News Ethiopian 737 crashed on way to Kenya, 157 people on-board

Zatnikitelman

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I'm beginning to think fly by wire was the single worst invention in aviation history. Sure, it's necessary on military planes, but I personally think it should be banned from civil aircraft.
 

MaverickSawyer

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From my understanding, the 737MAX retains the mechanical and hydraulic systems used from the very start in the -100, and the flight computer uses the autopilot servos to move the surfaces when it needs to. Unless they made some serious changes to the aircraft's stability and handling characteristics, the crew should, in a direction emergency, be able to control the 737MAX via the traditional control linkages. Could be wrong, though, as my classmate who works on the 737 line in Renton flat out refuses to consider that Boeing could be at fault, and refuses to discuss the situation as anything other than gross negligence on the part of the flight crew, maintenance technicians, and airlines.
 

Urwumpe

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From my understanding, the 737MAX retains the mechanical and hydraulic systems used from the very start in the -100, and the flight computer uses the autopilot servos to move the surfaces when it needs to. Unless they made some serious changes to the aircraft's stability and handling characteristics, the crew should, in a direction emergency, be able to control the 737MAX via the traditional control linkages.


Yes, but contrary to what you might expect, this means the hand trim wheels, not the yoke. The MCAS changes the trim and you need to disable ALL electric trim systems to disable it.



MCAS is adding a FBW like behavior without all the intelligence and safeguards of a FBW implementation, for example, while it considers Mach number for its trim response, it does not limit the trim range by Mach number - repeated activations of the MCAS will still move the horizontal stabilizer until the hard stop in small steps. And both aircraft accelerated to higher speeds before the crash, both approached VMO.



Not sure how the fight between trim wheels and electric trim system will end - could the crew fully counter the MCAS pulses by overriding it with the manual trim? Or would the MCAS win against the crew, unless the electric trim motor is completely powered down?

---------- Post added at 08:54 ---------- Previous post was at 08:25 ----------

I'm beginning to think fly by wire was the single worst invention in aviation history. Sure, it's necessary on military planes, but I personally think it should be banned from civil aircraft.


Just that this isn't a fly by wire system. Its not even a primitive one.



Also, the number of crashes caused by FBW is really low compared to classic pilot errors in non-FBW aircraft that would have been prevented by FBW. Its not that easy. Remember that all Airbus aircraft are using FBW now since the 1980s, with only very few crashes having the FBW system involved at all.



Just look at the A320 there, which had just 17 fatal accidents at all:



https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_the_Airbus_A320_family


Most FBW related accidents of Airbus are actually side-stick dual input situations. In one recent crash, the crew even disabled most protections of the FBW without taking control during a thunderstorm - they entered a steep 54° bank because of a hardware problem without even reacting for 9 seconds.
 

MaverickSawyer

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Yes, but contrary to what you might expect, this means the hand trim wheels, not the yoke. The MCAS changes the trim and you need to disable ALL electric trim systems to disable it.
Hmmm... I could have sworn that the yoke had direct connection to the surfaces and was simply hydraulically assisted, instead of the yoke only driving the hydraulic valves.

Not sure how the fight between trim wheels and electric trim system will end - could the crew fully counter the MCAS pulses by overriding it with the manual trim? Or would the MCAS win against the crew, unless the electric trim motor is completely powered down?
It would end very badly. The trim they're talking about with MCAS seems to be the stabilizer incidence, not the trim tabs on the elevator.

Overall, my biggest concern isn't necessarily the nature of the fault that has been found, or how it's being fixed...

It's how the fault got missed in the first place, and then seems to have been swept under the rug by both Boeing and the FAA after discovery.
I mean, how exactly did Boeing think that having no redundancy on the MCAS input was a good idea? that flies in the face of some very hard-learned lessons paid for in blood... you ALWAYS have separate and redundant instruments in IFR-rated aircraft, so that the failure of one system (like electrical or vacuum power in smaller aircraft) can't render the aircraft without reference data. Hell, transport aircraft have two or even three separate hydraulic systems and electrical sources to ensure the safety of the aircraft and its occupants. Yet, a system that can initiate a nose down motion without the input of the crew after the failure of ONE SINGLE SENSOR is considered to not need redundancy? I just cannot wrap my head around the logic that could possibly be used to justify this. I'm literally weeks from completing my A&P license, and therefor I have extremely limited experience in the maintenance field... but this is setting off all sorts of red flags for me.

Furthermore, the FAA signed off on the MCAS, with no input redundancy, as airworthy. Somehow, Boeing managed to convince the FAA that it was safe. That is in and of itself highly concerning. The fact that they've not taken any direct action to ensure that these aircraft are currently safe, such as imposing limitations on the aircraft so that the MCAS need not be active, or outright ordering the system to be disabled until fixes are made, tested, and distributed, is also disturbing. Historically, an Emergency Airworthiness Directive can be issued due to a single incident that either nearly caused an accident, or actually did. The fact that this has been a repeated occurrence and nothing had been even looked at until after the Lion Air 610 crash is extremely disturbing.

Personally, I flat-out will NOT fly aboard a 737MAX until the MCAS has been fitted with a redundant input, and am recommending that others do the same.

For the record, I'm also going to be keeping an eye out for the inevitable AD for this situation and will share it when it comes out.

EDIT: The existing AD, issued in the aftermath of the Lion Air 610 crash, is AD 2018-23-51, and can be found here.
 
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Its not Twitter. Its an official order. By a professional air safety agency. Not some politicians

You may think they're professional. There is a big problem if important safety organs are outsmarted by politicians. It were the politicians who were FIRST yesterday to stir this thing up. Not an official aviation safety organ. EASA's statement came hours later. EASA did what the politicians demanded them to do. Do you really think the EASA had taken the same decision at the same time if the politicians remained silent yesterday? I don't think so.
 

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You may think they're professional.

You know, I could now just come up and ask "And you are?" You can sure imagine how this will end up.

Lets just assume, for the sake of keeping the discussion civil, that the people at the EASA are still doing their job as they did over the past 11 years.

---------- Post added at 10:57 ---------- Previous post was at 10:52 ----------

Hmmm... I could have sworn that the yoke had direct connection to the surfaces and was simply hydraulically assisted, instead of the yoke only driving the hydraulic valves.

Yes, but remember how the trim system of the 737 works: It moves the whole stabilizer, while the yoke moves only the elevator.
 

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You know, I could now just come up and ask "And you are?" You can sure imagine how this will end up.

So, if someone does not agree with you, things are likely to become uncivil. Right.

I am a qualified flight instructor for more than 15 years now. As such, I've been involved on many occasions in all sorts of matters regarding safety in aviation. In the air, on the ground and in the classrooms.

What's your professional contribution to aviation safety?
 

Urwumpe

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So, if someone does not agree with you, things are likely to become uncivil. Right.

I am a qualified flight instructor for more than 15 years now. As such, I've been involved on many occasions in all sorts of matters regarding safety in aviation. In the air, on the ground and in the classrooms.

What's your professional contribution to aviation safety?

I am not talking about me. I am talking about YOU being more qualified than the people at the EASA and the NAAs that contribute technically to their decisions about aircraft safety. You tried to declare that the EASA is just following orders from obscure politicians - and so yeah: Do you think you are qualified to decide if an aircraft is safe or not?

You are aware that the EASA is also responsible for your job? You should know it, it was already there when you started instructing and it should be subject of your courses.
 
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Linguofreak

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Just posted by Dallas News

Slight nitpick: The domain name is dallasnews, the name of the paper is Dallas Morning News. Doesn't matter much, we've not subscribed to the paper in years.
 
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Marijn

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Now various news sources are now reporting that the grounding of the 737 is the result of a chain reaction in 'Public emotion'. Exactly the point I made. I named it a snow-ball effect. Again, important safety decision should not be the result op public outcries. That's a dangerous safety flaw by itself.

https://www.forbes.com/sites/marisa...rs-in-battle-for-public-opinion/#eddf2dc2e7b8
https://www.telegraaf.nl/financieel/3282600/publieke-emotie-zet-boeing-aan-de-grond (paywall, buy you can't miss the headline)
https://eu.usatoday.com/story/opini...ublic-pressure-editorials-debates/3145564002/

---------- Post added at 11:48 AM ---------- Previous post was at 11:46 AM ----------

You are aware that the EASA is also responsible for your job? You should know it, it was already there when you started instructing and it should be subject of your courses.

What point are you trying to make there?
 

Urwumpe

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What point are you trying to make there?

That you are making a VERY bad impression as European flight instructor, if you are talking nonsense about how the EASA operates. Especially if a student reads it. Did you never hear about the JAATO?

How would you feel as student if a US instructor would not know how the FAA works and which gravity their regulations and decisions have?
 

Linguofreak

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From my understanding, the 737MAX retains the mechanical and hydraulic systems used from the very start in the -100, and the flight computer uses the autopilot servos to move the surfaces when it needs to. Unless they made some serious changes to the aircraft's stability and handling characteristics, the crew should, in a direction emergency, be able to control the 737MAX via the traditional control linkages. Could be wrong, though, as my classmate who works on the 737 line in Renton flat out refuses to consider that Boeing could be at fault, and refuses to discuss the situation as anything other than gross negligence on the part of the flight crew, maintenance technicians, and airlines.

Heh. The issue is that if you advertise something as a drop in replacement for a previous model, and some form of incompetence can cause catastrophic failure of the new model when the old model was impervious to the same incompetence, that's a design flaw.

Most FBW related accidents of Airbus are actually side-stick dual input situations. In one recent crash, the crew even disabled most protections of the FBW without taking control during a thunderstorm - they entered a steep 54° bank because of a hardware problem without even reacting for 9 seconds.

The design flaw in the Airbus family there isn't that it has fly by wire, it's that the left and right seat sticks are not physically linked, so that either pilot can feel what the other is doing. You don't have to have physical linkages between the sticks and the control surfaces, just between the sticks.
 

Urwumpe

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The design flaw in the Airbus family there isn't that it has fly by wire, it's that the left and right seat sticks are not physically linked, so that either pilot can feel what the other is doing. You don't have to have physical linkages between the sticks and the control surfaces, just between the sticks.

Yes, though it took some time to realize, that dual input is really a bigger issue. I still wonder why Airbus did not include force feedback there and made showing a warning about dual input optional. I don't think physical connection between the sticks is really needed or the least complex solution.
 

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That you are making a VERY bad impression..

You somehow read things I haven't written. I have said that I think it's unprofesional -in general- when unqualified people take control over important decisions affecting safety in aviation. This is echoed by many news sources at this very moment. I have also said that it is partcularly ridiculous that planes enroute are affected and did have to divert. You can keep denying it. But the ministers of indidual countries grounded the plane first yesterday and EASA basicly confirmed this at a later moment. It's obviously a messy situation and if you don't think so, that's your opinion and I will respect that. You seem to have little respect over other people's opinion by becoming personal about things you know nothing about.

And you are wrong about quite a few things. I am not an European flight instructor. I am a Dutch flight instructor. I have never represented EASA. None of my licenses were ever printed on EASA paper. My signature is on it. And the signature of the Dutch minister. Soon the licenses will all be issued by EASA though. In my case, that will happen this year for the first time. Not eleven years ago. The transition to EASA is ongoing for quite some time now. It was postponed several times.

Do you think you are qualified to decide if an aircraft is safe or not?
No idea why you think this is relevant. But the answer is simple. Yes. It's the duty of any pilot in command to make sure the plane is safe before flight by doing an inspection and signing off the paperwork to indicate this.

May I remind you of your claim that European aviation is safer than US aviation? You 'forgot' to answer thay one. Who's talking nonsense?
 
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Urwumpe

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You somehow read things I haven't written. I have said that I think it's unprofesional -in general- when unqualified people take control over important decisions affecting safety in aviation. This is echoed by many news sources at this very moment.

Yes - and that assumes that the EASA is unprofessional and controlled by obscure politicians. Read below why:

I have also said that it is partcularly ridiculous that planes enroute are effected and did have to divert. You can keep denying it. But the ministers of indidual countries grounded the plane first yesterday and EASA basicly confirmed this at a later moment. It'a obviously a messy situation and if you don't think so, that's your opinion and I will respect that. You seem to have little respect over other people's opinion by becoming personal about things you know nothing about.

It is not like you are not "personal" against the engineers at the EASA and the NAAs, including the Dutch NAA?

Do you really believe the EASA decided in 20 minutes that the 737 MAX will be grounded? Or any other national agency involved?

That Scheuers statement preempted the EASA decisions is bad timing (and typically egoistic) and I would not exclude him to decide this after reading the tabloids about it. But he was not alone.

And fact is: In the background of such news, EASA and NAAs had already been busy getting all information about the 737 Max on the table and exchange with FAA and NTSB right after dust at the crash site settled. And you can be sure, the meeting with the decision to close European airspace did not happen after Scheuers statement, but in the early afternoon before Italy closed their airspace as well. Maybe they did not decide as fast as others.

Also, the CAA of Britain is sure not less professional than others or would you also say, they are ruled by politicians? Or the CASA of Australia, which had been among the first to decide to ground the 737 Max.

And you are wrong about quite a few things. I am not an European flight instructor. I am a Dutch flight instructor. I have never represented EASA. None of my licenses were ever printed on EASA paper. My signature is on it. And the signature of the Dutch minister. Soon the licenses will all be issued by EASA though. In my case, that will happen this year for the first time. Not eleven years ago. The transition to EASA is ongoing for quite some time now. It was postponed several times.

Still, all safety decisions are already coordinated by EASA since 2002 and EASA is fully operational in its own decisions since 2008. So, even without you being under direct control of EASA in your job, the European legislation and the responsibilities already switched to EASA 17 years ago. Even the dutch aviation authority is member of the EASA.



No idea why you think this is relevant. But the answer is simple. Yes. It's the duty of any pilot in command to make sure the plane is safe before flight by doing an inspection and signing off the paperwork to indicate this.

So you think there is no difference between an individual aircraft and a model? Why are those people who decide over the airworthiness engineers then in both Europe and the USA, while its not mandatory to be an engineer for a pilots license? Do you think your pre-flight checks will detect hidden design flaws in the aircraft software? And how long are you checking before each flight? Sure no full day, do you?

For being able to fly, you are depending implicitly on FAA or EASA doing their job properly. You trust them with your life. If they do a bad job, you won't notice it before you left the ground.

May I remind you of your claim that European aviation is safer than US aviation? You 'forgot' to answer thay one. Who's talking nonsense?

I did never say "safer". I said a different doctrine is behind the decisions (precautionary principle vs scientific principle, the former is a EU standard for all regulations, regardless if its about aircraft or children toys). That is why the FAA can still permit a model to fly, while the EASA already decides to play safe. For Europe, its enough to have "potentially unsafe" to ground an aircraft or ban an airline, while in the USA its "known unsafe".

Maybe this appears to be "safer", but no, it isn't. It just means putting different emphasis on how to prevent accidents. It also means a difference on WHO has to prove that something is unsafe. In the EU, the manufacturers have to prove something is safe, in the USA the FAA has essentially to prove something is unsafe.

---------- Post added at 16:05 ---------- Previous post was at 14:00 ----------

And a new (tiny) vote of non-confidence against the USA and Boeing... Ethiopia wants that a European country analyzes the black boxes for the investigation, not the country of the manufacturer (USA) as alternative when the country of the airline or the accident is not able to investigate it.

Which country is still unknown, but the best candidate organizations regarding Boeing aircraft would be AAIB (UK) and BfU (Germany). I don't think the BEA of France would be chosen for a Boeing aircraft, AFAIR, they cooperated with the BfU to analyze Boeing black boxes.

https://globalnews.ca/news/5050774/ethiopia-black-box-ethiopian-airlines-crash/
 
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MaverickSawyer

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Good. I'm not confident in Boeing and the FAA to be unbiased, and I agree with your assessment that the UK or Germany are much better suited to the investigation. Personally, I'd lean towards Germany.
 

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Among bits and Bytes...
There's a software patch in the works to fix the behavior 737 MAX have been experiencing. The patch has been in the works for some time, but was delayed by 5 weeks because of US government shutdown.

Welp...
 

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There's a software patch in the works to fix the behavior 737 MAX have been experiencing. The patch has been in the works for some time, but was delayed by 5 weeks because of US government shutdown.

Welp...

I knew it, Boeing is actually a federal US agency. :lol:

:j/k:

---------- Post added at 19:19 ---------- Previous post was at 18:19 ----------

And it was decided the black boxes go to the evil empire: Germany.

The BFU (federal agency for aircraft accident investigation) will do the analysis... so, the blackboxes will be next to my former workplace. :rofl:
 
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