MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
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In fact, ALL people divide safe and unsafe as black and white. Either the manufacturer guarantees that the plane will be safe and pilots in full control till the plane is disembarked at the gate, or it is unsafe. For the same reason the pregnancy test only has two indications. You cannot be "slightly pregnant".
I am always conscious that nothing is completely safe even just viewing the risks we considered and analysed in the design and there may obscure unlikely risks we have not thought of. Whenever humans are involved there is a high degree of uncertainty. As a rule we consider it safe, in other words an acceptable risk, that a system failure which results in a serious hazard is very unlikely eg. two failure required and there is advice that a trained operator will be present, who will be given a clear indication of the issue and has the training to handle the situation successfully. Yet we know that sometimes in this situation the trained individual will not be there, or fail to understand what is happening and do completely the wrong thing. In my carerr I have had to investigate three incidents where people were or could have been severly injured and in every case the operators of the equipment deviated massively from the procedures, installation procedure etc. and this occured on top of unlikely combinations of events and failures, where is the absolute safety you talk of? It does not exist.
Probably not. The issues with the aircraft seem well understood. There are much larger issues of regulator capture, inappropriate delegation of certification responsibility and the ongoing legislative gelding of the FAA to deal with. I think that the former trusting relationship the FAA had with the other regulators has evaporated and that presents the higher hurdle to the MAX, or indeed any new American aircraft.
Just like elections, capitalist dogma has consequences. The FAA, the FDA and the other oversight agencies are all tainted now, and any approval from them now will be subject to verification.
What follows after a nuisance stall warning is by no means trivial, and I am definitely not in the blame-the-pilots camp.*
*As an aside, I asked for a failed alpha vane on my last NG simulator take-off. The simulator (CAE, 737-800) did not have that as a menu option, so the best they could do was a blocked pitot tube. The resulting stick shaker, UAS, windshear warning was very busy and distracting. I remain astonished that Boeing thought that adding an undocumented, intermittent, fast, stab trim input would not trip the crews into cognitive and manipulation overload.
*As an aside, I asked for a failed alpha vane on my last NG simulator take-off. The simulator (CAE, 737-800) did not have that as a menu option, so the best they could do was a blocked pitot tube. The resulting stick shaker, UAS, windshear warning was very busy and distracting. I remain astonished that Boeing thought that adding an undocumented, intermittent, fast, stab trim input would not trip the crews into cognitive and manipulation overload.
"Boeing engineers seemed to realize they had underestimated MCAS's ability to push the plane's nose down forcefully and repeatedly, and overestimated how pilots would respond, said a person familiar with the FAA's response."
**IF TRUE** this would indicate that even Boeing didn't know how effective MCAS was.
It is also striking how often the report repeats that FAA experts struggled to understand the intricacies of MCAS, and yet continued to sanction the delivery of an AD as a risk control for a system that air crew were not being informed of nor trained for.
As an aside, I asked for a failed alpha vane on my last NG simulator take-off. The simulator (CAE, 737-800) did not have that as a menu option, so the best they could do was a blocked pitot tube. The resulting stick shaker, UAS, windshear warning was very busy and distracting.
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It is a sweeping generalisation and in my case at least completely false that all people divide safe and unsafe as black and white, and I often work developing safety related products. In my industry (medical devices) safe is defined as 'free from unacceptable risk' which begs the question as to what is acceptable but also makes it clear that everything has risk and we are trying to make sure that the risks are low and proportionate given the benefits and what is achievable.
It always starts with the brainstorm, where you simply throw everything out there that you may even think of can go wrong, then you start grading it according to risk of accidents and so on, in the end figure out how to mitigate the risks, that could be via inspection routines, re-programming, etc. In the end you have this fine schematic showing, hopefully, everything that can go wrong, and what has been done to mitigate it.
I love making these assessments, my first line is always "Nuclear detonation nearby"...... for some reason I don't do them anymore?
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In the wake of the two MAX accidents, pilots shouldn't have to ask to see either an Airspeed Unreliabe during takeoff or Runaway Stab Trim. Lack of familiarity and/or proficiency with these procedures played a role in both crashes. They are memory items for goodness sakes, and pilots shouldn't expect to become proficient in their execution by reading a manual. This should absolutely be one of recommendations coming out of these investigations. Another troubling aspect is that a single AOA malfunction cannot be accurately depicted with the current sim programming. Another thing that needs to be fixed.
I was astonished to read, in the report quoted by Grebe, that
"Boeing engineers seemed to realize they had underestimated MCAS's ability to push the plane's nose down forcefully and repeatedly, and overestimated how pilots would respond, said a person familiar with the FAA's response."
**IF TRUE** this would indicate that even Boeing didn't know how effective MCAS was.
It is also striking how often the report repeats that FAA experts struggled to understand the intricacies of MCAS, and yet continued to sanction the delivery of an AD as a risk control for a system that air crew were not being informed of nor trained for.
"Boeing engineers seemed to realize they had underestimated MCAS's ability to push the plane's nose down forcefully and repeatedly, and overestimated how pilots would respond, said a person familiar with the FAA's response."
**IF TRUE** this would indicate that even Boeing didn't know how effective MCAS was.
It is also striking how often the report repeats that FAA experts struggled to understand the intricacies of MCAS, and yet continued to sanction the delivery of an AD as a risk control for a system that air crew were not being informed of nor trained for.
We learn from bleeding.
AoA disagree messages might be useful in some scenarios, but when presented with a sole stick shaker on take-off it would be pretty obvious five seconds later that if you were still climbing normally that the alpha vane was providing bad information. (And hence in disagreement with both the wing and the other vane). A useful thing AoA disagree could have done was disable the MCAS, but of course it wasn’t so designed
Don't you recognise a general statement of concept when you see it? Take as long as you need Mike. If you have the correct attitude, planned thrust and the planned flaps you should be able to assess your energy and lift state pretty quickly. These aircraft come with FPV, so if the speed, theta and gamma values are normal where's the mystery? AoA disagree on a duplex instillation on the other hand does not tell you anything about your proximity to a stall.
The fact that you can't cancel all the erroneous warnings alone is already enough reason the NG should not been certified.
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Live Senate hearings:
https://www.commerce.senate.gov/2019...1-957d0e82f168
https://www.commerce.senate.gov/2019...1-957d0e82f168
Mr. Dennis Muilenburg
President and Chief Executive Officer
The Boeing Company
Mr. Muilenburg Testimony.pdf (136.63 KB)
The Honorable Robert Sumwalt
Chairman
National Transportation Safety Board
Chairman Sumwalt Testimony (1).pdf (253.78 KB)
The Honorable Christopher Hart
Chairman
Joint Authorities Technical Review
Chairman Hart Testimony.pdf (280.84 KB)
Just curious. How many safety analysis have you been involved with, with writing or reviewing?
FHA, FMEA, FTA, etc.
Having been involved with several and what has been published about the process with MCAS I disagree with your assessment.
I've seen many similar to what was done with MCAS. That's the standard way of doing them. Just as Boeing's use of their own test pilots for flight/SIM testing or using uncontrolled stab movement instead of simulating faults that could led to that are common.
There are processes issues that need dealt with. I don't know how they are going to fix it and maintain a commercially viable process.
They can move the line a bit to cover more cases, but there will still be cases not dealt with.
FHA, FMEA, FTA, etc.
Having been involved with several and what has been published about the process with MCAS I disagree with your assessment.
I've seen many similar to what was done with MCAS. That's the standard way of doing them. Just as Boeing's use of their own test pilots for flight/SIM testing or using uncontrolled stab movement instead of simulating faults that could led to that are common.
There are processes issues that need dealt with. I don't know how they are going to fix it and maintain a commercially viable process.
They can move the line a bit to cover more cases, but there will still be cases not dealt with.
The way you wrote that I think I am on Mikes side, and your snide reply doesn't help. AF447 was climbing very well while they got closer and closer to stalling, so apparently not that obvious in 5 seconds. It would not have been "useful", it should have been required to have two inputs for MCAS.
The fact that you can't cancel all the erroneous warnings alone is already enough reason the NG should not been certified.
The fact that you can't cancel all the erroneous warnings alone is already enough reason the NG should not been certified.
Stall recovery has evolved over the years from trying to power out of it while loosing minimum altitude to the current positive and deliberate reduction in pitch (and hence, it is assumed, alpha). The stall warning on take-off case isn’t currently addressed, and a tiny AoA disagree message, if fitted, surely wouldn’t be the key to detecting a nuisance warning.
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Just curious. How many safety analysis have you been involved with, with writing or reviewing?
FHA, FMEA, FTA, etc.
Having been involved with several and what has been published about the process with MCAS I disagree with your assessment.
I've seen many similar to what was done with MCAS. That's the standard way of doing them. Just as Boeing's use of their own test pilots for flight/SIM testing or using uncontrolled stab movement instead of simulating faults that could led to that are common.
There are processes issues that need dealt with. I don't know how they are going to fix it and maintain a commercially viable process.
They can move the line a bit to cover more cases, but there will still be cases not dealt with.
FHA, FMEA, FTA, etc.
Having been involved with several and what has been published about the process with MCAS I disagree with your assessment.
I've seen many similar to what was done with MCAS. That's the standard way of doing them. Just as Boeing's use of their own test pilots for flight/SIM testing or using uncontrolled stab movement instead of simulating faults that could led to that are common.
There are processes issues that need dealt with. I don't know how they are going to fix it and maintain a commercially viable process.
They can move the line a bit to cover more cases, but there will still be cases not dealt with.
Have you dealt with all levels of Boeing management ?
As to my " qualifications" to comment on the Boeing culture I can answer yes to the above for over 30 years before retiring .
So you disagree with my comments- which are and have been based on over 30 years with Boeing before retiring in the mid 90's. ?
And as to my schedule- cost- budget-comments ? Simply based on still knowing several Boeing employees who worked on 737 737MAX ,787, KC46A, etc and being more familiar with the complete story of KC46-767 starting in 2000-2001 then probably anybody posting here. And having dealt with both ' old time' executives both good and bad, before and after reitiring and those with the MDC-Jack Welch -focus on shareholder value and also being a shareholder
The change in Boeing culture has been well documented -- start with a book title " Turbulence " and follow the reports and documents and emails and whistle blowers since
While I have been involved in a very minor way re test failure analysis of non- aircraft ( Saturn 5 ) parts, and some manufacturing problems- I have not been involved with apparently what you describe as a ' safety analysis ' of aircraft re writing or reviewing such. So what is your point !
As of today, the Boeing CEO admitted he had not known of the now infamous email given to DOJ but not FAA. And his answer re What was foley thinking or describing was we have been trying to find out, yada yada. But then when asked about the other employee on the email who is still an employee, he had not talked to him and appaantly neither had company lawyers. IMHO- that answer says it ALL-
You do know that under contract- to SW -If Boeing change to 737 required sim time, that Boeing would have to pay 1 Million per plane ? and that was a major driver ?
Have a good day
Paxing All Over The World
From the hearings today in Senate, as reported by the BBC:
{my emphasis} Well, no $hit Sherlock. But are they going to add the FAA to the charge sheet?
US lawmakers have accused Boeing of engaging in a "pattern of deliberate concealment" as it sought approval for its 737 Max 8 plane to fly.The accusation came as Boeing chief executive Dennis Muilenburg was quizzed by the Senate Commerce Committee.
Senators said they had serious concerns that Boeing put profits over safety as it rushed to get clearance.
Senators said they had serious concerns that Boeing put profits over safety as it rushed to get clearance.
The resulting stick shaker, UAS, windshear warning was very busy and distracting. I remain astonished that Boeing thought that adding an undocumented, intermittent, fast, stab trim input would not trip the crews into cognitive and manipulation overload.
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Hi, I don't know if this has been posted here already...Reading was very, very disturbing (ATCO and PPL myself) and liberating at the same time. To pinpoint the exact origin of the disasters. Not only MCAS itself, but merger with Douglas and turn away from making aircraft towards making money.
https://newrepublic.com/article/1549...ial-revolution
https://newrepublic.com/article/1549...ial-revolution
Watching the hearings are disturbing and makes me think as follows.
first time I was confused as to the feedback loop of accident investigation to regulation were as follows.
One of the recommendations of the Helios accident was a “light” to differentiate between a decompression and a take off config warning. As far as I am aware that recommendation still hasn’t been implemented. The main argument being cost.
the developments of “speed trim” to MCAS and probably many other developments of the 737-100 to the 737 max are being done due to cost.
so who does the maths. Cost of safety?
first time I was confused as to the feedback loop of accident investigation to regulation were as follows.
One of the recommendations of the Helios accident was a “light” to differentiate between a decompression and a take off config warning. As far as I am aware that recommendation still hasn’t been implemented. The main argument being cost.
the developments of “speed trim” to MCAS and probably many other developments of the 737-100 to the 737 max are being done due to cost.
so who does the maths. Cost of safety?
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Watching the hearings are disturbing and makes me think as follows.
first time I was confused as to the feedback loop of accident investigation to regulation were as follows.
One of the recommendations of the Helios accident was a “light” to differentiate between a decompression and a take off config warning. As far as I am aware that recommendation still hasn’t been implemented. The main argument being cost.
the developments of “speed trim” to MCAS and probably many other developments of the 737-100 to the 737 max are being done due to cost.
so who does the maths. Cost of safety?
first time I was confused as to the feedback loop of accident investigation to regulation were as follows.
One of the recommendations of the Helios accident was a “light” to differentiate between a decompression and a take off config warning. As far as I am aware that recommendation still hasn’t been implemented. The main argument being cost.
the developments of “speed trim” to MCAS and probably many other developments of the 737-100 to the 737 max are being done due to cost.
so who does the maths. Cost of safety?
Just to clarify. Each light is on both sides. 4 lights in total.
Last edited by ARealTimTuffy; 30th Oct 2019 at 01:32. Reason: add
They certainly do come with a FPV. It’s also part of a long list of items that either fail or are unreliable in this scenario. Would you rely on it ? “Take as long as you like”.
I’m with Herr Brinker on this one - Your paragraph above acknowledges the cognitive overload (even without MCAS involvement). Your first attempt (post 3528) seemed to shrug it off as an almost trivial conclusion that the “alpha vane is proving bad information”. ‘A five second job’. So to speak. Ahem
You will agree we are discussing two different scenarios? With an angle of attack sensor failure, In the moments after takeoff the fpv provides actual flight path information, which are the moments I was addressing.
we were discussing the stall warning on take-off Hans, not the opposite AF447 case which was a different scenario that was always going to result in a stall. I am sorry that you dislike my tone, and I am sorry to have employed understatement by writing “useful” when yes, it should have been mandatory to have three independent alpha sources.
Stall recovery has evolved over the years from trying to power out of it while loosing minimum altitude to the current positive and deliberate reduction in pitch (and hence, it is assumed, alpha). The stall warning on take-off case isn’t currently addressed, and a tiny AoA disagree message, if fitted, surely wouldn’t be the key to detecting a nuisance warning.
Yes, definitely agree that B idea of crew alerting needs work. Cannot switch off the Stick shaker even after positively identifying the problem, tiny little AOA disagree in the corner of the display. It might have been okay in 1967, but it is not today, and when they put the big screens in the NG it should have been required to change the overhead as well, and install some sort of EICAS. Every other B product of that era is vastly superior as far as cockpit design is concerned. They put out the new B757/767/777 around the same time. The biggest one: the B747-400. Same type rating as the -300 and look at the cockpit:
https://www.quora.com/What-is-the-di...Boeing-747-400 (look at the overhead panel!!). There is no justification, and when "designing" the MAX the FAA should have stepped in and said no.
Having said that, and having read the Lion Air report, there is plenty of butter to pass around. It took the FO 4 minutes to find the MEMORY ITEMS IN THE QRH (!!!), while talking to ATC about headings and altitudes. Training & checking (because I don't believe it is just a training issue) needs to improve big time.