Jul 20, 2019, 7:49 pm
737-Max 8 safety concerns
Jul 31, 2019, 9:03 am
#511
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Jul 31, 2019, 10:45 am
#512
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Jul 31, 2019, 12:10 pm
#513
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What a shocker there 
I do apologize, but, I have not seen any articles from named aeronautical engineers that agree with your statement. I am not saying they don't exist, I just have not seen them.
(,,,)
I did a quick scan, and I still don't see the linked articles from aeronautical engineers stating what you (and others) state. Perhaps you could place them in the wiki for all to have ready access.
I do apologize in turn: doing quick scans of mainstream media probably hardly brushes the surface of this subject. I'm not saying mainstream media are awful, they try their best to summarize, but it doesn't replace following the discussions on specialist forums (which I have tried to do for the last 3 months) which are based on official boeing documentation and interim accident reports (which I have not read, but kind and passionate professionals do summarize and comment on them).
It's certainly not my place to advertise other forums on these boards, so no links, but you can find them by yourself for sure. This is a more casual forum, and that's cool; it's not really the place to get serious with full NTSB reports.
It's not the Seattle Times (out of all papers lol) which is going to give you a rundown of the aerodynamical flaws of the MAX envelope.
I did find two articles from Forbes which mention the bad stability of the cell. Maybe that's a good start for a short read?
https://www.forbes.com/sites/peterco.../#6bf3ee4540aa
https://www.forbes.com/sites/peterco.../#2736620e2e18
But even that's not a very complete and reliable info source, so it's not something I would personally add to the wiki.
I'm pretty sure Mentour pilot did a few videos about it as well, which are quite accessible, and Peter Lemme (who worked on the 767 iirc) might have tweeted some diagrams, but I'm a bit lazy to find the links now, sorry...
I don't have an agenda (I love flying Boeings), and I'm no conspiracy theorist. I have read enough on the 737 MAX that has seriously concerned me about flying on that plane. I can only encourage you to decide for yourself, but I can not provide a magic link that will instantly convince you. (Hey I'm not saying it doesn't exit, I just havn't seen it yet!)
I do apologize, but, I have not seen any articles from named aeronautical engineers that agree with your statement. I am not saying they don't exist, I just have not seen them.
(,,,)
I did a quick scan, and I still don't see the linked articles from aeronautical engineers stating what you (and others) state. Perhaps you could place them in the wiki for all to have ready access.
It's certainly not my place to advertise other forums on these boards, so no links, but you can find them by yourself for sure. This is a more casual forum, and that's cool; it's not really the place to get serious with full NTSB reports.
It's not the Seattle Times (out of all papers lol) which is going to give you a rundown of the aerodynamical flaws of the MAX envelope.
I did find two articles from Forbes which mention the bad stability of the cell. Maybe that's a good start for a short read?
https://www.forbes.com/sites/peterco.../#6bf3ee4540aa
https://www.forbes.com/sites/peterco.../#2736620e2e18
But even that's not a very complete and reliable info source, so it's not something I would personally add to the wiki.
I'm pretty sure Mentour pilot did a few videos about it as well, which are quite accessible, and Peter Lemme (who worked on the 767 iirc) might have tweeted some diagrams, but I'm a bit lazy to find the links now, sorry...
I don't have an agenda (I love flying Boeings), and I'm no conspiracy theorist. I have read enough on the 737 MAX that has seriously concerned me about flying on that plane. I can only encourage you to decide for yourself, but I can not provide a magic link that will instantly convince you. (Hey I'm not saying it doesn't exit, I just havn't seen it yet!)
Jul 31, 2019, 12:55 pm
#514
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If competing airlines and manufacturers are smart, they'll put forward a campaign to differentiate themselves by not using those aircraft.
Jul 31, 2019, 2:32 pm
#515
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Exploiting the deaths caused by a competitor’s product by directly and publicly campaigning against a company by using those tragedies is a dangerous recipe and risks coming across as a low class ploy in mass marketing and backfiring when a tragedy hits the dark campaign side. And there may also be the risk of defamation/libel/slander lawsuits in cherry-picked jurisdictions.
Jul 31, 2019, 5:09 pm
#516
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Ya, AB had run some nasty ads (IMHO) in Aviation Week before, but did not exploit any deaths ^
And you never.know what happens next ....
And you never.know what happens next ....
Jul 31, 2019, 5:53 pm
#517
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Thanks for sharing.
The first article is a good article. (The second article is just the writers' thoughts on the aircraft, nothing worth talking about.) The author of both articles – a writer with I believe ZERO hours flying and no degree in anything engineering related – is the one that purported a design flaw…
“An MIT expert raised a question in my mind of whether Boeing's fundamental design mistake was with the size and placement of the 737 MAX engine.”
Let me emphasize again. This statement is not from a pilot. It is not from an engineer.
Let’s talk about the expert in the article… R. John Hansman. His credentials…
Dr. Hansman holds 6 patents and has authored over 250 technical publications. He has over 5800 hours of pilot in-command time in airplanes, helicopters and sailplanes including meteorological, production and engineering flight test experience.
Dr. Hansman is certainly an expert, as both a pilot and aeronautical engineer proposes his own theory…
“This is called an unstable or divergent condition. It should be noted that many high performance aircraft have this tendency but it is not acceptable in transport category aircraft.” It is of note it is only a theory, but it is a theory from an expert.
But even accepting this expert’s theory as fact, we should also accept his followup statements…
“Boeing's installation of the MCAS system fixes the pitch up problem. It is not a bad design."
And most importantly Dr Hansman, the EXPERT, states…
"There is not a fundamental problem in the design of the aircraft."
Are there other experts that disagree with Dr Hansman? Probably. But, it does show some independent experts believe there is not a fundamental design problem.
Jul 31, 2019, 9:11 pm
#518
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(WSJ) Regulators Found High Risk of Emergency After First Boeing MAX Crash
https://www.wsj.com/articles/regulat...d=hp_lead_pos4
First, I would note that it is ridiculous for the FAA to suggest "disabling MCAS" when that's NOT POSSIBLE.
The steps which pilots were suppose to take is a matter of preventing MCAS from implementing its directives by removing built-in functionality from the 737 Max. The pilot must give up the use of the electrical trim motors in order to prevent the malware-MCAS from crashing the plane. It's the equivalent of claiming that the user can "fix" a broken caps-lock on their laptop through the use of the "Shift" key. That's not fixing the problem at all, and it's not possible to disable MCAS.
Secondly, the crash and the analysis clearly enumerate that Boeing lied to the FAA by submitting outdated design specs for MCAS. The coverage over past months amply illustrate that as far as official certification goes - MCAS was the original dual-sensor edge-case automation. When FAA's analysis discovered that the reality of MCAS differed so much from the official specs, how the heck could they simply permit the certification to stand?!?!
Especially since the software in question just contributed to a fatal crash?!?!?!?!
As far as giving Boeing 10 months... I think it would have taken no more than 2 months, tops, if Boeing was ordered to push an emergency update which creates an on-screen shutdown tool for MCAS. That would let the pilots shut it down (heck, maybe even before takeoff) instead of having to disable trim-motor control in order to prevent the malware from taking over the plane.
IMO, that was never considered seriously because Boeing still believed it was possible to keep the facade that 737 Max didn't require full retraining.
The more the incident is investigated, the more it's clear that both FAA and Boeing has lost sight of the importance of safety versus market share.
My perspective is that the key issues with the 737 is not aircraft design, or pilot procedure. It's that Boeing has a corporate culture problem and are incredibly incompetent at software architecture. They discard the basic principles of enterprise software design, possibly because they think that aviation software is somehow special and that they know best.
Clearly they do not. Boeing's entire software architecture and QA team leadership should be fired and replaced with more competent folks. This is not about aircraft-specific code - it's general incompetence/arrogance.
https://www.wsj.com/articles/regulat...d=hp_lead_pos4
July 31, 2019 12:59 pm ET
An internal risk analysis after the first of two Boeing 737 MAX airliner crashes showed the likelihood was high of a similar cockpit emergency within months, according to a Federal Aviation Administration official familiar with the details and others briefed on the matter.
The regulator’s analysis, not previously reported, showed that it “didn’t take that much” for a malfunction like the one confronted by the pilots of the Lion Air flight that crashed into the Java Sea last year to occur, one of the people briefed on the analysis said.
....
The analysis determined that the underlying risks from the MCAS design were unacceptably high without at least some FAA action, that they exceeded internal FAA safety standards and that the likelihood of another emergency or even accident “was over our threshold,” according to the FAA official. “We decided…it was not an acceptable situation,” the official said.
The directive to pilots essentially reiterated that cockpit crews should counteract and then disable an MCAS misfire by following long-established emergency procedures for a related flight-control problem that can similarly push down an aircraft’s nose.
...
Sen. Susan Collins, a Republican from Maine, referring to The Wall Street Journal’s story, said: “What troubles me about this is if the agency’s own analysis found MCAS to be an unacceptable risk, why did the FAA not take immediate action to address those risks?”
Ali Bahrami, the FAA’s associate administrator for aviation safety, said it is routine for the FAA to take interim actions while undertaking longer term measures to fix problems.
“From the safety perspective, we felt strongly that what we did was adequate,” he said. “We felt we had sufficient time to be able to do the modification and get the final fix,” he added later. Mr. Bahrami said that based on pending outside reviews, the agency plans to reassess whether it handled the safety issues appropriately.
An internal risk analysis after the first of two Boeing 737 MAX airliner crashes showed the likelihood was high of a similar cockpit emergency within months, according to a Federal Aviation Administration official familiar with the details and others briefed on the matter.
The regulator’s analysis, not previously reported, showed that it “didn’t take that much” for a malfunction like the one confronted by the pilots of the Lion Air flight that crashed into the Java Sea last year to occur, one of the people briefed on the analysis said.
....
The analysis determined that the underlying risks from the MCAS design were unacceptably high without at least some FAA action, that they exceeded internal FAA safety standards and that the likelihood of another emergency or even accident “was over our threshold,” according to the FAA official. “We decided…it was not an acceptable situation,” the official said.
The directive to pilots essentially reiterated that cockpit crews should counteract and then disable an MCAS misfire by following long-established emergency procedures for a related flight-control problem that can similarly push down an aircraft’s nose.
...
Sen. Susan Collins, a Republican from Maine, referring to The Wall Street Journal’s story, said: “What troubles me about this is if the agency’s own analysis found MCAS to be an unacceptable risk, why did the FAA not take immediate action to address those risks?”
Ali Bahrami, the FAA’s associate administrator for aviation safety, said it is routine for the FAA to take interim actions while undertaking longer term measures to fix problems.
“From the safety perspective, we felt strongly that what we did was adequate,” he said. “We felt we had sufficient time to be able to do the modification and get the final fix,” he added later. Mr. Bahrami said that based on pending outside reviews, the agency plans to reassess whether it handled the safety issues appropriately.
The steps which pilots were suppose to take is a matter of preventing MCAS from implementing its directives by removing built-in functionality from the 737 Max. The pilot must give up the use of the electrical trim motors in order to prevent the malware-MCAS from crashing the plane. It's the equivalent of claiming that the user can "fix" a broken caps-lock on their laptop through the use of the "Shift" key. That's not fixing the problem at all, and it's not possible to disable MCAS.
Secondly, the crash and the analysis clearly enumerate that Boeing lied to the FAA by submitting outdated design specs for MCAS. The coverage over past months amply illustrate that as far as official certification goes - MCAS was the original dual-sensor edge-case automation. When FAA's analysis discovered that the reality of MCAS differed so much from the official specs, how the heck could they simply permit the certification to stand?!?!
Especially since the software in question just contributed to a fatal crash?!?!?!?!
As far as giving Boeing 10 months... I think it would have taken no more than 2 months, tops, if Boeing was ordered to push an emergency update which creates an on-screen shutdown tool for MCAS. That would let the pilots shut it down (heck, maybe even before takeoff) instead of having to disable trim-motor control in order to prevent the malware from taking over the plane.
IMO, that was never considered seriously because Boeing still believed it was possible to keep the facade that 737 Max didn't require full retraining.
The more the incident is investigated, the more it's clear that both FAA and Boeing has lost sight of the importance of safety versus market share.
My perspective is that the key issues with the 737 is not aircraft design, or pilot procedure. It's that Boeing has a corporate culture problem and are incredibly incompetent at software architecture. They discard the basic principles of enterprise software design, possibly because they think that aviation software is somehow special and that they know best.
Clearly they do not. Boeing's entire software architecture and QA team leadership should be fired and replaced with more competent folks. This is not about aircraft-specific code - it's general incompetence/arrogance.
Last edited by Plato90s; Jul 31, 2019 at 9:17 pm
Jul 31, 2019, 10:06 pm
#519
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I don't consider myself a current authority on the subject, but I've been in and around the systems engineering and flight test communities in both the aerospace industry and Government for 40+ years (21 at Boeing, including 3 in Commercial Flight Test Engineering and 15+ in Systems Test on the military side of the company, where I was the Safety-of-Flight Subject Matter Expert for four different aircraft types)
there are a multitude of factors, a multitude of facts, and a multitude of opinions extant; while I won't disagree that the business case for Time-To-Market had too much influence on too many critical decisions, from a strictly technical standpoint I am coming to the conclusion that the certification process (in particular, the amount of delegation and the experience/qualification of the responsible engineers, at both Boeing and the FAA) was the weakest link ... a more comprehensive review of design, analysis, and test data would have likely shown that:
there are a multitude of factors, a multitude of facts, and a multitude of opinions extant; while I won't disagree that the business case for Time-To-Market had too much influence on too many critical decisions, from a strictly technical standpoint I am coming to the conclusion that the certification process (in particular, the amount of delegation and the experience/qualification of the responsible engineers, at both Boeing and the FAA) was the weakest link ... a more comprehensive review of design, analysis, and test data would have likely shown that:
- the basic design and architecture of the flight control system -- including MCAS -- should have been more robust
- the analysis process (in particular, the FMECA -- Failure Modes/Effects and Criticality Analysis) should have been more robust
- the risk assessment, risk mitigation, and risk acceptance processes -- which presumably included an analysis of the adequacy of flight crew training materials and methods -- should have been more robust, and followed more rigorously
Last edited by jrl767; Aug 1, 2019 at 5:47 pm
Aug 1, 2019, 6:47 am
#520
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I don't consider myself a current authority on the subject, but I've been in and around the systems engineering and flight test communities in both the aerospace industry and Government for 40+ years (21 at Boeing, including 3 in Commercial Flight Test Engineering and 15+ in Systems Test on the military side of the company, where I was the Safety-of-Flight Subject Matter Expert for four different aircraft types)
there are a multitude of factors, a multitude of facts, and a multitude of opinions extant; while I won't disagree that the business case for Time-To-Market had too much influence on too many critical decisions, from a strictly technical standpoint I am coming to the conclusion that the certification process (in particular, the amount of delegation and the experience/qualification of the responsible engineers, at both Boeing and the FAA) was the weakest link ... a more comprehensive review of design, analysis, and test data would have likely shown that:
there are a multitude of factors, a multitude of facts, and a multitude of opinions extant; while I won't disagree that the business case for Time-To-Market had too much influence on too many critical decisions, from a strictly technical standpoint I am coming to the conclusion that the certification process (in particular, the amount of delegation and the experience/qualification of the responsible engineers, at both Boeing and the FAA) was the weakest link ... a more comprehensive review of design, analysis, and test data would have likely shown that:
- the basic design and architecture of the flight control system -- including MCAS -- should have been more robust
- the analysis process (in particular, the FMECA -- Failure Modes/Effects and Criticality Analysis) should have been more robust
- the risk assessment, risk mitigation, and risk acceptance processes -- which presumably included an analysis of the adequacy of flight crew training materials and methods -- should have been more robust, and followed more rigorously [/indent]
Aug 1, 2019, 7:00 am
#521
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What a shocker there
I do apologize in turn: doing quick scans of mainstream media probably hardly brushes the surface of this subject. I'm not saying mainstream media are awful, they try their best to summarize, but it doesn't replace following the discussions on specialist forums (which I have tried to do for the last 3 months) which are based on official boeing documentation and interim accident reports (which I have not read, but kind and passionate professionals do summarize and comment on them).
It's certainly not my place to advertise other forums on these boards, so no links, but you can find them by yourself for sure. This is a more casual forum, and that's cool; it's not really the place to get serious with full NTSB reports.
It's not the Seattle Times (out of all papers lol) which is going to give you a rundown of the aerodynamical flaws of the MAX envelope.
I did find two articles from Forbes which mention the bad stability of the cell. Maybe that's a good start for a short read?
https://www.forbes.com/sites/peterco.../#6bf3ee4540aa
https://www.forbes.com/sites/peterco.../#2736620e2e18
But even that's not a very complete and reliable info source, so it's not something I would personally add to the wiki.
I'm pretty sure Mentour pilot did a few videos about it as well, which are quite accessible, and Peter Lemme (who worked on the 767 iirc) might have tweeted some diagrams, but I'm a bit lazy to find the links now, sorry...
I don't have an agenda (I love flying Boeings), and I'm no conspiracy theorist. I have read enough on the 737 MAX that has seriously concerned me about flying on that plane. I can only encourage you to decide for yourself, but I can not provide a magic link that will instantly convince you. (Hey I'm not saying it doesn't exit, I just haven't seen it yet!)
I do apologize in turn: doing quick scans of mainstream media probably hardly brushes the surface of this subject. I'm not saying mainstream media are awful, they try their best to summarize, but it doesn't replace following the discussions on specialist forums (which I have tried to do for the last 3 months) which are based on official boeing documentation and interim accident reports (which I have not read, but kind and passionate professionals do summarize and comment on them).
It's certainly not my place to advertise other forums on these boards, so no links, but you can find them by yourself for sure. This is a more casual forum, and that's cool; it's not really the place to get serious with full NTSB reports.
It's not the Seattle Times (out of all papers lol) which is going to give you a rundown of the aerodynamical flaws of the MAX envelope.
I did find two articles from Forbes which mention the bad stability of the cell. Maybe that's a good start for a short read?
https://www.forbes.com/sites/peterco.../#6bf3ee4540aa
https://www.forbes.com/sites/peterco.../#2736620e2e18
But even that's not a very complete and reliable info source, so it's not something I would personally add to the wiki.
I'm pretty sure Mentour pilot did a few videos about it as well, which are quite accessible, and Peter Lemme (who worked on the 767 iirc) might have tweeted some diagrams, but I'm a bit lazy to find the links now, sorry...
I don't have an agenda (I love flying Boeings), and I'm no conspiracy theorist. I have read enough on the 737 MAX that has seriously concerned me about flying on that plane. I can only encourage you to decide for yourself, but I can not provide a magic link that will instantly convince you. (Hey I'm not saying it doesn't exit, I just haven't seen it yet!)
Aug 1, 2019, 12:06 pm
#522
Join Date: Aug 2014
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I don't consider myself a current authority on the subject, but I've been in and around the systems engineering and flight test communities in both the aerospace industry and Government for 40+ years (21 at Boeing, including 3 in Commercial Flight Test Engineering and 15+ in Systems Test on the military side of the company, where I was the Safety-of-Flight Subject Matter Expert for four different aircraft types)
there are a multitude of factors, a multitude of facts, and a multitude of opinions extant; while I won't disagree that the business case for Time-To-Market had too much influence on too many critical decisions, from a strictly technical standpoint I am coming to the conclusion that the certification process (in particular, the amount of delegation and the experience/qualification of the responsible engineers, at both Boeing and the FAA) was the weakest link ... a more comprehensive review of design, analysis, and test data would have likely shown that:
there are a multitude of factors, a multitude of facts, and a multitude of opinions extant; while I won't disagree that the business case for Time-To-Market had too much influence on too many critical decisions, from a strictly technical standpoint I am coming to the conclusion that the certification process (in particular, the amount of delegation and the experience/qualification of the responsible engineers, at both Boeing and the FAA) was the weakest link ... a more comprehensive review of design, analysis, and test data would have likely shown that:
- the basic design and architecture of the flight control system -- including MCAS -- should have been more robust
- the analysis process (in particular, the FMECA -- Failure Modes/Effects and Criticality Analysis) should have been more robust
- the risk assessment, risk mitigation, and risk acceptance processes -- which presumably included an analysis of the adequacy of flight crew training materials and methods -- should have been more robust, and followed more rigorously [/indent]
Aug 1, 2019, 6:05 pm
#523
Join Date: Oct 2000
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https://www.seattletimes.com/busines...ight-controls/
The above article in today's Seattle Times is over my head in any number of ways. But the following caught my eye:
"…This change means the flight-control system will take input from both of the airplane’s flight computers and compare their outputs. This goes beyond what Boeing had previously decided to do, which is to adjust the MCAS software so that it took input from two angle of attack sensors instead of one..."
Why does a plane have two flight computers? Is one just a backup in case the primary one fails? The article makes it sound like it's a big deal that both will be used concurrently in the redesign.
Thanks to anyone who can explain this in layman's terms.
The above article in today's Seattle Times is over my head in any number of ways. But the following caught my eye:
"…This change means the flight-control system will take input from both of the airplane’s flight computers and compare their outputs. This goes beyond what Boeing had previously decided to do, which is to adjust the MCAS software so that it took input from two angle of attack sensors instead of one..."
Why does a plane have two flight computers? Is one just a backup in case the primary one fails? The article makes it sound like it's a big deal that both will be used concurrently in the redesign.
Thanks to anyone who can explain this in layman's terms.
Aug 1, 2019, 6:56 pm
#524
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The 737 and A320 series have two separate autopilots. The larger Boeings have three. (I don't have any direct experience with Airbus) Each autopilot has its own, separate, data, inertial reference, and power sources. Each pilot's flight instruments are also on the respective side's sources.
On 737s, since this is a 737 thread, when the Captain is flying, the left side is the "Master" and the Captain will use the "A" autopilot. When the F/O flies it is Right master and "B" autopilot. If something in the active system fails then you switch to the other system which isn't affected by the failure.
On the 757/767, with three sets of data and autopilots, we'd normally fly with the "Center" autopilot which isn't using the same data as either the Capt's or F/O's instruments.
In an autoland, all autopilots are engaged, and their data and power sources are isolated. That adds additional complexity, though, as the systems have to degrade properly when something does fail or a data source goes bad. You have to be able to identify the bad sources/channels and switch away from them either automatically or manually.
Aug 1, 2019, 7:20 pm
#525
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Makes sense. Thanks!