Ethiopian airliner down in Africa
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If you read the statement it goes to great lengths to show how they determined over and over again that the AOA disagree alert does not impact flight safety. Which, if there wasn't an autonomous flight control system that has full authority over the horizontal stabilizer based solely on the output of a single AOA vane, might actually be true.
Left unaddressed by the Boeing statement is that their determination is only operative until you have a previously unknown system that utilizes a single AOA input and can trim the horizontal stab down at 2.5 degree intervals all the way to the stops. Until the airplane is in an unrecoverable state should the crew not react quickly and accurately enough.
Oops!! We forgot about that one!!
I've got ten bucks that says Boeing ends up in bankruptcy to protect them from the various and numerous liabilities they are now facing. (Orders that won't be filled, dead people, lost revenues by airlines already in possession of the airframes, future liabilities, etc...)
I've got another tenner to donate if the MAX is flying again before the end of the year, and one more for it never flying again in passenger service.
That's my gambling quotient for this year- I hope it pays well!!
Regards,
dce
Boeing just issued a statement on their website:
Boeing Statement on AOA Disagree Alert
Getting confused here. Isnt it reported that MCAS only uses one AoA vane? If there is a disagreement, what does it matter if it relied on one? Add-on alert or not, didnt MCAS only use one?
Boeing Statement on AOA Disagree Alert
Getting confused here. Isnt it reported that MCAS only uses one AoA vane? If there is a disagreement, what does it matter if it relied on one? Add-on alert or not, didnt MCAS only use one?
NOTE - my understanding is that the LH aoa on Lion Air read 40 degrees different to the RH AoA in every position stationary or moving.
The FAA-OEM discussions on rules application is not nefarious, it arises as the aircraft has a right to legacy status, while experience has resulted in changes to the rules that would otherwise apply. The FAA may push and cajole, but the law is pretty straightforward as to the requirements and that is what TBC has likely complied with. That the rules that don't apply are more stringent is the way the world works. Legacy status is not unreasonable, it recognises that there is a long lead time in developing an aircraft, and there is a need to freeze the regulatory standard or no new product would ever be completed. On submission of a PSCP, a substantial amount of the process involves determining the rules revision status that applies to the design.
The FAA TAD and Boeing have good people within their programs, mistakes may occur, but so far, there has not been evidence of corporate irresponsibility, just lousy choices.
Rant follows:
[This is in contrast to the fiasco over the late 90's early 2000's supplier producing parts that were supposed to be CNC per the TC, but which were made literally by hand using templates and hand shears. That TBC sacked the whistleblowing QA engineers was unconscionable, just as the disgraceful behaviour to the whistleblower mechanic on the AS261 maintenance procedures, where many involved failed to act ethically. Trite words on ethics and morality are plentiful, from scripture, Sunday school, but the dirty little fact is that ethical stands usually end up with the whistleblower being punished. The most glaring example of that is still playing out today; Assange facilitates the disclosure of the simple fact that the US public were being fed false information on various subjects, in their name, specifically the video of the AH64 attack in Baghdad that killed a reporter and a number of other people through erroneous assessment of their combat status.This was the tape recording hi 5's on planting 30mike mike M789 rounds through the front windscreen of a van which was filled with civilians trying to provide aid to the dying, including in their midst a 2 Y/O child (deceased). The public get told post fact that the reporter was a terrorist. Assange is described as an enemy of the state, pilloried, and the VP, Biden suggests extrajudicial response (assassination of Assange). Years later, Snowden discloses illegal breaches of the US publics rights by No Such, breaching constitutional rights of Joe Citizen, and is branded a "traitor". The world ain't what it used to be, probably never was except in fairy tales. 200 years ago, people showing indignation would have ended up with schools, parks and roads named in their memory, today, they are the butt of derisive jokes.
Edmund Burke was right when he lamented in 1770 on what was necessary for evil to triumph in "Thoughts on the Cause of the Present Discontents", but today it may be that Burke would be considered to be an optimist]
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What a house of cards.
If you read the statement it goes to great lengths to show how they determined over and over again that the AOA disagree alert does not impact flight safety. Which, if there wasn't an autonomous flight control system that has full authority over the horizontal stabilizer based solely on the output of a single AOA vane, might actually be true.
Left unaddressed by the Boeing statement is that their determination is only operative until you have a previously unknown system that utilizes a single AOA input and can trim the horizontal stab down at 2.5 degree intervals all the way to the stops. Until the airplane is in an unrecoverable state should the crew not react quickly and accurately enough.
Oops!! We forgot about that one!!
I've got ten bucks that says Boeing ends up in bankruptcy to protect them from the various and numerous liabilities they are now facing. (Orders that won't be filled, dead people, lost revenues by airlines already in possession of the airframes, future liabilities, etc...)
I've got another tenner to donate if the MAX is flying again before the end of the year, and one more for it never flying again in passenger service.
That's my gambling quotient for this year- I hope it pays well!!
Regards,
dce
If you read the statement it goes to great lengths to show how they determined over and over again that the AOA disagree alert does not impact flight safety. Which, if there wasn't an autonomous flight control system that has full authority over the horizontal stabilizer based solely on the output of a single AOA vane, might actually be true.
Left unaddressed by the Boeing statement is that their determination is only operative until you have a previously unknown system that utilizes a single AOA input and can trim the horizontal stab down at 2.5 degree intervals all the way to the stops. Until the airplane is in an unrecoverable state should the crew not react quickly and accurately enough.
Oops!! We forgot about that one!!
I've got ten bucks that says Boeing ends up in bankruptcy to protect them from the various and numerous liabilities they are now facing. (Orders that won't be filled, dead people, lost revenues by airlines already in possession of the airframes, future liabilities, etc...)
I've got another tenner to donate if the MAX is flying again before the end of the year, and one more for it never flying again in passenger service.
That's my gambling quotient for this year- I hope it pays well!!
Regards,
dce
The "Boeing Statement on AOA Disagree Alert" tells us that the MAX has had an AoA disagree alert function from the outset, but in error, it was not displaying to the aircrew. There is a long and convoluted explanation/justification of why that deficiency may not have been critical.
Lets not be distracted by that argument. The real issue is that if the AoA disagree signal system was available " in keeping with Boeing’s fundamental design philosophy of retaining commonality with the 737NG" why on earth was it not used as a critical input to the MCAS activation logic ??
Lets not be distracted by that argument. The real issue is that if the AoA disagree signal system was available " in keeping with Boeing’s fundamental design philosophy of retaining commonality with the 737NG" why on earth was it not used as a critical input to the MCAS activation logic ??
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@Mach2point7
Valid point! This will be critical in lawsuits.
The "excuse" is a technical one IMO (not that Boeing has admitted anything). It is complicated to design a system such as MCAS that is both reliable and safe. The more inputs there are into a system, the more chance there is it will fail to carry out its intended purpose. In the case of MCAS, this would have severely delayed certification. Somewhere along the process, the urgency of reliable activation of MCAS became more important than the safety aspects, which were pushed onto the pilots, in the "unlikely" event of AOA failure.
Lets not be distracted by that argument. The real issue is that if the AoA disagree signal system was available " in keeping with Boeing’s fundamental design philosophy of retaining commonality with the 737NG" why on earth was it not used as a critical input to the MCAS activation logic ??
The "excuse" is a technical one IMO (not that Boeing has admitted anything). It is complicated to design a system such as MCAS that is both reliable and safe. The more inputs there are into a system, the more chance there is it will fail to carry out its intended purpose. In the case of MCAS, this would have severely delayed certification. Somewhere along the process, the urgency of reliable activation of MCAS became more important than the safety aspects, which were pushed onto the pilots, in the "unlikely" event of AOA failure.
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Not really, the highest likelihood would be of a disagree. To have failures and not have a disagree would come from multiple failures of identical types and outcomes. Now that more or less happened at perpignan IIRC but it may have still just been a single sensor failure, where 2 out of 3 vanes froze position literally due to servicing which didn't protect the vanes from water ingress. At altitude the vanes froze, and presumably the correct vane was voted out by the two stuck vanes. The vane is pretty reliable, but I replaced a couple on one B737 in fairly short order.
The conic-static pressure type on the westwind is reliable...
The conic-static pressure type on the westwind is reliable...
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Someone else has properly offered here that the ET incident may well be traced at it's most basic human factors core to the impairment the pilots experienced due to the previous Lion Air crash. In other words: Their consciousness knew how the last one went down, so their bodies responded accordingly, which left them poorly equipped to actually perform the steps you have been seemingly demanding that they do since shortly after they in fact died.
Regards-
dce
Regards-
dce
FWIW from and ex non-pilot military aircrew viewpoint, I have been in a few crappy situations when the day has just gone bad. In mil ops we operated close to the envelope in unfamiliar environments and it's the nature of these ops that means that sometimes, on thankfully very rare occasions, guys didn't come home. We all read the accident reports and make mental notes to ourselves...must be wary of that...must not do that ...must make sure I communicate that better...take another look at that checklist etc etc. But when it happens, the engine fire, the stuck main landing gear, the assymetric flap, the loss of hydraulics, smoke and fume, lightening strikes, severe CAT in the middle of an otherwise smooth moonlit cruise, flapless over the fence on short runway at 160 kts etc etc, there is a startle factor, there is time when you hear nothing and see nothing or can't make sense of anything, there is puzzlement and a fear that your event could well be the subject of the next accident report, and yes, a not unnatural fear that this could be your last flight. There is no immediate recall capacity because your senses are so overwhelmed with incoming information that you just can't assemble any course of action except whats right in your face and that leads to target fixation, like trying to control and uncontrollable wildly spinning aircraft, like trying to select the autopilot on, again and again and again!. It takes a few moments, but eventually, the haze clears. The airplane is still flying, (not in Wonkazoos case) new information is not coming and it seems like time has slowed down. Things start switching back on, you start to interpret the sounds you are hearing, the things you can see and thankfully, you start to recall memory actions. In Wonkazoos case the information didn't stop coming. Excessive and continuous G force is an overwhelming inhibitor to clear thinking. But fortunately he broke the target fixation and bailed. Everyone who has experienced hypoxia training will have experienced target fixation and how difficult it is to self recognise it let alone break it. Unlike Wonkazoos rather more desperate situation, my personal experiences were the type of things you might train for in a simulator. So much so that once you are over the startle and the haze, the immediate actions are almost routine. Importantly, you burst into pre-trained action safe in the knowledge that the event didn't kill you, that the bird still has its feathers and is flying and that if everyone does exactly as they are trained to do we'll get this thing on the ground even if the aircraft may not be reusable afterwards!
Wonkazoo and 737 Drivers' positions are so far apart but can easily be explained by the entirely different nature of events these guys have experienced and/or trained for. My experiences would lead me to agree with 737 Drivers view. That is, you get a scare, the event stabilises, you shake yourself off and go to memory recall. All going well, you, rather than someone else gets to write the event report afterwards. But now we come to ET. This should have been non-threatening 'routine' emergency. I know, using 'routine' and 'emergency' together is an oxymoron but you are trained for this right? That's why we are checked to fly. We are supposed to know what to do in these circumstances in the air because for all those recall items we maintain 100 percent recall training for them on the ground. The ET Captain would have been living under a rock and the airline grossly negligent if he wasn't aware of the Lion Air accident and what Boeing subsequently directed was his best and only courses of action to avoid disaster.
So why didn't he handled it correctly? Why didn't he just manage the UAS, turn back and land? My belief is that he didn't feel he was experiencing a routine UAS, or shall we call this a 737 Driver type of emergency, but rather that this nasty MCAS beast, that he only relatively recently become aware of, presaged by a UAS event had selected him that day. I believe there was too much information coming in for him to get out of startle mode and that this was aggravated by an early immediate assessment that he was in a fight for survival with MCAS right from the get go. He was thinking too far down track, to something that hadn't even happened yet but which led to target fixation on selecting auto pilot and his subsequent cognitive inability to deal with flaps, Vmo or cutout switches. He was not experiencing a 737 Driver "do the checklist your trained for" type of emergency but rather the "Oh no, not this" or Wonkazoo type of emergency where a fight to the death was about to start.
If the ET Captain had never heard of MCAS, he probably would have carried out the UAS and landed safely. Basically, his mere knowledge of MCAS but lack of full understanding of it may have scared the c##p out of him. How many reports have their since been of pilots that wont fly the airplane again until they are satisfied Boeing's fix and training solutions are 100 percent and in some cases others saying they just wont fly it again regardless. The ET Captain would have been deeply concerned about the possibility of a MCAS event and this self - fulfilling prophecy may have led him into the clutches of MCAS from which there was no escape.
Watch this scene from "Glory".
So sorry for the long opinionated post but I hope it provoked some thought. 737 Driver and Wonkazoo had an interesting, lively and ultimately respectful discussion some posts back from which I learnt a lot. I think ultimately they are both right..but for different reasons.
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There's no date on that Boeing statement. Was it issued before or after the Ethiopian crash?
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I believe they started delivering the MAX in May 2017?
How long does that process take? By October 2018, nothing had happened. Boeing have been vague about exactly when the discrepancy was noticed, so let's say they had seventeen months to get the software fix designed and installed. Is seventeen months the standard kind of time it takes for aviation software fixes to get implemented? (And there's not much evidence the fix was even under design, prior to Lion Air.)
Everything I've read suggests a major schism between the engineering layers at Boeing and the commercial execs, with all the power in the hands of the execs. So I'm not surprised to read:
In 2017, within several months after beginning 737 MAX deliveries, engineers at Boeing identified that the 737 MAX display system software did not correctly meet the AOA Disagree alert requirements
I believe they started delivering the MAX in May 2017?
Accordingly, the review concluded, the existing functionality was acceptable until the alert and the indicator could be delinked in the next planned display system software update.
Everything I've read suggests a major schism between the engineering layers at Boeing and the commercial execs, with all the power in the hands of the execs. So I'm not surprised to read:
Senior company leadership was not involved in the review and first became aware of this issue in the aftermath of the Lion Air accident.
Last edited by PaxBritannica; 6th May 2019 at 10:06.
Pegase Driver
Lord Farringdon thank you for posting that video. very enlightening , and conform to what I personally witnessed and experienced during an aviation accident a few yeas ago. Like you I do not consider Wonkazoo and 737 Drivers' positions to be opposite, but rather complementary to one another. Very good to have both of them here .
Pax Britanica :
This looks to me as been a sentence dictated by lawyers rather than a fact, but I am sure that if it is not true we will see copies of emails surfacing in the Seattle Times or Wall Street Journal pretty soon ...
Pax Britanica :
Senior company leadership was not involved in the review and first became aware of this issue in the aftermath of the Lion Air accident.
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The software delivered to Boeing linked the AOA Disagree alert to the AOA indicator, which is an optional feature on the MAX and the NG. Accordingly, the software activated the AOA Disagree alert only if an airline opted for the AOA indicator.
We're expected to believe that Boeing specified the feature correctly, but did not assess the software that got returned, or test it exhaustively? Did the contractor also get to self-certify?
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Senior company leadership was not involved in the review and first became aware of this issue in the aftermath of the Lion Air accident.
This is the sound of low level engineers being thrown under the wheels of the bus.
The question should be asked; in a safety first company how come the leadership didn't hear? There should have been a well established high priority channel within the company where safety issues could not be ignored or neglected or hushed up. If they want the flying public's confidence, and even more important the pilots confidence in their products, they need to rectify this see no evil hear no evil culture they've created.
G
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737D;
your posts indicate that the crew of the flights were less than competent in essence, however, you also suggest that the training standards are deficient. One specific on competency is your statement that you would respond in the event that these crews encountered by recognising the problem, identifying the cause and completing the action within "5 seconds".
your posts indicate that the crew of the flights were less than competent in essence, however, you also suggest that the training standards are deficient. One specific on competency is your statement that you would respond in the event that these crews encountered by recognising the problem, identifying the cause and completing the action within "5 seconds".
I agree that training needs to be lifted around the industry, we don't necessarily need more training, we need training that is not wasteful fo the resources that exist, as they are to day. We are currently governed by the aviation industries own version of political correctness, A.K.A. as SMS, and QA. In order to give a simplified box ticking exercise to regulators and managers, we come up with matrices and checklists that are fantastic for showing compliance, but, that is all. There is no closure of the loop on the fact that the crew may comply with a procedure or policy that in itself increases operational risk, or is impossible to do as it conflicts with the real world. The other sort of failure (think false negatives, false positives) arise when the boxes get ticked, but the impact of implementation is not observed. Our roles, policies and procedures are developed usually as bandaids on top of bandaids to reduce the risks of something, either real risk, or showing compliance (another form of risk - commercial). In all cases, however it is unlikely that the 200 hr pilot sitting in the RHS seat of the plane was the cause of the competency issues, he/she cannot be other than the logical outcome of what the industry has accepted as a good solution to unfettered growth (a cancer in effect, sounds good until the consequences start being felt).
A final thought: The crews encountered an unusual trim case, the checklist is for a runaway trim, yet the problem did not actually present as such, there was a trim error that occurred, but the trim responded normally to the crews trim inputs, and then after a period of time was anomalous again. That is not a simple set of facts to decipher in short order. Given their time over, I expect that the crew would follow your advice and act within 5 seconds and cure the ills of the world.
The mantra assumes that a flight crew may be presented with a novel situation that will require time to sort out. And I will say again, if either of the accident crews had done nothing but apply the mantra, particularly the "Trim the Aircraft" part, they would have bought themselves sufficient time - basically until fuel exhaustion - to figure out what was going on. That is way more than 5 seconds.
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The "Boeing Statement on AOA Disagree Alert" tells us that the MAX has had an AoA disagree alert function from the outset, but in error, it was not displaying to the aircrew. There is a long and convoluted explanation/justification of why that deficiency may not have been critical.
Strictly from a technical perspective, however, it needs to be pointed out that if a 737 crew were to receive an "AOA Disagree" message and go to the appropriate NNC, that checklist would simply direct them to the "IAS Disagree" checklist and/or the "ALT Disagree" checklist as appropriate. The "IAS Disagree" checklist would then direct the crew to the "Airspeed Unreliable" checklist, which has already been discussed extensively. In short, if the AOA disagreement becomes significant enough to impact the flight instruments or other systems, there will be plenty of other indicators for that problem (stick shaker, "IAS Disagree" alert) and so the "AOA Disagree" message is somewhat redundant in terms of directing the crew to the proper procedure.
The real issue is that if the AoA disagree signal system was available " in keeping with Boeing’s fundamental design philosophy of retaining commonality with the 737NG" why on earth was it not used as a critical input to the MCAS activation logic ??
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On UAS:
Does it include "land at nearest suitable airport".?
The Lion Air prelim report on the penultimate flight crew:
Seems to me with that much 'stuff hitting the fan' (polite form of a well known technical term) I think that pressing on was a bit of a gamble, that they did probably may relate to commercial pressure.
Interest to know what % of commercial pilots reading this would have pressed on.
737 driver
Could have made a big difference in Lion Air if the penultimate crew had included it in the tech log. I say if because they seem to have left out using trim cutout.
ET might have been the first one in that case,
Unfortunately, our company manuals don't go into that level of detail. It does have this little gem, though: "If the flight crew is aware of the problem, flight without the benefit of valid airspeed information can be safely conducted and should present little difficulty." Just a walk through the park.
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The Lion Air prelim report on the penultimate flight crew:
The pilot performed three Non-Normal Checklists (NNCs) consisting of Airspeed Unreliable, ALT DISAGREE, and Runaway Stabilizer. None of the NNCs performed contained the instruction “Plan to land at the nearest suitable airport”.
Interest to know what % of commercial pilots reading this would have pressed on.
737 driver
Reference deactivated "AOA Disagree" alert.
Sloppy, sloppy, sloppy.
That being said, I think it is fair to say that prior to the MAX accidents, most of the pilots at my airline had no clue that there was such a thing as an "AOA Disagree" alert. I'm not sure it would have made any difference.
Sloppy, sloppy, sloppy.
That being said, I think it is fair to say that prior to the MAX accidents, most of the pilots at my airline had no clue that there was such a thing as an "AOA Disagree" alert. I'm not sure it would have made any difference.
ET might have been the first one in that case,
Here is a link to a Wall Street Journal article which claims that Boeing had withheld information about MCAS for more than a year before the Ethiopian accident: BOEING WITHHELD MCAS SAFETY INFORMATION
- Ed
- Ed
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On the subject of training, what I find quite unbelievable is that every airline seems to have their own training procedures for a specific aircraft... Shouldn't there be just standard training dictated by the manufacturer of the aircraft and that should cover everything required.. there should be no need for carrier specific training other than perhaps some company policies, but nothing related to operating the equipment.
Sadly, this thought process does not stop at Boeing. I recently had an opportunity to fly with FO who was relatively new to the 737. During our trip, we discussed a number of issues that had come out of the recent MAX crashes. During this conversation, he confessed that before these accidents, he did not even know the stab trim wheel had a stowable handle and had never been trained in its use. Think about that for a moment. Also consider that a freshly-minted 737 Captain would have received the exact same training.
After I picked my jaw up off the floor, I proceeded to personally give the FO the training he had missed. Afterwords, I shared my concerns with my Fleet Manager and told him in no uncertain terms that our training programs needed a thorough review. The Fleet Manager replied that this was already in progress, and stated that our training programs were constantly being reviewed for improvement. He added a telling remark, however, that stab trim malfunctions had never been a statistically significant problem at our airline, implying of course that the training events our pilots are exposed to constantly needed to be justified by historical data. I told him that if the MAX accident had occurred at our airline, the family of those who perished would have been rightfully angered if it had come to be known that the crew had not been properly trained in a runaway stab procedure because the airline considered it to be a statistically insignificant event.
The degradation of pilot training and standards is a worldwide problem. It is being driven in large part by the beancounter mentality that attempts to justify every cost. Unfortunately this approach forgets that there are some costs that cannot be easily quantified, and eventually a price will be paid in bent metal and broken bodies. Sadly, even if the industry will not openly admit it, there seems to be an underlying assumption that there is an acceptable hull loss rate and that little will change until the body count goes up.