Ethiopian Max 8 crashes, Canadians on board

[Fuzz]

So if MCAS was deactivated, and the pilots did all the proper procedures, surly MCAS can't be to blame? I think we need to wait for more information...

[Red]

Originally Posted by Bigtime

[/B]

So what happened after that? If they flipped the trim switches to 'off' shouldn't that have been the end of it? Flying manually at that point and having to operate the trim wheel by hand. Or did the switch not work? Or did they switch it back on?

Some initial info.

“The Captain asked the First Officer to pitch up together and said that pitch is not enough,” the report reads. “The data indicates that aft force was applied to both columns simultaneously several times throughout the remainder of the recording.”

The report does not specifically name the Maneuvering Characteristics Augmentation System, which is a stabilization system, but makes it likely the MCAS pushed the plane into a dive fueled by erroneous angle of attack sensor readings. Boeing is currently working on a change to the system’s software.

It says the flight data recorder indicated “automatic aircraft nose down (AND) trim command four times without pilot’s input.”

[Red]

Originally Posted by Fuzz

So if MCAS was deactivated, and the pilots did all the proper procedures, surly MCAS can't be to blame? I think we need to wait for more information...

The one thing I am not clear about is if the MCAS was deactivated or the procedure to deactivate was performed, but it did not work or was not enough. Also, at this altitude, it may have been too late.

[Resolute 14]

Originally Posted by Fuzz

So if MCAS was deactivated, and the pilots did all the proper procedures, surly MCAS can't be to blame? I think we need to wait for more information...

The - still preliminary - information we currently have is that MCAS was re-enabled. It is unknown if the pilots re-enabled it, or if the software did so automatically. If the latter, Boeing is in a metric crapload of hurt, beyond what they're feeling now.

Also, lets face it, the FAA and Boeing has a far, far greater reason to push the pilot error narrative than Ethiopian authorities have to push the blame into Boeing's lap.

[Bigtime]

Could very well be that by the time they used the trim cutoff switch the stabilizer was in a very pitch down setting. Possible that even enough that both hauling back on the control columns wasn't going to be enough, and not enough time to start having one of them turn that wheel like crazy to start bringing the stab back to a degree where they could control without lots of force required.

[Ryan Coke]

Originally Posted by Red

Now that the initial report is out. Should we still be very cautious and sceptical when reading news or should we apply that when we are reading your opinions on this subject?

I’m happy to provide some thoughts and insight here, but you seem to be calling me out for no good reason. Nothing I said was incorrect, or made any hyperbolic assumptions. And nothing in the reports disagrees with what I said, even though you seem to think so.

So read things critically, and realize that you need to be skeptical of the accuracy of media reports of these types of technical issues.

The odds of turning off the stab trim cutout switches and having MCAS continue to trim nose down are not impossible, but extremely low. And there is nothing in what I have read that indicates that is what happened.

I am not saying what did or didn’t happen, because I don’t know. But I am advising on the realistic probabilities of some of these poorly written articles.

It appears the crew did the correct thing by turning off the stab trim cutout switches, but for some reason felt they needed to turn them back on. Why was that? I really don’t know, and I look forward to finding out. There are some legit theories written above by bigtime and fuzz, but no one really knows yet.

[FLAME ENVY]

Originally Posted by Resolute 14

The - still preliminary - information we currently have is that MCAS was re-enabled. It is unknown if the pilots re-enabled it, or if the software did so automatically. If the latter, Boeing is in a metric crapload of hurt, beyond what they're feeling now.

Also, lets face it, the FAA and Boeing has a far, far greater reason to push the pilot error narrative than Ethiopian authorities have to push the blame into Boeing's lap.

It has been reported that the pilots enabled the trim cut-out switches killing the MCAS system but re-activated the cut-out switches which in turn re-enabled the MCAS system. The crew did this numerous times which is not the proper procedure for a runaway trim situation.

People need to keep in mind that preliminary reporting thus far is from Ethiopian authorities, not EASA, FAA, NTSB who are all involved with the investigation. In the reports released by Ethiopian authorities they state that their pilots followed the proper procedures but fail to mention that the pilots re-activated the trim cut-out switches numerous times as stated in other reports, that is not in fact proper procedure if that bears true.

The link below is how the Ethiopian authorities reacted when their pilots were found to be at fault for the 2010 737-800 crash that killed all on board. Seems rational... Ethiopian still has the same CEO. You don't think they are going to take the same stance if their pilots are found in any way to have contributed to this crash?

https://www.flightglobal.com/news/ar...-crash-367118/

[Scroopy Noopers]

Originally Posted by Ryan Coke

but no one really knows yet.

I appreciate your efforts to explain what’s going on. I’ve enjoyed reading what most people have contributed, learned a lot.

Although you’re wrong on your last point.... Red ‘knows’.

[Red]

Originally Posted by Ryan Coke

I’m happy to provide some thoughts and insight here, but you seem to be calling me out for no good reason. Nothing I said was incorrect, or made any hyperbolic assumptions. And nothing in the reports disagrees with what I said, even though you seem to think so.

So read things critically, and realize that you need to be skeptical of the accuracy of media reports of these types of technical issues.

The odds of turning off the stab trim cutout switches and having MCAS continue to trim nose down are not impossible, but extremely low. And there is nothing in what I have read that indicates that is what happened.

I am not saying what did or didn’t happen, because I don’t know. But I am advising on the realistic probabilities of some of these poorly written articles.

It appears the crew did the correct thing by turning off the stab trim cutout switches, but for some reason felt they needed to turn them back on. Why was that? I really don’t know, and I look forward to finding out. There are some legit theories written above by bigtime and fuzz, but no one really knows yet.

That was a joke actually, but I can see why you took it the way you did.

Anyways, I also read things critically and realized that I needed to be skeptical of the accuracy of information coming from the media FAA and Boeing. This is where we differ.

I leave media out of it because while they are not always correct, they are there to inform the public and have good intentions to do so. The FAA and Boeing on the other hand deliberately misinformed the public about the safety of this plane.

[marsplasticeraser]

As somebody who knows nothing about how planes fly, this story was really interesting:

https://www.vox.com/business-and-fin...ndal-explained

TLDR in 4 points:

1. There is a huge incentive for the 737 Max to be judged the same as other 737's, and therefore require no retraining for pilots and airlines.

2. The 737 Max doesn't fly like other boeing 737's due to design compromises to make it more efficient. Boeing tried to use software to get around this plane flying differently, and the software is glitchy, which caused the two crashes. At the same time, Pilots had reported this issue anonymously before the crashes. Some pilots believe there should be formal training required to fly a 737 considering how different the plane is and the reliance on software.


3. Boeing was highly involved in the FAA review of this, performing many of the tasks. I think many people assume the FAA is completely independent in their reviews. This is definitely not the case.

4. Boeing also made a critical error light that would help in detecting a malfunction in the software optional. Carriers in developing countries didn't select.

Overall, it seems like separation of duties between regulators and industry would have solved this.

[Red]

Originally Posted by Scroopy Noopers

I appreciate your efforts to explain what’s going on. I’ve enjoyed reading what most people have contributed, learned a lot.

Although you’re wrong on your last point.... Red ‘knows’.

Thanks for the mention here. Can you tell me what I said that I knew about these planes? Like a quote of two where I pretended to know what happened, what should have happened while the plane was in trouble? I am heavily criticizing the FAA and Boeing for this, I will give you that. But I never said anything abuout how these systems worked, should have worked or what the pilots should or should not have done. I didn't say any of these things because I don't know. I am not a pilot.

At the other end of the spectrum, here are some snippets from a person that claims to not know what happened either

This malfunction was a manageable malfunction.

The odds of turning off the stab trim cutout switches and having MCAS continue to trim nose down are not impossible, but extremely low.

As for the report that the pilots disabled the software but the system continued trimming anyway....be very cautious and skeptical. It is highly unlikely. Nothing is impossible, but the odds of that being an incorrectly worded news story is magnitudes more likely than the trim continuing to run with the stab trim cutout switches placed in cutout.

[Bigtime]

Just spitballing here and hoping an operator on the 737 like Ryan Coke could answer. If it was a situation where after using trim cut-off switches and the stab was in such a pitch down setting that control manually was near impossible could a crew re-engage the cut-off and use the electric trim control on the column to bring the stab back to a reasonable setting and then disconnect the trim stab switch again to fly manual trim until back on the ground? Or would the MCAS keep trying to kick in at that point and thus override the control column trim switch inputs? MCAS operating in this case because of the AoA indicator issue.

[Snuffleupagus]

Originally Posted by Ducay

Tin foil hat much?

I literally don't even know what you're trying to argue.

At any rate Boeing and the FAA are two highly respected, world class organizations in their respective fields. Pilot standards are extremely high in US and Canada and these standards are lower elsewhere. No conspiracy here, just facts.

Boeing CEO admits they were working on a software update to fix MCAS after the Lion air tragedy yet they allowed 157 people to die 5 months later in Ethiopia. everyone who knew about this should be fired and the ones who made the decision not to ground this aircraft should be charged with manslaughter.

Respectability - toast

[Regorium]

So I'm reading this:
http://avherald.com/h?article=4c534c4a/0022&opt=1024

The odds of turning off the stab trim cutout switches and having MCAS continue to trim nose down are not impossible, but extremely low.

The cut-off switches disabled MCAS. This statement is completely correct. However, the manual trim adjustments to get them back to level did not appear to work.

As for the report that the pilots disabled the software but the system continued trimming anyway....be very cautious and skeptical. It is highly unlikely. Nothing is impossible, but the odds of that being an incorrectly worded news story is magnitudes more likely than the trim continuing to run with the stab trim cutout switches placed in cutout.

The pilots disabled the system and the system did not continue to trim automatically. However, the pilots couldn't get the trim back to the proper location with manual trim, and when they reactivated electric trim, that's when MCAS kicked in and sent them to an unrecoverable position. This statement is also correct based on the preliminary report. Note how stable the trim is for 2.5 minutes.

I think the preliminary report has some interesting tidbits. I wish there was more analysis - if I recall properly, if the pilots are turning that trim wheel, it's super loud and should be caught in the CVR. If there's something preventing them from doing that (like MCAS locking the trim wheel at 2.1 units when it senses a 75 degree nose up) then that's a massive blunder.

[Regorium]

Originally Posted by Bigtime

Just spitballing here and hoping an operator on the 737 like Ryan Coke could answer. If it was a situation where after using trim cut-off switches and the stab was in such a pitch down setting that control manually was near impossible could a crew re-engage the cut-off and use the electric trim control on the column to bring the stab back to a reasonable setting and then disconnect the trim stab switch again to fly manual trim until back on the ground? Or would the MCAS keep trying to kick in at that point and thus override the control column trim switch inputs? MCAS operating in this case because of the AoA indicator issue.

Based on the image from avherald of the FDR reading, I think this is what they tried at the end. I speculate they turned electric trim back on around 5:43:10 after having it cut off from ~5:40:35, had two nose up commands, then MCAS kicked in after that and put them into an unrecoverable position.

[Fuzz]

Starting to shine the light on the dangers of automation. It sure looks like Boeing didn't ask enough of the "well what if this happens?" type of questions.

[nik-]

Also, the optional angle of attack disagreement warning light was an $80,000 option. I know the plane is $100 million, but $80k for a warning light?

It's standard now.

https://www.cbsnews.com/news/boeing-...r-malfunction/

[Bigtime]

Originally Posted by nik-

Also, the optional angle of attack disagreement warning light was an $80,000 option. I know the plane is $100 million, but $80k for a warning light?

The wonderful world of aviation. 50 cent bolt at a hardware store. Same thing aviation certified? $10. I may be exaggerating but not by much most likely.

[Firebot]

Armchair 737 pilots here: "Derrr just manually adjust the trim. They were poorly trained, those 3rd world pilots."

https://www.cnn.com/2019/04/04/world...ntl/index.html

Recognizing a problem with the automatic trim, the pilots followed emergency procedures and turned off the system. Instead, the pilots tried to use the backup manual trim wheel to adjust the trim, but the airplane was traveling too fast and the manual trim wheel would have been physically impossible to operate, according to a 737 pilot who spoke with CNN.

In the final minute of the flight, the pilot told his first officer that they had to pull up together. Thirty-two seconds before the crash, both pilots tried to trim the nose up, and for a brief moment, the aircraft's stabilizer, controlled by the trim, made the corresponding change,
But five seconds later, the aircraft's automated systems once again trimmed the nose down, pitching the nose down even further, steepening the dive. The plane was angled 40 degrees nose down, hurtling towards the ground at 575 miles per hour as it crashed.

[speede5]

Originally Posted by Bigtime

The wonderful world of aviation. 50 cent bolt at a hardware store. Same thing aviation certified? $10. I may be exaggerating but not by much most likely.

I authorize buys on aircraft parts every day and you are not even close to exaggerating.

You pay for the Certificate of Conformance (C of C) not the part essentially. And if you think that's expensive, add in Military Standard and you are spending extraordinary amounts of money.