your arm and push up hard to get you to release the stick, followed by an abrupt nose going in up or down reinforcing the importance of trim. Then, you start formation and really discover the need for trim. IPs would wear out the thumb in their gloves trimming.

GF

That's not a problem, the problem is that the tool you're trying to use to put the plane in trim, the manual trim, is broken.


But, the manual ELECTRIC trim (yoke switches) was not broken and the FDR traces show functional inputs that were too brief to position the stab into a trimmed condition. Pilots were simply not aggressive enough and the the stab get so far out of position that the wheels wouldn’t work under the aerodynamic loads. If your flight SOP is autopilot ON at 400’ and OFF at 200’ on an ILS (an all too frequent training or laziness outcome), you’ll use the trim switches to the degree necessary during various speed and configuration changes. In fact, you probably get away never trimming. Trimming is not Chuck Yeager skills, either.

GF


There is NO evidence that the pilots did not properly use electric trimming. Au contraire, the FDR charts clearly show the use of electric up-trimming being applied many times. So they did understand how that works . . .

I'm baffled that some on here find it necessary to explain that (electric) “trimming is about second or third one learns during pilot training”, suggesting that these pilots did not know how to trim a 737. That borders at the R word.

The FDR traces show a total of four electric up-trims after MCAS became alive. And ALL FOUR of them stopped at exactly the same pitch trim: 2.3 degrees. Coincidence? Can any crew do such a thing on purpose? I'm having a hard time accepting that.
It must be noted that after take-off, electric trimming was applied several times (both up and down) resulting in a balanced control column. So again, they clearly knew how that works . . .

I’m baffled (AGAIN) why no one seems to be interested in this very peculiar behaviour of pitch trimming (stopping at 2.3 deg Pitch Trim), and trying to explore what the dynamics behind this behaviour would/could be, but in stead jump on the “crew doesn’t understand electric (and manual) up-trimming” bandwagon.

Why on earth would even “poorly trained third world operator crew” stop electric up-trimming way way before the control column is anywhere near being in balanced pitch condition??? That does not make any sense, at all.


The cut out switches were flipped before the control column was balanced in pitch. You ASSUME that was by pilot action. We have no evidence of that. All we know is that:
a) At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and First-Officer confirmed stab trim cut-out. (page 11);
b) At 05:40:37, electric up-trimming stopped (FDR trace);
c) At 05:40:42, MCAS command did not affect pitch trim, so at that point the cut-out switches were in flipped position (FDR trace).
Therefore, between 05:40:37 and 05:40:42, the cut-out switches were flipped.

So the question is, a) did up-trimming stop because the cut-out switches were flipped, or b) did they flip the switches because electric up-trimming stopped (uncommandedly) and was not working for them (beyond 2.3 deg Pitch Trim)?
I can’t find that answer in the report nor the FDR traces.

Further, I find following line (page 11) also very interesting: “At 05:40:27, the Captain advised the First-Officer to trim up with him.”:
At 05:40:00, MCAS became alive and completed a full 9 second cycle. This was quickly followed by electric up-trimming which stopped at . . . . 2.3 deg Pitch Trim.
At 05:40:21, second MCAS cycle, which was cut short by electric up-trimming (!!). This time the electric up-trimming is much longer in duration, but stopped AGAIN at . . . wait for it . . . 2.3 deg Pitch Trim.
At 05:40:27, the Captain advised the First-Officer to trim up with him.
Why would the captain ask the FO to trim up with him”?
That would suggest that his up-trimming was cut short not by his own choice, but by something else outside his control. Why else would he ask for help in up-trimming?

Why did up-trimming each time stop at 2.3 deg Pitch Trim?
Coincidence??? I don’t think so.
Crew not understanding up-trimming? I’m not buying that at this point, without strong evidence. Which has not (yet) been presented.

All in all, I have a lot of questions and am no way convinced that the crew did not understand electric up-trimming.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
User avatar
PixelFlight
Posts: 478
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 10:03 pm

morrisond wrote:
PixelFlight wrote:
From a personal point of view, I am for even more redundancies and high level algorithms that can still work with rare sensors failure, definitively not for single sensor and stupid code driving main control surface.

so what happens if something takes out all the auto-systems? Would you want to be on that flight in instrument conditions with the state of today's training?

Exactly the same as if you take out all the pilots. I explicitly want more redundancies precisely to avoid situation where all systems can be out. Well designed redundancies (ADIRU, FCC, AFDX, EBHA, BPS/BCM. etc...) proved very effective to improve flight safety.
 
User avatar
keesje
Posts: 12949
Joined: Thu Apr 12, 2001 2:08 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 10:07 pm

I think we will need a review of independency of the authorizing bodies, the rudgedness of the certification process under commercial pressure, continued grandfathering of 737 design & requirements and the factual handling of the Lionair and then the Ethiopian crash by Boeing and FAA.

The world saw what happened, acted & things have changed.
Last edited by keesje on Sun May 26, 2019 10:11 pm, edited 1 time in total.
"Never mistake motion for action." Ernest Hemingway
 
User avatar
PixelFlight
Posts: 478
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 10:10 pm

OldAeroGuy wrote:
PixelFlight wrote:
JT043, JT610 and ET302 proved that a new "potential failure or variation of failure" was not appropriately handled by the existing procedures and training.

Existing procedures and training seemed to work for JT043.
It did take someone who recognized a "Runaway Stabilizer" and advised applying the appropriate NNC.

When the 2 pilots need an other guy to save the aircraft, you are pretty certain that the "existing procedures and training" did _NOT_ work as expected.
 
User avatar
PW100
Posts: 3641
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 10:13 pm

PixelFlight wrote:
OldAeroGuy wrote:
PixelFlight wrote:
JT043, JT610 and ET302 proved that a new "potential failure or variation of failure" was not appropriately handled by the existing procedures and training.

Existing procedures and training seemed to work for JT043.
It did take someone who recognized a "Runaway Stabilizer" and advised applying the appropriate NNC.

When the 2 pilots need an other guy to save the aircraft, you are pretty certain that the "existing procedures and training" did _NOT_ work as expected.


But you don't underrstand, that's evidence of "declining pilot standards wroldwide". . . needing a third person to tell the pilots what to do . . . :duck: :white:
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
planecane
Posts: 872
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 10:19 pm

PW100 wrote:
GalaxyFlyer wrote:
zoom321 wrote:
That's not a problem, the problem is that the tool you're trying to use to put the plane in trim, the manual trim, is broken.


But, the manual ELECTRIC trim (yoke switches) was not broken and the FDR traces show functional inputs that were too brief to position the stab into a trimmed condition. Pilots were simply not aggressive enough and the the stab get so far out of position that the wheels wouldn’t work under the aerodynamic loads. If your flight SOP is autopilot ON at 400’ and OFF at 200’ on an ILS (an all too frequent training or laziness outcome), you’ll use the trim switches to the degree necessary during various speed and configuration changes. In fact, you probably get away never trimming. Trimming is not Chuck Yeager skills, either.

GF


There is NO evidence that the pilots did not properly use electric trimming. Au contraire, the FDR charts clearly show the use of electric up-trimming being applied many times. So they did understand how that works . . .

I'm baffled that some on here find it necessary to explain that (electric) “trimming is about second or third one learns during pilot training”, suggesting that these pilots did not know how to trim a 737. That borders at the R word.

The FDR traces show a total of four electric up-trims after MCAS became alive. And ALL FOUR of them stopped at exactly the same pitch trim: 2.3 degrees. Coincidence? Can any crew do such a thing on purpose? I'm having a hard time accepting that.
It must be noted that after take-off, electric trimming was applied several times (both up and down) resulting in a balanced control column. So again, they clearly knew how that works . . .

I’m baffled (AGAIN) why no one seems to be interested in this very peculiar behaviour of pitch trimming (stopping at 2.3 deg Pitch Trim), and trying to explore what the dynamics behind this behaviour would/could be, but in stead jump on the “crew doesn’t understand electric (and manual) up-trimming” bandwagon.

Why on earth would even “poorly trained third world operator crew” stop electric up-trimming way way before the control column is anywhere near being in balanced pitch condition??? That does not make any sense, at all.


The cut out switches were flipped before the control column was balanced in pitch. You ASSUME that was by pilot action. We have no evidence of that. All we know is that:
a) At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and First-Officer confirmed stab trim cut-out. (page 11);
b) At 05:40:37, electric up-trimming stopped (FDR trace);
c) At 05:40:42, MCAS command did not affect pitch trim, so at that point the cut-out switches were in flipped position (FDR trace).
Therefore, between 05:40:37 and 05:40:42, the cut-out switches were flipped.

So the question is, a) did up-trimming stop because the cut-out switches were flipped, or b) did they flip the switches because electric up-trimming stopped (uncommandedly) and was not working for them (beyond 2.3 deg Pitch Trim)?
I can’t find that answer in the report nor the FDR traces.

Further, I find following line (page 11) also very interesting: “At 05:40:27, the Captain advised the First-Officer to trim up with him.”:
At 05:40:00, MCAS became alive and completed a full 9 second cycle. This was quickly followed by electric up-trimming which stopped at . . . . 2.3 deg Pitch Trim.
At 05:40:21, second MCAS cycle, which was cut short by electric up-trimming (!!). This time the electric up-trimming is much longer in duration, but stopped AGAIN at . . . wait for it . . . 2.3 deg Pitch Trim.
At 05:40:27, the Captain advised the First-Officer to trim up with him.
Why would the captain ask the FO to trim up with him”?
That would suggest that his up-trimming was cut short not by his own choice, but by something else outside his control. Why else would he ask for help in up-trimming?

Why did up-trimming each time stop at 2.3 deg Pitch Trim?
Coincidence??? I don’t think so.
Crew not understanding up-trimming? I’m not buying that at this point, without strong evidence. Which has not (yet) been presented.

All in all, I have a lot of questions and am no way convinced that the crew did not understand electric up-trimming.


I can definitely see your curiousity regarding the trim seeming to stop in the same place each time. The final two commands I don't think can be used to draw any conclusion becuause they were so short. The resolution on the graph makes it very hard to tell for sure but it seems that the second to last input was less than a second and the final input was not more than a second.

As for the cutout, I would hope that they can analyze the CVR forensically and determine exactly when the switches were moved. As best as can be ascertained from the FDR plot, the electric trim power was removed at 05:40:36.5 when the manual trim command cuts off. It is definitely possible that for some reason the pilot stopped pressing the switch at that moment.

The other (very important) question is whether the 2.3 degrees is rounded in the report. Since the MCAS rate is given as 0.27 degrees per second and it operates for 9.2 seconds at a time, the actual trim change would be 2.484 degrees. If MCAS moves to a point that is measured in thousandths of a degree, it is unlikely for it to end up on an exact tenth of a degree. Is the resolution of the FDR only to tenths?
 
User avatar
PW100
Posts: 3641
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 10:33 pm

planecane wrote:
As for the cutout, I would hope that they can analyze the CVR forensically and determine exactly when the switches were moved. As best as can be ascertained from the FDR plot, the electric trim power was removed at 05:40:36.5 when the manual trim command cuts off. It is definitely possible that for some reason the pilot stopped pressing the switch at that moment.


That is possible.

But then again, the previous up-trim (following first MCAS cycle) also stopped at the same Pitch Trim angle. Too much of a co-incidence, in my mind.

Did the pilot stop pressing the switch there as well (for a totally different duration of pressing trim switch), but nevertheless miraculously finding the same Pitch Trim angle . . . ?
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
User avatar
PW100
Posts: 3641
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 10:40 pm

planecane wrote:
The other (very important) question is whether the 2.3 degrees is rounded in the report. Since the MCAS rate is given as 0.27 degrees per second and it operates for 9.2 seconds at a time, the actual trim change would be 2.484 degrees. If MCAS moves to a point that is measured in thousandths of a degree, it is unlikely for it to end up on an exact tenth of a degree. Is the resolution of the FDR only to tenths?


I'm sure the raw FDR data contains (much) more data and accuracy than displayed in the pdf document. The accuracy of the 2.3 deg Pitch Trim angle may or may not be important, depending on the dynamics behind that. I'm sure the investigation group as already digging into this.

BTW, I would be blown away if the accuracy of each MCAS cycle is indeed within 0.001 deg. I would expect variations in trim motor characteristics, power supply stability, aerodynamic loading etc would be more than 0.001 deg over the duration of a full MCAS cycle.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
frmrCapCadet
Posts: 2929
Joined: Thu May 29, 2008 8:24 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 11:22 pm

I also note, that what many are calling "pilot error" in this thread is much more likely a procedure or training issue, than actual pilot error.


This seems to be overlooked on any number of articles in the news media and in posts here
Buffet: the airline business...has eaten up capital...like..no other (business)
 
DenverTed
Posts: 207
Joined: Wed Mar 27, 2019 11:12 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 26, 2019 11:58 pm

PW100 wrote:
GalaxyFlyer wrote:
zoom321 wrote:
That's not a problem, the problem is that the tool you're trying to use to put the plane in trim, the manual trim, is broken.


But, the manual ELECTRIC trim (yoke switches) was not broken and the FDR traces show functional inputs that were too brief to position the stab into a trimmed condition. Pilots were simply not aggressive enough and the the stab get so far out of position that the wheels wouldn’t work under the aerodynamic loads. If your flight SOP is autopilot ON at 400’ and OFF at 200’ on an ILS (an all too frequent training or laziness outcome), you’ll use the trim switches to the degree necessary during various speed and configuration changes. In fact, you probably get away never trimming. Trimming is not Chuck Yeager skills, either.

GF


There is NO evidence that the pilots did not properly use electric trimming. Au contraire, the FDR charts clearly show the use of electric up-trimming being applied many times. So they did understand how that works . . .

I'm baffled that some on here find it necessary to explain that (electric) “trimming is about second or third one learns during pilot training”, suggesting that these pilots did not know how to trim a 737. That borders at the R word.

The FDR traces show a total of four electric up-trims after MCAS became alive. And ALL FOUR of them stopped at exactly the same pitch trim: 2.3 degrees. Coincidence? Can any crew do such a thing on purpose? I'm having a hard time accepting that.
It must be noted that after take-off, electric trimming was applied several times (both up and down) resulting in a balanced control column. So again, they clearly knew how that works . . .

I’m baffled (AGAIN) why no one seems to be interested in this very peculiar behaviour of pitch trimming (stopping at 2.3 deg Pitch Trim), and trying to explore what the dynamics behind this behaviour would/could be, but in stead jump on the “crew doesn’t understand electric (and manual) up-trimming” bandwagon.

Why on earth would even “poorly trained third world operator crew” stop electric up-trimming way way before the control column is anywhere near being in balanced pitch condition??? That does not make any sense, at all.


The cut out switches were flipped before the control column was balanced in pitch. You ASSUME that was by pilot action. We have no evidence of that. All we know is that:
a) At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and First-Officer confirmed stab trim cut-out. (page 11);
b) At 05:40:37, electric up-trimming stopped (FDR trace);
c) At 05:40:42, MCAS command did not affect pitch trim, so at that point the cut-out switches were in flipped position (FDR trace).
Therefore, between 05:40:37 and 05:40:42, the cut-out switches were flipped.

So the question is, a) did up-trimming stop because the cut-out switches were flipped, or b) did they flip the switches because electric up-trimming stopped (uncommandedly) and was not working for them (beyond 2.3 deg Pitch Trim)?
I can’t find that answer in the report nor the FDR traces.

Further, I find following line (page 11) also very interesting: “At 05:40:27, the Captain advised the First-Officer to trim up with him.”:
At 05:40:00, MCAS became alive and completed a full 9 second cycle. This was quickly followed by electric up-trimming which stopped at . . . . 2.3 deg Pitch Trim.
At 05:40:21, second MCAS cycle, which was cut short by electric up-trimming (!!). This time the electric up-trimming is much longer in duration, but stopped AGAIN at . . . wait for it . . . 2.3 deg Pitch Trim.
At 05:40:27, the Captain advised the First-Officer to trim up with him.
Why would the captain ask the FO to trim up with him”?
That would suggest that his up-trimming was cut short not by his own choice, but by something else outside his control. Why else would he ask for help in up-trimming?

Why did up-trimming each time stop at 2.3 deg Pitch Trim?
Coincidence??? I don’t think so.
Crew not understanding up-trimming? I’m not buying that at this point, without strong evidence. Which has not (yet) been presented.

All in all, I have a lot of questions and am no way convinced that the crew did not understand electric up-trimming.

That is an interesting theory that there is a genie in the system that has not been found or not publicly divulged.
The exact nature of the 2.3 stop is more than coincidence.
On that note, I think precise numbers are not random. How fast to make the rate? .06 for starters, not just .1 for 10s. Why exactly .06? If adjusted why not .07 or .08? .27 is a factor so far off that some detailed explanation is due there. If the pilots are under minute scrutiny, so should be the designers of the system. If the goal if improving safety is paramount.
 
DenverTed
Posts: 207
Joined: Wed Mar 27, 2019 11:12 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 12:03 am

Apportioning blame is one thing, that's for the courts to decide. In terms of safety, Boeing should be taken to task, but that isn't mutually exclusive of grounding ET and JT. Who has the power to do that? Like in the case of Boeing, perhaps world pressure should be applied. Obviously Boeing can't take that position as it contradicts selling aircraft. Looks like the pilots and maintenance made unforgivable errors that go beyond MCAS.
 
DenverTed
Posts: 207
Joined: Wed Mar 27, 2019 11:12 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 12:13 am

MSPNWA wrote:
PixelFlight wrote:
Never before the Runaway Stabilizer Procedure was about a repetitive discontinuous automatic movement that still allow the manual electric trim to work.


How do you know this for a fact?

"Boeing
737 Flight Crew Operations Manual
-Runaway Stabilizer
Condition: Uncommanded statbilizer trim movement occurs continuously."

Words and words meaning matter. In this case "continuously"
Since in the state of Washington, there was ten years, months of legislature extended sessions, and billions of dollars over one word, "paramount", and a case of closing toll lanes based on one "and" instead of "or", I doubt Boeing gets to make up the English language to suit their needs.
But hey, don't believe me, we'll see what the courts think the word "continuously" means.
 
GalaxyFlyer
Posts: 3152
Joined: Fri Jan 01, 2016 4:44 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 12:51 am

PW100 wrote:
GalaxyFlyer wrote:
zoom321 wrote:
That's not a problem, the problem is that the tool you're trying to use to put the plane in trim, the manual trim, is broken.


But, the manual ELECTRIC trim (yoke switches) was not broken and the FDR traces show functional inputs that were too brief to position the stab into a trimmed condition. Pilots were simply not aggressive enough and the the stab get so far out of position that the wheels wouldn’t work under the aerodynamic loads. If your flight SOP is autopilot ON at 400’ and OFF at 200’ on an ILS (an all too frequent training or laziness outcome), you’ll use the trim switches to the degree necessary during various speed and configuration changes. In fact, you probably get away never trimming. Trimming is not Chuck Yeager skills, either.

GF


There is NO evidence that the pilots did not properly use electric trimming. Au contraire, the FDR charts clearly show the use of electric up-trimming being applied many times. So they did understand how that works . . .

I'm baffled that some on here find it necessary to explain that (electric) “trimming is about second or third one learns during pilot training”, suggesting that these pilots did not know how to trim a 737. That borders at the R word.

The FDR traces show a total of four electric up-trims after MCAS became alive. And ALL FOUR of them stopped at exactly the same pitch trim: 2.3 degrees. Coincidence? Can any crew do such a thing on purpose? I'm having a hard time accepting that.
It must be noted that after take-off, electric trimming was applied several times (both up and down) resulting in a balanced control column. So again, they clearly knew how that works . . .

I’m baffled (AGAIN) why no one seems to be interested in this very peculiar behaviour of pitch trimming (stopping at 2.3 deg Pitch Trim), and trying to explore what the dynamics behind this behaviour would/could be, but in stead jump on the “crew doesn’t understand electric (and manual) up-trimming” bandwagon.

Why on earth would even “poorly trained third world operator crew” stop electric up-trimming way way before the control column is anywhere near being in balanced pitch condition??? That does not make any sense, at all.


The cut out switches were flipped before the control column was balanced in pitch. You ASSUME that was by pilot action. We have no evidence of that. All we know is that:
a) At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and First-Officer confirmed stab trim cut-out. (page 11);
b) At 05:40:37, electric up-trimming stopped (FDR trace);
c) At 05:40:42, MCAS command did not affect pitch trim, so at that point the cut-out switches were in flipped position (FDR trace).
Therefore, between 05:40:37 and 05:40:42, the cut-out switches were flipped.

So the question is, a) did up-trimming stop because the cut-out switches were flipped, or b) did they flip the switches because electric up-trimming stopped (uncommandedly) and was not working for them (beyond 2.3 deg Pitch Trim)?
I can’t find that answer in the report nor the FDR traces.

Further, I find following line (page 11) also very interesting: “At 05:40:27, the Captain advised the First-Officer to trim up with him.”:
At 05:40:00, MCAS became alive and completed a full 9 second cycle. This was quickly followed by electric up-trimming which stopped at . . . . 2.3 deg Pitch Trim.
At 05:40:21, second MCAS cycle, which was cut short by electric up-trimming (!!). This time the electric up-trimming is much longer in duration, but stopped AGAIN at . . . wait for it . . . 2.3 deg Pitch Trim.
At 05:40:27, the Captain advised the First-Officer to trim up with him.
Why would the captain ask the FO to trim up with him”?
That would suggest that his up-trimming was cut short not by his own choice, but by something else outside his control. Why else would he ask for help in up-trimming?

Why did up-trimming each time stop at 2.3 deg Pitch Trim?
Coincidence??? I don’t think so.
Crew not understanding up-trimming? I’m not buying that at this point, without strong evidence. Which has not (yet) been presented.

All in all, I have a lot of questions and am no way convinced that the crew did not understand electric up-trimming.


I just looked at the traces and only see two man electric trim inputs which bring the stab position to about 2.3 units nose up at about 05:40:21. Earlier, the stab trim was around 5 units (not degrees). The crew never trimmed out the MCAS inputs.
 
planecane
Posts: 872
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 1:53 am

DenverTed wrote:
MSPNWA wrote:
PixelFlight wrote:
Never before the Runaway Stabilizer Procedure was about a repetitive discontinuous automatic movement that still allow the manual electric trim to work.


How do you know this for a fact?

"Boeing
737 Flight Crew Operations Manual
-Runaway Stabilizer
Condition: Uncommanded statbilizer trim movement occurs continuously."

Words and words meaning matter. In this case "continuously"
Since in the state of Washington, there was ten years, months of legislature extended sessions, and billions of dollars over one word, "paramount", and a case of closing toll lanes based on one "and" instead of "or", I doubt Boeing gets to make up the English language to suit their needs.
But hey, don't believe me, we'll see what the courts think the word "continuously" means.


According to dictionary.com (and this surprised me because I've never really thought about it), there are two definitions for the word "continuous" which are below:

1) uninterrupted in time; without cessation:
-----continuous coughing during the concert.

2)being in immediate connection or spatial relationship:
-----a continuous series of blasts; a continuous row of warehouses.


Therefore, MCAS runaway can be defined as uncommanded stabilzer trim movement that occurs continuously.

In all cases of runaway, the uncommanded stabilizer movement will stop at some point. It will either stop when it reaches max nose up or max nose down or be interrupted by an input from a pilot. If the movement needs to be uninterrupted to qualify as runaway, then you could never have a definied runaway.

For the NNC condition, you can't just say uncommanded stabilizer trim movement because that happens all the time from other systems like STS.
 
User avatar
aerolimani
Posts: 1116
Joined: Tue Jun 18, 2013 5:46 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 2:53 am

planecane wrote:
DenverTed wrote:
MSPNWA wrote:

How do you know this for a fact?

"Boeing
737 Flight Crew Operations Manual
-Runaway Stabilizer
Condition: Uncommanded statbilizer trim movement occurs continuously."

Words and words meaning matter. In this case "continuously"
Since in the state of Washington, there was ten years, months of legislature extended sessions, and billions of dollars over one word, "paramount", and a case of closing toll lanes based on one "and" instead of "or", I doubt Boeing gets to make up the English language to suit their needs.
But hey, don't believe me, we'll see what the courts think the word "continuously" means.


According to dictionary.com (and this surprised me because I've never really thought about it), there are two definitions for the word "continuous" which are below:

1) uninterrupted in time; without cessation:
-----continuous coughing during the concert.

2)being in immediate connection or spatial relationship:
-----a continuous series of blasts; a continuous row of warehouses.


Therefore, MCAS runaway can be defined as uncommanded stabilzer trim movement that occurs continuously.

In all cases of runaway, the uncommanded stabilizer movement will stop at some point. It will either stop when it reaches max nose up or max nose down or be interrupted by an input from a pilot. If the movement needs to be uninterrupted to qualify as runaway, then you could never have a definied runaway.

For the NNC condition, you can't just say uncommanded stabilizer trim movement because that happens all the time from other systems like STS.

Except that the word is continuously, not continuous.

From Merriam-Webster:
Definition of continuously
: in a continuous manner : without interruption

From Oxford:
continuously
ADVERB

1Without interruption or gaps.
‘these images loop continuously’
More example sentences
1.1 Repeatedly without exceptions or reversals.
‘their performance has continuously improved’
 
RickNRoll
Posts: 1664
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 2:53 am

OldAeroGuy wrote:
PixelFlight wrote:
JT043, JT610 and ET302 proved that a new "potential failure or variation of failure" was not appropriately handled by the existing procedures and training.


Existing procedures and training seemed to work for JT043.

It did take someone who recognized a "Runaway Stabilizer" and advised applying the appropriate NNC.


Read the full story on JT043.

https://www.theverge.com/2019/5/2/18518 ... r-mcas-faa

The pilots were not seeing something obvious so tried all the possibilities.

All this while the plane was actively trying to kill them.
 
PixelPilot
Posts: 250
Joined: Tue Jan 16, 2018 1:19 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 3:07 am

PixelFlight wrote:
OldAeroGuy wrote:
PixelFlight wrote:
JT043, JT610 and ET302 proved that a new "potential failure or variation of failure" was not appropriately handled by the existing procedures and training.

Existing procedures and training seemed to work for JT043.
It did take someone who recognized a "Runaway Stabilizer" and advised applying the appropriate NNC.

When the 2 pilots need an other guy to save the aircraft, you are pretty certain that the "existing procedures and training" did _NOT_ work as expected.


That actually tells that the crew in command didn’t do their job. They couldn’t fix the problem while somebody else did it for them. That somebody was in the same cockpit.
Stress, overwhelming situational tunnel and etc I get it but still. One would like to think that the pilots in command are capable of doing what was done for them by a stowaway don’t you think?
 
AABusDrvr
Posts: 33
Joined: Sat Dec 03, 2016 6:48 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 3:42 am

DenverTed wrote:
MSPNWA wrote:
PixelFlight wrote:
Never before the Runaway Stabilizer Procedure was about a repetitive discontinuous automatic movement that still allow the manual electric trim to work.


How do you know this for a fact?

"Boeing
737 Flight Crew Operations Manual
-Runaway Stabilizer
Condition: Uncommanded statbilizer trim movement occurs continuously."

Words and words meaning matter. In this case "continuously"
Since in the state of Washington, there was ten years, months of legislature extended sessions, and billions of dollars over one word, "paramount", and a case of closing toll lanes based on one "and" instead of "or", I doubt Boeing gets to make up the English language to suit their needs.
But hey, don't believe me, we'll see what the courts think the word "continuously" means.


I'm sorry, but in my humble 737 pilot opinion, this is the most ridiculous of all the arguments everyone is having here.

On the 737NG/MAX, there are only five non normal checklists that deal with the stabilizer trim.
-RUNAWAY STABILIZER
-MACH TRIM FAIL
-SPEED TRIM FAIL
-STABILIZER OUT OF TRIM
-STABILIZER TRIM INOPERATIVE

If the stabilizer trim keeps running opposite of what you told it to, repeatedly, the appropriate checklist is RUNAWAY STABILIZER. Just like any automation on any airplane, if the electric trim isn't doing what it's supposed to, or what you want it to do, you turn it off. Thats pretty basic "pilot stuff".

If a "trained" crew cant figure that out, their training isn't where it needs to be.

Again, this quote from an airplane operating manual applies.

"Checklists cannot be created for all conceivable situations and are not intended to
replace good judgment. In some situations, at the captain’s discretion, checklist
deviation(s) may be necessary."
Last edited by AABusDrvr on Mon May 27, 2019 3:44 am, edited 1 time in total.
 
planecane
Posts: 872
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 3:43 am

aerolimani wrote:
planecane wrote:
DenverTed wrote:
"Boeing
737 Flight Crew Operations Manual
-Runaway Stabilizer
Condition: Uncommanded statbilizer trim movement occurs continuously."

Words and words meaning matter. In this case "continuously"
Since in the state of Washington, there was ten years, months of legislature extended sessions, and billions of dollars over one word, "paramount", and a case of closing toll lanes based on one "and" instead of "or", I doubt Boeing gets to make up the English language to suit their needs.
But hey, don't believe me, we'll see what the courts think the word "continuously" means.


According to dictionary.com (and this surprised me because I've never really thought about it), there are two definitions for the word "continuous" which are below:

1) uninterrupted in time; without cessation:
-----continuous coughing during the concert.

2)being in immediate connection or spatial relationship:
-----a continuous series of blasts; a continuous row of warehouses.


Therefore, MCAS runaway can be defined as uncommanded stabilzer trim movement that occurs continuously.

In all cases of runaway, the uncommanded stabilizer movement will stop at some point. It will either stop when it reaches max nose up or max nose down or be interrupted by an input from a pilot. If the movement needs to be uninterrupted to qualify as runaway, then you could never have a definied runaway.

For the NNC condition, you can't just say uncommanded stabilizer trim movement because that happens all the time from other systems like STS.

Except that the word is continuously, not continuous.

From Merriam-Webster:
Definition of continuously
: in a continuous manner : without interruption

From Oxford:
continuously
ADVERB

1Without interruption or gaps.
‘these images loop continuously’
More example sentences
1.1 Repeatedly without exceptions or reversals.
‘their performance has continuously improved’


1.1 from oxford allows for interruption.
 
Cerecl
Posts: 564
Joined: Sun Jul 13, 2008 10:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 4:23 am

2175301 wrote:
1) Misconception & Outright Not True: Boeing hid the MCAS system, its design functions, etc from anyone.

I found this claim baffling when the Boeing itself said a description of the MCAS was not included in FCOM and it was reported the company withheld information from pilots for concern about "inundating pilots with too much information" ? Surely "anyone" should include the people who fly the aircraft??
https://www.wsj.com/articles/boeing-wit ... 1542082575
Boeing are so open about MCAS MAX simulators didn't even have it incorporated. Boeing changed from 0.6 to 2.5 degrees after FAA reviewed MCAS for safety
There are well documented reasons why it was in Boeing's financial interest to minimise differences between MAX and NG. While I believe Boeing did not intentionally cut corners knowing that it would lead to such disastrous consequences, it is very clear there was a systematic attempt at prioritisng financial gain over safety.

2175301 wrote:
3) Problems with Certification & Regulatory Approval Process. The Manufacturers will still do much of the specific certification work, the regulators will do a high level review and approval.

The "high level review" clearly worked really well for the MAX...
Do you still think it is OK to have Boeing (or Airbus for that matter) employees to act as regulators' representatives while having to report to manufacturer's managers??

2175301 wrote:
4) Worldwide certification of the "Fix." By all historical patterns and processes the FAA must first approve it as they are the original certifier as the 737-8Max is designed and built in the USA.

And now FAA's reputation is in the boots.

2175301 wrote:

Other countries (especially Brazil, Canada, and Europe, with China as a lessor player) are playing with fire not to provide additional items and then rapidly approve with out any other major work.

The other regulators will do whatever they consider is appropriate particularly after many failings of the MAX certification process have come to light. The loss of the 2 MAX crashes are tragic and if more regulatory oversight is required to ensure safety of new aircrafts I don't think anyone should be against it.
Fokker-100 SAAB 340 Q400 E190 717 737 738 763ER 787-8 772 77E 773 77W 747-400 747-400ER A319 A320 A321 A332 A333 A343 A346 A359 A380
 
User avatar
aerolimani
Posts: 1116
Joined: Tue Jun 18, 2013 5:46 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 4:55 am

planecane wrote:
aerolimani wrote:
planecane wrote:

According to dictionary.com (and this surprised me because I've never really thought about it), there are two definitions for the word "continuous" which are below:



Therefore, MCAS runaway can be defined as uncommanded stabilzer trim movement that occurs continuously.

In all cases of runaway, the uncommanded stabilizer movement will stop at some point. It will either stop when it reaches max nose up or max nose down or be interrupted by an input from a pilot. If the movement needs to be uninterrupted to qualify as runaway, then you could never have a definied runaway.

For the NNC condition, you can't just say uncommanded stabilizer trim movement because that happens all the time from other systems like STS.

Except that the word is continuously, not continuous.

From Merriam-Webster:
Definition of continuously
: in a continuous manner : without interruption

From Oxford:
continuously
ADVERB

1Without interruption or gaps.
‘these images loop continuously’
More example sentences
1.1 Repeatedly without exceptions or reversals.
‘their performance has continuously improved’


1.1 from oxford allows for interruption.

Grasping at straws.

Even the FAA is re-examining the checklists/procedures, and their wording, back as far as the Classic series. In fact, they have already indicated that they feel there are inconsistencies and a lack of clarity. So, Boeing’s written procedures are being questioned by the FAA. It’s not just a few rogue a-net members.
 
346fetish
Posts: 27
Joined: Thu Feb 22, 2018 12:00 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 5:39 am

How many 7M9s/7M8s was FI supposed to have in summer 2019? Had there not be any MAX grounding, would they have retired any 75s & 76s?

Best,
346fetish
"BA have got waterfalls in their head office. The only time we have waterfalls in the Ryanair office is when the toilet leaks."
 
zippy
Posts: 139
Joined: Sun May 11, 2014 9:46 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 5:46 am

morrisond wrote:
Your avoiding the question - so what happens if something takes out all the auto-systems? Would you want to be on that flight in instrument conditions with the state of today's training?


Presumably you're left with buggy Boeing instruments. Boeing hid the malfunctioning "AOA DISAGREE" annunciator (which is presumably a minor issue). What other (potentially more significant) problems with the PFD haven't been disclosed to airlines and regulatory agencies?
 
DenverTed
Posts: 207
Joined: Wed Mar 27, 2019 11:12 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 5:54 am

AABusDrvr wrote:

On the 737NG/MAX, there are only five non normal checklists that deal with the stabilizer trim.
-RUNAWAY STABILIZER
-MACH TRIM FAIL
-SPEED TRIM FAIL
-STABILIZER OUT OF TRIM
-STABILIZER TRIM INOPERATIVE

If the stabilizer trim keeps running opposite of what you told it to, repeatedly, the appropriate checklist is RUNAWAY STABILIZER. Just like any automation on any airplane, if the electric trim isn't doing what it's supposed to, or what you want it to do, you turn it off. Thats pretty basic "pilot stuff".

If a "trained" crew cant figure that out, their training isn't where it needs to be.

Again, this quote from an airplane operating manual applies.

"Checklists cannot be created for all conceivable situations and are not intended to
replace good judgment. In some situations, at the captain’s discretion, checklist
deviation(s) may be necessary."

Fair enough. Possibly not all conceivable situations, I can see that. One procedure for those five?

1-Recognize a malfunction. (Condition: current definition or something better?)
2-Use electric trim to try to neutralize column force
3-Flip electric trim switch cutout switch
4-Use manual trim wheel

Or return the autopilot cutout switch?

1-Recognize a malfunction. (Condition: current definition or something better?)
2-Flip autopilot trim cutout switch
3-Use electric trim to try to neutralize column force
4-If malfunction continues, flip electric trim cutout switch
5-Use manual trim wheel

Or just

1-Recognize a malfunction.
2-Flip electric trim switch cutout switch
3-Use manual trim wheel

Or two procedures depending on runaway motor or autopilot malfunction?

To a degree, I agree with Boeing's position that the pilots were the backup for MCAS failure. I think they would have a foolproof case if they had written foolproof documentation.
 
User avatar
PW100
Posts: 3641
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 7:16 am

GalaxyFlyer wrote:
I just looked at the traces and only see two man electric trim inputs which bring the stab position to about 2.3 units nose up at about 05:40:21. Earlier, the stab trim was around 5 units (not degrees). The crew never trimmed out the MCAS inputs.


"The crew never trimmed out the MCAS inputs."
Right, and water is wet. That is exactly what I wrote.

"The crew never trimmed out the MCAS inputs."
WHY would that be?
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
XRAYretired
Posts: 421
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 9:08 am

PW100 wrote:
GalaxyFlyer wrote:
I just looked at the traces and only see two man electric trim inputs which bring the stab position to about 2.3 units nose up at about 05:40:21. Earlier, the stab trim was around 5 units (not degrees). The crew never trimmed out the MCAS inputs.


"The crew never trimmed out the MCAS inputs."
Right, and water is wet. That is exactly what I wrote.

"The crew never trimmed out the MCAS inputs."
WHY would that be?

As PW100 - What I see is a total of 4 attempts of trim switch ANU. The first got to 2.4 and the other three all stopped at 2.3. Too much of a coincidence for me. I dont believe in coincidence. I would be looking for a common factor, and I dont think the pilots could be quite that accurate on purpose.

At 05:40:12, approximately three seconds after AND stabilizer motion ends, electric trim (from pilot activated switches on the yoke) in the Aircraft nose up (ANU) direction is recorded on the DFDR and the stabilizer moved in the ANU direction to 2.4 units. The Aircraft pitch attitude remained about the same as the back pressure on the column increased.
At 05:40:28 Manual electric trim in the ANU direction was recorded and the stabilizer reversed moving in the ANU direction and then the trim reached 2.3 units.
At 05:43:11, about 32 seconds before the end of the recording, at approximately 13,4002 ft, two momentary manual electric trim inputs are recorded in the ANU direction. The stabilizer moved in the ANU direction from 2.1 units to 2.3 units.

Ray
 
User avatar
kelvin933
Posts: 449
Joined: Tue Aug 19, 2014 9:20 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 10:00 am

346fetish wrote:
How many 7M9s/7M8s was FI supposed to have in summer 2019? Had there not be any MAX grounding, would they have retired any 75s & 76s?

Best,
346fetish


6 MAX8, 5 already delivered 1 in storage at PAE awaiting delivery, 3 MAX9 1 delivered 2 in storage at PAE awaiting delivery
“Nations have no permanent friends or allies, they only have permanent interests.”
 
StTim
Posts: 3358
Joined: Thu Aug 08, 2013 7:39 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 10:33 am

Are Boeing doing the normal pre customer test flights on produced frames? I presume each of these would require approval. I know some are positioned elsewhere for storage capacity.
 
mjoelnir
Posts: 8361
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 10:52 am

346fetish wrote:
How many 7M9s/7M8s was FI supposed to have in summer 2019? Had there not be any MAX grounding, would they have retired any 75s & 76s?

Best,
346fetish


9 Max frames, 6 737-8 and 3737-9, should have been in use at Icelandair this summer.

There was no plan to retire 757 or 767 this summer. The one retired 757-200 was replaced by a slightly newer one.

Icelandair is cutting down on charter flights, asking customers to try to move to other airlines.
 
User avatar
ExperimentalFTE
Posts: 26
Joined: Sun Mar 10, 2019 7:59 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 11:43 am

OldAeroGuy wrote:
IADFCO wrote:
furthermore, MCAS 2.0 will turn itself off *by design* after activating once. So, after the "protection" is needed once, it will not be available again (not clear for how long).


I think you're incorrect on how MCAS 2.0 will function.

- MCAS 2.0 will activate once when both AoA vanes exceed the trigger AoA. If AoA remains above the trigger AoA, it will not activate again.

- If both AoA's drop below the trigger AoA, MCAS 2.0 will re-activate if trigger AoA is again exceeded.

- If Left/Right AoA disagree by more than X deg, MCAS 2.0 will be shut down.

OAG


I personally think that with current hardware configuration functionality you mention for MCAS 2.0 is as uncertifiable as it gets.

IMHO that is mainly the reason why other certification authorities are keeping tight grip on it regardless of local outcome.

One thing is certain, this will be game changing event in global aviation and aerospace industry, flight testing and certification.

Cheers
 
ltbewr
Posts: 14111
Joined: Thu Jan 29, 2004 1:24 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 12:01 pm

davidjohnson6 wrote:
If the US FAA allows the 737 Max to fly but the European or Chinese try to require a permanent grounding of the 737 Max, then one can expect Boeing to call in some favours and for the US Govt to become much more active in helping Boeing through diplomatic means. The US Govt is not shy about protecting its strategic interests when they are under threat

I am quite sure that President Trump or any US President along with most members of both parties of our House and Senate would call out China or Europe if they were to delay or deny the certification of the fix for the 737MAX. I don't think Europe will be a problem, but unfortunately though the current hostile trade disputes with China that Pres. Trump has created mainly for internal US political reasons could encourage China to delay or deny unless get major trade concessions. China could say we will ok the 737MAX changes, but only if parts of the that and other Boeing a/c are made in China or are shipped to China for interior fittings as well as ending other general trade and tariffs to that prior to Pres. Trump.
 
AIRT0M
Posts: 64
Joined: Thu Mar 01, 2018 8:54 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 12:18 pm

ltbewr wrote:
davidjohnson6 wrote:
If the US FAA allows the 737 Max to fly but the European or Chinese try to require a permanent grounding of the 737 Max, then one can expect Boeing to call in some favours and for the US Govt to become much more active in helping Boeing through diplomatic means. The US Govt is not shy about protecting its strategic interests when they are under threat

I am quite sure that President Trump or any US President along with most members of both parties of our House and Senate would call out China or Europe if they were to delay or deny the certification of the fix for the 737MAX. I don't think Europe will be a problem, but unfortunately though the current hostile trade disputes with China that Pres. Trump has created mainly for internal US political reasons could encourage China to delay or deny unless get major trade concessions. China could say we will ok the 737MAX changes, but only if parts of the that and other Boeing a/c are made in China or are shipped to China for interior fittings as well as ending other general trade and tariffs to that prior to Pres. Trump.


Geez .... since Trump the US had lost so much credibility in the world. Don't think you can bully the EU, China or anybody into accepting a fix, if they're not convinced.
 
OldAeroGuy
Posts: 3858
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 12:33 pm

ExperimentalFTE wrote:
I personally think that with current hardware configuration functionality you mention for MCAS 2.0 is as uncertifiable as it gets.


Please explain why you think that MCAS 2.0 as described is not certifiable.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
User avatar
ExperimentalFTE
Posts: 26
Joined: Sun Mar 10, 2019 7:59 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 12:47 pm

OldAeroGuy wrote:
ExperimentalFTE wrote:
I personally think that with current hardware configuration functionality you mention for MCAS 2.0 is as uncertifiable as it gets.


Please explain why you think that MCAS 2.0 as described is not certifiable.


-Cannot obtain meaningful voting on the validity of the data source, it is either OP or INOP.

-Cannot achieve failure rate (typ 10^-9) for critical flight control components and thus probability vs severity wrt stalling and departure from controlled flight.

-Without it aircraft is still uncertifiable wrt to 25.203 and it is still very shady wrt 25.1309 and single source failure.

-Ah and also, lets discuss bit a windsheer scenario, full power on application and pitch up.....

;)
 
brindabella
Posts: 562
Joined: Fri Apr 30, 2010 10:38 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 12:56 pm

planecane wrote:
aerolimani wrote:
planecane wrote:

According to dictionary.com (and this surprised me because I've never really thought about it), there are two definitions for the word "continuous" which are below:



Therefore, MCAS runaway can be defined as uncommanded stabilzer trim movement that occurs continuously.

In all cases of runaway, the uncommanded stabilizer movement will stop at some point. It will either stop when it reaches max nose up or max nose down or be interrupted by an input from a pilot. If the movement needs to be uninterrupted to qualify as runaway, then you could never have a definied runaway.

For the NNC condition, you can't just say uncommanded stabilizer trim movement because that happens all the time from other systems like STS.

Except that the word is continuously, not continuous.

From Merriam-Webster:
Definition of continuously
: in a continuous manner : without interruption

From Oxford:
continuously
ADVERB

1Without interruption or gaps.
‘these images loop continuously’
More example sentences
1.1 Repeatedly without exceptions or reversals.
‘their performance has continuously improved’


1.1 from oxford allows for interruption.


Came in a little late; sorry if repetitive..

The trend of the posts above are trending that BA Tech assumed that any trained 737 pilot would recognise an inappropriate stab trim movement, however In a Court of Law the discontinuous movement may defeat this.

Expand please.



cheers Billy
Billy
 
planecane
Posts: 872
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 1:03 pm

brindabella wrote:
planecane wrote:
aerolimani wrote:
Except that the word is continuously, not continuous.

From Merriam-Webster:
Definition of continuously
: in a continuous manner : without interruption

From Oxford:
continuously
ADVERB

1Without interruption or gaps.
‘these images loop continuously’
More example sentences
1.1 Repeatedly without exceptions or reversals.
‘their performance has continuously improved’


1.1 from oxford allows for interruption.


Came in a little late; sorry if repetitive..

The trend of the posts above are trending that BA Tech assumed that any trained 737 pilot would recognise an inappropriate stab trim movement, however In a Court of Law the discontinuous movement may defeat this.

Expand please.



cheers Billy


In civil court Boeing will be found to have some percentage of liability anyway even if the procedure came with a video that showed MCAS failing.

In criminal court I doubt it would get near that far since I still can't find any federal law that could possibly be used to find Boeing guilty of the crashes as a homicide. Any criminal case will be mail fraud or wire fraud for lying to the FCC or something like that. Therefore, the semantics of the NNC condition will probably not come into play.
 
GalaxyFlyer
Posts: 3152
Joined: Fri Jan 01, 2016 4:44 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 27, 2019 1:25 pm

At 05:40:12, approximately three seconds after AND stabilizer motion ends, electric trim (from pilot activated switches on the yoke) in the Aircraft nose up (ANU) direction is recorded on the DFDR and the stabilizer moved in the ANU direction to 2.4 units. The Aircraft pitch attitude remained about the same as the back pressure on the column increased.
At 05:40:28 Manual electric trim in the ANU direction was recorded and the stabilizer reversed moving in the ANU direction and then the trim reached 2.3 units.


Why while increasing back pressure, did they not continue trimming? The switches worked. I think they weren’t trimming as every manually switch moved the stab. It lifted off with about 5 units up but never got back to anything 5 units. Take off trim is approximately V2.


Gf

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