osiris30 wrote:

Pitch and power requires no airspeed indicator at all.

Fly pitch & power.

MCAS kicks in. Run auto-trim cut off. Trim manually.

The last one is an added complication, BUT, in light of ALL the talk in the community (including professionally) after Lion Air, that should have been a given.

Sure it 'should' have been a given - but it seems to me that the issues with MCAS are also coming to the surface during low-level flight segments. The lack of reliable airspeed indicators at takeoff has caused several tragedies in the past and is not outwith the realms of causing another one in the future. It overwhelms the pilots with contradicting messages, aural alarms and troubleshooting in instances where they have basically zero altitude already, which is why it is so deadly. Now you consider a scenario like that where there is ALSO a system kicking in doing what it is designed to do, and that's MCAS trimming downwards? NOT good.

Easy to say fly pitch and power and immediately deal with MCAS by flipping the STABTRIM CUTOUT switches.......but I imagine it is less than simple to do when on the verge of a stall at ~1,000AGL just post-takeoff.

MrBretz wrote:

Asdf said “unreliable airspeed
pitch&power mode
flaps UP on climb at 210kts
http://www.b737mrg.net/downloads/b737mr ... 737-NG.pdf

but you need a reliable AoA
if you dont have a AoA info
and you dont have a speed info

well
sorry”

So you struggle to get in the air, you retract the flaps, all h... is breaking lose, you are at low altitude, then MCAS kicks in and points the nose down.....gads.

Let's not get carried away. They were in the air for 7 or 8 minutes. *IF* MCAS kicked in that is MORE than enough time to diagnose and correct the issue.

Let me throw out another equally likely scenario:

Aircraft is misbehaving due to mechanical or instrument failure. Pilots having heard so much about MCAS recently have it in the back of their mind. MCAS isn't even active but pilots believe the root problem IS MCAS and misdiagnosing the correct issue. They lose situational awareness and ...

This is why MCAS needs a very visible PFD call out so the crews don't have to guess.

Trin wrote:

osiris30 wrote:

Pitch and power requires no airspeed indicator at all.

Fly pitch & power.

MCAS kicks in. Run auto-trim cut off. Trim manually.

The last one is an added complication, BUT, in light of ALL the talk in the community (including professionally) after Lion Air, that should have been a given.

Sure it 'should' have been a given - but it seems to me that the issues with MCAS are also coming to the surface during low-level flight segments. The lack of reliable airspeed indicators at takeoff has caused several tragedies in the past and is not outwith the realms of causing another one in the future. It overwhelms the pilots with contradicting messages, aural alarms and troubleshooting in instances where they have basically zero altitude already, which is why it is so deadly. Now you consider a scenario like that where there is ALSO a system kicking in doing what it is designed to do, and that's MCAS trimming downwards? NOT good.

Easy to say fly pitch and power and immediately deal with MCAS by flipping the STABTRIM CUTOUT switches.......but I imagine it is less than simple to do when on the verge of a stall at ~1,000AGL just post-takeoff.

Stop. Your assessment of when they crashed is wrong. They go above 1000 agl. 1000' AGL is just where the flight radar cuts out. The aircraft was in the air for another 4 minutes beyond that data. They did not crash at that impact angle coming out of 1000' AGL. The 737 just isn't that nimble to acquire that angle from that altitude.

here is an interesting link, YouTube video, of a very plausible theory of what might have happened.
This is one the best explanations and theory of what could have caused this tragedy, even both 737 MAX8 tragedies, compared to a lot of, in my humble opinion, useless and time wasting posts in both the Lion Air and this discussion thread.

https://www.youtube.com/watch?v=3jGNn2T_gyU

VeeCee wrote:

planecane wrote:

Also, Boeing wants/needs to know the actual cause as well. Doctoring data to reduce liability for this accident does nothing for them if there is a design flaw. If they keep selling a model with a fundamental flaw, there will be more crashes and the 737 MAX will have all orders cancelled and the program will fail.

You and me and the majority of posters and airlines etc know this. Boeing genuinely wants to know if there is a problem so they can fix it. The NTSB has proven to be independent and trustworthy. The BEA wants to know too. They don't WANT to ban planes from their airspace. And every bit of new information we gain about aircraft safety benefits ALL manufacturers.

But public perception matters. If we want the public to have faith in the industry and trust the system to keep them safe, then you have to listen to the public. It can't be a one way street. In this case it's easy. There was more than one facility capable of reading the FDR and CVR. Choose one that helps alleviate concerns about bias in favor of the manufacturer.

I agree. After all, wasn't it the NTSB that identified the 737 rudder hardover issue back in the 90's. The end goal is always safety in something like this.

I just want to know why they didn't gain altitude in those first 3 minutes.

Will also be interesting to see if their FDR data has the same mismatches as Lion Air.

ytz wrote:

I just want to know why they didn't gain altitude in those first 3 minutes.

Will also be interesting to see if their FDR data has the same mismatches as Lion Air.

Don't we all want to know why.. I am feeling less and less like this has much if anything to do with Lion Air. Everything we know is different to this point apart from aircraft type and end result.

ytz wrote:

I just want to know why they didn't gain altitude in those first 3 minutes.

Will also be interesting to see if their FDR data has the same mismatches as Lion Air.

I am wondering the very same question

osiris30 wrote:

Trin wrote:

osiris30 wrote:

Pitch and power requires no airspeed indicator at all.

Fly pitch & power.

MCAS kicks in. Run auto-trim cut off. Trim manually.

The last one is an added complication, BUT, in light of ALL the talk in the community (including professionally) after Lion Air, that should have been a given.

Sure it 'should' have been a given - but it seems to me that the issues with MCAS are also coming to the surface during low-level flight segments. The lack of reliable airspeed indicators at takeoff has caused several tragedies in the past and is not outwith the realms of causing another one in the future. It overwhelms the pilots with contradicting messages, aural alarms and troubleshooting in instances where they have basically zero altitude already, which is why it is so deadly. Now you consider a scenario like that where there is ALSO a system kicking in doing what it is designed to do, and that's MCAS trimming downwards? NOT good.

Easy to say fly pitch and power and immediately deal with MCAS by flipping the STABTRIM CUTOUT switches.......but I imagine it is less than simple to do when on the verge of a stall at ~1,000AGL just post-takeoff.

Stop. Your assessment of when they crashed is wrong. They go above 1000 agl. 1000' AGL is just where the flight radar cuts out. The aircraft was in the air for another 4 minutes beyond that data. They did not crash at that impact angle coming out of 1000' AGL. The 737 just isn't that nimble to acquire that angle from that altitude.

OK - fair enough. I did get carried away there and forgot that the flight carried on for many minutes before crashing. Sorry about that.

I do have a question now though. If it is possible that both of these (JT610 and ET302) flights had already begun their requested emergency turn back towards the airport (the Lion Air thread was just as long as this one and it's difficult to recall - but I at least seem to remember that this was suggested), should we be considering that these pilots were fighting a domineering MCAS with either faulty AOA sensors, faulty IAS sensors or both? For sure all they needed to be doing was flying pitch and power (and cutting out the STABTRIM) until they got back to the airport......but in that case what could be happening during their attempted turn back that causes the plane to fly itself into the ground?

It's been widely said lately about how EA's training is on par with some of the best so I would highly doubt that inadequate training is to blame here......I mean if the MAX8 is so different to control that it would require a new type certification then that is just ridiculous.

I still want to know if Boeing simulated flights during testing for the MAX that began with faulty sensors. Wouldn't that be standard procedure? Surely they have to know how their new plane will react when something is wrong?

Trin, I am certain Boeing simulated many, many flights long before certification. And you can bet they have done many more on the so called software update to the MCAS we keep hearing about. And all the cases were probably written up by test engineers while the software developers were programming the fix. It is not one guy coding this up, saying load it, and let's see what happens. It is the aerospace way of development. That's why it has taken months for an update. It just that even with all the test cases, some scenario is not tested. That's got to be what happened here.

Aerospace product development, especially software development, is a very methodical process. That's what had me move from aerospace to the other side. I can just imagine that the software group probably had a fix within a month or so. But that fix was probably iterated so many times with tests. It's just that whatever has happened here was not thought about or tested. But it will be caught in the next update.

MrBretz wrote:

Trin, I am certain Boeing simulated many, many flights long before certification. And you can bet they have done many more on the so called software update to the MCAS we keep hearing about. And all the cases were probably written up by test engineers while the software developers were programming the fix. It is not one guy coding this up, saying load it, and let's see what happens. It is the aerospace way of development. That's why it has taken months for an update. It just that even with all the test cases, some scenario is not tested. That's got to be what happened here.

Aerospace product development, especially software development, is a very methodical process. That's what had me move from aerospace to the other side. I can just imagine that the software group probably had a fix within a month or so. But that fix was probably iterated so many times with tests. It's just that whatever has happened here was not thought about or tested. But it will be caught in the next update.

This is what people don't seem to understand who have never worked in the space or near it. Nothing is 'quick'. The huge amount of documentation and regular you need to create ALONE stops it from being quick. Then you add the testing, retesting, re-retesting, etc... every change and you have to regression test and re-simulate, even if you corrected a misspelled word on some user interface.

JoeCanuck wrote:

Still so much focus on MCAS. While there is always a chance that MCAS may be involved on some way, if the flaps are extended, MCAS is designed to be disabled...which means that the sensors which trigger MCAS, are irrelevant in this case, as would be their potential failure modes.

If the flaps were down and MCAS somehow activated, that would mean that both the flaps extension MCAS lockout AND the default AOA vane must have failed, which is possible, but seems unlikely.

If the FR24 data is correct, the Ethiopian flight never reached flaps retraction altitude or airspeed, so it's unlikely, in my opinion, that MCAS would have been triggered.

So if not MCAS related...then what? Weather? Pilot error? Other mechanical problems? Bad fuel? Sabotage?

Admittedly not a pilot, but I'd expect that close to 400 kts airspeed would (far) exceed flaps retraction airspeed?

osiris30 wrote:

Trin wrote:

osiris30 wrote:

Pitch and power requires no airspeed indicator at all.

Fly pitch & power.

MCAS kicks in. Run auto-trim cut off. Trim manually.

The last one is an added complication, BUT, in light of ALL the talk in the community (including professionally) after Lion Air, that should have been a given.

Sure it 'should' have been a given - but it seems to me that the issues with MCAS are also coming to the surface during low-level flight segments. The lack of reliable airspeed indicators at takeoff has caused several tragedies in the past and is not outwith the realms of causing another one in the future. It overwhelms the pilots with contradicting messages, aural alarms and troubleshooting in instances where they have basically zero altitude already, which is why it is so deadly. Now you consider a scenario like that where there is ALSO a system kicking in doing what it is designed to do, and that's MCAS trimming downwards? NOT good.

Easy to say fly pitch and power and immediately deal with MCAS by flipping the STABTRIM CUTOUT switches.......but I imagine it is less than simple to do when on the verge of a stall at ~1,000AGL just post-takeoff.

Stop. Your assessment of when they crashed is wrong. They go above 1000 agl. 1000' AGL is just where the flight radar cuts out. The aircraft was in the air for another 4 minutes beyond that data. They did not crash at that impact angle coming out of 1000' AGL. The 737 just isn't that nimble to acquire that angle from that altitude.

This would seem to indicate that about 1,300 feet is as high as the plane got?

On Mar 13th 2019 the Canadian TSB reported: "Shortly after the departure from Runway 07R at HAAB, the aircraft was levelled off at approximately 9000 feet MSL. The flight crew transmitted a distress call, and ATC authorized the flight to return to HAAB. Radar contact was lost shortly after at 0844L (0544Z). The aircraft impacted terrain, and the wreckage was found near Ejere, Ethiopia, which is located approximately 28 nm east of HAAB. All persons on board received fatal injuries, including 18 Canadian Nationals; the aircraft was destroyed. Ethiopia’s Accident Investigation Bureau is investigating. In accordance with ICAO Annex 13 5.27, the Transportation Safety Board (TSB) of Canada assigned an expert to the investigation."

osiris30 said "This is what people don't seem to understand who have never worked in the space or near it. Nothing is 'quick'. The huge amount of documentation and regular you need to create ALONE stops it from being quick. Then you add the testing, retesting, re-retesting, etc... every change and you have to regression test and re-simulate, even if you corrected a misspelled word on some user interface."

I bet the MCAS has simulator software that drives it. I can see the developers coming up with ideas right away on how to fix the problems. I say problems because we don't understand all the inputs, their variations, etc. like the developers do. I see them software simulation wise beating the heck out of their fixes with the engineering manager breathing down their backs. But then, you have to tests with "real"(probably flight simulator inputs), and run through a bunch of regression tests to see if the fixes worked or unfixed something else. All this takes times. There are so many subsystems and inputs. And it's not like some field on a webpage doesn't work. This is mission critical, life threatening development. It takes time. Patience folks. It will be fixed.

MrBretz wrote:

osiris30 said "This is what people don't seem to understand who have never worked in the space or near it. Nothing is 'quick'. The huge amount of documentation and regular you need to create ALONE stops it from being quick. Then you add the testing, retesting, re-retesting, etc... every change and you have to regression test and re-simulate, even if you corrected a misspelled word on some user interface."

I bet the MCAS has simulator software that drives it. I can see the developers coming up with ideas right away on how to fix the problems. I say problems because we don't understand all the inputs, their variations, etc. like the developers do. I see them software simulation wise beating the heck out of their fixes with the engineering manager breathing down their backs. But then, you have to tests with "real"(probably flight simulator inputs), and run through a bunch of regression tests to see if the fixes worked or unfixed something else. All this takes times. There are so many subsystems and inputs. And it's not like some field on a webpage doesn't work. This is mission critical, life threatening development. It takes time. Patience folks. It will be fixed.

Absolutely. First solution and then bug squashing/chasing.
I do simple computer games and the amount of crap that can crawl due to a missing/extra comma is crazy.
I'm sure they can fix it but I wouldn't pressure them on that part.

hivue wrote:

scythemk wrote:

hivue wrote:

For sure. The whole reason for Boeing coming up with MCAS was because the airplane could become "uncontrollable at certain corners of the flight envelope."

My understanding is that MCAS was implemented to make the handling resemble that of the 737NG in high thrust situations where the engine mounting caused upward pitch. It was a patch of sorts to make this handling difference transparent to the pilots and I believe was a condition required for it to be certified as essentially the same type rating as 737NG instead of its own type rating.

It's not because the plane became "uncontrollable". There's nothing that MCAS does while in operation that the pilot couldn't do themselves.

My understanding (gleaned months ago from the Lion Air thread so no documentation; anyone with documentation feel free to correct me) is that during the flight test campaign it was discovered that at certain points in the envelope the more forwardly located engines generated unanticipated (during the design and development phases) lift of a sufficiently robust nature to generate a nose-up moment, from where a stall could ensue. A stall is uncontrolled flight. The airplane was deemed not certifiable with this undesirable characteristic so MCAS was put together to mitigate it -- even though the situation likely would never be encountered in normal airline operations.

My thesis was, that due to initial problems with unreliable speed, they did cut off the trim, loosing as a result MCAS, and then while dealing with the unreliable speed they encountered those parts of the flight envelope, where they would have needed MCAS to fly a normal behaving, stable plane. Do you understand? The combination of having lost MCAS and being dependent on it at the same time.

To be clear, this thesis is only one of many possible. And probably not even the most probable one. But the impact would be severe: it would mean, that the trim cut off switches are not eligible to fix a malfunctioning MCAS.

LTC8K6 wrote:

osiris30 wrote:

Trin wrote:

Sure it 'should' have been a given - but it seems to me that the issues with MCAS are also coming to the surface during low-level flight segments. The lack of reliable airspeed indicators at takeoff has caused several tragedies in the past and is not outwith the realms of causing another one in the future. It overwhelms the pilots with contradicting messages, aural alarms and troubleshooting in instances where they have basically zero altitude already, which is why it is so deadly. Now you consider a scenario like that where there is ALSO a system kicking in doing what it is designed to do, and that's MCAS trimming downwards? NOT good.

Easy to say fly pitch and power and immediately deal with MCAS by flipping the STABTRIM CUTOUT switches.......but I imagine it is less than simple to do when on the verge of a stall at ~1,000AGL just post-takeoff.

Stop. Your assessment of when they crashed is wrong. They go above 1000 agl. 1000' AGL is just where the flight radar cuts out. The aircraft was in the air for another 4 minutes beyond that data. They did not crash at that impact angle coming out of 1000' AGL. The 737 just isn't that nimble to acquire that angle from that altitude.

This would seem to indicate that about 1,300 feet is as high as the plane got?

On Mar 13th 2019 the Canadian TSB reported: "Shortly after the departure from Runway 07R at HAAB, the aircraft was levelled off at approximately 9000 feet MSL. The flight crew transmitted a distress call, and ATC authorized the flight to return to HAAB. Radar contact was lost shortly after at 0844L (0544Z). The aircraft impacted terrain, and the wreckage was found near Ejere, Ethiopia, which is located approximately 28 nm east of HAAB. All persons on board received fatal injuries, including 18 Canadian Nationals; the aircraft was destroyed. Ethiopia’s Accident Investigation Bureau is investigating. In accordance with ICAO Annex 13 5.27, the Transportation Safety Board (TSB) of Canada assigned an expert to the investigation."

is that 9000 feet based on the mercury reading (aka 9400 irl).. if they are using the raw ADS-B data they may be 400 feet off. But around 2K feet AGL would seem about right based on the data we have for the first half of the flight.

rheinwaldner wrote:

hivue wrote:

scythemk wrote:

My understanding is that MCAS was implemented to make the handling resemble that of the 737NG in high thrust situations where the engine mounting caused upward pitch. It was a patch of sorts to make this handling difference transparent to the pilots and I believe was a condition required for it to be certified as essentially the same type rating as 737NG instead of its own type rating.

It's not because the plane became "uncontrollable". There's nothing that MCAS does while in operation that the pilot couldn't do themselves.

My understanding (gleaned months ago from the Lion Air thread so no documentation; anyone with documentation feel free to correct me) is that during the flight test campaign it was discovered that at certain points in the envelope the more forwardly located engines generated unanticipated (during the design and development phases) lift of a sufficiently robust nature to generate a nose-up moment, from where a stall could ensue. A stall is uncontrolled flight. The airplane was deemed not certifiable with this undesirable characteristic so MCAS was put together to mitigate it -- even though the situation likely would never be encountered in normal airline operations.

My thesis was, that due to initial problems with unreliable speed, they did cut off the trim, loosing as a result MCAS, and then while dealing with the unreliable speed they encountered those parts of the flight envelope, where they would have needed MCAS to fly a normal behaving, stable plane. Do you understand? The combination of having lost MCAS and being dependent on it at the same time.

To be clear, this thesis is only one of many possible. And probably not even the most probable one. But the impact would be severe: it would mean, that the trim cut off switches are not eligible to fix a malfunctioning MCAS.

Which if that is what they did is NOT what they should have done. Airspeed shouldn't affect MCAS and there should have been no need to cut it in this instance if AoA was working.

Edit: Incidentally this is EXACTLY why paranoia and kneejerk reactions are a bad thing in safety. The last AD was rushed and unclear IMHO and has likely lead to more confusion than that there should be around this one system. Similarly, the grounding will have everyone paranoid when we still have no evidence the two accidents are at all related. What we DO have is a large body of data so far that points to an aircraft in trouble before it ever left the ground, which means it SHOULD HAVE STAYED THERE.

I hate to say it because it's so unpopular, but this looks like pilot error as a root cause, regardless of contributors.

MD80Ttail wrote:

Based on the info we have currently no matter the problem having a 200hr total time FO lowers the chances of any successful outcome.

There is not one single fact supporting any relation to the 200 hr FO, at this point.

osiris30 wrote:

LTC8K6 wrote:

osiris30 wrote:

Stop. Your assessment of when they crashed is wrong. They go above 1000 agl. 1000' AGL is just where the flight radar cuts out. The aircraft was in the air for another 4 minutes beyond that data. They did not crash at that impact angle coming out of 1000' AGL. The 737 just isn't that nimble to acquire that angle from that altitude.

This would seem to indicate that about 1,300 feet is as high as the plane got?

On Mar 13th 2019 the Canadian TSB reported: "Shortly after the departure from Runway 07R at HAAB, the aircraft was levelled off at approximately 9000 feet MSL. The flight crew transmitted a distress call, and ATC authorized the flight to return to HAAB. Radar contact was lost shortly after at 0844L (0544Z). The aircraft impacted terrain, and the wreckage was found near Ejere, Ethiopia, which is located approximately 28 nm east of HAAB. All persons on board received fatal injuries, including 18 Canadian Nationals; the aircraft was destroyed. Ethiopia’s Accident Investigation Bureau is investigating. In accordance with ICAO Annex 13 5.27, the Transportation Safety Board (TSB) of Canada assigned an expert to the investigation."

is that 9000 feet based on the mercury reading (aka 9400 irl).. if they are using the raw ADS-B data they may be 400 feet off. But around 2K feet AGL would seem about right based on the data we have for the first half of the flight.

I was thinking that as of that statement, it should indeed be the Aireon data they are using, which is apparently what prompted the total grounding.

carbon787 wrote:

here is an interesting link, YouTube video, of a very plausible theory of what might have happened.
This is one the best explanations and theory of what could have caused this tragedy, even both 737 MAX8 tragedies, compared to a lot of, in my humble opinion, useless and time wasting posts in both the Lion Air and this discussion thread.

https://www.youtube.com/watch?v=3jGNn2T_gyU

Jesus, dont spread these kind of unconfirmed things.

ec99 wrote:

downdata wrote:

France Has Black Boxes (7:47 a.m.)

The voice and data recorders from the crashed Ethiopian Airlines Boeing 737 Max have arrived in France, a spokesman for the French BEA air-accident investigation office said.

so airbus now has the blackboxes

So I get why they didn't want to send the blackboxes to DC but sending them to France seems like the next worst option. The French Government is reading the boxes. The french government owns 11% of Airbus. Airbus employes tens of thousands of French workers. This would be like Apple leading the investigation into exploding Samsung phones. The french Government stands to benefit financially and politically from a finding that the 737 Max has a inherent problem.

This is just not how one would want an impartial investigation to work.

Well, the US Government (which NTSB is part of) and Boeing also seem to be pretty good friends. Boeing employs tens of thousands of US workers. That line of thinking will bring us nowhere.

I'd expect that as tax income, employment and institutional knowledge far outweigh the 11% stake in terms of financially, political and economical benefit.

PW100 wrote:

ec99 wrote:

downdata wrote:

France Has Black Boxes (7:47 a.m.)

The voice and data recorders from the crashed Ethiopian Airlines Boeing 737 Max have arrived in France, a spokesman for the French BEA air-accident investigation office said.

so airbus now has the blackboxes

So I get why they didn't want to send the blackboxes to DC but sending them to France seems like the next worst option. The French Government is reading the boxes. The french government owns 11% of Airbus. Airbus employes tens of thousands of French workers. This would be like Apple leading the investigation into exploding Samsung phones. The french Government stands to benefit financially and politically from a finding that the 737 Max has a inherent problem.

This is just not how one would want an impartial investigation to work.

Well, the US Government (which NTSB is part of) and Boeing also seem to be pretty good friends. Boeing employs tens of thousands of US workers. That line of thinking will bring us nowhere.

I'd expect that as tax income, employment and institutional knowledge far outweigh the 11% stake in terms of financially, political and economical benefit.

I am assuming you are playing devil's advocate but if you are:. All that applies to Boeing applies to Airbus vis-a-vis France too. Both arguments are silly IMHO

MD80Ttail wrote:

I think this is very significant. We have a worldwide grounding of the Max due to this crash. Irreparable harm has been done to the poor souls on board, Boeing, 737, many airlines and great stress placed on the flying public. All of this comes down to the actions and / or reactions of the pilots. One of which had only 200hrs total time. We have no idea If this accident is even related to MCAS.

So that’s where we are here and in the world . . .

Correct. We have no idea if this accident is related to MCAS. We should not throw MCAS / Boeing under the bus before we have facts. Agree wholeheartedly.

But then again, we also have no idea of this accident is related to the 200 hr FO. But here you have issues whatsoever throwing him under the bus.

So that’s where we are here and in the world . . .

The info coming out of the Lion Air investigation is very interesting. Apparently the suspect info about AoA didn't come from the sensors. Instead, it came somewhere downstream--exactly where it occurred either isn't known or hasn't been disclosed yet.

FWIW, I would not be surprised if the ET investigation showed that the pilots had switched the Stab trim off, but continued to have problems. Perhpas that's what they found at the crash site that led to the final grounding order in the US.

dtw2hyd wrote:

mrbots wrote:

Does it really matter where the FDR and CVR go? How do you bias flight data and voice recordings? There'd be third parties present either way. It's not like the NTSB, EASA, BEA, etc. don't deal with each other and work together regularly. The boxes should have been on their way anywhere capable immediately after they were discovered. Whatever has been holding up getting the boxes to someone for two days needs to be investigated. I don't care if it was Trump, NTSB, Ethiopia, BEA, etc. this shit should not happen after an accident. People died, loved ones are in grieving, and companies are losing money by the second, not the time for pissing matches.

End of the day it is probably some guy from Honeywell actually downloading the data. Rest all is posturing and politics.

Thanks for the laugh! Best post in days on this subject.

Can we now leave this behind us . . .?

osiris30 wrote:

Which if that is what they did is NOT what they should have done. Airspeed shouldn't affect MCAS and there should have been no need to cut it in this instance if AoA was working.

Edit: Incidentally this is EXACTLY why paranoia and kneejerk reactions are a bad thing in safety. The last AD was rushed and unclear IMHO and has likely lead to more confusion than that there should be around this one system. Similarly, the grounding will have everyone paranoid when we still have no evidence the two accidents are at all related. What we DO have is a large body of data so far that points to an aircraft in trouble before it ever left the ground, which means it SHOULD HAVE STAYED THERE.

I hate to say it because it's so unpopular, but this looks like pilot error as a root cause, regardless of contributors.

Afaik airspeed is an input for MCAS. Airspeed is also just an example. In my thesis, cutting off the trim could be triggered by justified MCAS, malfunctioning MCAS or even by perceived MCAS like behaving. The reason does not matter. The question is, whether the aircraft in troubled situations without MCAS would behave always fine.

I mean, Boeings advice, "use just the stab runaway nnc and cut off the trim at the slightest suspicion" (see emergency AD) assumes that in most cases such a condition does not occur in combination with flying a high AoAs (which would be the flight state, in which MCAS would be exactly needed). What if this assumption was too optimistic?

PixelPilot wrote:

MrBretz wrote:

osiris30 said "This is what people don't seem to understand who have never worked in the space or near it. Nothing is 'quick'. The huge amount of documentation and regular you need to create ALONE stops it from being quick. Then you add the testing, retesting, re-retesting, etc... every change and you have to regression test and re-simulate, even if you corrected a misspelled word on some user interface."

I bet the MCAS has simulator software that drives it. I can see the developers coming up with ideas right away on how to fix the problems. I say problems because we don't understand all the inputs, their variations, etc. like the developers do. I see them software simulation wise beating the heck out of their fixes with the engineering manager breathing down their backs. But then, you have to tests with "real"(probably flight simulator inputs), and run through a bunch of regression tests to see if the fixes worked or unfixed something else. All this takes times. There are so many subsystems and inputs. And it's not like some field on a webpage doesn't work. This is mission critical, life threatening development. It takes time. Patience folks. It will be fixed.

Absolutely. First solution and then bug squashing/chasing.
I do simple computer games and the amount of crap that can crawl due to a missing/extra comma is crazy.
I'm sure they can fix it but I wouldn't pressure them on that part.

programming free form.

with a god conception phase most of that shit should not happen.
interactions should have been researched long before any line of code was written.
but this MCAS stuff and the "synthetic" generation of air sensor data looks like the stuff microsoft would release on the world.
super bright ideas that never deviated from objectives. Never looking left or right what could go wrong.
dumb programmers program to a simple target. The brighter ones work on what can go wrong the target is reached after you have handled all possible errors.
Additionally never start from new. Always layer the next layer of shit on that old shit you have inherited making it blend in.

WIederling wrote:

Elementalism wrote:

This is the equivalent of hiring a college grad to perform a senior level position. Nobody in their right mind would do such a thing due to the lack of experience.

the requirements shift from 250 to 1500 hours came about in 2013.
Under the pretext of increasing safety ( ref Colgan, both pilots had hours to no end.)
with a designed in intention of advantaging military pilots transfering into civil life:
https://www.faa.gov/news/press_releases ... wsId=14838
( its in the catalog presented in the link )

Could you please show the resultant significant increase in commercial flying safety?

Only thing visible is pilot shortage and thus airlines having to scrape the bottom coming up with
pilots that have the hours but are apparently sub par in effectively gained competence.

Not only that; the majority of the current 5000+ hrs pilots in the USA built their experience (going from 250 and 1500 hrs), in the right hand seat of a commercial jet. Was that so unsafe?

This is an armchair question by a non-pilot, so I acknowledge going in that it may prove to be 'dumb'. Nevertheless:

ET302 was moving fast--fast enough to suggest they had plenty of juice to climb. It seems fair to rule out engine failure or something like an explosion that might have greatly increased drag.

Meanwhile, early evidence (the commentary from the pilot watching ET302 leave, plus the available flight data) suggests that ET302's pilots had, and knew they had a problem right after takeoff, while flaps were probably still extended. As discussed, MCAS isn't supposed to come into play until flaps are retracted and in any case it's intended to counter issues that arise during turns and at slower speeds than what ET302 was doing. Regardless, a pilot that's aware of MCAS--as Ethiopian has said its pilots were--should theoretically be able to disable it and fly manually if they suspect an issue.

Next there's the hypothetical matter of faulty AoA sensors--e.g., the sensors indicate a stall and the pilots don't want to put the nose up to climb lest they exacerbate the situation. This might make sense at night or during poor visibility, but this happened in the morning with good visibility. Surely, at ~1000' AGL and 300+ kn, the pilots would be able to determine that they were not entering a stall and that the sensor was wonky. Again, you'd think this might lead to a decision to fly manually--and conditions seemed conducive to doing so, if it came to that.

Anyway, finally to the question. If a crew encounters control problems soon after takeoff, is it accepted practice to stay at lower altitude, or would it be more normal to climb (if possible) to a higher altitude that allows for more margin for error while determining the nature and extent of the problem? Basically I'm wondering to what extent we can infer from the flight staying at ~1000' AGL that they COULDN'T climb, vs. that they CHOSE not to climb because things were weird and they were planning to immediately return to the airport.

(In my own uneducated, totally speculative view, their speed suggests they were probably trying to climb yet couldn't. That, in turn, suggests two possibilities: that they didn't disengage the automatic systems, whether through choice or ignorance, and were indeed fighting the plane a la JT610; or that the control problem was unrelated to MCAS or other automatic systems regardless of whether they disengaged them. Loss of hydraulic power, stripped jackscrews, or other 'maintenance' issues have caused control loss in past incidents, except this was a new aircraft and ET has a decent reputation. Meanwhile, terrorism or explosions also seem unlikely both because of the speed/drag issue noted above, and especially because I don't think we'd have a worldwide grounding if there was evidence for extrinsic causation. So, to me, and again purely speculatively, some version of the 'pilots fighting the plane' scenario seems most supported by logic and current evidence. If so, it obviously remains to be determined whether this entailed some kind of pilot error, or a new wrinkle that the pilots couldn't have foreseen.)

Thanks!

PW100 wrote:

Correct. We have no idea if this accident is related to MCAS. We should not throw MCAS / Boeing under the bus before we have facts. Agree wholeheartedly.

But then again, we also have no idea of this accident is related to the 200 hr FO. But here you have issues whatsoever throwing him under the bus.

So that’s where we are here and in the world . . .

This is just a sign of the times, everyone wants the information yesterday.

I cannot blame the regulators from taking a conservative path until more is known. Grounding does not mean they have a related cause, it just means it is unknown. Unknown does not mean unsafe. What is common between the two is the aircraft were relatively new.

When it comes to public transport safety should always come before commercial priorities.

It is very common for joe public to take the latests buzz word and become an instant accident investigator. You are not going to be able to temper the number of uniformed posts and topics on this subject.

We have seen this behaviour on this time and again on this site when an accident occurs. Every time an accident occurs on an Airbus normally always FBW, sidesticks, non moving thrust levers etc all are blamed.

We need to remember the 737 series is one of the safest aircraft flying, a family of aircraft that has been flying millions of people safely for over 50 years.

This will be resolved soon, and the aircraft will return to service. In the meantime a little patience is required when they work out the root cause and clear the aircraft to fly again.

Etheereal wrote:

carbon787 wrote:

here is an interesting link, YouTube video, of a very plausible theory of what might have happened.
This is one the best explanations and theory of what could have caused this tragedy, even both 737 MAX8 tragedies, compared to a lot of, in my humble opinion, useless and time wasting posts in both the Lion Air and this discussion thread.

https://www.youtube.com/watch?v=3jGNn2T_gyU

Jesus, dont spread these kind of unconfirmed things.

Like all the other dozen unconfirmed conclusions people have already made?

osiris30 wrote:

PW100 wrote:

ec99 wrote:

So I get why they didn't want to send the blackboxes to DC but sending them to France seems like the next worst option. The French Government is reading the boxes. The french government owns 11% of Airbus. Airbus employes tens of thousands of French workers. This would be like Apple leading the investigation into exploding Samsung phones. The french Government stands to benefit financially and politically from a finding that the 737 Max has a inherent problem.

This is just not how one would want an impartial investigation to work.

Well, the US Government (which NTSB is part of) and Boeing also seem to be pretty good friends. Boeing employs tens of thousands of US workers. That line of thinking will bring us nowhere.

I'd expect that as tax income, employment and institutional knowledge far outweigh the 11% stake in terms of financially, political and economical benefit.

I am assuming you are playing devil's advocate but if you are:. All that applies to Boeing applies to Airbus vis-a-vis France too. Both arguments are silly IMHO

Correct.

They recovered the black boxes yesterday right? Or two days ago Ethiopian time. Where is the hard data? What's the hold up? I can't keep up with all the airliners theories.

maui19 wrote:

The info coming out of the Lion Air investigation is very interesting. Apparently the suspect info about AoA didn't come from the sensors. Instead, it came somewhere downstream--exactly where it occurred either isn't known or hasn't been disclosed yet.

FWIW, I would not be surprised if the ET investigation showed that the pilots had switched the Stab trim off, but continued to have problems. Perhpas that's what they found at the crash site that led to the final grounding order in the US.

Any sources for the Lion Air info?

The Asiana 214 crew had over 25,000 hours of flight time among the three of them but that didn't prevent them from pancaking a 777 onto the threshold at SFO.....

Read this in one of the forums when JT 610 crashed and now ET302 crashes in extraordinarily similar circumstances.

"Death by Computer

189 people recently died in a tragic crash. The crew and passengers of JT610 never had a chance.

The Boeing 737 MAX 8 plane had a new software in it. They called it MCAS or Maneuvering Characteristics Augmentations System. MCAS was a system that didn't exist in any of the Boeing 737's before. However, when they built the 737 MAX version, in layman's term, they built the plane with a larger and more efficient engine.

However, this larger engine, which delivered a further 14% fuel efficiency had to be fitted further forward under the low wings of the 737. This potentially may cause the plane to stall. Stalling is bad. It is basically when a plane stops flying and starts falling.

In order to avoid this, Boeing installed the new MCAS software. This software is designed to tell the plane to move its nose down to increase its speed and avoid it from stalling.

So here comes the problem.

In the computer world, we have this term called GIGO. The old school fella's will know this. Yes. Garbage In, Garbage Out.

The problem based on the findings so far is this.

On the plane there is a sensor called the Alpha Vane which measures the Angle of Attack (AOA) of the plane. It looks like a small little wing, and they have two of it, one on the pilot side, and the other on the co-pilot's.

The sensor's job is to tell the computer the angle the plane is flying at. And if the AOA of the plane is too high, this will result in the plane stalling. Typically the AOA is below 15 to 20 degrees, and the new MCAS software will push the plane's nose down if it thinks that the AOA is too high.

Now.

With this flight the Alpha Vane sensor measuring the AOA on the Captain's side was reported to be faulty. So they changed it. That fault was reported from the equally harrowing flight from Bali to Jakarta.

On the fateful final flight, the plane which arrived from Bali the night before, had the sensor changed, and then it took off in the morning.

No one knew what was really wrong with the plane, or about the new MCAS software. No one. Not the maintenance folks, and in fact not even the pilot.

And once in the air, the faulty sensor told the computer that the plane is stalling. The computer then, without the pilot ever knowing pushed the nose of the plane down further, while the pilot was trying to raise the plane.

In this battle between the pilot and the computer, the computer won. And the pilot, the crew, and the passengers lost and they died. The plane was too low, and the pilot didn't have enough air to raise the plane and fly it.

The computer literally flew the plane into the ocean.

A few weeks later, Boeing issued an update on the plane, and informed that should the plane have an issue with it's AOA sensors, one of the way to stop the computer was to switch it off!

Apparently 189 lives could have been saved, had the pilot knew about the software, and flipped a switch to turn it off.

A switch!

A single simple switch was the difference between life and death.

I am still fuming thinking about this. A switch!"

Unsure how much of this dramatized post is technically correct. Its bone chilling to hear the CVR transcript of the Lion Air Indian pilot, who requested an air corridor lock up over the ocean to troubleshoot the problem (reminds one of Alaska Air tragedy) but lost to an unknown enemy. Ironic that humans start blaming humans, when their own complex engineering is the culprit.

One wonders that it's not a bad idea to revert back to basics and manually fly aircrafts during take offs and landings the most riskiest part of flying.

drajoshi wrote:

Ironic that humans start blaming humans, when their own complex engineering is the culprit.

Going by what is visible Boeing engineers did not write complex software they wrote simplistic software.
Cargo Cult.
Copy the superficially visible of another complex product and expect the copy to perform to the full specs of the complex product.
We saw the same when Boeing tried to copy the manufacturing model from Airbus.

drajoshi wrote:

One wonders that it's not a bad idea to revert back to basics and manually fly aircrafts during take offs and landings the most riskiest part of flying.

These MCAS events can only happen during manual flying.

And yes, lot of dramatizing and mistakes in that article.

danj555 wrote:

They recovered the black boxes yesterday right? Or two days ago Ethiopian time. Where is the hard data? What's the hold up? I can't keep up with all the airliners theories.

The boxes had to be taken somewhere to be read. The USA wanted them, but Ethiopian officials wanted Germany to read them. German officials said they did not have the correct equipment, and declined. So they asked BEA. BEA said yes, and the boxes and the ETH officials arrived at BEA today, I believe.

I do think that the lack of manual flying experience is not a good thing, and could be causing problems these days.

It is encouraging to read that US officials believe the black boxes can be read out.
Pictures show heavy damage of course, after a high energy impact.
I am sure that the BEA will do their utmost to properly and rapidly extract the data.
They have the tools and experience to carefully remove and analyze the individual chips if necessary.
Manufacturer assistance will probably be required.

NYT: The captain of a doomed Ethiopian Airlines jetliner faced an emergency almost immediately after takeoff from Addis Ababa, requesting permission in a panicky voice to return after three minutes as the aircraft accelerated to abnormal speed, a person who reviewed air traffic communications said Thursday.

“Break break, request back to home,” the captain told air traffic controllers as they scrambled to divert two other flights approaching the airport. “Request vector for landing.”

Controllers also observed that the aircraft, a new Boeing 737 Max 8, was oscillating up and down by hundreds of feet — a sign that something was extraordinarily wrong.

https://www.nytimes.com/2019/03/14/busi ... lines.html

He didn't say why he wanted to return?

drajoshi wrote:

Read this in one of the forums when JT 610 crashed and now ET302 crashes in extraordinarily similar circumstances.

"Death by Computer

189 people recently died in a tragic crash. The crew and passengers of JT610 never had a chance.

The Boeing 737 MAX 8 plane had a new software in it. They called it MCAS or Maneuvering Characteristics Augmentations System. MCAS was a system that didn't exist in any of the Boeing 737's before. However, when they built the 737 MAX version, in layman's term, they built the plane with a larger and more efficient engine.

However, this larger engine, which delivered a further 14% fuel efficiency had to be fitted further forward under the low wings of the 737. This potentially may cause the plane to stall. Stalling is bad. It is basically when a plane stops flying and starts falling.

In order to avoid this, Boeing installed the new MCAS software. This software is designed to tell the plane to move its nose down to increase its speed and avoid it from stalling.

So here comes the problem.

In the computer world, we have this term called GIGO. The old school fella's will know this. Yes. Garbage In, Garbage Out.

The problem based on the findings so far is this.

On the plane there is a sensor called the Alpha Vane which measures the Angle of Attack (AOA) of the plane. It looks like a small little wing, and they have two of it, one on the pilot side, and the other on the co-pilot's.

The sensor's job is to tell the computer the angle the plane is flying at. And if the AOA of the plane is too high, this will result in the plane stalling. Typically the AOA is below 15 to 20 degrees, and the new MCAS software will push the plane's nose down if it thinks that the AOA is too high.

Now.

With this flight the Alpha Vane sensor measuring the AOA on the Captain's side was reported to be faulty. So they changed it. That fault was reported from the equally harrowing flight from Bali to Jakarta.

On the fateful final flight, the plane which arrived from Bali the night before, had the sensor changed, and then it took off in the morning.

No one knew what was really wrong with the plane, or about the new MCAS software. No one. Not the maintenance folks, and in fact not even the pilot.

And once in the air, the faulty sensor told the computer that the plane is stalling. The computer then, without the pilot ever knowing pushed the nose of the plane down further, while the pilot was trying to raise the plane.

In this battle between the pilot and the computer, the computer won. And the pilot, the crew, and the passengers lost and they died. The plane was too low, and the pilot didn't have enough air to raise the plane and fly it.

The computer literally flew the plane into the ocean.

A few weeks later, Boeing issued an update on the plane, and informed that should the plane have an issue with it's AOA sensors, one of the way to stop the computer was to switch it off!

Apparently 189 lives could have been saved, had the pilot knew about the software, and flipped a switch to turn it off.

A switch!

A single simple switch was the difference between life and death.

I am still fuming thinking about this. A switch!"

Unsure how much of this dramatized post is technically correct. Its bone chilling to hear the CVR transcript of the Lion Air Indian pilot, who requested an air corridor lock up over the ocean to troubleshoot the problem (reminds one of Alaska Air tragedy) but lost to an unknown enemy. Ironic that humans start blaming humans, when their own complex engineering is the culprit.

One wonders that it's not a bad idea to revert back to basics and manually fly aircrafts during take offs and landings the most riskiest part of flying.

.

Thanks for explaining the AoA and MCAS. Very dangerous when you think about it. However from the Lion Air Crash to the Ethiopian would not have the ET pilots known about the switch?

Edit. just read MCAS is during manual flight. Will just wait for the Investigation to complete.

enilria wrote:

NYT: The captain of a doomed Ethiopian Airlines jetliner faced an emergency almost immediately after takeoff from Addis Ababa, requesting permission in a panicky voice to return after three minutes as the aircraft accelerated to abnormal speed, a person who reviewed air traffic communications said Thursday.

“Break break, request back to home,” the captain told air traffic controllers as they scrambled to divert two other flights approaching the airport. “Request vector for landing.”

Controllers also observed that the aircraft, a new Boeing 737 Max 8, was oscillating up and down by hundreds of feet — a sign that something was extraordinarily wrong.

https://www.nytimes.com/2019/03/14/busi ... lines.html

I just read this article also. The anonymous officials indicate the pilots were concerned the plane was traveling much faster than it should have been, and others mention that the plane's speed exceeded its safety limits. In addition, the plane was rising and falling in an erratic manner. The plane's speed ties into many comments posted online here re: the plane's excessive speed.

What sort of malfunction would cause the plane to accelerate to such an extent and why couldn't the pilots rectify that situation?

WIederling wrote:

drajoshi wrote:

Ironic that humans start blaming humans, when their own complex engineering is the culprit.

Going by what is visible Boeing engineers did not write complex software they wrote simplistic software.
Cargo Cult.
Copy the superficially visible of another complex product and expect the copy to perform to the full specs of the complex product.
We saw the same when Boeing tried to copy the manufacturing model from Airbus.

Have you seen the code and do you have any basis on that apart from a Boeing bash? Just curious? Any facts to go with that load of drivel you just wrote?

drajoshi wrote:

Its bone chilling to hear the CVR transcript of the Lion Air Indian pilot

No Lion Air CVR transcript (or audio) has been publicly released yet.

Flightsimboy wrote:

would not have the ET pilots known about the switch?

Any 737 pilot who doesn't know about employing the runaway stab trim procedure to cure an MCAS issue has been living on Mars for the last 4 months.

osiris30, clearly he doesn't have the foggiest. Maybe he is a high level manager? Did you see the comment a long time ago about someone stating "we have had machine learning since the 80s"? So he could not figure out how this could possibly happen. Possibly another high level manager type? It's best to ignore comments like this but hard to do when it shows a complete lack of understanding or, as they say, a fan of other than Boeing or a troll. Drivel is too polite a word.