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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 7:29 pm
by PW100
seahawk wrote:
You could fly the MAX without any changes safely today. But that would require crew training for the MCAS and that is something Boeing does not want, as customers do not want any extra training (apart from some ipad hours) when changing from the NG to the MAX.

All it needs is a working AoA disagree warning in the cockpit and a MCAS failure checklist. (which would probably be trained for in the sim when adding the type rating)


No. The regulators (and EASA in particular) have made it very clear that even with properly trained crews, the risk associated with MCAS is way to large (at least an order of magnitude) to rely on a cockpit crew. Or in other words, it does not meed the Certification Specifications, even before considering training requirements.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 7:30 pm
by PW100
morrisond wrote:
asdf wrote:
[
they had no clue how to stop MCAS
they had no clue that slowing down maybe would have helped them to a better outcome


Finally we agree on something. Yes - unfortunately for themselves and the passengers on those flights due to the probable bad training at ET - it appears they had no clue what they were doing.



???
Right. SouthWest pilots perfectly knew how to stop MCAS.

Oh, wait, they just sued Boeing for not telling them, . . . just that!!

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 7:35 pm
by morrisond
PW100 wrote:
morrisond wrote:
asdf wrote:
[
they had no clue how to stop MCAS
they had no clue that slowing down maybe would have helped them to a better outcome


Finally we agree on something. Yes - unfortunately for themselves and the passengers on those flights due to the probable bad training at ET - it appears they had no clue what they were doing.



???
Right. SouthWest pilots perfectly knew how to stop MCAS.

Oh, wait, they just sued Boeing for not telling them, . . . just that!!


Southwest was referring to pre Lionair - not after Lionair when MCAS was disclosed - and BTW it was disclosed in the maintenance manuals to the airlines pre-Lionair it was just incorrectly not included as part of the differences training.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 7:41 pm
by PW100
morrisond wrote:
Noshow wrote:
Again pointing at the customer and not at the manufacturer that had kept the system a secret?


No - Boeing totally screwed up but as I have said many times - the crashes uncovered some real deficiencies in training.

By the time of the ET crash they knew all about MCAS and the flight should most probably not have resulted in a crash.


Before the ET accident:

1) Did Boeing tell them that MCAS would run the trim down for over 9 seconds per cycle?

2) Did Boeing tell them that MCAS would trim down faster than electric trimming?

3) Did Boeing tell them that MCAS would stop (temporarily) with electric trim inputs?

4) Did Boeing tell them that MCAS would NOT stop by pulling on the control column (unlike STS)?

5) Did Boeing tell them that MCAS would start again after 5 seconds?

6) Did Boeing tell them that MCAS would be inhibited with flaps down?

7) Did Boeing tell them that MCAS was relying on one single AoA sensor input?

8) Did Boeing tell them that AoA disagree is a vital ingredient for MCAS run-away?

9) Did Boeing tell them that electric trimming ANU is not working at air speed (well) below Vmo in case of out-of trim condition?

10) Did Boeing provide a chart showing air speed limits for ever .1 degree of out out-of-trim condition? (it is easy to say not to let speed out of hand, but really such graph is needed to be a little more specific. Come ot think of it, such a graph should really be part of the performance and limitations chart book).

None of the above can be answered with yes (perhaps you would say yes to 9) as per the AD, but even there many - including myself - disagree).

So really, the ET crew knew almost nothing about MCAS.

I'll bet they would have like to know what you know of MCAS at this point in time. In fact, they would have been able to participate in this thread as well.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 7:42 pm
by PW100
Revelation wrote:
keesje wrote:
In a cockpit full of (in)correct vocal alerts, warning lights, single points of failure, refusing trim wheels, stall rumbling sticks that can't be stopped, a pilot theoretically could have saved the aircraft. So we can try focussing on training to handle, trouble shoot, pull circuit breakers by the pilots. In the seconds they have. Or conclude it's a bad cockpit. Certainly if requirements were customized for it by the builder itself.

Interestingly enough, you, I and morrisond are saying the same thing.

The flight before JT610 shows the exact same plane could be saved by pilot actions.

Both Boeing and FAA have confirmed that MCAS 1.0 put too much workload on the pilot.

Given the cockpit is the pilot's user interface, it is fair to say a bad cockpit put too much workload on the pilot.

FAA gave Boeing exemptions based on similarity to NG, but MCAS made MAX quite different from NG.

Once MAX is fixed chances are good that it will be safer than NG since the two FCC outputs will be compared, something NG does not do.


Good, clear post.

I just want to add that making such a change as linking FCC input/ouput introduces new risks.
So the same action that removes one risk item (MCAS), introduces new potential risk item(s). Which troubles the water a bit with respect to your saftey comparison to the NG.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 8:42 pm
by morrisond
PW100 wrote:
morrisond wrote:
Noshow wrote:
Again pointing at the customer and not at the manufacturer that had kept the system a secret?


No - Boeing totally screwed up but as I have said many times - the crashes uncovered some real deficiencies in training.

By the time of the ET crash they knew all about MCAS and the flight should most probably not have resulted in a crash.


Before the ET accident:

1) Did Boeing tell them that MCAS would run the trim down for over 9 seconds per cycle?

2) Did Boeing tell them that MCAS would trim down faster than electric trimming?

3) Did Boeing tell them that MCAS would stop (temporarily) with electric trim inputs?

4) Did Boeing tell them that MCAS would NOT stop by pulling on the control column (unlike STS)?

5) Did Boeing tell them that MCAS would start again after 5 seconds?

6) Did Boeing tell them that MCAS would be inhibited with flaps down?

7) Did Boeing tell them that MCAS was relying on one single AoA sensor input?

8) Did Boeing tell them that AoA disagree is a vital ingredient for MCAS run-away?

9) Did Boeing tell them that electric trimming ANU is not working at air speed (well) below Vmo in case of out-of trim condition?

10) Did Boeing provide a chart showing air speed limits for ever .1 degree of out out-of-trim condition? (it is easy to say not to let speed out of hand, but really such graph is needed to be a little more specific. Come ot think of it, such a graph should really be part of the performance and limitations chart book).

None of the above can be answered with yes (perhaps you would say yes to 9) as per the AD, but even there many - including myself - disagree).

So really, the ET crew knew almost nothing about MCAS.

I'll bet they would have like to know what you know of MCAS at this point in time. In fact, they would have been able to participate in this thread as well.


A lot of what you wrote (incorrectly) is right in the MCAS FCOM bulletin - I'll let you fix your list after you take a look at it and then we can discuss it.

Interesting that on that page there is a Page from a Boeing Training Manual on the flight controls from Jan 2017 that talks about MCAS.

That may be the Maintenance manual.

The FCOM bulletin where you will find your answers is on the page as well http://www.b737.org.uk/mcas.htm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 8:46 pm
by Revelation
JAAlbert wrote:
Nice summation of the big picture problems that caused these crashes. What I don't understand is how you managed to sum all this up without including the traditional adjectives, judgments, condemnations and outrage! :D

Maybe we should lock the thread now? :biggrin:

B777LRF wrote:
I appreciate the effort you've taken to dissect my post. I shall not be responding in kind, but would rather we both agree on having different views on the situation. Yours may be perfectly correct, or it may not. Same as mine, and only time shall tell.

IMO you are certainly entitled to have your own view on the situation, but I don't see how any of the recent media reports support your view.

I don't have enough info to form my own opinion, so maybe it'd be similar to yours if I had such info, I'm just going off what the media is reporting.

I have posted a few times now that I think people are over-reacting to the the phrase "architecture change" since these are often done to minimize change and risk, and have also pointed out we do not know exactly how long this change has been in the works but we do have some suggestions that work was begun last November.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 9:22 pm
by hondah35
Prediction for the Record:

None of these MAX aircraft will ever return to a fleet. Not due to technical issues, but because there is going to be a multiyear downturn in aviation which will render them useless.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 9:26 pm
by MrBretz
So Revelation, if you are right, the architecture change has been in works for about a year and the changes have not been completely submitted to the FAA for approval or flight testing yet. That seems to be about the right time for that type of fix. My experience with failover between computers in the past has taught me such a thing is always a challenge. The complexities can be endless and hard to comment on since none of us understand the architecture to any extent. But a year seems to be in the ball park.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Wed Oct 09, 2019 10:12 pm
by scbriml
morrisond wrote:
Interesting that on that page there is a Page from a Boeing Training Manual on the flight controls from Jan 2017 that talks about MCAS.

That may be the Maintenance manual.


That was the maintenance manual that the vast majority of pilots would never see.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:33 am
by morrisond
Actually what shocks me the most is the POH is 1,300 pages long. The whole thing probably has way more detail in it than anyone can hope to know due to all the automated systems.

It probably would be a lot safer that if anything goes wrong - just push a big red button to turn off all the automatic systems and fly manually and focus training on manual flying skills - although make sure Electric Trim is available with a wire directly to a motor that can't be acted on by any computer system wouldn't be a bad idea.

Planes are just getting too complex/automated and Pilots will have less and less involvement - they will just need to be there for when the S**t hits the fan but need to be proficient at it when it does.

Stop trying to problem solve in the air and just return to base with Stick and Rudder skills.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:55 am
by aerolimani
Except that we want to make things ever more efficient. So, physical design choices are made which require computer assistance to fly. If stick and rudder is what you want, then you’d really better not fly on a 787 or A350, with electrically actuated flight controls.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:56 am
by sgrow787
morrisond wrote:
PW100 wrote:
morrisond wrote:

No - Boeing totally screwed up but as I have said many times - the crashes uncovered some real deficiencies in training.

By the time of the ET crash they knew all about MCAS and the flight should most probably not have resulted in a crash.


Before the ET accident:

1) Did Boeing tell them that MCAS would run the trim down for over 9 seconds per cycle?

2) Did Boeing tell them that MCAS would trim down faster than electric trimming?

3) Did Boeing tell them that MCAS would stop (temporarily) with electric trim inputs?

4) Did Boeing tell them that MCAS would NOT stop by pulling on the control column (unlike STS)?

5) Did Boeing tell them that MCAS would start again after 5 seconds?

6) Did Boeing tell them that MCAS would be inhibited with flaps down?

7) Did Boeing tell them that MCAS was relying on one single AoA sensor input?

8) Did Boeing tell them that AoA disagree is a vital ingredient for MCAS run-away?

9) Did Boeing tell them that electric trimming ANU is not working at air speed (well) below Vmo in case of out-of trim condition?

10) Did Boeing provide a chart showing air speed limits for ever .1 degree of out out-of-trim condition? (it is easy to say not to let speed out of hand, but really such graph is needed to be a little more specific. Come ot think of it, such a graph should really be part of the performance and limitations chart book).

None of the above can be answered with yes (perhaps you would say yes to 9) as per the AD, but even there many - including myself - disagree).

So really, the ET crew knew almost nothing about MCAS.

I'll bet they would have like to know what you know of MCAS at this point in time. In fact, they would have been able to participate in this thread as well.


A lot of what you wrote (incorrectly) is right in the MCAS FCOM bulletin - I'll let you fix your list after you take a look at it and then we can discuss it.

Interesting that on that page there is a Page from a Boeing Training Manual on the flight controls from Jan 2017 that talks about MCAS.

That may be the Maintenance manual.

The FCOM bulletin where you will find your answers is on the page as well http://www.b737.org.uk/mcas.htm


Looks like the author of that website agrees with my conclusion re the AOA disagree light. He/she has no information confirming this option was installed pre-grounding. So today, no one has confirmed a working light exists/existed. AOA redundancy therefore must be a difficult thing to implement on the legacy FCC hardware that is the Max.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 1:12 am
by TTailedTiger
hondah35 wrote:
Prediction for the Record:

None of these MAX aircraft will ever return to a fleet. Not due to technical issues, but because there is going to be a multiyear downturn in aviation which will render them useless.


Nonsense. Older planes would be parked and the most fuel efficient planes kept in the fleet.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 1:40 am
by JAAlbert
Revelation wrote:
JAAlbert wrote:
Nice summation of the big picture problems that caused these crashes. What I don't understand is how you managed to sum all this up without including the traditional adjectives, judgments, condemnations and outrage! :D

Maybe we should lock the thread now? :biggrin:


If I ruled the world, any discussion about fault would have been excised!

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 1:59 am
by RickNRoll
MrBretz wrote:
So Revelation, if you are right, the architecture change has been in works for about a year and the changes have not been completely submitted to the FAA for approval or flight testing yet. That seems to be about the right time for that type of fix. My experience with failover between computers in the past has taught me such a thing is always a challenge. The complexities can be endless and hard to comment on since none of us understand the architecture to any extent. But a year seems to be in the ball park.
Failover is always a can of worms. By definition there is something unexpected going wrong so it is extremely difficult for all reasons for a fail status to be known and then tested. A lot of computer systems will not opt for fail over just for simplicity you get to deal with. It can be, and had been, fine many times. It just takes a lot of work to know it will work as expected.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:03 am
by RickNRoll
morrisond wrote:
Actually what shocks me the most is the POH is 1,300 pages long. The whole thing probably has way more detail in it than anyone can hope to know due to all the automated systems.

It probably would be a lot safer that if anything goes wrong - just push a big red button to turn off all the automatic systems and fly manually and focus training on manual flying skills - although make sure Electric Trim is available with a wire directly to a motor that can't be acted on by any computer system wouldn't be a bad idea.

Planes are just getting too complex/automated and Pilots will have less and less involvement - they will just need to be there for when the S**t hits the fan but need to be proficient at it when it does.

Stop trying to problem solve in the air and just return to base with Stick and Rudder skills.
The modern FBW systems will have a relatively consistent architecture with redundany built in from the start. The 737 is an ongoing series of patches on top of patches on top of something that was originally very simple. Since it is not a coherent system from the beginning that introduces other complexities for the pilots to deal with.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:18 am
by aerolimani
RickNRoll wrote:
morrisond wrote:
Actually what shocks me the most is the POH is 1,300 pages long. The whole thing probably has way more detail in it than anyone can hope to know due to all the automated systems.

It probably would be a lot safer that if anything goes wrong - just push a big red button to turn off all the automatic systems and fly manually and focus training on manual flying skills - although make sure Electric Trim is available with a wire directly to a motor that can't be acted on by any computer system wouldn't be a bad idea.

Planes are just getting too complex/automated and Pilots will have less and less involvement - they will just need to be there for when the S**t hits the fan but need to be proficient at it when it does.

Stop trying to problem solve in the air and just return to base with Stick and Rudder skills.
The modern FBW systems will have a relatively consistent architecture with redundany built in from the start. The 737 is an ongoing series of patches on top of patches on top of something that was originally very simple. Since it is not a coherent system from the beginning that introduces other complexities for the pilots to deal with.

In addition, unlike planes of today, I don’t think that future development were at all considered as part of the initial design. The 737 was very much designed for a purpose of the day. It was designed for airports with little infrastructure, and didn’t take into account the likelihood that future development of the civil aviation industry would improve infrastructure everywhere. Just as Alaska no longer flies the 200 with gravel kit, and has not sought a replacement, because all those strips have since been paved.

It’s impossible to completely future-proof any product, of course, but I think today’s designs leave more room for potential future developments.

As concerns the 737, the first high-bypass turbofan was built in 1964, the same year that the 737 design began. So, the writing was on the wall. I can’t believe that Boeing didn’t already know that it was the way of the future. They just had other priorities for the 737 than future-proofing it.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:25 am
by DenverTed
hondah35 wrote:
Prediction for the Record:

None of these MAX aircraft will ever return to a fleet. Not due to technical issues, but because there is going to be a multiyear downturn in aviation which will render them useless.

If they have built about 1,000 of these at 50M a piece, that is 50B of aircraft. That is a large investment. Even if they required hardware changes of 25M per aircraft or 25B total, it would still be cost effective to do that. So I don't see them getting melted down quite yet.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:38 am
by timh4000
Personally I wish we would hear from more 737drivers who cam compare the max to the ng series or even the older classics. Is it a better plane fly now or then. Is the automation helpful or is it becoming more difficult. There's a lot of very smart non pilots who can speculate quite well. But in the end it really comes down to the pilots operating the plane.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 4:31 am
by spacecookie
The FAA failed to certificate the plane properly.
I hope EASA don’t let the plane fly until they are 100% sure that the plane is now safe.


The max should never been made in my opinion,
AirBus has now a lot of advantage thanks to Boeing ...

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 5:01 am
by seahawk
morrisond wrote:
PW100 wrote:
morrisond wrote:

No - Boeing totally screwed up but as I have said many times - the crashes uncovered some real deficiencies in training.

By the time of the ET crash they knew all about MCAS and the flight should most probably not have resulted in a crash.


Before the ET accident:

1) Did Boeing tell them that MCAS would run the trim down for over 9 seconds per cycle?

2) Did Boeing tell them that MCAS would trim down faster than electric trimming?

3) Did Boeing tell them that MCAS would stop (temporarily) with electric trim inputs?

4) Did Boeing tell them that MCAS would NOT stop by pulling on the control column (unlike STS)?

5) Did Boeing tell them that MCAS would start again after 5 seconds?

6) Did Boeing tell them that MCAS would be inhibited with flaps down?

7) Did Boeing tell them that MCAS was relying on one single AoA sensor input?

8) Did Boeing tell them that AoA disagree is a vital ingredient for MCAS run-away?

9) Did Boeing tell them that electric trimming ANU is not working at air speed (well) below Vmo in case of out-of trim condition?

10) Did Boeing provide a chart showing air speed limits for ever .1 degree of out out-of-trim condition? (it is easy to say not to let speed out of hand, but really such graph is needed to be a little more specific. Come ot think of it, such a graph should really be part of the performance and limitations chart book).

None of the above can be answered with yes (perhaps you would say yes to 9) as per the AD, but even there many - including myself - disagree).

So really, the ET crew knew almost nothing about MCAS.

I'll bet they would have like to know what you know of MCAS at this point in time. In fact, they would have been able to participate in this thread as well.


A lot of what you wrote (incorrectly) is right in the MCAS FCOM bulletin - I'll let you fix your list after you take a look at it and then we can discuss it.

Interesting that on that page there is a Page from a Boeing Training Manual on the flight controls from Jan 2017 that talks about MCAS.

That may be the Maintenance manual.

The FCOM bulletin where you will find your answers is on the page as well http://www.b737.org.uk/mcas.htm


Well said! With the knowledge provided in the bulletin any halfway trained crew should have had no problems detecting and fixing the problem without crashing the plane.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 5:35 am
by Chemist
morrisond wrote:
Actually what shocks me the most is the POH is 1,300 pages long. The whole thing probably has way more detail in it than anyone can hope to know due to all the automated systems.

It probably would be a lot safer that if anything goes wrong - just push a big red button to turn off all the automatic systems and fly manually and focus training on manual flying skills - although make sure Electric Trim is available with a wire directly to a motor that can't be acted on by any computer system wouldn't be a bad idea.

Planes are just getting too complex/automated and Pilots will have less and less involvement - they will just need to be there for when the S**t hits the fan but need to be proficient at it when it does.

Stop trying to problem solve in the air and just return to base with Stick and Rudder skills.


Yes, except that it appears that for many of today's airline pilots, they get to 500 feet and they push the AP button. And when they get back down to 500 feet, they turn off the AP and fly a short-final landing. And if they need to fly in between those regimes, they don't really have much experience with that. And their employers dissuade them from doing that.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 8:33 am
by JibberJim
TTailedTiger wrote:
Nonsense. Older planes would be parked and the most fuel efficient planes kept in the fleet.


No, the most cost efficient planes kept in the fleet, the argument presumably is that the extra insurance, extra training, return to service costs along with the penalties enabling a way out for the airline will render these planes less cost efficient, despite their fuel efficiencies, especially if there are other modern fuel efficient planes available that can be obtained cheaply (ie a load of 320 Neo's come on the market as other airlines go out of business)

I don't actually agree, but fuel efficiency is not the only thing.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 9:05 am
by asdf
and now we really are on automation vs. manual flying discussion?

this is kindergarden

boeing has a full FBW plane (787) since years out there and it works flawless
no nosedive-of-death
no hidden "features"
no unworkable manual trim

this epic thread would really benefit a lot from a pinned summary
even if that summary is controversial and would need thousands of words

it maybe would help preventing contributors from starting the same discussions all over again

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 9:53 am
by planecane
asdf wrote:
and now we really are on automation vs. manual flying discussion?

this is kindergarden

boeing has a full FBW plane (787) since years out there and it works flawless
no nosedive-of-death
no hidden "features"
no unworkable manual trim

this epic thread would really benefit a lot from a pinned summary
even if that summary is controversial and would need thousands of words

it maybe would help preventing contributors from starting the same discussions all over again


They also have the 777 flying for almost 25 years full FBW.

But, all pilots of FBW aircraft from all manufacturers should have the skill and training to fly and land safely if a failure causes a reversion to direct mode (or whatever each manufacturer calls it), no matter the phase of flight it happens in.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 9:59 am
by PixelFlight
morrisond wrote:
Actually what shocks me the most is the POH is 1,300 pages long. The whole thing probably has way more detail in it than anyone can hope to know due to all the automated systems.

It probably would be a lot safer that if anything goes wrong - just push a big red button to turn off all the automatic systems and fly manually and focus training on manual flying skills - although make sure Electric Trim is available with a wire directly to a motor that can't be acted on by any computer system wouldn't be a bad idea.

Planes are just getting too complex/automated and Pilots will have less and less involvement - they will just need to be there for when the S**t hits the fan but need to be proficient at it when it does.

Stop trying to problem solve in the air and just return to base with Stick and Rudder skills.

Please understand that the MCAS is only active while in manual flight on a 737-8/9 MAX, as clearly written in the EAD. MCAS was added not to have less and less pilots involvement, but to keep the pilots involvement the same as in a 737-x00 NG in situation where the 737-8/9 MAX aerodynamic alone did not comply with the safety regulation.

From a safety regulation point to view the 37-8/9 MAX aerodynamic alone is less safe than the 737-x00 NG aerodynamic alone in manual flight. Given the rate Boeing is still producing it, it's unlikely that this fact will ever change. So something other than on the aerodynamic alone must be done. Training is not an option to solve this problem:
1) EASA: "Pilot training requirements are not meant to compensate for non-acceptable design on the compliance and safety standpoint."
2) Boeing: MAX == NG, no extra training.
3) At least 1 operator: USD 1M contractual obligation per frame for Boeing in case of extra training.
So there is no other way than to have a very reliable active system, whenever you call it, to safely flight the 737-8/9 MAX in manual flight according to the actual safety regulation. The idea of a "big red button to turn off all the automatic systems and fly manually and focus training on manual flying skills" is a dead path.

Basically, the aerodynamic of the 737-8/9 MAX can only fully comply with the actual safety regulation in manual flight if augmented by a highly redundant and reliable FBW system.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 10:04 am
by mjoelnir
planecane wrote:
asdf wrote:
and now we really are on automation vs. manual flying discussion?

this is kindergarden

boeing has a full FBW plane (787) since years out there and it works flawless
no nosedive-of-death
no hidden "features"
no unworkable manual trim

this epic thread would really benefit a lot from a pinned summary
even if that summary is controversial and would need thousands of words

it maybe would help preventing contributors from starting the same discussions all over again


They also have the 777 flying for almost 25 years full FBW.

But, all pilots of FBW aircraft from all manufacturers should have the skill and training to fly and land safely if a failure causes a reversion to direct mode (or whatever each manufacturer calls it), no matter the phase of flight it happens in.


There seems to be a complete misunderstanding here. FBW does not denote the automatic features. An aircraft having FBW, dropping down to direct mode, is still using the FBW, just in a different more direct mode.

One should keep apart FBW and automation as different concepts. FBW makes automation easier and more integrated if well done.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 10:38 am
by Amiga500
PW100 wrote:
Before the ET accident:

1) Did Boeing tell them that MCAS would run the trim down for over 9 seconds per cycle?

2) Did Boeing tell them that MCAS would trim down faster than electric trimming?

3) Did Boeing tell them that MCAS would stop (temporarily) with electric trim inputs?

4) Did Boeing tell them that MCAS would NOT stop by pulling on the control column (unlike STS)?

5) Did Boeing tell them that MCAS would start again after 5 seconds?

6) Did Boeing tell them that MCAS would be inhibited with flaps down?

7) Did Boeing tell them that MCAS was relying on one single AoA sensor input?

8) Did Boeing tell them that AoA disagree is a vital ingredient for MCAS run-away?

9) Did Boeing tell them that electric trimming ANU is not working at air speed (well) below Vmo in case of out-of trim condition?

10) Did Boeing provide a chart showing air speed limits for ever .1 degree of out out-of-trim condition? (it is easy to say not to let speed out of hand, but really such graph is needed to be a little more specific. Come ot think of it, such a graph should really be part of the performance and limitations chart book).


From AD 2018-23-51

1. Yes
2. No - they inferred the opposite
3. No
4. No
5. No
6. No
7. Kinda
8. Yes
9. No
10. No

Just the 2.5 out of 10 right.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 11:28 am
by seahawk
In the end we do not know enough on how a MAX behaves without MCAS. Is the non-linear response small or is it big? Is it more something that you just need to know as a pilot but not a big problem, or is it a rapid movement and hard to counter?

We do not even know if the original amount of trim change reported to the FAA is enough or if it needs the hard reaction of MCAS 1.0. Without knowing this it is impossible to actually formulate the requirements for MCAS 2.0 - except that it has to follow current safety standards and use at least 2 sensors.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:12 pm
by asdf
seahawk wrote:
In the end we do not know enough on how a MAX behaves without MCAS. Is the non-linear response small or is it big? Is it more something that you just need to know as a pilot but not a big problem, or is it a rapid movement and hard to counter?

We do not even know if the original amount of trim change reported to the FAA is enough or if it needs the hard reaction of MCAS 1.0. Without knowing this it is impossible to actually formulate the requirements for MCAS 2.0 - except that it has to follow current safety standards and use at least 2 sensors.


EASA ist asking for that test-flights since months
even in open public

trying out the attitude of the plane WITHOUT augmention in manual flight in sharp and high turns

i hope the reason why they dont get is is not related to be feared results

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:21 pm
by Revelation
Speaking of the MAX un-grounding,

FluidFlow wrote:
AA expects their RTS from the 16th of January 2020:

https://www.bbc.com/news/live/business-49960083

Also: https://abcnews.go.com/Politics/america ... d=66149278 says:

American Airlines announced in a Securities and Exchange Commission filing on Wednesday that it expects to start flying the troubled Boeing 737 MAX aircraft on Jan. 16.

The airline said it expects the two software upgrades to be approved before the end of the year and it is notifying Wall Street on when it intends to fly the MAX again.

It seems AA has been the most aggressive of the US operators (AA, US, WN) about drawing a line in the sand about when MAX will fly again.

It seems they are willing to put their "expecations" into writing, for what ever that is worth.

Also https://www.reuters.com/article/us-ethi ... SKBN1WN249 has a reaction from EASA on the WSJ report:

The European Union Aviation Safety Agency (EASA) said on Tuesday it was still assessing proposed changes to Boeing (BA.N) software for the grounded 737 MAX and had yet not found anything that would undermine hopes for a coordinated return to service.

“EASA is still assessing the latest Flight Control Computer software - the work is ongoing and not completed yet,” an agency spokeswoman said by email.

We do not at this stage have any specific concerns resulting from that assessment that would mean that we could not agree to a coordinated return to service. We are in continuous contact with both the FAA and Boeing.”

Nothing to see here?

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:22 pm
by planecane
seahawk wrote:
In the end we do not know enough on how a MAX behaves without MCAS. Is the non-linear response small or is it big? Is it more something that you just need to know as a pilot but not a big problem, or is it a rapid movement and hard to counter?

We do not even know if the original amount of trim change reported to the FAA is enough or if it needs the hard reaction of MCAS 1.0. Without knowing this it is impossible to actually formulate the requirements for MCAS 2.0 - except that it has to follow current safety standards and use at least 2 sensors.


As far as I can ascertain from various reports, the difference in authority from MCAS 1.0 to 2.0 is that where 1.0 would have only changed the trim the necessary amount for a given airspeed in normal operation, it was not limited to this amount. MCAS 2.0 will actually limit the movement based on airspeed so that even under a dual AoA sensor failed high within 5.5 degrees of each other scenario, it will never change the trim past the point where there is elevator authority to maintain level flight.

The additional authority given to MCAS 1.0 was for it to be effective in the low speed situations that they discovered in flight testing. It was never intended to change the trim so much at high airspeed.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:31 pm
by kalvado
planecane wrote:
seahawk wrote:
In the end we do not know enough on how a MAX behaves without MCAS. Is the non-linear response small or is it big? Is it more something that you just need to know as a pilot but not a big problem, or is it a rapid movement and hard to counter?

We do not even know if the original amount of trim change reported to the FAA is enough or if it needs the hard reaction of MCAS 1.0. Without knowing this it is impossible to actually formulate the requirements for MCAS 2.0 - except that it has to follow current safety standards and use at least 2 sensors.


As far as I can ascertain from various reports, the difference in authority from MCAS 1.0 to 2.0 is that where 1.0 would have only changed the trim the necessary amount for a given airspeed in normal operation, it was not limited to this amount. MCAS 2.0 will actually limit the movement based on airspeed so that even under a dual AoA sensor failed high within 5.5 degrees of each other scenario, it will never change the trim past the point where there is elevator authority to maintain level flight.

The additional authority given to MCAS 1.0 was for it to be effective in the low speed situations that they discovered in flight testing. It was never intended to change the trim so much at high airspeed.

Next thing you have to keep in mind is that airspeed is calculated with AoA input, and once AoA data goes bad, so does airspeed data. Now all failure modes may require extra consideration with that in mind to make sure those failure modes are consistent.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:33 pm
by morrisond
Amiga500 wrote:
PW100 wrote:
Before the ET accident:

1) Did Boeing tell them that MCAS would run the trim down for over 9 seconds per cycle?

2) Did Boeing tell them that MCAS would trim down faster than electric trimming?

3) Did Boeing tell them that MCAS would stop (temporarily) with electric trim inputs?

4) Did Boeing tell them that MCAS would NOT stop by pulling on the control column (unlike STS)?

5) Did Boeing tell them that MCAS would start again after 5 seconds?

6) Did Boeing tell them that MCAS would be inhibited with flaps down?

7) Did Boeing tell them that MCAS was relying on one single AoA sensor input?

8) Did Boeing tell them that AoA disagree is a vital ingredient for MCAS run-away?

9) Did Boeing tell them that electric trimming ANU is not working at air speed (well) below Vmo in case of out-of trim condition?

10) Did Boeing provide a chart showing air speed limits for ever .1 degree of out out-of-trim condition? (it is easy to say not to let speed out of hand, but really such graph is needed to be a little more specific. Come ot think of it, such a graph should really be part of the performance and limitations chart book).


From AD 2018-23-51

1. Yes
2. No - they inferred the opposite
3. No
4. No
5. No
6. No
7. Kinda
8. Yes
9. No
10. No

Just the 2.5 out of 10 right.


Read the ops bulletin right below that.

2, 4, 6 and 7 were known before ET, 3 and 5 are Yes, 9 - there is no clear evidence this is true, 10 is ridiculous - that is why they have Vmo.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:45 pm
by morrisond
planecane wrote:
seahawk wrote:
In the end we do not know enough on how a MAX behaves without MCAS. Is the non-linear response small or is it big? Is it more something that you just need to know as a pilot but not a big problem, or is it a rapid movement and hard to counter?

We do not even know if the original amount of trim change reported to the FAA is enough or if it needs the hard reaction of MCAS 1.0. Without knowing this it is impossible to actually formulate the requirements for MCAS 2.0 - except that it has to follow current safety standards and use at least 2 sensors.


As far as I can ascertain from various reports, the difference in authority from MCAS 1.0 to 2.0 is that where 1.0 would have only changed the trim the necessary amount for a given airspeed in normal operation, it was not limited to this amount. MCAS 2.0 will actually limit the movement based on airspeed so that even under a dual AoA sensor failed high within 5.5 degrees of each other scenario, it will never change the trim past the point where there is elevator authority to maintain level flight.

The additional authority given to MCAS 1.0 was for it to be effective in the low speed situations that they discovered in flight testing. It was never intended to change the trim so much at high airspeed.


My understanding is that MCAS 1.0 was only put into place as the the force on the control column did not increase in an linear manner as you got close to stall at very light weights and aft COG - it never went negative.

It's a good rule as it does make things marginally safer - but I don't believe that this non-linear control feel would cause any pilot to pull through that easier area of resistance and actually put the plane into a stall while ignoring the Stall Warnings, frame buffeting, stick shaker, etc..

It's well intentioned but unless testing shows up some other handling quirk - automation was added that made things unnecessarily complex leading to more possible failure modes.

If MCAS never existed and the MAX had been given an exemption on this rule (it seems like they exempted almost everything else) I'm pretty confident the MAX would still be flying with 0 hull losses and 0 fatalities.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 12:47 pm
by morrisond
Revelation wrote:
Speaking of the MAX un-grounding,

FluidFlow wrote:
AA expects their RTS from the 16th of January 2020:

https://www.bbc.com/news/live/business-49960083

Also: https://abcnews.go.com/Politics/america ... d=66149278 says:

American Airlines announced in a Securities and Exchange Commission filing on Wednesday that it expects to start flying the troubled Boeing 737 MAX aircraft on Jan. 16.

The airline said it expects the two software upgrades to be approved before the end of the year and it is notifying Wall Street on when it intends to fly the MAX again.

It seems AA has been the most aggressive of the US operators (AA, US, WN) about drawing a line in the sand about when MAX will fly again.

It seems they are willing to put their "expecations" into writing, for what ever that is worth.

Also https://www.reuters.com/article/us-ethi ... SKBN1WN249 has a reaction from EASA on the WSJ report:

The European Union Aviation Safety Agency (EASA) said on Tuesday it was still assessing proposed changes to Boeing (BA.N) software for the grounded 737 MAX and had yet not found anything that would undermine hopes for a coordinated return to service.

“EASA is still assessing the latest Flight Control Computer software - the work is ongoing and not completed yet,” an agency spokeswoman said by email.

We do not at this stage have any specific concerns resulting from that assessment that would mean that we could not agree to a coordinated return to service. We are in continuous contact with both the FAA and Boeing.”

Nothing to see here?


So does that mean they are accessing the Final Fix? Or if everything is found to be okay this is the Final Fix?

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 1:00 pm
by Noshow
How can AA know what and when the FAA will decide?
I think they just said they schedule their MAXes not before mid january anymore. So no more x-mas business for the MAX.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 1:25 pm
by Revelation
morrisond wrote:
So does that mean they are accessing the Final Fix? Or if everything is found to be okay this is the Final Fix?

Even the pessimistic WSJ report ( https://www.wsj.com/articles/friction-b ... 1570527001 ) said:

Before the recent concerns expressed by EASA, senior FAA officials were growing optimistic they would be ready to give the green light for MAX flights as soon as early November, according to people familiar with the matter. The friction with their European counterparts is likely to delay that timeline until at least later that month, these people added.

Clearly the final fix is ready and Boeing is just trying to make sure it has all bases covered before it hits 'send'.

IMO, if a person is willing to believe the reports that the EASA wants more test points for the data compare change, then that person is also tacitly admitting they believe MAX flights are likely to happen some time early to late November, unless they are just cherry picking the WSJ report for things that fit a chosen narrative.

The WSJ report also said Boeing is not clear on what additional test points EASA wants performed, which fits the idea that they are trying to cover all bases before hitting 'send'.

Given my Reuters link above, it seems both FAA and EASA are trying to find a way to keep the idea of a joint release intact.

Personally I really doubt the politics will allow for that.

One or more regulators will have a political need to show they are being tough.

In the long run, though, that won't matter.

In the short run, it'll be hundreds if not thousands more posts for this thread! :-)

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 1:33 pm
by AABusDrvr
timh4000 wrote:
Personally I wish we would hear from more 737drivers who cam compare the max to the ng series or even the older classics. Is it a better plane fly now or then. Is the automation helpful or is it becoming more difficult. There's a lot of very smart non pilots who can speculate quite well. But in the end it really comes down to the pilots operating the plane.



I've never flown a classic, but I have flown both the NG and the MAX. From a pilots perspective, the MAX isn't really any different than the NG. The flight directors/autopilot/autothrottles and the FMC/VNAV are the same, as well as most of the systems management. Some will say the MAX feels more solid in roll, due to the electronic spoiler mixing, and it's easier to make nice landings with a little help from the landing attitude modifier. The large displays are very nice.

Automation in the flight deck can be a great tool to reduce workload, it can become a terrible crutch, and it can lead you down the path to a very bad place, in a big hurry. Very seldom, do we fly a flight, where we don't have to intervene, and correct the automation at some point. I'd say the most important thing in an automated airplane, is knowing what's an appropirate level of automation for whats going on, and knowing when to step down, or up a level. But being able to properly hand fly the airplane, when the automation reaches it's limit, is also very important.

For the record, I'm also type rated in, and have flown the Airbus 320 series. Really the only thing I like about the bus, is it has very roomy, comfortable flight deck, and the APU does a great job of keeping the cabin comfortable on the ground.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 1:48 pm
by par13del
asdf wrote:
EASA ist asking for that test-flights since months
even in open public

trying out the attitude of the plane WITHOUT augmention in manual flight in sharp and high turns

i hope the reason why they dont get is is not related to be feared results

So all the test flights that Boeing conducted prior to the June submission of MCAS 2.0 and other test flights since the bit flip issue in June, none of those results were shared with EASA?

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:10 pm
by frmrCapCadet
If MCAS never existed and the MAX had been given an exemption on this rule (it seems like they exempted almost everything else) I'm pretty confident the MAX would still be flying with 0 hull losses and 0 fatalities.


Not a pilot, but think I could remember 'do not combine a very high AOA with a sharp turn'.

This is not the first time that an automated safety feature has killed. Car seats and CAT span machines are the most conspicuous, but I suspect it has happened in every sector of our economy.

I have considered writing a longer post about all of the added automation to automobiles. Some of the most important have created confusion in certain incidents because I was not aware, or could not figure out just why the car was doing what it did. Buttons, switches, alert lights still are not ergonomically organized.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:17 pm
by asdf
par13del wrote:
asdf wrote:
EASA ist asking for that test-flights since months
even in open public

trying out the attitude of the plane WITHOUT augmention in manual flight in sharp and high turns

i hope the reason why they dont get is is not related to be feared results

So all the test flights that Boeing conducted prior to the June submission of MCAS 2.0 and other test flights since the bit flip issue in June, none of those results were shared with EASA?


i do not know
one should never draw quick conclusions

but if the EASA announces for months that it wants to test the plane, and also indicates which special flight maneuver it wants to test in particular ... then there is reason to believe that the tests that Boeing carried out in the road of the MCAS development and which undoubtedly included these sharp turns with high AoA were not passed on to EASA (or the results passed on is doubtful for EASA)

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:24 pm
by Noshow
Couldn't EASA just do it themselves in Europe? If it is just about the raw flight behavior without protections.
There must be enough MAXes parked there and they have test pilots as well.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:30 pm
by morrisond
Noshow wrote:
Couldn't EASA just do it themselves in Europe? If it is just about the raw flight behavior without protections.
There must be enough MAXes parked there and they have test pilots as well.


Yes they could - it wouldn't be that hard - just turn off the electric trim to disable MCAS ability to afffect the Horizontal Stabilizer and use the manual trim wheel.

It should be relatively easy to do.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:32 pm
by kyu
par13del wrote:
asdf wrote:
EASA ist asking for that test-flights since months
even in open public

trying out the attitude of the plane WITHOUT augmention in manual flight in sharp and high turns

i hope the reason why they dont get is is not related to be feared results

So all the test flights that Boeing conducted prior to the June submission of MCAS 2.0 and other test flights since the bit flip issue in June, none of those results were shared with EASA?

Why would EASA believe what Boeing reports about the outcome of their unattended test flights?

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:32 pm
by par13del
morrisond wrote:
Yes they could - it wouldn't be that hard - just turn off the electric trim to disable MCAS ability to afffect the Horizontal Stabilizer and use the manual trim wheel.

It should be relatively easy to do.

Except earlier in this thread we had some saying that EASA would not be conducting the test flights, Boeing has to conduct them under EASA supervision....
A bit of a lengthy thread for me to scroll back up and point to post numbers.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:37 pm
by kalvado
kyu wrote:
par13del wrote:
asdf wrote:
EASA ist asking for that test-flights since months
even in open public

trying out the attitude of the plane WITHOUT augmention in manual flight in sharp and high turns

i hope the reason why they dont get is is not related to be feared results

So all the test flights that Boeing conducted prior to the June submission of MCAS 2.0 and other test flights since the bit flip issue in June, none of those results were shared with EASA?

Why would EASA believe what Boeing reports about the outcome of their unattended test flights?

Is shouldn't be about belief - those flights were likely not included in certification application package, if occurred at all. And doing such things without OEM support could be illegal as this is a non-authorized modification..

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:38 pm
by par13del
kyu wrote:
par13del wrote:
asdf wrote:
EASA ist asking for that test-flights since months
even in open public

trying out the attitude of the plane WITHOUT augmention in manual flight in sharp and high turns

i hope the reason why they dont get is is not related to be feared results

So all the test flights that Boeing conducted prior to the June submission of MCAS 2.0 and other test flights since the bit flip issue in June, none of those results were shared with EASA?

Why would EASA believe what Boeing reports about the outcome of their unattended test flights?

They don't, just going forward do not expect the USA or any other country to believe anything Airbus and or EASA says about test flighst on a/c under their certification, you are getting into politics, the fact that Boeing had two crashes would become irrelevant.

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Posted: Thu Oct 10, 2019 2:55 pm
by morrisond
par13del wrote:
morrisond wrote:
Yes they could - it wouldn't be that hard - just turn off the electric trim to disable MCAS ability to afffect the Horizontal Stabilizer and use the manual trim wheel.

It should be relatively easy to do.

Except earlier in this thread we had some saying that EASA would not be conducting the test flights, Boeing has to conduct them under EASA supervision....
A bit of a lengthy thread for me to scroll back up and point to post numbers.


I know that - someone asked if it was theoretically possible - Yes it is. They wouldn't need to modify the aircraft at all to check out it's base handling qualities.