mjoelnir wrote:

Boeing did practical nothing. They did not explain how MCAS functioned. They did not give out how you recognize and train for MCAS failure mode. They did not fix the simulators so they would show how MCAS works and how it behaves with an AoA failure.
Boeing just pointed to the runaway trim procedure.
Boeing even kept quite over the non existence of the light declaring AoA disagree, pointing exactly at the situation that could produce a MCAS going amok situation. Even if this light should have been a standard feature and being described in the manual.

7BOEING7 wrote:

With the IAS DISAGREE alert staring the captain in the face (probably more visible to him than the AOA DISAGREE would have been), if the ET crew had been more familiar with the bulletin and managed the thrust properly, that could have saved the flight.

afgeneral wrote:

planecane wrote:

PixelFlight wrote:

From that post about the STS and control column in the opposite direction:
https://www.pprune.org/tech-log/614997-b-737-speed-trim-system.html#post10300036

The difference between the STS and the MCAS is how there respective code can go wrong. There are some grey area about the STS as it can potentially send dangerous stab trim command too if it goes very erratic. Satcom Guru explained that STS (and MCAS) run on a single CPU on an single side FCC in manual flight mode. Could be an another certification issue for the 737 NG and 737 MAX now that the design is reviewed in detail...

I think that STS has proven itself not to be a problem. With 7000 NGs flying around for what has to be over 50 million flights, the fact that there hasn't been an STS related crash would seem to prove that it is not a safety issue.

Do we really know that? Are there some previously unexplained crashes which may now be explained by STS? Did they review any past incidents to make sure?

Aesma wrote:

Remember the roller coaster procedure ? Clearly at some point Boeing thought it useful to explain to pilots how to manually trim if high aerodynamic forces are at play. I wonder if that will go back in the manuals.

planecane wrote:

Aesma wrote:

Remember the roller coaster procedure ? Clearly at some point Boeing thought it useful to explain to pilots how to manually trim if high aerodynamic forces are at play. I wonder if that will go back in the manuals.

According to a Mentour Pilot video, it is still documented in some way in the FCOM.

planecane wrote:

Aesma wrote:

Remember the roller coaster procedure ? Clearly at some point Boeing thought it useful to explain to pilots how to manually trim if high aerodynamic forces are at play. I wonder if that will go back in the manuals.

According to a Mentour Pilot video, it is still documented in some way in the FCOM.

Interested wrote:

https://www.bbc.co.uk/news/amp/business-48461110

The author of the Boeing 737 technical guide is saying he is confident the Ethiopia plane wouldn't have crashed had the disagree light been working.

He says it would have given an earlier indication to the pilots of what they were dealing with and what they needed to do

Interestingly Boeing CEO seems to be acknowledging this in the same article. I know it's not good for boeing to admit mistakes but PERHAPS a big part of getting the planes ungrounded relies on the indicator light making a difference to pilots understanding of the situation and what to do next

So it's better for Boeing to say this would help pilots save a plane than deny it. As they can make sure it's there in the future and help get the planes ungrounded?

Accept more blame now to allow the planes to fly again and get ungrounded?

Obviously the initial response when the disagree light issue came up was to claim it would have made no difference. Seems that approach is changing now everybody is getting an understanding of what happened and what's needed to get the plane flying again?

Makes me feel a bit cynical but I think that's what may be happening here. Accept some mistakes, take a hit on Ethiopia but get the planes back in the air sooner by saying the disagree light would have made a difference.

PixelFlight wrote:

morrisond wrote:

They didn't follow any other procedure 100% - why does he assume they would have done so in this case?

"morrisond", for me, you just passed the red line of unacceptable wording about the pilots that was killed.

smartplane wrote:

In the MAX, is the AoA warning light installed in all aircraft delivered, but only enabled if the customer specifically purchases the feature package? In other words, are there cockpits with the warning light installed, but not operative? Is the disagree light fitted to Lion and Ethiopian MAX's?

smartplane wrote:

Boeing CEO is taking the course of least resistance. Enable a feature which is already cabled and ready, to shorten the grounding.

smartplane wrote:

Some posters clearly need an update from their employer or client, because they earlier claimed enabling the warning light would have made zero difference to the diagnosis or outcome. Standby for a flurry of activity, as earlier posts are edited or deleted.

7BOEING7 wrote:

planecane wrote:

Aesma wrote:

Remember the roller coaster procedure ? Clearly at some point Boeing thought it useful to explain to pilots how to manually trim if high aerodynamic forces are at play. I wonder if that will go back in the manuals.

According to a Mentour Pilot video, it is still documented in some way in the FCOM.

I can't find it in the FCOM I have but it's a few years old -- maybe it was reinserted within the last few years but I doubt it..

7BOEING7 wrote:

The Lion Air captain was in control of the airplane for the most part and neglected to turn off a system that was misbehaving -- if every time you engaged the autopilot it dove for the ground would you continue to engage it?

mjoelnir wrote:

The big question for me is, if a serious safety revue is done, will that impact the NG too?

7BOEING7 wrote:

First it's not a warning light. The AOA DISAGREE alert is an amber alert message that pops up on the PFD (Primary Flight Display) just like the IAS DISAGREE and the ALTITUDE DISAGREE alerts.

In the 737NG it was standard. My understanding is that in the MAX only customers (very few) that bought the AOA Indicator were supposed to get it but there was a mistake by the vendor and nobody got it. After the grounding is lifted everybody will get it whether you purchase the AOA indicator or not.

SEU wrote:

PixelFlight wrote:

morrisond wrote:

They didn't follow any other procedure 100% - why does he assume they would have done so in this case?

"morrisond", for me, you just passed the red line of unacceptable wording about the pilots that was killed.

You have only just realised this guy is deluded about the pilots?

Morrisond - take a break - the world doesnt believe the pilots caused the crash, hence they grounded the plane and didnt put it down to pilot error.

7BOEING7 wrote:

In the 737NG it was standard. My understanding is that in the MAX only customers (very few) that bought the AOA Indicator were supposed to get it but there was a mistake by the vendor and nobody got it. After the grounding is lifted everybody will get it whether you purchase the AOA indicator or not.

Norah O'Donnell: Both of those planes took a nose dive because of that erroneous flight sensor information, and if one of the sensors is off, it's my understanding that there could be a warning light. But that light was supposed to be active on all 737 Max jets, and it was not, and you knew this in 2017 and you did not tell the FAA for 13 months. Why?

Dennis Muilenburg: The implementation of that software, we did not do it correctly. Our engineers discovered that.

Norah O'Donnell: So you're fixing that now?

Dennis Muilenburg: We are fixing it now and our communication on that was not what it should have been.

Norah O'Donnell: Does Boeing have a credibility and transparency problem if they don't admit what were the mistakes in the past?

Dennis Muilenburg: We clearly fell short and the implementation of the angle of attack disagree alert was a mistake.

AABusDrvr wrote:

If the lack AOA disagree message was all that stopped the crew from preforming the proper procedures, just another reason for ET to take a hard look at their training. And I'm not talking about 737 specific training, they need to go back to the beginning of their primary flight training syllabus.

GalaxyFlyer wrote:

What in the world does EA 401 have to do with these two accidents? It was gear light there.

GalaxyFlyer wrote:

And, to repeat for the tenth time, there is NO “roller coaster” maneuver. The pilot merely relieves the load on the stab trim jackscrew by releasing enough yoke back pressure. It should be a smooth nose down maneuver, just enough to allow the trim motor to work. Where does these ideas come from?

Manual rotation of the trim wheels can be used to override autopilot or main electric trim. The effort required to manually rotate the stabilizer trim wheels may be higher under certain flight conditions. Grasping the stabilizer trim wheel will stop stabilizer motion.

GalaxyFlyer wrote:

What in the world does EA 401 have to do with these two accidents? It was gear light there.

And, to repeat for the tenth time, there is NO “roller coaster” maneuver. The pilot merely relieves the load on the stab trim jackscrew by releasing enough yoke back pressure. It should be a smooth nose down maneuver, just enough to allow the trim motor to work. Where does these ideas come from?

GF

zippy wrote:

GalaxyFlyer wrote:

What in the world does EA 401 have to do with these two accidents? It was gear light there.

EA 401 was an example of humans being so fixated on one thing that they fail to address the other issues at hand.

GalaxyFlyer wrote:

And, to repeat for the tenth time, there is NO “roller coaster” maneuver. The pilot merely relieves the load on the stab trim jackscrew by releasing enough yoke back pressure. It should be a smooth nose down maneuver, just enough to allow the trim motor to work. Where does these ideas come from?

With what spare altitude? The last sim tests that tried this maneuver showed pilots losing about 8,000 ft. Great if you're at cruising altitude, not so doable right after takeoff.

DenverTed wrote:

GalaxyFlyer wrote:

What in the world does EA 401 have to do with these two accidents? It was gear light there.

And, to repeat for the tenth time, there is NO “roller coaster” maneuver. The pilot merely relieves the load on the stab trim jackscrew by releasing enough yoke back pressure. It should be a smooth nose down maneuver, just enough to allow the trim motor to work. Where does these ideas come from?

GF

I read about this idea on Peter Lemme's site, satguru.com. I believe the 'rollercoaster' is for the trim Flinstone power method.

GalaxyFlyer wrote:

zippy wrote:

GalaxyFlyer wrote:

What in the world does EA 401 have to do with these two accidents? It was gear light there.

EA 401 was an example of humans being so fixated on one thing that they fail to address the other issues at hand.

GalaxyFlyer wrote:

And, to repeat for the tenth time, there is NO “roller coaster” maneuver. The pilot merely relieves the load on the stab trim jackscrew by releasing enough yoke back pressure. It should be a smooth nose down maneuver, just enough to allow the trim motor to work. Where does these ideas come from?

With what spare altitude? The last sim tests that tried this maneuver showed pilots losing about 8,000 ft. Great if you're at cruising altitude, not so doable right after takeoff.

Did I say anything about altitude?

GF

GalaxyFlyer wrote:

Not interesting at all, merely proper flying technique and understanding what’s going on. Controlling airspeed in vital to dealing with runaway stab. No need for checklist, it’s an immediate action item.

smartplane wrote:

Interested wrote:

https://www.bbc.co.uk/news/amp/business-48461110

The author of the Boeing 737 technical guide is saying he is confident the Ethiopia plane wouldn't have crashed had the disagree light been working.

He says it would have given an earlier indication to the pilots of what they were dealing with and what they needed to do

Interestingly Boeing CEO seems to be acknowledging this in the same article. I know it's not good for boeing to admit mistakes but PERHAPS a big part of getting the planes ungrounded relies on the indicator light making a difference to pilots understanding of the situation and what to do next

So it's better for Boeing to say this would help pilots save a plane than deny it. As they can make sure it's there in the future and help get the planes ungrounded?

Accept more blame now to allow the planes to fly again and get ungrounded?

Obviously the initial response when the disagree light issue came up was to claim it would have made no difference. Seems that approach is changing now everybody is getting an understanding of what happened and what's needed to get the plane flying again?

Makes me feel a bit cynical but I think that's what may be happening here. Accept some mistakes, take a hit on Ethiopia but get the planes back in the air sooner by saying the disagree light would have made a difference.

Some posters clearly need an update from their employer or client, because they earlier claimed enabling the warning light would have made zero difference to the diagnosis or outcome. Standby for a flurry of activity, as earlier posts are edited or deleted.

zippy wrote:

7BOEING7 wrote:

In the 737NG it was standard. My understanding is that in the MAX only customers (very few) that bought the AOA Indicator were supposed to get it but there was a mistake by the vendor and nobody got it. After the grounding is lifted everybody will get it whether you purchase the AOA indicator or not.

The "AOA DISAGREE" annunciator was intended to be standard on all 737 MAX planes. certified it with the FAA as such, documented it as such, sold the MAX to airlines as such. Unfortunately Boeing did exactly zero QA and the annunciator only works/worked on MAX planes with the AOA gauge option. This defect was discovered in 2017 and decided against disclosing it to the airlines or FAA.

The problems with the 737 MAX go well beyond whether MCAS actuation in error can be managed by pilots.


https://www.cbsnews.com/news/boeing-ceo ... d=68292842

Norah O'Donnell: Both of those planes took a nose dive because of that erroneous flight sensor information, and if one of the sensors is off, it's my understanding that there could be a warning light. But that light was supposed to be active on all 737 Max jets, and it was not, and you knew this in 2017 and you did not tell the FAA for 13 months. Why?

Dennis Muilenburg: The implementation of that software, we did not do it correctly. Our engineers discovered that.

Norah O'Donnell: So you're fixing that now?

Dennis Muilenburg: We are fixing it now and our communication on that was not what it should have been.

Norah O'Donnell: Does Boeing have a credibility and transparency problem if they don't admit what were the mistakes in the past?

Dennis Muilenburg: We clearly fell short and the implementation of the angle of attack disagree alert was a mistake.

xmp125a wrote:

mjoelnir wrote:

Boeing did practical nothing. They did not explain how MCAS functioned. They did not give out how you recognize and train for MCAS failure mode. They did not fix the simulators so they would show how MCAS works and how it behaves with an AoA failure.
Boeing just pointed to the runaway trim procedure.
Boeing even kept quite over the non existence of the light declaring AoA disagree, pointing exactly at the situation that could produce a MCAS going amok situation. Even if this light should have been a standard feature and being described in the manual.

Apologies if this was posted here before.

https://www.bloomberg.com/news/articles ... of-dangers

It documents the complaints of one of the senior 737 pilots at Ethiopian about the insufficient pilot training regarding MCAS, which is apparently well documented (all before ET crash). The article implies that ET is to blame, but the journalist probably does not have a clue that these facts are damning for Boeing... The pilot demanded 737MAX specific training, which of course, Ethiopian was unable to provide, as despite having one of the few MAX simulators in the world it actually DID NOT include MAX specific failure modes nor did Boeing provide enough info to provide MCAS related training, SPECIFICALLY how to recognize MCAS failure!

SEU wrote:

PixelFlight wrote:

morrisond wrote:

They didn't follow any other procedure 100% - why does he assume they would have done so in this case?

"morrisond", for me, you just passed the red line of unacceptable wording about the pilots that was killed.

You have only just realised this guy is deluded about the pilots?

Morrisond - take a break - the world doesnt believe the pilots caused the crash, hence they grounded the plane and didnt put it down to pilot error.

Interested wrote:

xmp125a wrote:

mjoelnir wrote:

Boeing did practical nothing. They did not explain how MCAS functioned. They did not give out how you recognize and train for MCAS failure mode. They did not fix the simulators so they would show how MCAS works and how it behaves with an AoA failure.
Boeing just pointed to the runaway trim procedure.
Boeing even kept quite over the non existence of the light declaring AoA disagree, pointing exactly at the situation that could produce a MCAS going amok situation. Even if this light should have been a standard feature and being described in the manual.

Apologies if this was posted here before.

https://www.bloomberg.com/news/articles ... of-dangers

It documents the complaints of one of the senior 737 pilots at Ethiopian about the insufficient pilot training regarding MCAS, which is apparently well documented (all before ET crash). The article implies that ET is to blame, but the journalist probably does not have a clue that these facts are damning for Boeing... The pilot demanded 737MAX specific training, which of course, Ethiopian was unable to provide, as despite having one of the few MAX simulators in the world it actually DID NOT include MAX specific failure modes nor did Boeing provide enough info to provide MCAS related training, SPECIFICALLY how to recognize MCAS failure!

New CNN report today suggests Boeing is NOT recommending simulator training and are proposing any training delivered before the planes are ungrounded will be iPad training

https://www.cnn.com/2019/05/30/politics ... index.html

Ugly51 wrote:

It's Boeing attempting to save money. If 737 Max simulator training is required, this is a Red Flag concerning Southwest Airlines.
Boeing will have to pay/train all Southwest Pilot's at no cost to the airline. All Southwest Pilot's should be able to fly any 737 model without any simulator training. Two words... Absolutely frightening.

ArgentoSystems wrote:

smartplane wrote:

In the MAX, is the AoA warning light installed in all aircraft delivered, but only enabled if the customer specifically purchases the feature package? In other words, are there cockpits with the warning light installed, but not operative? Is the disagree light fitted to Lion and Ethiopian MAX's?

there is no light. it is an icon on PFD.

morrisond wrote:

Interested wrote:

morrisond wrote:

I'm not going to disagree with you on the Pilot's part in either crash .

So if you agree with the above isn't that substantial enough to stop worrying about the pilots actions and to focus on what Boeing need to do to stop pilots anywhere in the world facing a similar situation in the future

I think we all accept that huge mistakes in design and implementation and communication have been made by Boeing. The CEO has just apologised for what's happened again and acknowledged they need to regain trust etc. He's said it's going to be a gradual process.

Ive seen the head of the US pilots union saying it's inexcusable to blame the pilots for these crashes and saying shame on Boeing for do so. He's not head of the Ethiopian pilots union.

Ive just seen the guy who wrote the technical guide for Boeing 737s saying the flight would have been saved had the disagree light worked whilst the CEO of Boeing on same day accepts that was a mistake etc

Isn't that enough to just move on now and stop clutching at any kind of real blame for the pilots and just accept Boeing messed up and now lets get this sorted for future pilots and passengers

I said it weeks ago - I never want to be on a plane that ever needs these manual trim procedures using. They scare the life out of me. I can't believe they even exist in this day and age. So let's just get back to having planes that are designed so these trims are never needed. And when they are you can't die whilst pilots struggle to have to use them.

For sure Morrison if you want these guys trained to use the trim etc let's do it as well. But that's not the real issue here. The Max flawed design has led us to spend weeks analysing and dissecting the ins and outs of something we should never even need to be discussing.

Nice - taking partial quotes again and ignoring my comments about training. I have always said it's a training issue.

You better never fly on an A320 then either as it has a backup trim wheel.

The technical writer said - it might have been saved - there was a lot of hedging in his response. If they had trimmed out the out of trim with Electric before switching it off or never put up the flaps or disengaged TOGA thrust they might have been saved as well.

All the conditions the ET Pilots were were right on the front page of the FCOM update. If they had read that and understood it - there should have been no issue identifying MCAS intervention.

planecane wrote:

Another video I found from 2015 of a runaway trim in a 737 classic simulator. They cutout the electric trim quickly without really going through the checklist and then trimmed with the wheel. The interesting thing is that disengaging autothrottle and reducing thrust was done by instinct. I can't really tell how out of trim they got but they didn't do a rollercoaster procedure but they did point out the force the copilot was using to hold the column before they got back in trim.

https://www.youtube.com/watch?v=3pPRuFHR1co

GalaxyFlyer wrote:

Not interesting at all, merely proper flying technique and understanding what’s going on

planecane wrote:

With MCAS 2.0, what exactly would simulator training be needed for? What would they be training to do? Don't approach a stall with an AoA disagree warning?

morrisond wrote:

Nice - taking partial quotes again and ignoring my comments about training. I have always said it's a training issue.

PixelFlight wrote:

(b) How single sensor input is ambiguous ?

(c) Boeing PR about fixes: "Flight control system will now compare inputs from both AOA sensors." https://www.boeing.com/commercial/737max/737-max-software-updates.page

xmp125a wrote:

morrisond wrote:

Nice - taking partial quotes again and ignoring my comments about training. I have always said it's a training issue.

GalaxyFlyer wrote:

DenverTed wrote:

GalaxyFlyer wrote:

What in the world does EA 401 have to do with these two accidents? It was gear light there.

And, to repeat for the tenth time, there is NO “roller coaster” maneuver. The pilot merely relieves the load on the stab trim jackscrew by releasing enough yoke back pressure. It should be a smooth nose down maneuver, just enough to allow the trim motor to work. Where does these ideas come from?

GF

I read about this idea on Peter Lemme's site, satguru.com. I believe the 'rollercoaster' is for the trim Flinstone power method.

D.P Davies in Handling the Big Jets covered the procedure for trim motor stalling in about 1973 and Boeing instructed long before that. It’s nothing new and it’s not a roller coaster. As I stated, hold the trim switch and release the aerodynamic pressure by relaxing the stick force being applied. If you let the trim position far out of proper, it’s going take some time. Best be aggressive keeping it in trim.

GF

Interested wrote:

Ugly51 wrote:

It's Boeing attempting to save money. If 737 Max simulator training is required, this is a Red Flag concerning Southwest Airlines.
Boeing will have to pay/train all Southwest Pilot's at no cost to the airline. All Southwest Pilot's should be able to fly any 737 model without any simulator training. Two words... Absolutely frightening.

I think this is about how quickly these planes can become ungrounded. As far as I've seen there aren't anywhere near enough Max simulators around the world to handle the amount of training needed. And the existing simulators airlines bought that they thought were Max simulators are all flawed!

So if Max simulator training IS deemed necessary it would severely delay these planes being ungrounded as the simulators just aren't available. Regardless of the costs involved - the simulators aren't there.

XRAYretired wrote:

Interested wrote:

Ugly51 wrote:

It's Boeing attempting to save money. If 737 Max simulator training is required, this is a Red Flag concerning Southwest Airlines.
Boeing will have to pay/train all Southwest Pilot's at no cost to the airline. All Southwest Pilot's should be able to fly any 737 model without any simulator training. Two words... Absolutely frightening.

I think this is about how quickly these planes can become ungrounded. As far as I've seen there aren't anywhere near enough Max simulators around the world to handle the amount of training needed. And the existing simulators airlines bought that they thought were Max simulators are all flawed!

So if Max simulator training IS deemed necessary it would severely delay these planes being ungrounded as the simulators just aren't available. Regardless of the costs involved - the simulators aren't there.

Ethiopian have one. Southwest could sub-contract pilot training to them!

Interested wrote:

Ugly51 wrote:

It's Boeing attempting to save money. If 737 Max simulator training is required, this is a Red Flag concerning Southwest Airlines.
Boeing will have to pay/train all Southwest Pilot's at no cost to the airline. All Southwest Pilot's should be able to fly any 737 model without any simulator training. Two words... Absolutely frightening.

I think this is about how quickly these planes can become ungrounded. As far as I've seen there aren't anywhere near enough Max simulators around the world to handle the amount of training needed. And the existing simulators airlines bought that they thought were Max simulators are all flawed!

So if Max simulator training IS deemed necessary it would severely delay these planes being ungrounded as the simulators just aren't available. Regardless of the costs involved - the simulators aren't there.

Interested wrote:

XRAYretired wrote:

Interested wrote:

I think this is about how quickly these planes can become ungrounded. As far as I've seen there aren't anywhere near enough Max simulators around the world to handle the amount of training needed. And the existing simulators airlines bought that they thought were Max simulators are all flawed!

So if Max simulator training IS deemed necessary it would severely delay these planes being ungrounded as the simulators just aren't available. Regardless of the costs involved - the simulators aren't there.

Ethiopian have one. Southwest could sub-contract pilot training to them!

If only the one they had could replicate MCAS

xmp125a wrote:

ArgentoSystems wrote:

smartplane wrote:

In the MAX, is the AoA warning light installed in all aircraft delivered, but only enabled if the customer specifically purchases the feature package? In other words, are there cockpits with the warning light installed, but not operative? Is the disagree light fitted to Lion and Ethiopian MAX's?

there is no light. it is an icon on PFD.

In grandfatheringspeak, it is a light

(if pre-NG aircraft had that functionality it could only be a light, right?)