xmp125a wrote:

I am curious whether a very normal female of 1.6 cm and 50 kg would actually be able to handle 737 (MAX or NG).

Any thoughts or even data on this?

I'm pretty sure a 1.6cm person of any sort would find piloting a MAX tricky. How would they even get from the pedals to the top of the yoke?

marcelh wrote:

morrisond wrote:

FluidFlow wrote:

Is it not a bit scary that you last line of defense, if you want to call it that way, when everything else fails, is not working in every scenario?

In general it should be that the less complicated the system the broader it should be usable?

The fact that the back up system is heavily limited is kind of a really bad design because in general when you need the back up system you are already in a bad situation.

If your electirc supply in a hospital fails and the back up generator only works wednesdays its not a great design.

Same should go for manual trim, it should work always no matter how fast you are, it should never fail except you have a structural failure. That should be the design limit and not overspeed.

Well then you would have to redesign most of the control surfaces on all Commercial Aircraft - not many of them are going to be that effective beyond Vmo. There is a reason there is a Vmo limit.

Still blaming the pilots?

Nope 60-80% Boeing as I have said multiple times. I'm just getting sick of typing - "It's mainly Boeing's fault - however the accidents have also exposed some real deficiencies in Pilot training that need to be addressed as well"

morrisond wrote:

marcelh wrote:

morrisond wrote:

Well then you would have to redesign most of the control surfaces on all Commercial Aircraft - not many of them are going to be that effective beyond Vmo. There is a reason there is a Vmo limit.

Still blaming the pilots?

Nope 60-80% Boeing as I have said multiple times. I'm just getting sick of typing - "It's mainly Boeing's fault - however the accidents have also exposed some real deficiencies in Pilot training that need to be addressed as well"

If by deficiencies you mean 'clairvoyance' especially in terms of the lion Air pilots then many would be in complete agreement with you.

xmp125a wrote:

bgm wrote:

To be fair, it's probably because a lot of the systems haven't been updated since 1967... I guess at this point we can call it great-grandfathering?

I think this is slowly becoming a problem on its own. Overspeed in ET flight notwithstanding, you do need certain amount of physical power to fly the 737 plane and to adjust the trim with the trim wheel. There have been barely any female pilots in 1967, but now the female pilots are something that has to be expected. Let's wait until someone finds out that the 737 would need different medical examination, which would make sure the pilots possess enough physical force to fly the plane.

As far as I know, the limits on pilot height and weight have never been an issue, and I am pretty sure that historically, the candidates who were too far from median simply were not selected to become pilots. But now there is a ton of regulations which prevent any kind of bias, as long as pilot fulfills the criteria. I am curious whether a very normal female of 1.6 cm and 50 kg would actually be able to handle 737 (MAX or NG). Medical standards only require that pilot comfortably reaches switches and controls, nothing about how much he/she has to bench...

Any thoughts or even data on this?

During production acceptance flights, the 737NG is flown in manual reversion (no hydraulics except standby rudder) and the trim wheel is also used -- there have been no noticeable issues with any of the pilots who come in all ages, sizes, shapes and genders -- IMHO the MAX would not be any different.

planecane wrote:

I don't have any way to find the statistics, but I am assuming that runaway stabilizer on an NG is an extremely rare event. The reason no NG has crashed because of it may be luck in that it almost never happens and, if it has, it was lucky that the crews for those flights did recognize it. My though is that MCAS just made it an order of magnitude or more higher chance to have a runaway stabilizer but that there may be an underlying training issue for all runaway stabilizer situations (possibly in all countries).

I think exactly the same. If the investigators confirms a such finding, the issue could touch more than the 737-8/9 MAX.

vrbarreto wrote:

morrisond wrote:

marcelh wrote:

Still blaming the pilots?

Nope 60-80% Boeing as I have said multiple times. I'm just getting sick of typing - "It's mainly Boeing's fault - however the accidents have also exposed some real deficiencies in Pilot training that need to be addressed as well"

If by deficiencies you mean 'clairvoyance' especially in terms of the lion Air pilots then many would be in complete agreement with you.

I will reserve judgement until the final reports are out, but it appears he isn't wrong. Why the Lion air crew didn't jump on the "RUNAWAY STABILIZER' NNC is an issue. On the 737, it's the only proper checklist to address any uncommanded and/or inappropriate movement of the stabilizer. If they didn't know that, it's a clear deficiency in their training.

The wildcard with ET in my mind is the normal stab trim system. Boeing states it will stop, and reverse the MCAS trim commands. If it was working as advertised, then the crew wasn't flying the airplane, it was flying them. Thats another training or experience issue.

But again, the full CVR transcripts, and final reports should clear a bunch of this up for everyone.

xmp125a wrote:

7BOEING7 wrote:

14ccKemiskt wrote:

This i probably old news, but the claim that MCAS relied on only one AoA sensor was a deliberate design choice in order to avoid extra training for pilots, since new two-sensor features would require just that, is horrifying.

https://youtu.be/QytfYyHmxtc?t=35m23s

And doesn't make any sense, especially because the FAA doesn't appear to require any sim training for MCAS 2.0 -- see discussion going on around near the end of previous page.

There is no good way to explain away the botched MCAS 1.0. Either:

- Boeing engineers did not interpret the regulations properly or
- Boeing engineers did interpret the regulations properly, but instead of following them, tried to hide recertification-prone design.

Pick one. Both of them are disastrous for the reputation of Boeing's plane design process.

Also, there's no good way for Boeing to formulate a standpoint in general for the MAX (featuring MCAS 1.0). Either:

-The plane was badly designed and faulty and should not have been delivered to customers.
or
-The plane was ok, but so difficult to fly during certain conditions that not all pilots could handle it.

Pick one. Either is disastrous for Boeing.

14ccKemiskt wrote:

xmp125a wrote:

7BOEING7 wrote:

And doesn't make any sense, especially because the FAA doesn't appear to require any sim training for MCAS 2.0 -- see discussion going on around near the end of previous page.

There is no good way to explain away the botched MCAS 1.0. Either:

- Boeing engineers did not interpret the regulations properly or
- Boeing engineers did interpret the regulations properly, but instead of following them, tried to hide recertification-prone design.

Pick one. Both of them are disastrous for the reputation of Boeing's plane design process.

Also, there's no good way for Boeing to formulate a standpoint in general for the MAX (featuring MCAS 1.0). Either:

-The plane was badly designed and faulty and should not have been delivered to customers.
or
-The plane was ok, but so difficult to fly during certain conditions that not all pilots could handle it.

Pick one. Either is disastrous for Boeing.

Meanwhile, Boeing insists/hints - at the same time - that:
a) MAX with MCAS v 1.0 had no deficiencies and was perfectly safe (no need to panic, no need to ground)
b) No simulator training whatsoever is needed between NG and MAX, 90 minutes on iPad will do
c) No pilots needed to know anything about MCAS, because because it is not really a new subsystem, it's just part of mumble jumble (*inaudible*)
d) When Lion Air crashed the MAX with MCAS v 1.0 they did so because pilots lacked training and knowledge
c) When Ethiopian crashed MAX with MCAS v 1.0 they did so because pilots should have known better (Boeing Bulletin) but apparently lacked training.

So at the same time, it's the airlines fault because of lack of training, yet the perfectly safe plane requires next to no particular training whatsoever.

AABusDrvr wrote:

vrbarreto wrote:

morrisond wrote:

Nope 60-80% Boeing as I have said multiple times. I'm just getting sick of typing - "It's mainly Boeing's fault - however the accidents have also exposed some real deficiencies in Pilot training that need to be addressed as well"

If by deficiencies you mean 'clairvoyance' especially in terms of the lion Air pilots then many would be in complete agreement with you.

I will reserve judgement until the final reports are out, but it appears he isn't wrong. Why the Lion air crew didn't jump on the "RUNAWAY STABILIZER' NNC is an issue. On the 737, it's the only proper checklist to address any uncommanded and/or inappropriate movement of the stabilizer. If they didn't know that, it's a clear deficiency in their training.

The wildcard with ET in my mind is the normal stab trim system. Boeing states it will stop, and reverse the MCAS trim commands. If it was working as advertised, then the crew wasn't flying the airplane, it was flying them. Thats another training or experience issue.

But again, the full CVR transcripts, and final reports should clear a bunch of this up for everyone.

Remember, there was more than just a trim issue. There is also an unreliable airspeed and stick shaker. How do you know trim is the root cause?
There were mentions that high lift malfunction on the wing can cause the shaker; so maybe that is the root cause? or something else?

IMHO biggest design flaw here is not a single sensor reliance or anything else - it is the fact that single failure escalates into multiple problems - airspeed disagree, stick shaker, nose down - with GPWS as an icing on the cake. Chances of properly sorting that out may be pretty high.... for Chuck Eager or Neil Armstrong, but apparently not for a regular guy. .

morrisond wrote:

FluidFlow wrote:

morrisond wrote:

Only 9 seconds elapsed between the Captains request and the Co-Pilot coming back and saying it didn't work. That doesn't seem like he gave it much of an effort if he was trying the manual wheel. He may have tried just spinning the wheel by hand and not knowing that there was a fold out handle to assist - or why didn't he ask the Pilot to help if he couldn't budge it by himself. In any case even if he tried it properly the overspeed at that point probably made it impossible to use.

Is it not a bit scary that you last line of defense, if you want to call it that way, when everything else fails, is not working in every scenario?

In general it should be that the less complicated the system the broader it should be usable?

The fact that the back up system is heavily limited is kind of a really bad design because in general when you need the back up system you are already in a bad situation.

If your electirc supply in a hospital fails and the back up generator only works wednesdays its not a great design.

Same should go for manual trim, it should work always no matter how fast you are, it should never fail except you have a structural failure. That should be the design limit and not overspeed.

Well then you would have to redesign most of the control surfaces on all Commercial Aircraft - not many of them are going to be that effective beyond Vmo. There is a reason there is a Vmo limit.

First I think working and being less effective is way better than not working at all and second the H-Stab is very effective at high speeds so if you can trim it you can stabilize the aircraft even if the elevator is useless.

The vmo is also there to prevent structural damage. But if you exceeded, for what ever reason, manual trim should still work if your h-stab is still there because while the elevators are useless the trim can help to pitch the nose up and reduce speed.

planecane wrote:

DocLightning wrote:

I think Boeing may have to eat the US$1M/frame charge, which is going to hurt. Right now, it seems as if they are trying to have their cake and eat it, too. They want a fix that isn't going to mean sim training, but I'm not sure that the various international regulators are going to let that happen, and US customers aren't going to buy a model that needs to be modified before it can be sold internationally.

The fix won't be any different. There may be foreign countries that require SIM training if the FAA doesn't but the aircraft will be the same.

Having two classes of pilots, one "universal" and the one certified for "US flights only" would be a big mess. It would not help US carriers a bit. If RoW (Rest of the World) demands sim training, US carriers would probably be best off if they train and recertify all of their 737 pilots. And I even don't envision the process of checking whether the pilot is certified or not. Imagine flight from Miami to Santo Domingo where Dominican authorities board the plane and demands proof that the pilot is properly 737 certified according to RoW criteria.

hilram wrote:

Meanwhile, Boeing insists/hints - at the same time - that:
a) MAX with MCAS v 1.0 had no deficiencies and was perfectly safe (no need to panic, no need to ground)
b) No simulator training whatsoever is needed between NG and MAX, 90 minutes on iPad will do
c) No pilots needed to know anything about MCAS, because because it is not really a new subsystem, it's just part of mumble jumble (*inaudible*)
d) When Lion Air crashed the MAX with MCAS v 1.0 they did so because pilots lacked training and knowledge
c) When Ethiopian crashed MAX with MCAS v 1.0 they did so because pilots should have known better (Boeing Bulletin) but apparently lacked training.

So at the same time, it's the airlines fault because of lack of training, yet the perfectly safe plane requires next to no particular training whatsoever.

Yes, I am also surprised that no one seriously challenges Boeing on this matter. How can you implicitly blame insufficient pilot training and in the next moment swear to the cert authorities that plane is good without additional training?

7BOEING7 wrote:

During production acceptance flights, the 737NG is flown in manual reversion (no hydraulics except standby rudder) and the trim wheel is also used -- there have been no noticeable issues with any of the pilots who come in all ages, sizes, shapes and genders -- IMHO the MAX would not be any different.

Really? Are we sure production acceptance flights cover the whole gamut of pilots that will fly it? I would expect that airlines send most experienced pilots, who have special training for product acceptance flights, and not a randomly chosen Joe or Jane.

planecane wrote:

frmrCapCadet wrote:

Stricter certification processes does not need to be a matter of retaliation. If the international committee recommends more analysis of the MAX it will be appropriate to extend analyses of the whole bunch of re-dos. (and there is no evidence that the rest need to be grounded - just maybe a closer look at them)

If they apply that logic, wouldn't it follow that logically, if MCAS was missed on the MAX then something could be lurking on the A320NEO or A330NEO that hasn't manifested yet. If that is a possibility then shouldn't they be grounded and fully recertified without grandfathering?

We are talking about basically total breakdown of Boeing's 737 MAX design process, which was due to unrealistic deadlines, caused by management failing to anticipate A320neo and then demanding that plane be delivered in about half of the usually required time. Breakdown includes possibly undue pressure on not only engineering team, but also certification officials, who were employed and paid by Boeing.

So far there are no indications that something like this happened at Airbus, or, in the development of new 777.

If this what we consider an abberation and isolated case at Boeing somehow became a default practice at Airbus too, then God help us, we will need to travel by sea again until the mess is cleared up!

xmp125a wrote:

planecane wrote:

frmrCapCadet wrote:

Stricter certification processes does not need to be a matter of retaliation. If the international committee recommends more analysis of the MAX it will be appropriate to extend analyses of the whole bunch of re-dos. (and there is no evidence that the rest need to be grounded - just maybe a closer look at them)

If they apply that logic, wouldn't it follow that logically, if MCAS was missed on the MAX then something could be lurking on the A320NEO or A330NEO that hasn't manifested yet. If that is a possibility then shouldn't they be grounded and fully recertified without grandfathering?

We are talking about basically total breakdown of Boeing's 737 MAX design process, which was due to unrealistic deadlines, caused by management failing to anticipate A320neo and then demanding that plane be delivered in about half of the usually required time. Breakdown includes possibly undue pressure on not only engineering team, but also certification officials, who were employed and paid by Boeing.

So far there are no indications that something like this happened at Airbus, or, in the development of new 777.

If this what we consider an abberation and isolated case at Boeing somehow became a default practice at Airbus too, then God help us, we will need to travel by sea again until the mess is cleared up!

Launch was in 2011 and first Delivery 2017 - six years for a minor derivative is not half the required time and was about the same as the NEO. That is closer to the time needed for a clean sheet design (787 - 7 Years and A350 8 Years but was supposed to be about 6.5) and new production system.

XRAYretired wrote:

kalvado wrote:

spinotter wrote:

From someone who knows nothing about a flying a plane, but after reading many comments on the MAX accident threads, it seems to me that the measures which needed to be taken to save JT and ET were just too complicated for ordinary human beings. Does it have to be so extremely complex? You'd like to think that a pilot is the equivalent of the sensory/motor activities of a bird in flight? Do birds have MCAS?

You know the story about old guy who fixes machine by a single stroke of the hammer, and then bills owner as "hammer stroke $1, diagnostics $999"?
My impression is that cockpit situation was similar: fixes were not that complicated, but realization of how to do things right took days and weeks of discussion. Human nature is such that even well-trained procedures can be - and do - get messed up; something that was just read before has little chance of being recalled correctly in a high stress situation. Hindsight is 20/20 or better, so now we know how to act in those situations.
Birds are somewhat different; I would compare MCAS with some things people do while loosing balance on slippery ice. Which is trying to react to a non-normal situation with crude and barely efficient balancing moves.

The picture of flayling arms and legs has cheered my day up. Anyway, birds would probably describes as fully FBW ('W' selection is entirely personal!) wouldn't they?

Ray

Good comparisons, both of you. Slipping on the ice and trying to recover, and flying by wing (FBW!).

xmp125a wrote:

If this what we consider an abberation and isolated case at Boeing somehow became a default practice at Airbus too, then God help us, we will need to travel by sea again until the mess is cleared up!

Well, there is the monthly Queen Mary 2 departure from New York to Southampton but I have a hard time seeing her being able to take on all air passengers. And then there are all other routes...

I don't think we by default should assume that similar issues that the MAX have are present in any other major aircraft type. But it is a wake up call for the industry in general and for Boeing and the FAA in particular.

xmp125a wrote:

bgm wrote:

To be fair, it's probably because a lot of the systems haven't been updated since 1967... I guess at this point we can call it great-grandfathering?

I think this is slowly becoming a problem on its own. Overspeed in ET flight notwithstanding, you do need certain amount of physical power to fly the 737 plane and to adjust the trim with the trim wheel. There have been barely any female pilots in 1967, but now the female pilots are something that has to be expected. Let's wait until someone finds out that the 737 would need different medical examination, which would make sure the pilots possess enough physical force to fly the plane.

As far as I know, the limits on pilot height and weight have never been an issue, and I am pretty sure that historically, the candidates who were too far from median simply were not selected to become pilots. But now there is a ton of regulations which prevent any kind of bias, as long as pilot fulfills the criteria. I am curious whether a very normal female of 1.6 cm and 50 kg would actually be able to handle 737 (MAX or NG). Medical standards only require that pilot comfortably reaches switches and controls, nothing about how much he/she has to bench...

Any thoughts or even data on this?

Well, I was on the flight deck of a 737 NG once and watched Suzanna Darcy-Henneman fly the airplane in manual reversion (no hydraulics) which included the use of the manual trim wheels. The flight was from cruise to landing. Of course, the airplane was at normal operating speeds, no where near Vmo/Mmo.

Suzanna closely met your 1.6 m and 50 kg criteria. (I don't think you meant 1.6 cm.)

Here she is along side Frank Santoni, who at one time was the 777 Chief Pilot.

https://media.gettyimages.com/photos/lo ... ?s=594x594

https://www.biographies.net/people/en/s ... y_henneman

kalvado wrote:

AABusDrvr wrote:

vrbarreto wrote:

If by deficiencies you mean 'clairvoyance' especially in terms of the lion Air pilots then many would be in complete agreement with you.

I will reserve judgement until the final reports are out, but it appears he isn't wrong. Why the Lion air crew didn't jump on the "RUNAWAY STABILIZER' NNC is an issue. On the 737, it's the only proper checklist to address any uncommanded and/or inappropriate movement of the stabilizer. If they didn't know that, it's a clear deficiency in their training.

The wildcard with ET in my mind is the normal stab trim system. Boeing states it will stop, and reverse the MCAS trim commands. If it was working as advertised, then the crew wasn't flying the airplane, it was flying them. Thats another training or experience issue.

But again, the full CVR transcripts, and final reports should clear a bunch of this up for everyone.

Remember, there was more than just a trim issue. There is also an unreliable airspeed and stick shaker. How do you know trim is the root cause?
There were mentions that high lift malfunction on the wing can cause the shaker; so maybe that is the root cause? or something else?

IMHO biggest design flaw here is not a single sensor reliance or anything else - it is the fact that single failure escalates into multiple problems - airspeed disagree, stick shaker, nose down - with GPWS as an icing on the cake. Chances of properly sorting that out may be pretty high.... for Chuck Eager or Neil Armstrong, but apparently not for a regular guy. .

This is where training, and experience become a major player. Prioritization of tasks, and flying the airplane always has to come first. The undue activation of the stick shaker would lead you into the unreliable airspeed checklist. At some point, as the stick forces keep getting heavier towards nose down, but lighten up as you trim nose up, one would believe that the crew would begin to think there was a problem with the stab trim. Since it's not doing what you told it to, and go into that check list.

The airplane will keep flying with unreliable airspeed, and an undue stick shaker, uncommanded stabilizer motion, or a runaway stab is a much bigger threat.

Probably the most famous example of what I'm getting at is United 232. Al Haynes and his crew were handed an airplane that was essentially unflyable, with multiple failures no one ever thought were going to happen. There wasn't a single check list that would have helped them recover the airplane. They fell back on their training and experience (IIRC, there was over 60,000+ hours of combined flight time in that cockpit), and they made the outcome, bad as it was, much better than it could have been.

Just about any modern airplane will exhibit multiple failures with bad air data inputs, the 737 isn't alone in that regard.

I'll again include this snippet from an airplane operating manual.

"Checklists cannot be created for all conceivable situations and are not intended to
replace good judgment. In some situations, at the captain’s discretion, checklist
deviation(s) may be necessary."

It still applies in any airplane.

xmp125a wrote:

hilram wrote:

Meanwhile, Boeing insists/hints - at the same time - that:
a) MAX with MCAS v 1.0 had no deficiencies and was perfectly safe (no need to panic, no need to ground)
b) No simulator training whatsoever is needed between NG and MAX, 90 minutes on iPad will do
c) No pilots needed to know anything about MCAS, because because it is not really a new subsystem, it's just part of mumble jumble (*inaudible*)
d) When Lion Air crashed the MAX with MCAS v 1.0 they did so because pilots lacked training and knowledge
c) When Ethiopian crashed MAX with MCAS v 1.0 they did so because pilots should have known better (Boeing Bulletin) but apparently lacked training.

So at the same time, it's the airlines fault because of lack of training, yet the perfectly safe plane requires next to no particular training whatsoever.

Yes, I am also surprised that no one seriously challenges Boeing on this matter. How can you implicitly blame insufficient pilot training and in the next moment swear to the cert authorities that plane is good without additional training?

They are sort of logical.
what they say is that same procedure as must be known to every 737 pilot, and procedure that is the same for NG-Classic-Jurassic, should be known to MAX pilots. Now that means no MAX specific training, but lack of baseline 737 training.
Now there is a lot of fine (and not so fine) print to argue about, but there is some logic here.

AABusDrvr wrote:

kalvado wrote:

AABusDrvr wrote:

I will reserve judgement until the final reports are out, but it appears he isn't wrong. Why the Lion air crew didn't jump on the "RUNAWAY STABILIZER' NNC is an issue. On the 737, it's the only proper checklist to address any uncommanded and/or inappropriate movement of the stabilizer. If they didn't know that, it's a clear deficiency in their training.

The wildcard with ET in my mind is the normal stab trim system. Boeing states it will stop, and reverse the MCAS trim commands. If it was working as advertised, then the crew wasn't flying the airplane, it was flying them. Thats another training or experience issue.

But again, the full CVR transcripts, and final reports should clear a bunch of this up for everyone.

Remember, there was more than just a trim issue. There is also an unreliable airspeed and stick shaker. How do you know trim is the root cause?
There were mentions that high lift malfunction on the wing can cause the shaker; so maybe that is the root cause? or something else?

IMHO biggest design flaw here is not a single sensor reliance or anything else - it is the fact that single failure escalates into multiple problems - airspeed disagree, stick shaker, nose down - with GPWS as an icing on the cake. Chances of properly sorting that out may be pretty high.... for Chuck Eager or Neil Armstrong, but apparently not for a regular guy. .

This is where training, and experience become a major player. Prioritization of tasks, and flying the airplane always has to come first. The undue activation of the stick shaker would lead you into the unreliable airspeed checklist. At some point, as the stick forces keep getting heavier towards nose down, but lighten up as you trim nose up, one would believe that the crew would begin to think there was a problem with the stab trim. Since it's not doing what you told it to, and go into that check list.

The airplane will keep flying with unreliable airspeed, and an undue stick shaker, uncommanded stabilizer motion, or a runaway stab is a much bigger threat.

Probably the most famous example of what I'm getting at is United 232. Al Haynes and his crew were handed an airplane that was essentially unflyable, with multiple failures no one ever thought were going to happen. There wasn't a single check list that would have helped them recover the airplane. They fell back on their training and experience (IIRC, there was over 60,000+ hours of combined flight time in that cockpit), and they made the outcome, bad as it was, much better than it could have been.

Just about any modern airplane will exhibit multiple failures with bad air data inputs, the 737 isn't alone in that regard.

I'll again include this snippet from an airplane operating manual.

"Checklists cannot be created for all conceivable situations and are not intended to
replace good judgment. In some situations, at the captain’s discretion, checklist
deviation(s) may be necessary."

It still applies in any airplane.

This is where engineering psychology should apply. Miracles happen; but you cannot design for aces only. Not mass produced vehicles anyway - Shuttle or Apollo may be a different story.
And I heavily doubt success rate will be above 50% for experienced and trained line pilots for scenarios we discuss. If I remember correctly, sim success in UA232 scenario was very low..

OldAeroGuy wrote:

xmp125a wrote:

As far as I know, the limits on pilot height and weight have never been an issue, and I am pretty sure that historically, the candidates who were too far from median simply were not selected to become pilots. But now there is a ton of regulations which prevent any kind of bias, as long as pilot fulfills the criteria. I am curious whether a very normal female of 1.6 cm and 50 kg would actually be able to handle 737 (MAX or NG). Medical standards only require that pilot comfortably reaches switches and controls, nothing about how much he/she has to bench...

Any thoughts or even data on this?

Well, I was on the flight deck of a 737 NG once and watched Suzanna Darcy-Henneman fly the airplane in manual reversion (no hydraulics) which included the use of the manual trim wheels. The flight was from cruise to landing. Of course, the airplane was at normal operating speeds, no where near Vmo/Mmo.

Suzanna closely met your 1.6 m and 50 kg criteria. (I don't think you meant 1.6 cm.)

Of course, that was a typo, it was 1.6m. I am happy and a bit relieved to hear this. I instantly asked if great-grandfathering, like 737 are becoming a problem due to societal changes. In 1960s, employers had total discretion on whom to hire. Now, much less so - and this is very significant societal change, that may influence the safety in many unanticipated ways. In addition to that, there is shortage of pilots so people with much less experience are in the very responsible role.

My point was - not every grandfathering aspect is exclusively related to technology, changes in society in such long time frame should be analyzed too. A person with as much psychiatric problems as that suicidal Germanwings pilot would probably be acknowledged as "loonie" in 1960s and would not be let onto airplane even as passenger, let alone pilots But in 50 years, medicines for depression made such a big leap that medicated people can work almost anywhere and it is possibly to hide such difficult conditions and pretend you are allright and fly a plane.

xmp125a wrote:

Of course, that was a typo, it was 1.6m. I am happy and a bit relieved to hear this. I instantly asked if great-grandfathering, like 737 are becoming a problem due to societal changes. In 1960s, employers had total discretion on whom to hire. Now, much less so - and this is very significant societal change, that may influence the safety in many unanticipated ways. In addition to that, there is shortage of pilots so people with much less experience are in the very responsible role.

My point was - not every grandfathering aspect is exclusively related to technology, changes in society in such long time frame should be analyzed too. A person with as much psychiatric problems as that suicidal Germanwings pilot would probably be acknowledged as "loonie" in 1960s and would not be let onto airplane even as passenger, let alone pilots But in 50 years, medicines for depression made such a big leap that medicated people can work almost anywhere and it is possibly to hide such difficult conditions and pretend you are allright and fly a plane.

There are certification requirements for the forces to be used on controls, and they are what I would call reasonable.
What happened with MAX, is that plane got too far away from normal conditions, and that meant that forces were high as required for certification because things were so abnormal. That includes yoke force, which was I believe >40lb ~ 20 kg in case of MentourPilot sim run. Would a small lady be able to handle force that an able-body gentlemen struggles with? Not sure.
So, add to list of Boeing failures: automation pushing plane where it should never be to begin with, so that controls go crazy. Should you interpret that as "no tiny ladies at controls" or in some other way is up to you.

xmp125a wrote:

7BOEING7 wrote:

14ccKemiskt wrote:

This i probably old news, but the claim that MCAS relied on only one AoA sensor was a deliberate design choice in order to avoid extra training for pilots, since new two-sensor features would require just that, is horrifying.

https://youtu.be/QytfYyHmxtc?t=35m23s

And doesn't make any sense, especially because the FAA doesn't appear to require any sim training for MCAS 2.0 -- see discussion going on around near the end of previous page.

There is no good way to explain away the botched MCAS 1.0. Either:

- Boeing engineers did not interpret the regulations properly or
- Boeing engineers did interpret the regulations properly, but instead of following them, tried to hide recertification-prone design.

Pick one. Both of them are disastrous for the reputation of Boeing's plane design process.

I suspect that there is at least one other explanation.

The MCAS FMEA (Failure Modes & Effects Analysis) included probably a historic AoA signal failure rate that was on the order of 1 X 10-6 and postulated that only 1 crew in 1000 wouldn't be able to deal with the potential Stab Runaway. The 1 crew in 1000 is why Stab Runaway is a memory item.

That's probably the same logic that the pre-MAX and MAX Stab Runaway is certified. Many other airplanes may use the same Stab Runaway logic.

MCASv.2 is a good idea, but the AoA vane signal failure frequency should be a huge concern as many systems (on many airplanes) depend on reliable AoA signal information.

OldAeroGuy wrote:

xmp125a wrote:

7BOEING7 wrote:

And doesn't make any sense, especially because the FAA doesn't appear to require any sim training for MCAS 2.0 -- see discussion going on around near the end of previous page.

There is no good way to explain away the botched MCAS 1.0. Either:

- Boeing engineers did not interpret the regulations properly or
- Boeing engineers did interpret the regulations properly, but instead of following them, tried to hide recertification-prone design.

Pick one. Both of them are disastrous for the reputation of Boeing's plane design process.

I suspect that there is at least one other explanation.

The MCAS FMEA (Failure Modes & Effects Analysis) included probably a historic AoA signal failure rate that was on the order of 1 X 10-6 and postulated that only 1 crew in 1000 wouldn't be able to deal with the potential Stab Runaway. The 1 crew in 1000 is why Stab Runaway is a memory item.

That's probably the same logic that the pre-MAX and MAX Stab Runaway is certified. Many other airplanes may use the same Stab Runaway logic.

MCASv.2 is a good idea, but the AoA vane signal failure frequency should be a huge concern as many systems (on many airplanes) depend on reliable AoA signal information.

Nope. Boeing commented that AoA sensor MTBF is below 1e5 hours.
1 in 1000 human error can be achieved if, and only if, that specific procedure is practiced on a regular basis.
So nope, that is not an explanation.

7BOEING7 wrote:

During production acceptance flights, the 737NG is flown in manual reversion (no hydraulics except standby rudder) and the trim wheel is also used -- there have been no noticeable issues with any of the pilots who come in all ages, sizes, shapes and genders -- IMHO the MAX would not be any different.

Are you sure this is still done in 2019? Three decades or more ago, all sorts of 'tests' (even pranks?) were performed.

In 2019, there are airlines that don't even perform a CAF / delegate CAF to the OEM or third party.

Boeing must be carrying the insurance for the customer designated crew, which means for the purposes of the CAF, the crew have been approved by Boeing's insurer, which in turn would require refresher simulator time specifically covering manual reversion.

Perhaps with concerns regarding pilot competence, this is a good idea. Could add RTO's to CAF as well.

kalvado wrote:

Remember, there was more than just a trim issue. There is also an unreliable airspeed and stick shaker. How do you know trim is the root cause?
There were mentions that high lift malfunction on the wing can cause the shaker; so maybe that is the root cause? or something else?

IMHO biggest design flaw here is not a single sensor reliance or anything else - it is the fact that single failure escalates into multiple problems - airspeed disagree, stick shaker, nose down - with GPWS as an icing on the cake. Chances of properly sorting that out may be pretty high.... for Chuck Eager or Neil Armstrong, but apparently not for a regular guy. .

While the AoA signal failure activated the stick shaker and caused the "Airspeed Unreliable" and "Altitude Unreliable" flags, it did not immediately result in any MCAS related trim issues. MCAS only started after the crew retracted Flaps after not dealing with the Airspeed and Altitude problems at Flaps 5.

In response to your high lift malfunction question, a LE slat problem could cause a stick shaker activation but as long as the AoA signal was reliable, it would not result Airspeed and Altitude errors.

AABusDrvr wrote:

Probably the most famous example of what I'm getting at is United 232. Al Haynes and his crew were handed an airplane that was essentially unflyable, with multiple failures no one ever thought were going to happen. There wasn't a single check list that would have helped them recover the airplane. They fell back on their training and experience (IIRC, there was over 60,000+ hours of combined flight time in that cockpit), and they made the outcome, bad as it was, much better than it could have been.

But how many Al Haynes worked at United?

If you want to use him as a template, replicating his experience / hours throughout the World, given the growth of commercial aircraft numbers, we either need a lot of A380's (so status quo with crew numbers), or 3-4 crew even on a 737, or better simulators (compared to MAX-badged NG simulators) and vastly more simulator time.

Yay! More Simulators and Sim time gets my vote.

OldAeroGuy wrote:

Well, I was on the flight deck of a 737 NG once and watched Suzanna Darcy-Henneman fly the airplane in manual reversion (no hydraulics) which included the use of the manual trim wheels. The flight was from cruise to landing. Of course, the airplane was at normal operating speeds, no where near Vmo/Mmo.

Suzanna closely met your 1.6 m and 50 kg criteria. (I don't think you meant 1.6 cm.)
Here she is along side Frank Santoni, who at one time was the 777 Chief Pilot.

https://media.gettyimages.com/photos/lo ... ?s=594x594
https://www.biographies.net/people/en/s ... y_henneman

Is that example representative for the condition discussed? Which was a (severely) out-of-trim condition on the elevator. Did Suzanna and Frank replicate or experience an out-of-trim condition during that flight?

* Vmo became an issue only *after* MCAS cycle(s);
* MCAS was responsible for creating the out-of-trim condition;
* The out-of trim condition - in combination with high(ish) speed - caused the manual handwheel trim to be not working (as confirmed by several parties by now);
* This same condition *may* have also prevented electric trimming from reaching balanced pitch trim (can't find the reference right now, but I'm sure I've read somewhere that - also on the NG - electric trim motor may not always be able to overcome aerodynamic loading at full elevator loading).

Air speed at first MCAS cycle was perhaps highish, but not excessive and nowhere near Vmo.
It has been argued in this thread that other crews (including well trained USA opertors) on MAX and NG followed a similar flight path and air speed profile (up to the point of first MCAS cycle) when encountered with AoA disagree and unrelibale airspeed.

OldAeroGuy wrote:

kalvado wrote:

Remember, there was more than just a trim issue. There is also an unreliable airspeed and stick shaker. How do you know trim is the root cause?
There were mentions that high lift malfunction on the wing can cause the shaker; so maybe that is the root cause? or something else?

IMHO biggest design flaw here is not a single sensor reliance or anything else - it is the fact that single failure escalates into multiple problems - airspeed disagree, stick shaker, nose down - with GPWS as an icing on the cake. Chances of properly sorting that out may be pretty high.... for Chuck Eager or Neil Armstrong, but apparently not for a regular guy. .

While the AoA signal failure activated the stick shaker and caused the "Airspeed Unreliable" and "Altitude Unreliable" flags, it did not immediately result in any MCAS related trim issues. MCAS only started after the crew retracted Flaps after not dealing with the Airspeed and Altitude problems at Flaps 5.

In response to your high lift malfunction question, a LE slat problem could cause a stick shaker activation but as long as the AoA signal was reliable, it would not result Airspeed and Altitude errors.

I think by now we can agree that flaps up wasn't procedure mandated mode in current iteration of manuals, but it shouldn't cause any drastic effects - and likely would not in NG.
My message, though, is that quick troubleshooting is anything but a simple task. Piecing together information from multiple channels into a non-standard picture in an emergency is something where failure shouldn't be unexpected.

OldAeroGuy wrote:

[
I suspect that there is at least one other explanation.

The MCAS FMEA (Failure Modes & Effects Analysis) included probably a historic AoA signal failure rate that was on the order of 1 X 10-6 and postulated that only 1 crew in 1000 wouldn't be able to deal with the potential Stab Runaway. The 1 crew in 1000 is why Stab Runaway is a memory item.

Is that an actual, industry accepted, failure rate for AoA?
I mean, I can easily understand a somewhat/much higher failure rate considering the wide operating conditions this moving and calibrated part is exposed to in free air stream. Not withstanding frequent birdstrikes . . .

smartplane wrote:

7BOEING7 wrote:

During production acceptance flights, the 737NG is flown in manual reversion (no hydraulics except standby rudder) and the trim wheel is also used -- there have been no noticeable issues with any of the pilots who come in all ages, sizes, shapes and genders -- IMHO the MAX would not be any different.

Are you sure this is still done in 2019? Three decades or more ago, all sorts of 'tests' (even pranks?) were performed.

In 2019, there are airlines that don't even perform a CAF / delegate CAF to the OEM or third party.

Boeing must be carrying the insurance for the customer designated crew, which means for the purposes of the CAF, the crew have been approved by Boeing's insurer, which in turn would require refresher simulator time specifically covering manual reversion.

Perhaps with concerns regarding pilot competence, this is a good idea. Could add RTO's to CAF as well.

The 737 production profile for FAA acceptance (which is very similar to other Boeing models) was basically the same from the late 70’s thru the early 2010’s so I don’t think it has changed much in the last few years.

There have been airlines that accept a “Boeing Buy” (no CAF - Customer Acceptance Flight) on the 737 for over 40 years — it’s nothing new.

No special insurance above what Boeing normally carries is required on the CAF — the Boeing pilot is always in charge. The customer pilots are not even required to be familiar with the profile — its explained in the preflight and inflight as we go along. Nor is there any requirement for refresher simulators for manual reversion that I know of, why?

OldAeroGuy wrote:

kalvado wrote:

Remember, there was more than just a trim issue. There is also an unreliable airspeed and stick shaker. How do you know trim is the root cause?
There were mentions that high lift malfunction on the wing can cause the shaker; so maybe that is the root cause? or something else?

IMHO biggest design flaw here is not a single sensor reliance or anything else - it is the fact that single failure escalates into multiple problems - airspeed disagree, stick shaker, nose down - with GPWS as an icing on the cake. Chances of properly sorting that out may be pretty high.... for Chuck Eager or Neil Armstrong, but apparently not for a regular guy. .

While the AoA signal failure activated the stick shaker and caused the "Airspeed Unreliable" and "Altitude Unreliable" flags, it did not immediately result in any MCAS related trim issues. MCAS only started after the crew retracted Flaps after not dealing with the Airspeed and Altitude problems at Flaps 5.

In response to your high lift malfunction question, a LE slat problem could cause a stick shaker activation but as long as the AoA signal was reliable, it would not result Airspeed and Altitude errors.

Do you think the crew perceived they had altitude problems, considering daylight and clear skies? Air speed. Yes. Altitude? Hmm, just look out the window and fly the plane, some would argue.

Perhaps it was by choice to let airspeed increase, by not going to climb thrust bug and keeping a shallow climb profile, because of stick shaker and stall warnings? And which of course required them to retract flaps when approaching max flap speed?

PW100 wrote:

OldAeroGuy wrote:

[
I suspect that there is at least one other explanation.

The MCAS FMEA (Failure Modes & Effects Analysis) included probably a historic AoA signal failure rate that was on the order of 1 X 10-6 and postulated that only 1 crew in 1000 wouldn't be able to deal with the potential Stab Runaway. The 1 crew in 1000 is why Stab Runaway is a memory item.

Is that an actual, industry accepted, failure rate for AoA?
I mean, I can easily understand a somewhat/much higher failure rate considering the wide operating conditions this moving and calibrated part is exposed to in free air stream. Not withstanding frequent birdstrikes . . .

.
1 million hours is certainly NOT an accepted value. I cannot find Rosemount datasheet; a number of 70k hours was mentioned
A competing product from Goodrich used on CRJs is advertised as Fleet MTBF greater than 20,000 flight hours
http://www.goodrich.com/cap/systems/sis ... ack%20(AOA)%20Systems%20Model%200861HB.pdf

smartplane wrote:

7BOEING7 wrote:

During production acceptance flights, the 737NG is flown in manual reversion (no hydraulics except standby rudder) and the trim wheel is also used -- there have been no noticeable issues with any of the pilots who come in all ages, sizes, shapes and genders -- IMHO the MAX would not be any different.

Are you sure this is still done in 2019? Three decades or more ago, all sorts of 'tests' (even pranks?) were performed.

In 2019, there are airlines that don't even perform a CAF / delegate CAF to the OEM or third party.

Boeing must be carrying the insurance for the customer designated crew, which means for the purposes of the CAF, the crew have been approved by Boeing's insurer, which in turn would require refresher simulator time specifically covering manual reversion.

Perhaps with concerns regarding pilot competence, this is a good idea. Could add RTO's to CAF as well.

Boeing has been modifying the CAFs to do less of the B-1 profile recently and would ideally like to do away with customer flights entirely but that will take a while. The RTO with a customer may have already been discontinued but previously was always done.

Pilot competence was never an issue — they had a rating, put them in the left seat and they were good to go.

SomebodyInTLS wrote:

xmp125a wrote:

I am curious whether a very normal female of 1.6 cm and 50 kg would actually be able to handle 737 (MAX or NG).

Any thoughts or even data on this?

I'm pretty sure a 1.6cm person of any sort would find piloting a MAX tricky. How would they even get from the pedals to the top of the yoke?

high heels would work ....

morrisond wrote:

marcelh wrote:

morrisond wrote:

Well then you would have to redesign most of the control surfaces on all Commercial Aircraft - not many of them are going to be that effective beyond Vmo. There is a reason there is a Vmo limit.

Still blaming the pilots?

Nope 60-80% Boeing as I have said multiple times. I'm just getting sick of typing - "It's mainly Boeing's fault - however the accidents have also exposed some real deficiencies in Pilot training that need to be addressed as well"

Not including the following topics in the NG to MAX pilot training are REAL DEFICIENCIES in pilot training that are also 100% on Boeing:
- The existence of MCAS, what it does, and what it could potentially do when a sensor fails
- The fact that the AoA disagree light is no longer operative on the MAX for planes not equipped with the AoA Indicator (that's different from the NG as well)

NYT has released another article regarding the MAX and some of the American Airlines pilots frustrated with Boeing not being more proactive after the Lion Air crash.

https://www.nytimes.com/2019/05/14/busi ... crash.html

Knowing what we know at this point you won't see me on a MAX anytime soon. I don't even think that is an issue as I doubt we see then return to service in 2019. Boeing thru the whole process sacrificed safety to rush this plane on the market. $ over innocent peoples lives. Hope the executives sleep well at night.

It's not shock that Boeing have zero sales on the books for April. Everyone knows this is going to take way longer than anyone wants and Boeing discounts and offers could be very good. Even if you want to order the 787 or 777 airlines are waiting, they can see good deals coming.

slcdeltarumd11 wrote:

Knowing what we know at this point you won't see me on a MAX anytime soon. I don't even think that is an issue as I doubt we see then return to service in 2019. Boeing thru the whole process sacrificed safety to rush this plane on the market. $ over innocent peoples lives. Hope the executives sleep well at night.

It's not shock that Boeing have zero sales on the books for April. Everyone knows this is going to take way longer than anyone wants and Boeing discounts and offers could be very good. Even if you want to order the 787 or 777 airlines are waiting, they can see good deals coming.

They actually receive an order for 4 737 MAX in April...

AABusDrvr wrote:

vrbarreto wrote:

morrisond wrote:

Nope 60-80% Boeing as I have said multiple times. I'm just getting sick of typing - "It's mainly Boeing's fault - however the accidents have also exposed some real deficiencies in Pilot training that need to be addressed as well"

If by deficiencies you mean 'clairvoyance' especially in terms of the lion Air pilots then many would be in complete agreement with you.

I will reserve judgement until the final reports are out, but it appears he isn't wrong. Why the Lion air crew didn't jump on the "RUNAWAY STABILIZER' NNC is an issue. On the 737, it's the only proper checklist to address any uncommanded and/or inappropriate movement of the stabilizer. If they didn't know that, it's a clear deficiency in their training.

The wildcard with ET in my mind is the normal stab trim system. Boeing states it will stop, and reverse the MCAS trim commands. If it was working as advertised, then the crew wasn't flying the airplane, it was flying them. Thats another training or experience issue.

But again, the full CVR transcripts, and final reports should clear a bunch of this up for everyone.

They were dealing with issues from the moment they took off. With multiple issues to deal with runaway stabiliser was down on the list. Pilot overload.

many321 wrote:

NYT has released another article regarding the MAX and some of the American Airlines pilots frustrated with Boeing not being more proactive after the Lion Air crash.

https://www.nytimes.com/2019/05/14/busi ... crash.html

Pretty damning stuff in there.

Aviation737 wrote:

slcdeltarumd11 wrote:

Knowing what we know at this point you won't see me on a MAX anytime soon. I don't even think that is an issue as I doubt we see then return to service in 2019. Boeing thru the whole process sacrificed safety to rush this plane on the market. $ over innocent peoples lives. Hope the executives sleep well at night.

It's not shock that Boeing have zero sales on the books for April. Everyone knows this is going to take way longer than anyone wants and Boeing discounts and offers could be very good. Even if you want to order the 787 or 777 airlines are waiting, they can see good deals coming.

They actually receive an order for 4 737 MAX in April...

Apparently CNN reports that their four are order transferred from an unnamed lessor.

slcdeltarumd11 wrote:

Knowing what we know at this point you won't see me on a MAX anytime soon. I don't even think that is an issue as I doubt we see then return to service in 2019.

Interesting point of view.

Here's what Morgan Stanley's analyst recently wrote:

The MAX certification is progressing with the May 23 FAA event being a key watch item. Following the most recent earnings call on April 24, there was a view that an effective FAA handover was imminent of the software fixes on the MAX via a certification flight, which has yet to occur. However, management pointed out that there was no delay in the process and that the FAA has been engaged with Boeing on a consistent basis. Moreover, it was even noted that such a certification flight is not a prerequisite to returning the aircraft to service. Nonetheless, that process does seem like it will move forward over the coming weeks, with the most important milestone now being the May 23 meeting between the FAA and global aviation officials. Following this meeting, there is the potential for a clearer path forward relating to a removal of the grounding, certifying of fixes, and necessary training, all through a more consensual path. We find this encouraging given the opportunity for clarity and a return to service consistent with our late 2Q19 / early 3Q19 assumption.

Ref: https://leehamnews.com/2019/05/10/boein ... l-analyst/

It will be interesting to see how well that time line holds.

Boeing seems to presume the outcome of the May 23rd event will be more consent with regard to return to service.

Time will tell if this is wishful thinking or not.

14ccKemiskt wrote:

xmp125a wrote:

If this what we consider an abberation and isolated case at Boeing somehow became a default practice at Airbus too, then God help us, we will need to travel by sea again until the mess is cleared up!

Well, there is the monthly Queen Mary 2 departure from New York to Southampton but I have a hard time seeing her being able to take on all air passengers. And then there are all other routes...

I don't think we by default should assume that similar issues that the MAX have are present in any other major aircraft type. But it is a wake up call for the industry in general and for Boeing and the FAA in particular.

In that case, will Boeing provide subsidized tickets for QM2?

RickNRoll wrote:

many321 wrote:

NYT has released another article regarding the MAX and some of the American Airlines pilots frustrated with Boeing not being more proactive after the Lion Air crash.

https://www.nytimes.com/2019/05/14/busi ... crash.html

Pretty damning stuff in there.

Yes and no.

It should be no surprise to anyone that the pilots in general and their union reps in particular were pissed off about not being told about MCAS.

It's pretty strange that someone recorded the meeting, no?

I'm sure those issuing the subpoenas are glad that such a recording exists.

My impression is, if anything else, Boeing is consistent about how it views the issue:

“The assumption is that the flight crews have been trained,” Mr. Sinnett said in the meeting. He added later: “Rightly or wrongly, that was the design criteria and that’s how the airplane was certified with the system and pilot working together.”

At least the inclusion of "rightly or wrongly" shows some introspection, and a degree of vulnerability that presumably makes Boeing's lawyers cringe.

On the other hand, he's almost daring the regulators to change certification criteria in a way that would disallow future MCASes to pass muster.

I wonder if in the end the regulators will be so bold, or if Boeing is making a calculated bet that they will not be that bold?

Another thing he said that would make the lawyers cringe:

Mr. Sinnett acknowledged that the company was looking into potential mistakes in the design of the jet.

“One of the questions will be, is our design assumption wrong?” Mr. Sinnett said. “We’re going through that whole thought process of, were our assumptions really even valid when we did this?”

But he remained steadfast that pilots should know how to handle a malfunction of the new software on the plane, given their existing training.

It seems the public line is that they now have looked at things and convinced themselves their assumptions were valid.

It seems the public and the international regulators are not willing to accept their self assessment.

However the ever present pressure along the lines of "too big to fail" is clearly not going to go away.

Revelation wrote:

slcdeltarumd11 wrote:

Knowing what we know at this point you won't see me on a MAX anytime soon. I don't even think that is an issue as I doubt we see then return to service in 2019.

Interesting point of view.

Here's what Morgan Stanley's analyst recently wrote:

The MAX certification is progressing with the May 23 FAA event being a key watch item. Following the most recent earnings call on April 24, there was a view that an effective FAA handover was imminent of the software fixes on the MAX via a certification flight, which has yet to occur. However, management pointed out that there was no delay in the process and that the FAA has been engaged with Boeing on a consistent basis. Moreover, it was even noted that such a certification flight is not a prerequisite to returning the aircraft to service. Nonetheless, that process does seem like it will move forward over the coming weeks, with the most important milestone now being the May 23 meeting between the FAA and global aviation officials. Following this meeting, there is the potential for a clearer path forward relating to a removal of the grounding, certifying of fixes, and necessary training, all through a more consensual path. We find this encouraging given the opportunity for clarity and a return to service consistent with our late 2Q19 / early 3Q19 assumption.

Ref: https://leehamnews.com/2019/05/10/boein ... l-analyst/

It will be interesting to see how well that time line holds.

Boeing seems to presume the outcome of the May 23rd event will be more consent with regard to return to service.

Time will tell if this is wishful thinking or not.

This would be a great timeline under the assumption that nobody questions any other aspect of MAX and only a small piece of code needs a fix. Apparently FAA doesn't have further questions; apparently, some other parties do. Will be interesting to see how things will unfold.
Nobody can hold plane on the ground just-because. There has to be a good reason and a clear path towards return to flight. So far, certification review is the words I heard - but I wonder if there is anything specific they're looking at.

My confidence and trust is forever shaken in Boeing. After watching the 60 minutes Australia, reading commentary from pilots and this article https://medium.com/@gregoryreedtravis/t ... b1869839b6 I don't know how the Max could ever be trusted.

A question for 737 pilots, if the need for MCAS was driven by quirky aerodynamics then why should we even trust the aircraft design?

RickNRoll wrote:

AABusDrvr wrote:

vrbarreto wrote:

If by deficiencies you mean 'clairvoyance' especially in terms of the lion Air pilots then many would be in complete agreement with you.

I will reserve judgement until the final reports are out, but it appears he isn't wrong. Why the Lion air crew didn't jump on the "RUNAWAY STABILIZER' NNC is an issue. On the 737, it's the only proper checklist to address any uncommanded and/or inappropriate movement of the stabilizer. If they didn't know that, it's a clear deficiency in their training.

The wildcard with ET in my mind is the normal stab trim system. Boeing states it will stop, and reverse the MCAS trim commands. If it was working as advertised, then the crew wasn't flying the airplane, it was flying them. Thats another training or experience issue.

But again, the full CVR transcripts, and final reports should clear a bunch of this up for everyone.

They were dealing with issues from the moment they took off. With multiple issues to deal with runaway stabiliser was down on the list. Pilot overload.

Once the airplane was under control, the uncommanded stabilizer movement was far and away the biggest threat for that crew. Had it been dealt with properly, and in a timely fashion, we wouldn't be having the conversation we are.

Multiple failures/issues with spurious warnings is a challenge, but is not an insurmountable problem.