DL757NYC wrote:

A320FlyGuy wrote:

Bobloblaw wrote:

For everyone saying Boeing should have made a clean sheet design to replace the 737, do you realize Boeing didn’t and doesn’t have the resources for a 737 replacement AND the 787??? It was one of the other. Clean sheet 737 replacement means no 787, giving away the market to the A350.. btw same thing with Airbus. Either 320 replacement Or 350, both cannot be built.

Your logic is a tad flawed here:

With Boeing:

The 737 should have been replaced as it is the volume leader - there is a larger market for single aisle aircraft like the 737 and it should be the focus of the company’s developement resources. Instead of doing a full clean sheet design and creating the 787, it would have made more sense to invest the funds in the 737 replacement and create a 767MAX. Funds that were wasted on the 747-8 could and should have been directed to the 737 since it is the only single aisle aircraft model still in production at Boeing and there is very healthy demand.

With Airbus:

The A320 being a newer design in comparison to the 737 has greater development potential and a clean sheet replacement was not as pressing - Also, Airbus began a program in 2006 known as the A320 Enhanced - a series of improvements that would deliver a 4-6% increase in efficiency. The A320 has benefitted from this program of continuous improvement with incremental modifications and improvements. Also, the A320 benefits from having a very efficient airframe that is now dependent on improvements in engine technology to better the performance of the aircraft.

Airlines have clearly responded to the A320neo as being a superior alternative to the 737MAX based on sales - Airbus has a healthy 1,350 aircraft lead over the 737MAX in terms of sales.

They pushed the design to compete with the A320 and A321 and the 737 was never meant to be that large. They literally crammed those engine in there. Look at the landing gear and how much they spent on design for the max 10’The A320/321 has room under the wings for larger engines. This is a direct result of the gap they have between the 737 and the 787. In my humble opinion you can only push a design so far.

And your expertise is what?

estorilm wrote:

journeyperson wrote:

estorilm wrote:

It wasn't just "required by FAA rules" - it was required because the aircraft was inherently (or dangerously) unstable vs. NG in power-on stall or pre-stall situations. Also, that's NO BUENO in my book (and regardless of MCAS, could have been a contributing factor to this crash).

I think this is the crux of the decisions around the world to ground this aircraft. The plane is inherently unstable due to changes in the design from previous versions and the software fix is not 100% reliable. This much seems to have been acknowledged by the industry.

Who will have faith in any further fixes? I have always loved flying in the 737 as a passenger and have always felt it was about the safest commercial airliner. I don't think I will ever fly in a 737 MAX. I don't think I will have the option.

Yeah - I mean I'm not too worried about the aircraft itself, I just REALLY REALLY wish I knew exactly what the thing does in situations where they decided MCAS was required. I'm way more curious about that lately than I am about the MCAS system being at fault. It would be nice to know how the aircraft itself naturally flies and what it's trying to do.

It was explained million times: MCAS should come into play when pilot pushes aircraft into a deep stall. It is a last resort effort to save the day, on par with life rafts. Regulators will not let you fly without either (yes, I know, overwater etc., but still) - chances of actually using either are very slim
It takes a lot of unusual things - either pilot error or some very unusual set of events - for MCAS to come into play. It was not MCAS per se, it was way it was programmed, that came into play for Lion air crash. Think about life raft expanding in cruise and pushing pilots into controls...

sadiqutp wrote:

Curiousflyer wrote:

Is Boeing becoming like US car makers? Building new products that are so far behind technological progress that buyers turn towards foreign makers who make much better and cheaper stuff. Is the 737 MAX the SUV of short-haul?

Really????
Tesla????

Good point, the US may need a Tesla of aviation.

Curiousflyer wrote:

sadiqutp wrote:

Curiousflyer wrote:

Is Boeing becoming like US car makers? Building new products that are so far behind technological progress that buyers turn towards foreign makers who make much better and cheaper stuff. Is the 737 MAX the SUV of short-haul?

Really????
Tesla????

Good point, the US may need a Tesla of aviation.

A stoned man-child who abuses workers and rejects safety protocols because he doesn't like the color yellow?

SomebodyInTLS wrote:

TheOldDude wrote:

Even IF the MCAS situation is the issue, there's a known condition and a known procedure. Just like any other known condition and known procedure.

I'll say it again - the source of the bad AoA data in the Lion Air case has still not been established. Several corrective actions were taken by maintenance.

Design screw ups aside, it's quite possible that MCAS activation was just the symptom of something else in the avionics.

Thanks for making that excellent point. We have two crashes with unknown causes.

Presently we already have a 767 crash with an unknown cause (Atlas Air), a 777 crash with an unknown cause (MH370), and perhaps others. If the policy of grounding a fleet for two crashes of unknown cases were strictly applied, one more crash of will be sufficient to ground the entire fleet. If the policy were amended to say "recent crash", what is the definition of recent, and what is the cutoff?

Once those decision are made, the proponents of grounding should look retrospectively at crashes and tell us how many lives would have been saved, and at what cost (before anyone shrieks about cost, the value of life is typically considered in the cost/benefit of environmental policies, nuclear policies, and other policies. It's well accepted.)

A320FlyGuy wrote:

One book that is extremely interesting and is for the most part extremely accurate is “The Sporty Game”. It covers all aspects of the birth and development of the A300, DC-10 and L-1011 as well as to a lesser extent the 747. It goes into extensive detail of the DER system and it’s flawed execution.

Self certification is a popular game. ... and a lawyers wet expensive but harmless dream
Things go to pot when the involved parties think that this is the perfect playground for brinkmanship.
( GFC and its run up of reducing supervision and going by authoritative say so ran a similar way.)

I can't grok the strange combination
of
cavalier attitude towards a major issue
apparently listless execution of a solution.
But then also
taking care by keeping this out of the manual
and thus pilot instruction that hickups have a good chance of escalating unpleasantly.
while giving this a cheap pretext : no additional simulator time necessary. (Better than Airbus! haha!)

Any truth in an Airbus subsidiary doing the MAX training for Lion Air?

Bobloblaw wrote:

And you know for certain that Boeing had all the available resources to do a replacement for the 737 in 2011 after it dedicated billions to the 787 programs the most complex and difficult program Boeing had ever done.

The quarterlies show a flood of profits all the time during that period.
Money for another project, certainly?

ExperimentalFTE wrote:

It would be very interesting to understand rationale and approach to how MCAS and flight controls with MCAS using single source air data was approved for certification...

That's sort of the point I was making earlier upthread. What I *really* want to know throughout all of this (thought originally provoked by the Lion Air tragedy) is whether or not Boeing EVER simulated how MCAS would behave IF and WHEN its ONLY sensor input was invalid. Pretty simple question, really. That's all I really want an answer to.

TUI Belgium (former JetairFly) is also (voluntary?) grounding the Boeing 737MAX, it currently has 4 planes in service all delivered last year.

VeeCee wrote:

Curiousflyer wrote:

sadiqutp wrote:

Really????
Tesla????

Good point, the US may need a Tesla of aviation.

A stoned man-child who abuses workers and rejects safety protocols because he doesn't like the color yellow?

You mean a genius ?

TheOldDude wrote:

SomebodyInTLS wrote:

Design screw ups aside, it's quite possible that MCAS activation was just the symptom of something else in the avionics.

Thanks for making that excellent point. We have two crashes with unknown causes.

[...]

If the policy of grounding a fleet for two crashes of unknown cases were strictly applied, one more crash of will be sufficient to ground the entire fleet.

Interesting take - because what I was actually suggesting is that avionics issues could be a common cause for both of these accidents!

kalvado wrote:

estorilm wrote:

Yeah - I mean I'm not too worried about the aircraft itself, I just REALLY REALLY wish I knew exactly what the thing does in situations where they decided MCAS was required. I'm way more curious about that lately than I am about the MCAS system being at fault. It would be nice to know how the aircraft itself naturally flies and what it's trying to do.

It was explained million times: MCAS should come into play when pilot pushes aircraft into a deep stall. It is a last resort effort to save the day, on par with life rafts. Regulators will not let you fly without either (yes, I know, overwater etc., but still) - chances of actually using either are very slim
It takes a lot of unusual things - either pilot error or some very unusual set of events - for MCAS to come into play. It was not MCAS per se, it was way it was programmed, that came into play for Lion air crash. Think about life raft expanding in cruise and pushing pilots into controls...

You COMPLETELY misread my post.

I was inquiring about the aircraft's NATURAL handling characteristics, not MCAS. I'm very well aware of what MCAS is, how it works, when it becomes active, when it enables, how it is disabled, what data sources it uses, and how it impacts control of the aircraft, etc etc.

I was basically asking, if I disabled MCAS and approached a stall at high AoA in a 737NG and a 737MAX, what would the differences be? I'm asking because clearly Boeing had enough data on some rather unfriendly discoveries during modeling / testing to justify the implementation of MCAS. I just want to know what exactly they found, and how severe it is.

One question, maybe someone knows the answer. If an airline operates 737 normal (NG?) and 737 Max, will a Max pilot always fly his max plane, or will he switch occasionaly between Max and NG? You know why I'm asking. Thanks.

Apparently EASA is thinking about following the British CAA and could be ready to issue a blanket ban for the 737 MAX in European airspace. Later today a statement from EASA is being expected.

estorilm wrote:

kalvado wrote:

I was basically asking, if I disabled MCAS and approached a stall at high AoA in a 737NG and a 737MAX, what would the differences be? I'm asking because clearly Boeing had enough data on some rather unfriendly discoveries during modeling / testing to justify the implementation of MCAS. I just want to know what exactly they found, and how severe it is.

One of the most pointed and impressively simple questions I've seen so far on here. My thoughts EXACTLY. It is high time that we got some answers as to the basic handling characteristics of this airframe, and what was discovered ruing testing/modeling that made the need for MCAS (or, if you are being pedantic - 'enhanced MCAS' on the MAX) to be implemented/allowed such aggressive and exclusive/recurring control of certain situations.

VeeCee wrote:

Curiousflyer wrote:

sadiqutp wrote:

Really????
Tesla????

Good point, the US may need a Tesla of aviation.

A stoned man-child who abuses workers and rejects safety protocols because he doesn't like the color yellow?

He's a genius visionary, one of the most famous men of our time. You? Anonymous internet cheap shot artist. A mismatch of epic proportion.

New quote by the Ethiopian Airlines CEO just now:

The pilots of the doomed Ethiopian Airlines flight told air traffic control they were having “flight control problems” before the crash, airline CEO Tewolde GebreMariam told CNN’s Richard Quest Tuesday.

Admittedly the pedantic can construe 'flight control problems' to encompass anything from problems with turbulence and spatial-D, to elevator control issues to a stuck flap. But it seems that this quote does little to discount a similar MCAS scenario to that of Lion Air.

So sad.

A number of assumptions in this thread are simply wrong.

Boeing did not do the MAX because they were short of money. They in fact wanted to do an all new plane - airlines would not wait after the 320neo came out.

FAA and NTSB are not beholden to the senate (or the president, or the supreme court). They grounded the 787 without ANY adverse political repercussions. EASA and others will not be reluctant to act if US agencies were to slow, and action by one or more foreign agencies are given very serious action by other agencies.

Eye witness by definition cannot be hearsay, although the term is often used incorrectly to mean you don't like what someone says

LAW
the report of another person's words by a witness, which is usually disallowed as evidence in a court of law.
"everything they had told him would have been ruled out as hearsay"

And it looks to me like the MAX will be grounded, perhaps even before I manage to post this.

Bricktop wrote:

VeeCee wrote:

Curiousflyer wrote:

Good point, the US may need a Tesla of aviation.

A stoned man-child who abuses workers and rejects safety protocols because he doesn't like the color yellow?

He's a genius visionary, one of the most famous men of our time. You? Anonymous internet cheap shot artist. A mismatch of epic proportion.

So Musk has a few good ideas and it justifies horrible health and safety in Telsa factories, which by the way are the least efficient in the car industry taking triple the amount of workers to produce a car when compared to other car plants.


To stay on topic, if EASA bans the 737 MAX 8, are there any other countries that would immediately follow suit such as North African countries? I'm just wondering how much influence they have in matters like these.

Sent from my Mi MIX 2S using Tapatalk

Bricktop wrote:

VeeCee wrote:

Curiousflyer wrote:

Good point, the US may need a Tesla of aviation.

A stoned man-child who abuses workers and rejects safety protocols because he doesn't like the color yellow?

He's a genius visionary, one of the most famous men of our time. You? Anonymous internet cheap shot artist. A mismatch of epic proportion.

No. You're right. Let's throw off decades of safety protocols for a "visionary" I'm sure nothing bad will happen.

Another (stupid ?) question: Is the NTSB really entitled to harm Boeing ?

DocLightning wrote:

Norwegian has suspended 737MAX ops. Article in Norwegian.

https://e24.no/boers-og-finans/norwegia ... Ae9I6ZG_f8

18 planes, big news here in Sweden where Norwegian operate a lot of routes domestically. Just wondering if the general publig can tell the difference between a 737-800 and a 737 8 MAX as the 800 is the most common version operated by DY here

estorilm wrote:

I was basically asking, if I disabled MCAS and approached a stall at high AoA in a 737NG and a 737MAX, what would the differences be? I'm asking because clearly Boeing had enough data on some rather unfriendly discoveries during modeling / testing to justify the implementation of MCAS. I just want to know what exactly they found, and how severe it is.

The MAX should "like" sitting in a stall. ( engines cause a pitch up moment that works against the designed in aerodynamic nose down moment. )

What would be of interest too is :
Was MCAS introduced in the flow of design changes preparing for the bigger engines
or was it added after unpleasant test flight results?

In scope of this my guess for the changed tail would go towards cleaner airflow at the tail
and thus better rudder/elevator authority
than what Boeing presented as reason i.e. 1% better drag.

The new tail was a feature from the get go afair.

a few witness said the plane was on fire / trail of smoke from the plane before it went down, on cnn

Pluto707 wrote:

Another (stupid ?) question: Is the NTSB really entitled to harm Boeing ?

NTSB has ZERO regulatory authority. They investigate and issue recommendations. The FAA or other regulatory agency/governing body then issues directives.

Trin wrote:

estorilm wrote:

kalvado wrote:

I was basically asking, if I disabled MCAS and approached a stall at high AoA in a 737NG and a 737MAX, what would the differences be? I'm asking because clearly Boeing had enough data on some rather unfriendly discoveries during modeling / testing to justify the implementation of MCAS. I just want to know what exactly they found, and how severe it is.

One of the most pointed and impressively simple questions I've seen so far on here. My thoughts EXACTLY. It is high time that we got some answers as to the basic handling characteristics of this airframe, and what was discovered ruing testing/modeling that made the need for MCAS (or, if you are being pedantic - 'enhanced MCAS' on the MAX) to be implemented/allowed such aggressive and exclusive/recurring control of certain situations.

The Max is not inherently unstable (like some fighter planes may be to achieve better maneuverability as someone upthread quipped). It will fly straight and level under normal conditions just like the NG will. What differs is the behavior as you approach edge of the flight envelope. The closer to stall you get in a max the harder it is to recover in relation to the NG* Note, this does not mean that you cannot recover from that portion of the envelope, only that it does not behave, or feel like the NG does. To help assist, and to maintain type ratings, the MCAS was introduced to adjust horizontal stab trim automatically. The result was that as you approach these edges of the flight envelope you would perceive virtually no difference in aircraft behavior between the Max and the NG.

CAA now following others and grounding the MAX. Sad day for aviation and for Boeing. Hopefully a fix will be found soon and flying can restart. How long before we have s total grounding?

N1KE wrote:

CAA now following others and grounding the MAX. Sad day for aviation and for Boeing. Hopefully a fix will be found soon and flying can restart. How long before we have s total grounding?

A fix? A fix for what? We don't even know what caused the Ethiopian crash at this point. Just educated guesses. For all we know it could be a terrorist act that led to elevator control issues.

Pluto707 wrote:

Another (stupid ?) question: Is the NTSB really entitled to harm Boeing ?

Being entitled is not the issue here... They will find a way to put it in between the lines in the report or "ommit" something that can be really harmful and deal with it behind doors.

Flying should be a celebration of humanity, not removing skilled pilots replacing them with computers, or accountants leaning on regulators.
Does anyone even want to fly, the passengers staring at screens the pilots stare at screens, the computers are the only ones "alive", and if something goes wrong ... corporate apologies backside covering, etc...
It's all so insincere and dead inside.
Bring back the engineers, explorers and the living please.

trpmb6 wrote:

Trin wrote:

estorilm wrote:

One of the most pointed and impressively simple questions I've seen so far on here. My thoughts EXACTLY. It is high time that we got some answers as to the basic handling characteristics of this airframe, and what was discovered ruing testing/modeling that made the need for MCAS (or, if you are being pedantic - 'enhanced MCAS' on the MAX) to be implemented/allowed such aggressive and exclusive/recurring control of certain situations.

The Max is not inherently unstable (like some fighter planes may be to achieve better maneuverability as someone upthread quipped). It will fly straight and level under normal conditions just like the NG will. What differs is the behavior as you approach edge of the flight envelope. The closer to stall you get in a max the harder it is to recover in relation to the NG* Note, this does not mean that you cannot recover from that portion of the envelope, only that it does not behave, or feel like the NG does. To help assist, and to maintain type ratings, the MCAS was introduced to adjust horizontal stab trim automatically. The result was that as you approach these edges of the flight envelope you would perceive virtually no difference in aircraft behavior between the Max and the NG.

So what happened in testing/simulation when they programmed invalid AOA data into the MCAS during its active phase?

Germany has now closed its airspace to the 737 MAX.

estorilm wrote:

kalvado wrote:

estorilm wrote:

Yeah - I mean I'm not too worried about the aircraft itself, I just REALLY REALLY wish I knew exactly what the thing does in situations where they decided MCAS was required. I'm way more curious about that lately than I am about the MCAS system being at fault. It would be nice to know how the aircraft itself naturally flies and what it's trying to do.

It was explained million times: MCAS should come into play when pilot pushes aircraft into a deep stall. It is a last resort effort to save the day, on par with life rafts. Regulators will not let you fly without either (yes, I know, overwater etc., but still) - chances of actually using either are very slim
It takes a lot of unusual things - either pilot error or some very unusual set of events - for MCAS to come into play. It was not MCAS per se, it was way it was programmed, that came into play for Lion air crash. Think about life raft expanding in cruise and pushing pilots into controls...

You COMPLETELY misread my post.

I was inquiring about the aircraft's NATURAL handling characteristics, not MCAS. I'm very well aware of what MCAS is, how it works, when it becomes active, when it enables, how it is disabled, what data sources it uses, and how it impacts control of the aircraft, etc etc.

I was basically asking, if I disabled MCAS and approached a stall at high AoA in a 737NG and a 737MAX, what would the differences be? I'm asking because clearly Boeing had enough data on some rather unfriendly discoveries during modeling / testing to justify the implementation of MCAS. I just want to know what exactly they found, and how severe it is.

Differences seem to be severe, with NG harder to enter deep stall and easier to recover from spin. But this is akin of asking what would happen if you have to jump from top floor of 5-floor building vs 15-floor building.
Boeing biggest point here - you shouldn't ever be there to find that out . Yes, 5 floor jump is more survivable. Spin recovery on a jet is not part of regular training for pretty much the same reason.

WIederling wrote:

Bobloblaw wrote:

And you know for certain that Boeing had all the available resources to do a replacement for the 737 in 2011 after it dedicated billions to the 787 programs the most complex and difficult program Boeing had ever done.

The quarterlies show a flood of profits all the time during that period.
Money for another project, certainly?

And you know this how??? You audited Boeing’s books.

I’m stunned by the number of aviation engineers and financial experts here on a free aviation blog. I’d like to know your background.

Curiousflyer wrote:

Is Boeing becoming like US car makers? Building new products that are so far behind technological progress that buyers turn towards foreign makers who make much better and cheaper stuff. Is the 737 MAX the SUV of short-haul?

Other than the fact the fuselage of a MAX is shaped like a plane from 1958, all of the other components of the aircraft are state-of-the art.

trpmb6 wrote:

N1KE wrote:

CAA now following others and grounding the MAX. Sad day for aviation and for Boeing. Hopefully a fix will be found soon and flying can restart. How long before we have s total grounding?

A fix? A fix for what? We don't even know what caused the Ethiopian crash at this point. Just educated guesses. For all we know it could be a terrorist act that led to elevator control issues.

If they suspected terrorism then I don’t think we would be seeing groundings of the aircraft. Maybe it is terrorism but looking at a lot of posts on here it would appear to be more of an airframe related issue. Whether it’s the same issues as Lion Air who knows, but I think the engineers are going to be busy at Boeing.

Norwegians flight from Stockholm to Tel Aviv turned back home over Moldova, Germany airspace is now void of MAX.

VeeCee wrote:

Pluto707 wrote:

Another (stupid ?) question: Is the NTSB really entitled to harm Boeing ?

NTSB has ZERO regulatory authority. They investigate and issue recommendations. The FAA or other regulatory agency/governing body then issues directives.

There are no situations that turn people into idiots.
There are only situations that expose people as idiots.

NTSB does not harm Boeing. Boeing harmed itself and the NTSB exposes it. rightly so.

So is it only US airlines that has not grounded it's Max's now ?

Curiousflyer wrote:

Is Boeing becoming like US car makers? Building new products that are so far behind technological progress that buyers turn towards foreign makers who make much better and cheaper stuff. Is the 737 MAX the SUV of short-haul?

Or maybe it is that RAM truck with the oversized wheels... I wonder what the Boeing CEO drives.

Is it really sooo difficult to wait for the preliminary results before launching such accusations?

estorilm wrote:

An NG pilot familiar with STS will NOT be expecting MCAS-type behavior at any point. ... my point is that such an action is not something that NG's auto trim has EVER done, nor could do. ... Keep in mind at the time of the Lion Air crash, there WAS no training, and the system wasn't even in FCOM. It's easy for us to sit here and say "hit the damn switch", but IMO it would have been confusing given the situation they were in.

Focusing on the training part. Assuming that MCAS plays a role here, which is a possibility, but as agreed not proven (yet). What if the crews were simulator trained - as far as I understood, this is all that was required to transfer from NG to MAX - and they handled everything perfectly while in the simulator, but the simulator situation isn't what they would encounter in flight? I mean, a simulator is just filled with all situations and parameters that are known to have occurred until that time or that can reasonably be expected. A system which hasn't been around for long can only be in the simulator with the behaviour that it was programmed to show, but due to lack of first-hand knowledge, you can't be sure that what was programmed into it is what it really does. There may be unintended side effects that nobody expected to have and thus they couldn't be shown in the simulator. (non-aviation example for such: In the car of a friend, the reading light was flickering. When I asked him about it, he told me to open and close the glove box. I thought he was joking, but that really solved it. Who would have guessed?)

So, might there be a chance that the crew was properly trained, no matter how low on hours on type they were, but the obvious solutions - like the several times suggested "stab trim cutout" - just didn't work? Or even worse, MCAS overrides a stab trim cutout; or cutting out stab trim while MCAS is active doesn't have any effect or results in the opposite of the desired?
From a pure logical standpoint, I would certainly dismiss that, expecting that noone in development would allow this to happen. But then again, there's the unexpected to which you wouldn't develop any countermeasures because, why would you try to prevent something that you wouldn't expect to happen?

Sorry if some of this sounds a bit confusing. Basically, I'm just trying to expand on "Something happened that shouldn't have". How would you judge the chances of the above?

Cdydatzigs wrote:

Other than the fact the fuselage of a MAX is shaped like a plane from 1958, all of the other components of the aircraft are state-of-the art.

About as state of the art as an US SUV ( i.e. a ~1930ties chassis SCNR

Mortyman wrote:

So is it only US airlines that has not grounded it's Max's now ?

Other than them .. There two of significance that appear to continue normally .. FlyDubai & SpiceJet

Cdydatzigs wrote:

Curiousflyer wrote:

Is Boeing becoming like US car makers? Building new products that are so far behind technological progress that buyers turn towards foreign makers who make much better and cheaper stuff. Is the 737 MAX the SUV of short-haul?

Other than the fact the fuselage of a MAX is shaped like a plane from 1958, all of the other components of the aircraft are state-of-the art.

Sure sure. Especially the flight control system.

Please remember there is a separate thread to discuss the 737 Max groundings.

viewtopic.php?f=3&t=1417545

We should be discussing the specifics of the incident in this thread.

trpmb6 wrote:

N1KE wrote:

CAA now following others and grounding the MAX. Sad day for aviation and for Boeing. Hopefully a fix will be found soon and flying can restart. How long before we have s total grounding?

A fix? A fix for what? We don't even know what caused the Ethiopian crash at this point. Just educated guesses. For all we know it could be a terrorist act that led to elevator control issues.

People who like to play devils advocates also denied that pilot error could be responsible for AF447......before it was revealed that that's what it was. As I said before - the pedantic amongst us will argue that "flight control issues" could reference anything that a person individually WANTS it to, but the fact remains that if this incident was more strongly pointing towards 'terrorism' than an issue with the airframe itself, we would probably already know - and rather than news stories of nations grounding their MAX fleets, we would be reading about nations elevating their terror levels. A lot more is always known much earlier in private in these cases than is released to the public - but we CAN construe what is known privately from the (necessarily) public reactions of companies and nations to that private information.

estorilm wrote:

I was basically asking, if I disabled MCAS and approached a stall at high AoA in a 737NG and a 737MAX, what would the differences be? I'm asking because clearly Boeing had enough data on some rather unfriendly discoveries during modeling / testing to justify the implementation of MCAS. I just want to know what exactly they found, and how severe it is.

The aircraft is not certifiable without MCAS, which in essence tells you all you need to know. In more details, if the crew find themselves in an "extreme" nose-high situation and shove the throttles forward to prevent a stall, the position of the engines (causing lateral instability) will result in the nose going even further up thus entering a stall situation. To prevent that from happening, MCAS was installed. In other words, it's a band-aid addressing the lack of natural stability in an extreme situation coupled with an excessive nose-up momentum with engine thrust.

If you're flying a NG, the engines are mounted lower and further back thus a) securing natural stability and b) cause much less of a nose-up momentum in high thrust situations.

IMHO, the MAX should not be allowed to fly on the same type rating as a 737 Jurassic, Classic and NG.

If it is determined that broken AOA sensors contributed to faulty activation of MCAS in both scenarios, is there a chance that some preflight checklist item, maybe as something as innocent as opening and closing the forward cargo door, is adding to the likelihood that the AOA sensor is being damaged?

Mortyman wrote:

So is it only US airlines that has not grounded it's Max's now ?

https://flightaware.com/live/aircrafttype/B38M
U.S., Canada and many others.... for now..

Cdydatzigs wrote:

Other than the fact the fuselage of a MAX is shaped like a plane from 1958, all of the other components of the aircraft are state-of-the art.

The 737 MAX overhead panel and centre pedestal just called, you owe them a new keyboard. Same goes for much of the structure. Seriously, it has a new panel, engines, electronics, nose-gear and wings. Hydraulic, electric and pneumatics are more or less the samen, and it's all bolted onto 1950s era structure.

It is the aviation epitome of applying ever thicker coats of lipstick to a pig.