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Ethiopian airliner down in Africa

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Ethiopian airliner down in Africa

Old 3rd May 2019, 20:01
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Originally Posted by A0283

737 Driver the image you posted has only one of the smaller strakes ... so when was the second strake introduced ... my guess based on Takwis answer and PEI's post is the -600 to -900 ... so you would expect a reason for that... do you know what 737-model that KLM plane was?

737 Driver in the image that I posted I indicated the difference between the 'trapdoor' and the 'leading edge' ...IIRC the trapdoor opens down and forward and is as far as I could see not a part of the moveable leading edge/slats ... it would require a detailed picture of a MAX to clear that up I guess (would be nice to see one),
The picture was found online by Takwis, and there was no explanation of its context. I was merely assisting him with posting it. As far as your other queries, I have reached the extent of my expertise in these matters except to say that apparently someone thought these devices were necessary to accommodate the changes in airflow around the new engines.
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Old 3rd May 2019, 20:17
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Originally Posted by ams6110
I agree. This is how commercial aviation has become as safe as it is. When accidents happen, we seek not to blame individuals, but to understand root causes, and prevent or reduce the chance of the same thing happening again by correcting design or materials defects, augmenting training, changing procedures, improving regulatory oversight, documentation, and communication, or all of those things.

Sadly it seems there is a trend in society (I call it "outrage culture") where the response to any calamity is one driven by anger and blame, and not one seeking to solve actual problems. Or maybe I'm just getting old.
"This is how commercial aviation has become as safe as it is" I suspect that it is rather an Alice in Wonderland perspective. Every accident that involves loss of life, ultimately requires the investigation and apportionment of blame. Nothing has significantly changed in that respect. Air accident investigation does its best not to make legal findings because that is for the courts. Liability for mistakes is an important part of concentrating the mind... not just in the aviation world. Improving safety standards is largely due to commercial necessity. Public trust goes hand in hand with passenger volume. It is the breach of trust that can harm aviation. Countries have laws and hopefully those laws are respected and enforced when appropriate. Negligence, criminal negligence, dishonesty and corruption are possible in aviation as with every other walk of life. If individuals knowingly allowed or concealed unsafe systems being incorporated into the 737 MAX they will be be culpable. It is not a witch-hunt for the law to be enforced. The criminal test is an actus reus combined with mens rea. It is a high bar but one that could be reached. There are already signs that there have been some concealment and lack of candor. The circumstances demand that there will be further criminal and civil investigation to properly apportion blame. It may be that there were a series of innocent mistakes but that does not seem to be the most likely. Regardless of innocence, blame will still have to be apportioned to calculate compensation claims.
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Old 3rd May 2019, 20:22
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Originally Posted by wheelsright
"This is how commercial aviation has become as safe as it is" I suspect that it is rather an Alice in Wonderland perspective. Every accident that involves loss of life, ultimately requires the investigation and apportionment of blame. .
Spoken like a lawyer, not an accident investigator.
In blame there is profit - and a payday for a lawyer.
The criminal test is an actus reus combined with mens rea.
If you want people not to speak freely during an accident investigation, keep that attitude foremost.
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Old 3rd May 2019, 20:45
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Originally Posted by MurphyWasRight
That is 35 seconds with only 2 MCAS .
35 seconds. That is exactly the time "wasted" by captain Sullenberger's reaction time - he could have landed at La Guardia had he reacted "properly"!

In other words, Sully would have crashed this airplane, too. Must be a terrible pilot with no skills and no aviation safety insight.
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Old 3rd May 2019, 21:18
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A big part of our problems today is that many if not most of our politicians are in fact lawyers
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Old 3rd May 2019, 22:01
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Originally Posted by L39 Guy
And, for all we know, the B747-800 might have the odd bandaid too for some obscure issue just like the MAX.
All aircraft experimental flight test campaigns uncover issues which were not expected during the design of the aircraft, and require some sort of change to rectify. In the case of the 747-8, it was outboard aileron flutter, which was corrected with a *GASP* software fix. The engineering team was lauded for creating a software-only fix which required no hardware changes.

https://www.seattletimes.com/busines...iation-honors/



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Old 3rd May 2019, 22:13
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Originally Posted by derjodel

35 seconds. That is exactly the time "wasted" by captain Sullenberger's reaction time - he could have landed at La Guardia had he reacted "properly"!

In other words, Sully would have crashed this airplane, too. Must be a terrible pilot with no skills and no aviation safety insight.
Okay, Sully wasn't piloting a 737, but let's say he did. Somehow I just don't think Sully would have allowed his stab trim to run for 9 continuous seconds (that would be 37 spins of the trim wheel) before doing something about it, say like hitting the yoke trim switch with his left thumb. I certainly don't think he would let that happen twice. Maybe we should also note that Sully wasn't piloting Lion Air 610 the day before the accident (same aircraft, different crew in the very first documented case of the MCAS malfunction), and yet they still managed to figure out that when an automated system puts in some stab trim you don't want, it is entirely possible to take it right back out again.
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Old 3rd May 2019, 22:40
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Originally Posted by JLWSanDiego
A big part of our problems today is that many if not most of our politicians are in fact lawyers
The problem more related to this thread is that the industry seems to have established a trend, and built momentum in that direction, of dumbing down the flight deck positions and only retaining them so that there is someone to blame. (Yes, very cynical view, but that "Children of the Magenta Line" theory didn't arrive out of nowwhere).
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Old 3rd May 2019, 22:58
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737 Driver--
Okay, Sully wasn't piloting a 737, but let's say he did. Somehow I just don't think Sully would have allowed his stab trim to run for 9 continuous seconds (that would be 37 spins of the trim wheel) before doing something about it, say like hitting the yoke trim switch with his left thumb. I certainly don't think he would let that happen twice. Maybe we should also note that Sully wasn't piloting Lion Air 610 the day before the accident (same aircraft, different crew in the very first documented case of the MCAS malfunction), and yet they still managed to figure out that when an automated system puts in some stab trim you don't want, it is entirely possible to take it right back out again.
First, let me congratulate you ( like others have done ) on comprehensive and insightful analysis of this sad episode in aviation . It is just a pity that your observations /advice seem to be falling on so many deaf ears . Hence this thread continues to go round in ever widening circles , with no apparent end in sight .
There is an old saying -" a good workman never blames his tools " ; to that end , we can add the mantra--" Safety is a well trained pilot " .

Continuing on the same path of quotations , there is the favourite from Shakespeare --" Man has oft more need to be reminded than informed " . We forget past lessons easily .

Which brings me to the final , main point , (which you have stressed , in bold type , goodness knows how many times )--FLY THE AIRCRAFT. This is drummed into every pilot from day one . Sadly , this fairly simple piece of advice often falls by the wayside in the heat of the moment . The basics have been forgotten . Now , why this is so is another matter entirely .
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Old 3rd May 2019, 23:54
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Originally Posted by 737 Driver
Obvious errors were made that had fatal consequences. Since most of us would like to assume that this wasn't a case of malicious or negligent behavior, then presumably there were some significant human factor element behind these lapses.

I am referring, of course, to the various engineers, technical and supervisory staff that designed and approved MCAS for service.
I would like to assume they were not malicious or negligent too. But unfortunately a certain percentage of the population consists of sociopaths and psychopaths. And studies have shown that percentage is higher for people in senior executive positions, going as high as 20% psychopaths among CEOs, for example: https://www.washingtonpost.com/news/...=.549ab86d739e. With that in mind, I tend to be very suspicious when I hear a large company has made a "mistake", especially when that "mistake" has the potential to increase the profits of the company. At least until the public becomes aware of it.

You can look at the Volkswagen emissions scandal for example. A lot of people conspired to disregard the regulations to increase profits. I see no reason something similar wouldn't be possible at Boeing. It wouldn't surprise me at all if it turns out Boeing ignored or even deliberately covered up the MCAS safety issues, hoping they wouldn't get caught.

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Old 4th May 2019, 00:10
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So you are saying that Boeing was on the same path as Volkswagen and had specifically designed software that operated when it was tested. Wow you really have no idea of the people in Boeing. I don't work for them but I have had a lot to do with them and that is not what they are about culturally.

I agree with some of the posts above: If the Aircraft is not doing what you want then make it do what you want. Take out the automation and hand fly it if need be but take control of it.

Have a look at the data released in the preliminary report for ET302 and see if you can work out what they were doing in the 2 minutes before MCAS came in. That would also be the MCAS they were supposed to have been informed about after the release of the bulletin by Boeing. There are a lot of factors to this one and although MCAS is a flawed concept and has to be fixed the aircraft around it is fine and actually very nice to operate.

As for psychopaths in corporate structures I have meet some definite candidates over the years as well as some in Pilots uniforms.
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Old 4th May 2019, 00:35
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Originally Posted by coaldemon
So you are saying that Boeing was on the same path as Volkswagen and had specifically designed software that operated when it was tested. Wow you really have no idea of the people in Boeing. I don't work for them but I have had a lot to do with them and that is not what they are about culturally.
I didn't say that MCAS operated only when tested, but still a lot of parallels can be drawn between the two situations. I have no reason not to believe that MCAS works properly when the AOA sensors work properly, which was not what was going on at Volkswagen. But I still believe it is highly likely that in both cases there some unethical people ignored that their products can kill people, to increase profits.

And I don't mean to blame all the Boeing employees, or even a majority of Boeing's employees. I'm sure many of them are fine people that do their best every day, and are sickened and angry about the situation. But it's enough to have a few dozens of people in key positions being unethical. It doesn't matter if 99% of the employees are not like that, the final outcome can be the same.
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Old 4th May 2019, 01:13
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Originally Posted by coaldemon

I agree with some of the posts above: If the Aircraft is not doing what you want then make it do what you want. Take out the automation and hand fly it if need be but take control of it.
Hello,

will you explain how to take out the automation, in this case MCAS, unless you mean indeed to crank the wheels?
i might missed the switch to do so, would appreciate if you can point it to me
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Old 4th May 2019, 01:50
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Originally Posted by Ian W
As stated by SystemsNerd, the human cognition has limitations and foibles that many people are unaware of. One of these is the limited number of 'cognitive channels' also known as multiple resource theory. (see papers by Christopher Wickens and Erik Hollnagel) Simply you cannot read this posting and recite a something you have learned like NNC memory items at the same time - both use verbal cognition - if you are reading and someone says something you may hear them but you will not understand what they said and you will stop reading and ask them to repeat what they said. If you have to read, talk and listen at the same time you can only really do one at a time (we have all had to read a paragraph again as we stopped understanding what we were reading and listened instead).
So if you are running through memory items of an NNC - and you read the EICAS you may miss NNC items or not understand the EICAS - if the PM is shouting at you it may just be noise - if there is sufficient noise that channel stops completely and you do not even hear/comprehend the PM or that cavalry charge.

Mixed into this is the effect of the level of stress/alertness. This is normally referred to as an 'inverted U'.


from MindTools.com

So when you are bored with low stress your performance is actually poor, A little pressure / stress and your performance is ideal, but too much high stress and your performance will drop off rapidly.

Putting all that into an aviation perspective, A well trained pilot with experience of things going pear shaped and operating under pressure will not feel so much stress and concentrate on one item at a time and a lot of what will be done will be (what is called here ) muscle memory - innate training like stamping on a brake or steering a bike to stay balanced - or trimming an aircraft - it requires no thought as it is second nature. This is the importance of training - with not so much training it is easy to get into the overstressed very low performance state and 'get behind the aircraft'. The more inputs you are given the higher the stress and the less you are able to process and the normal human reaction to that is what is known as attentional or cognitive tunneling - a concentration on one aspect of what is happening that you _do_ think you can control and a total disregard of anything else. Everyone is different in this regard and the only way to avoid getting into the wrong side of the U is training, repeated training to get that muscle memory. Unfortunately, there is always a beancounter standing in the way of that.
I would like to see a stick shaker attached to a judges chair and then watch him make some complicated judgement with all that racket and distraction going on, but he won't die if he gets it wrong.

Where the MCAS trim runaway becomes difficult to deal with is it's transient nature, kind of like a partial engine failure in a single, oh, the engine has died, ok look for a landing area, good, got that, oh it's going again, so I'll turn a 180 and try to head back to the strip, oh no, it's failed again, now where was that grassy field, but if it was a straight out constant trim runaway, it would most likely have been caught sooner as there was training for that scenario.
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Old 4th May 2019, 01:52
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Originally Posted by coaldemon
Have a look at the data released in the preliminary report for ET302 and see if you can work out what they were doing in the 2 minutes before MCAS came in. That would also be the MCAS they were supposed to have been informed about after the release of the bulletin by Boeing. There are a lot of factors to this one and although MCAS is a flawed concept and has to be fixed the aircraft around it is fine and actually very nice to operate.
.
OK. here is my take, where possible times are from the text of report, assumed to be more accurate than reading the chart:
Takeoff roll began from runway 07R at a field elevation of 2333.5 m at approximately 05:38,
Everything looks nominal.
At 05:38:44, shortly after liftoff, the left and right recorded AOA values deviated
This was first indication of trouble, stick shaker and UAS indications.
Although the prelim report does not contain details it is possible the crew determined the UAS to be due to AoA; from Boeing flow chart someone posted a while back. Double quoted so my comments stand out better:
If AoA sensor is failed high,stick shaker on failed side will activate on rotation accompanied by IAS/ALT disagree warning flags
If the pitch power and config are consistent with takeoff and the good side ASI agrees with the Standby ASI,then it is a false warning ----------- >If in any doubt execute the UAS NNC
The symptoms match exact;y and there was not a huge difference in airspeed so they likely did not have a doubt. Anyone know what the standby ASI would show?
The pilot with good side data becomes PF
That did not happen as shown by pilot side AP warnings. The 360 total hours FO just might have something to do with that.
Land immediately
Appears they were not planning an immediate landing, although some of the ATC requests might have been from an 'automatic script' they were used to following.
There were a couple of attempts to engage auto pilot. ending in success at:
At 05:39:22 and about 1,000 feet the left autopilot (AP) was engaged (it disengaged about 33 seconds later),
At this point one could say they were flying the aircraft as they were trained/used to doing. Whether that is a good thing is a different discusion.
At 05:39:42, Level Change mode was engaged. The selected altitude was 32000 ft. Shortly after the mode change, the selected airspeed was set to 238 kt.
More normal procedure, this is probably the last time anyone thought about airspeed, at least until the clackers went off.
At 05:39:45, Captain requested flaps up and First-Officer acknowledged. One second later, flap handle moved from 5 to 0 degrees and flaps retraction began.
Still a surprisingly 'normal day at the office, although they would not be the first crew to ignore stick shaker and complete a flight, and no I am not referring to Lion air but a US crew report in safety database.
At 05:39:55, Autopilot disengaged,
And this is when MCAS kicked in 5 seconds later. So about 75 seconds from first fault to MCAS, with about half of that with a working autopilot leading them to believe things were basically OK, which in a 737NG they would have been. They were possibly even intending to complete flight for 'commercial' reasons.
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Old 4th May 2019, 02:09
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ICAO Annex 13 and the associated manual of accident/incident investigation clearly define the responsibilities and dissemination requirements for information including CVFDR Data. Ethiopea is a signatory to this (and all other) annexes to the convention. The international “aviation” community effectively “own” this information although it does of course imply that all States comply in full regarding these requirements.
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Old 4th May 2019, 02:13
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Originally Posted by FrequentSLF

will you explain how to take out the automation, in this case MCAS, unless you mean indeed to crank the wheels?
i might missed the switch to do so, would appreciate if you can point it to me
A MCAS failure presents itself as runaway stab trim. This uncommanded motion can be caused by a number of different malfunctions, MCAS being only one of them. The runaway stab trim procedure is agnostic as to the underlying cause of the the malfunction.

The procedure itself calls for disengagement of the Autopilot, use of Main Electric Trim (yoke trim switch) as necessary, disengagement of the Autothrottles, and if the runaway has not ceased, use of the stab trim cutout switches. Once all electric trim has been terminated, you would use manual trim as needed until landing.

Though it is not currently procedure, if you had a good idea that the problem really was MCAS (presumably because of an erroneous AOA or airspeed input), you could extend the flaps and restore the electric trim since MCAS only works with the flaps up. Technically, engaging the autopilot would also cause MCAS inputs to cease, however, our manuals contain warnings that the autopilot may not stay engaged with an erroneous AOA or airspeed.
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Old 4th May 2019, 02:21
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Originally Posted by JLWSanDiego
A big part of our problems today is that many if not most of our politicians are in fact lawyers
Both occupations are interchangeable, they are equal parts public debating, show biz, and BS, i.e. convincing that black is white.
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Old 4th May 2019, 02:25
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Originally Posted by 737 Driver
A MCAS failure presents itself as runaway stab trim. This uncommanded motion can be caused by a number of different malfunctions, MCAS being only one of them. The runaway stab trim procedure is agnostic as to the underlying cause of the the malfunction.

The procedure itself calls for disengagement of the Autopilot, use of Main Electric Trim (yoke trim switch) as necessary, disengagement of the Autothrottles, and if the runaway has not ceased, use of the stab trim cutout switches. Once all electric trim has been terminated, you would use manual trim as needed until landing.

Though it is not currently procedure, if you had a good idea that the problem really was MCAS (presumably because of an erroneous AOA or airspeed input), you could extend the flaps and restore the electric trim since MCAS only works with the flaps up. Technically, engaging the autopilot would also cause MCAS inputs to cease, however, our manuals contain warnings that the autopilot may not stay engaged with an erroneous AOA or airspeed.
I'm not sure if this has been discussed already and I've missed it, but is it possible for the electric stab trim to become stalled or overwhelmed by aerodynamic forces when there's a combination of a bit of speed and full stab deflection.
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Old 4th May 2019, 02:45
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Originally Posted by slacktide
All aircraft experimental flight test campaigns uncover issues which were not expected during the design of the aircraft, and require some sort of change to rectify. In the case of the 747-8, it was outboard aileron flutter, which was corrected with a *GASP* software fix. The engineering team was lauded for creating a software-only fix which required no hardware changes.

https://www.seattletimes.com/busines...iation-honors/
Thanks for the interesting article. However it is ironic in many ways, highlighting the difference between the development of the B747-8 and the B737 MAX.

The other difference is corporate culture. The 2nd most read article on the Seattle Times website is the appointment of a legal czar to deal with the B737 MAX fallout: https://www.seattletimes.com/business/boeing-aerospace/boeing-appoints-legal-czar-to-oversee-fallout-from-fatal-max-crashes/

The first article celebrates the achievement of a young engineer, the second is all about hiding behind layers of corporate accountability, As the saying goes: success has a thousand fathers, but failure is an orphan.
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