kalvado
Posts: 2025
Joined: Wed Mar 01, 2006 4:29 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 12:46 pm

SomebodyInTLS wrote:
kalvado wrote:
OldAeroGuy wrote:
I have a huge problem with it because MCAS is not fitted as a stall protection system and it does not prevent stalls

Nope. Protection does not assume prevention.

[...]

Are you having hard time understanding terminology?


It does seem like people are mentally twisting to avoid having the word "stall" associated with MCAS, despite it being right there in the very regulations MCAS was created to address!

Two S-words that get some people going wild: Stall and Stability, inventing all sorts of euphemisms here. Best part is demanding proper terminology from others.
 
OldAeroGuy
Posts: 3886
Joined: Sun Dec 05, 2004 6:50 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 12:57 pm

zeke wrote:
planecane wrote:
I think from the block diagrams that it is simply because there is no AoA input to the eleveator feel computer so the EFC has no way to "know" that the force is getting light because it is AoA dependent. Either that or the elevator feel system can't add enough required force.


There is via the elevator shift, that’s how control force is added for STS.


Hi Zeke

In answer to your earlier question, I don't know why STS wasn't utilized to incorporate the column force part of MCAS.

What I can say is that for MCAS to have the desired function, it must be activated by AoA and not Speed. That's why MCAS will increase Stick Force required for a straight ahead 1G stall at 120 kts or for a 2G, 60 deg banked turn at 180 kts.

Perhaps it was easier to incorporate an AoA based column force system separately.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
morrisond
Posts: 1402
Joined: Thu Jan 07, 2010 12:22 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 1:15 pm

Interested wrote:
speedking wrote:
I agree this is a training problem in the end. Physical training specifically. If the pilots were strong enough, they could have saved the plane by using the manual trim wheels as they are supposed to do as final backup when all the automation and electrical systems have failed.


It's so much not a training problem

It's a design problem where training is the last chance to prevent it becoming an accident

It's so wrong to focus on training

It's like saying cancer is all about the treatment rather than prevention in the first place

It's incredible how this thread has had so much focus on the pilots and training rather than the far bigger issues which is how we ended up with a plane design like this to start with

We are discussing training issues we now have to solve that need never have existed with a more safely designed plane


That's like saying we should totally focus on eradicating all forms of cancer and Doctors don't need to go Med School to learn how to manage cancer until we have a cure. Screw the people that already have cancer - if we lose a few so what that's wasted resources.

We will eventually be able to build the perfect airplane and be able to take the Pilot out of the equation with AI - which should be better than an Pilot as they should have perfect memory. But until the perfect airplane can be built - training is needed.

Find me a fatal crash in the last 20 years where the pilots did everything right and the plane still crashed.

You are also not accounting for the fact that parts can fail in a perfectly designed aircraft or Metal Fatigue leading to loss of control surfaces, dual flameouts due to bird strikes or all out engine failure, Uncontained Engine failures leading to control surface damage. The list goes on and on.

Certain procedures need to be understood, practiced and memorized as the time to respond to most emergencies is not long enough to go look up the proper procedure in the manuals.

If you are comfortable with the current state of training fine. How confident would you be of being on a flight with 150 Hour Wonder pilots out of the current training system and an uncontained engine failure caused the loss of some control surfaces on one side of the plane? It has almost happened a few times in the past few years.

Due to automation Piloting has gotten a lot simpler in the past 30 years. They should have the time to practice unusual situations for when things happen - for even in a perfectly designed airplane parts can fail.

Yes - Boeing's botched design were responsible for these terrible tragedies. But you cannot blame them 100% and ignore the other factors.

Would you let the FAA off the hook or the other Safety agencies worldwide who rubber stamped the FAA's certification of the MAX?

There are always multiple factors to crashes and shame on us if we don't look at all of them and do what we can to improve every part.

Is it boring not just bashing on Boeing 100% - yes I can see that as People are always looking for that one thing to pin it on.

Airplane crashes however a lot more complicated.
 
kalvado
Posts: 2025
Joined: Wed Mar 01, 2006 4:29 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 1:24 pm

OldAeroGuy wrote:
zeke wrote:
planecane wrote:
I think from the block diagrams that it is simply because there is no AoA input to the eleveator feel computer so the EFC has no way to "know" that the force is getting light because it is AoA dependent. Either that or the elevator feel system can't add enough required force.


There is via the elevator shift, that’s how control force is added for STS.


Hi Zeke

In answer to your earlier question, I don't know why STS wasn't utilized to incorporate the column force part of MCAS.

What I can say is that for MCAS to have the desired function, it must be activated by AoA and not Speed. That's why MCAS will increase Stick Force required for a straight ahead 1G stall at 120 kts or for a 2G, 60 deg banked turn at 180 kts.

Perhaps it was easier to incorporate an AoA based column force system separately.

Which again brings MCAS desired function into question. As far as I understand, STS operates within certain speed window. MCAS is active throughout, with last actuation on ET flight in overspeed condition.
So either MCAS is designed for situations beyond low speed stall, as we discussed - or it is designed without understanding design goals.
 
morrisond
Posts: 1402
Joined: Thu Jan 07, 2010 12:22 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 1:26 pm

kalvado wrote:
OldAeroGuy wrote:
zeke wrote:

There is via the elevator shift, that’s how control force is added for STS.


Hi Zeke

In answer to your earlier question, I don't know why STS wasn't utilized to incorporate the column force part of MCAS.

What I can say is that for MCAS to have the desired function, it must be activated by AoA and not Speed. That's why MCAS will increase Stick Force required for a straight ahead 1G stall at 120 kts or for a 2G, 60 deg banked turn at 180 kts.

Perhaps it was easier to incorporate an AoA based column force system separately.

Which again brings MCAS desired function into question. As far as I understand, STS operates within certain speed window. MCAS is active throughout, with last actuation on ET flight in overspeed condition.
So either MCAS is designed for situations beyond low speed stall, as we discussed - or it is designed without understanding design goals.


I don't think anyone is disputing that MCAS isn't a totally screwed up design.
 
Interested
Posts: 647
Joined: Thu May 19, 2016 12:19 pm

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 1:27 pm

morrisond wrote:
Interested wrote:
speedking wrote:
I agree this is a training problem in the end. Physical training specifically. If the pilots were strong enough, they could have saved the plane by using the manual trim wheels as they are supposed to do as final backup when all the automation and electrical systems have failed.


It's so much not a training problem

It's a design problem where training is the last chance to prevent it becoming an accident

It's so wrong to focus on training

It's like saying cancer is all about the treatment rather than prevention in the first place

It's incredible how this thread has had so much focus on the pilots and training rather than the far bigger issues which is how we ended up with a plane design like this to start with

We are discussing training issues we now have to solve that need never have existed with a more safely designed plane


That's like saying we should totally focus on eradicating all forms of cancer and Doctors don't need to go Med School to learn how to manage cancer until we have a cure. Screw the people that already have cancer - if we lose a few so what that's wasted resources.

We will eventually be able to build the perfect airplane and be able to take the Pilot out of the equation with AI - which should be better than an Pilot as they should have perfect memory. But until the perfect airplane can be built - training is needed.

Find me a fatal crash in the last 20 years where the pilots did everything right and the plane still crashed.

You are also not accounting for the fact that parts can fail in a perfectly designed aircraft or Metal Fatigue leading to loss of control surfaces, dual flameouts due to bird strikes or all out engine failure, Uncontained Engine failures leading to control surface damage. The list goes on and on.

Certain procedures need to be understood, practiced and memorized as the time to respond to most emergencies is not long enough to go look up the proper procedure in the manuals.

If you are comfortable with the current state of training fine. How confident would you be of being on a flight with 150 Hour Wonder pilots out of the current training system and an uncontained engine failure caused the loss of some control surfaces on one side of the plane? It has almost happened a few times in the past few years.

Due to automation Piloting has gotten a lot simpler in the past 30 years. They should have the time to practice unusual situations for when things happen - for even in a perfectly designed airplane parts can fail.

Yes - Boeing's botched design were responsible for these terrible tragedies. But you cannot blame them 100% and ignore the other factors.

Would you let the FAA off the hook or the other Safety agencies worldwide who rubber stamped the FAA's certification of the MAX?

There are always multiple factors to crashes and shame on us if we don't look at all of them and do what we can to improve every part.

Is it boring not just bashing on Boeing 100% - yes I can see that as People are always looking for that one thing to pin it on.

Airplane crashes however a lot more complicated.


The design of this plane is leading to more "cancers" to cure

With better design we could have actually reduced the amount of "cancers" to cure

Without even discussing training - surely you can accept the above?

Once you accept that I'm more than happy to agree more training would be great as well. I do have to remind you it's Boeing who promised no sim training would be needed to fly these planes.

I'm sure that may have been the case with a better design.
 
Interested
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 1:31 pm

morrisond wrote:
kalvado wrote:
OldAeroGuy wrote:

Hi Zeke

In answer to your earlier question, I don't know why STS wasn't utilized to incorporate the column force part of MCAS.

What I can say is that for MCAS to have the desired function, it must be activated by AoA and not Speed. That's why MCAS will increase Stick Force required for a straight ahead 1G stall at 120 kts or for a 2G, 60 deg banked turn at 180 kts.

Perhaps it was easier to incorporate an AoA based column force system separately.

Which again brings MCAS desired function into question. As far as I understand, STS operates within certain speed window. MCAS is active throughout, with last actuation on ET flight in overspeed condition.
So either MCAS is designed for situations beyond low speed stall, as we discussed - or it is designed without understanding design goals.


I don't think anyone is disputing that MCAS isn't a totally screwed up design.


That's secondary to me

The main point is with a better designed plane MCAS wouldn't have been needed to start with

We've got a badly designed plane to start with (that's the worst part). A plane that needs a software patch that's causing extra risk and needs for training now (MCAS).

The fact MCAS has itself gone badly wrong and has been handled awfully is secondary

Boeing and the FAA should never have designed a plane that needed it to start with

The world of aviation is the loser twice above

And as I said earlier - weve then got poor or zero training to worry about on top!! That's just the icing on the top!!

But this is all just a result of a badly designed plane to start with. That's the HUGE mistake in all of this. The initial plane design. Everything leads from that. And it's all bad following after bad.
Last edited by Interested on Tue Apr 23, 2019 1:49 pm, edited 2 times in total.
 
dakota123
Posts: 233
Joined: Wed Aug 30, 2006 11:03 pm

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 1:32 pm

WPIAeroGuy wrote:
kalvado wrote:
frmrCapCadet wrote:
I think what people have been saying is "stall prevention systems" have a very specific definition. MCAS does not meet that definition. It is about stall prevention, but that is not quite the same. And the Red Queen says ..... LOL

Can you show "stall prevention system" being defined in a real document? I cannot find any definition which would be relevant to certification issues.


I couldn't find a formal definition in Part 25, but I think the difference that people are trying to get across is that a "stall prevention" system will not allow even intentional entry into a stall. MCAS does not do that. All MCAS does is make sure the control feel is appropriate up to the stall. I know the point you're trying to make is that "well if the pilot accidentally pulls to hard, the plane will stall, therefore MCAS prevents that!" And that's true, but it is vastly different to say a system that reduces the chance of an inadvertent stall is the same as a system that prevents intentional stalls.


Indeed, the difference between augmentation and prevention is common sense, and is just part of the discipline’s general knowledge. What is so hard to understand is beyond me. D.P. Davies (CAA chief test pilot) in Handling the Big Jets, page 115 (an ancient book, which proves the point that the distinction has been around forever), talks about the difference between bona fide pushers (prevention) and augmentation systems, and specifically discusses how if an augmentation system is installed, a pilot is free to stall the aircraft if he so choses, and so is most definitely not a stall prevention device. Exactly as so many of us have been saying.
“And If I claim to be a wise man, well surely it means that I don’t know”
 
FluidFlow
Posts: 298
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 1:59 pm

A poster mentioned a few pages ago, that the NG has 5 different failures that can lead to a runaway trim and the MAX has now 6 due to MCAS. If the 5 failures grandfathered from the NG have the same possi-bility to occur on the MAX plus the new one from MCAS has a possibility to trigger, the chance to get a runaway trim (or runaway like trim) is higher on the MAX than on the NG. That is ok, if there is something done to prevent such a failure to lead to a crash. For example additional training mandated by the manu-facturer.

Another thing I stated earlier is that the MAX behaves different from the NG in certain situations. That was the reason to add MCAS in the first place. To change the feel so that the two feel the same and have the same flight characteristics. That’s not a problem per se but it is not at all optimal.
If you design your aircraft from the beginning to have software support to fly in a certain way, everything is optimised for this design. If you take something old and combine it with something new and you then need software to force it into the same behaviour as the old version it compromises both, the new and the old design.

There is the compatibility mode on new windows machines, and yes you can run old software on new hardware with this mode, it does not have the same performance as the old software on the old hard-ware.

The MAX, by design, has less performance than a new plane with the engines from the max. The new en-gines + MACS limit the performance of the old frame. To make them compatible additional software was needed.

All them points are not inherent bad, or a bad decision by Boeing. This compromises were made inten-tionally and don’t lead to an unsafe aircraft if done properly. Compromises can be a good thing if done right.

The problem was Boeing made two crucial mistakes:
1. the software that brought the compromise to life (MCAS) was flawed. Seriously flawed. This will hopefully be changed now.
2. they hoped, that pilot experience from the NG will be enough to handle a new aircraft that should feel the same as the old one. Unfortunately failure of point 1 will lead to failure of point 2.

Boeing could have addressed the two flaws from the beginning, by review the plane better and not rush the process of the risk assessment and also mandate more training just in case to address failure of the new software. The reason they did not do this will be investigated by the DOJ so we will see if this was done intentionally or was just bad management.

Unfortunately another body could have prevented this mistakes, the FAA but they did not review MCAS properly (and hopefully only MCAS) and they did not mandated additional training.
That seems also unfortunate and will be checked.

What I think is personally sad is (mentioned by a lot of posters here) that training seems not to be that good. And I think the manufacturers know this.
Why is the minimum training for pilots not increased by manufacturers for new models, instead of re-duced so they can sell more aircrafts. Clearly this backfired now for Boeing but it could have hit Airbus aswell.

If a transition to the MAX would have required min 1000h in an NG + difference training including simula-tor time, this accidents would maybe not have happened. Same should go for the transition from the 320ceo to neo.
Yes it could reduce sales a bit, but crashes also cost a lot and are in the long run probably even more expensive. Both seem to play with fire and Boeing got burned this time.
 
morrisond
Posts: 1402
Joined: Thu Jan 07, 2010 12:22 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 2:06 pm

Interested wrote:
morrisond wrote:
Interested wrote:

It's so much not a training problem

It's a design problem where training is the last chance to prevent it becoming an accident

It's so wrong to focus on training

It's like saying cancer is all about the treatment rather than prevention in the first place

It's incredible how this thread has had so much focus on the pilots and training rather than the far bigger issues which is how we ended up with a plane design like this to start with

We are discussing training issues we now have to solve that need never have existed with a more safely designed plane


That's like saying we should totally focus on eradicating all forms of cancer and Doctors don't need to go Med School to learn how to manage cancer until we have a cure. Screw the people that already have cancer - if we lose a few so what that's wasted resources.

We will eventually be able to build the perfect airplane and be able to take the Pilot out of the equation with AI - which should be better than an Pilot as they should have perfect memory. But until the perfect airplane can be built - training is needed.

Find me a fatal crash in the last 20 years where the pilots did everything right and the plane still crashed.

You are also not accounting for the fact that parts can fail in a perfectly designed aircraft or Metal Fatigue leading to loss of control surfaces, dual flameouts due to bird strikes or all out engine failure, Uncontained Engine failures leading to control surface damage. The list goes on and on.

Certain procedures need to be understood, practiced and memorized as the time to respond to most emergencies is not long enough to go look up the proper procedure in the manuals.

If you are comfortable with the current state of training fine. How confident would you be of being on a flight with 150 Hour Wonder pilots out of the current training system and an uncontained engine failure caused the loss of some control surfaces on one side of the plane? It has almost happened a few times in the past few years.

Due to automation Piloting has gotten a lot simpler in the past 30 years. They should have the time to practice unusual situations for when things happen - for even in a perfectly designed airplane parts can fail.

Yes - Boeing's botched design were responsible for these terrible tragedies. But you cannot blame them 100% and ignore the other factors.

Would you let the FAA off the hook or the other Safety agencies worldwide who rubber stamped the FAA's certification of the MAX?

There are always multiple factors to crashes and shame on us if we don't look at all of them and do what we can to improve every part.

Is it boring not just bashing on Boeing 100% - yes I can see that as People are always looking for that one thing to pin it on.

Airplane crashes however a lot more complicated.


The design of this plane is leading to more "cancers" to cure

With better design we could have actually reduced the amount of "cancers" to cure

Without even discussing training - surely you can accept the above?

Once you accept that I'm more than happy to agree more training would be great as well. I do have to remind you it's Boeing who promised no sim training would be needed to fly these planes.

I'm sure that may have been the case with a better design.


I have never said it wasn't a totally screwed up design. It was terrible. I totally accept that - but errors will always be made and parts in perfectly made airplanes can fail as well which is why better training is needed.

No SIM training should have been needed with a better design - you are right.

That is what I'm advocating for - more frequent recurrent training with a larger focus on Non-Normal procedures. The Worldwide standard really seems to be lacking in this regard.
 
planecane
Posts: 1155
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 2:13 pm

Interested wrote:
morrisond wrote:
kalvado wrote:
Which again brings MCAS desired function into question. As far as I understand, STS operates within certain speed window. MCAS is active throughout, with last actuation on ET flight in overspeed condition.
So either MCAS is designed for situations beyond low speed stall, as we discussed - or it is designed without understanding design goals.


I don't think anyone is disputing that MCAS isn't a totally screwed up design.


That's secondary to me

The main point is with a better designed plane MCAS wouldn't have been needed to start with

We've got a badly designed plane to start with (that's the worst part). A plane that needs a software patch that's causing extra risk and needs for training now (MCAS).

The fact MCAS has itself gone badly wrong and has been handled awfully is secondary

Boeing and the FAA should never have designed a plane that needed it to start with

The world of aviation is the loser twice above

And as I said earlier - weve then got poor or zero training to worry about on top!! That's just the icing on the top!!

But this is all just a result of a badly designed plane to start with. That's the HUGE mistake in all of this. The initial plane design. Everything leads from that. And it's all bad following after bad.


Nobody knows what software "patches" were necessary for the A320NEO, A330NEO or 777-200LR/300ER because they are integrated in the FBW system which is designed with proper redundancy and fail safes.

For all we know any, or all, of those re-engined models could have just as much of a "bad design" as the MAX.
 
morrisond
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 2:16 pm

Interested wrote:
morrisond wrote:
kalvado wrote:
Which again brings MCAS desired function into question. As far as I understand, STS operates within certain speed window. MCAS is active throughout, with last actuation on ET flight in overspeed condition.
So either MCAS is designed for situations beyond low speed stall, as we discussed - or it is designed without understanding design goals.


I don't think anyone is disputing that MCAS isn't a totally screwed up design.


That's secondary to me

The main point is with a better designed plane MCAS wouldn't have been needed to start with

We've got a badly designed plane to start with (that's the worst part). A plane that needs a software patch that's causing extra risk and needs for training now (MCAS).

The fact MCAS has itself gone badly wrong and has been handled awfully is secondary

Boeing and the FAA should never have designed a plane that needed it to start with

The world of aviation is the loser twice above

And as I said earlier - weve then got poor or zero training to worry about on top!! That's just the icing on the top!!

But this is all just a result of a badly designed plane to start with. That's the HUGE mistake in all of this. The initial plane design. Everything leads from that. And it's all bad following after bad.


Yes MCAS was bad.

However I don't agree that the basic design of the MAX was bad or unsafe without MCAS.

In retrospect a better approach may have been to try to get around the FAR that said no-no to stick forces getting light at full AFT COG and very light weights by getting an exception (if that is even possible) and requiring pilots to do training on that scenario on what to expect.

Even with my ranting on about Pilot training standards - I don't think that there is a pilot in the world who would be bad enough to allow a MAX to get into an actual stall due to the too light controls. The stick shaker, audio warnings and frame buffeting would have been more than enough information for any Pilot to know they need to reduce the AOA.

Well well intended - Over regulation could be at fault in this case as well.
 
GalaxyFlyer
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 2:16 pm

Interested wrote:
seahawk wrote:
Interested wrote:

Is this a wind up?

Are you just a troll?

You do Boeing no favours at all


Imagine all 737MAX would have the AoA disagree warning and would automatically disable MCAS in the case. There would be no problems at all flying the planes. It is a problem of the documentation of MCAS, how it is programmed, the man to machine interface and how crews were not trained to identify and handle the problem correctly.


You think any member of the public wants to fly on a plane where their safety relies on pilots being able to turn those trim wheels at the right time

Boeing have designed planes that have software patches that make that more likely to be needed

No thank you. I would rather stay in the UK thanks.


Well, the traveling public world-wide has done exactly that since about 1959. I’d bet the n7mber of times the manual trim has been used in all those flights is under a 100.

GF
 
User avatar
zeke
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 2:30 pm

SomebodyInTLS wrote:
It does seem like people are mentally twisting to avoid having the word "stall" associated with MCAS, despite it being right there in the very regulations MCAS was created to address!


MCAS does not prevent a stall any more than a stick shaker does.

The idea behind MCAS is to have consistent control force up to a stall. If the control forces got lighter, the humans operating the aircraft would continue to pull at the same pressure, and as a result would unknowingly increase the rate of change as they applied constant pressure.

MCAS is there to try and overcome predictable human performance issues.
Human rights lawyers are "ambulance chasers of the very worst kind.'" - Sky News
 
dakota123
Posts: 233
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 2:36 pm

planecane wrote:
Interested wrote:
morrisond wrote:

I don't think anyone is disputing that MCAS isn't a totally screwed up design.


That's secondary to me

The main point is with a better designed plane MCAS wouldn't have been needed to start with

We've got a badly designed plane to start with (that's the worst part). A plane that needs a software patch that's causing extra risk and needs for training now (MCAS).

The fact MCAS has itself gone badly wrong and has been handled awfully is secondary

Boeing and the FAA should never have designed a plane that needed it to start with

The world of aviation is the loser twice above

And as I said earlier - weve then got poor or zero training to worry about on top!! That's just the icing on the top!!

But this is all just a result of a badly designed plane to start with. That's the HUGE mistake in all of this. The initial plane design. Everything leads from that. And it's all bad following after bad.


Nobody knows what software "patches" were necessary for the A320NEO, A330NEO or 777-200LR/300ER because they are integrated in the FBW system which is designed with proper redundancy and fail safes.

For all we know any, or all, of those re-engined models could have just as much of a "bad design" as the MAX.


So true. A380 apparently has a system to warn pilots when control authority is running out of room. Should we be worried that running out of authority is a possibility? WHy didn’t they give it more authority to begin with, then such a system wouldn’t be necessary!!!!

There’s a lot going on in the sausage factory, no matter whose factory it is. We just (very unfortunately) know of this particular situation.
“And If I claim to be a wise man, well surely it means that I don’t know”
 
kalvado
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Joined: Wed Mar 01, 2006 4:29 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 2:56 pm

zeke wrote:
SomebodyInTLS wrote:
It does seem like people are mentally twisting to avoid having the word "stall" associated with MCAS, despite it being right there in the very regulations MCAS was created to address!


MCAS does not prevent a stall any more than a stick shaker does.

The idea behind MCAS is to have consistent control force up to a stall. If the control forces got lighter, the humans operating the aircraft would continue to pull at the same pressure, and as a result would unknowingly increase the rate of change as they applied constant pressure.

MCAS is there to try and overcome predictable human performance issues.

Very hard to buy such a statement when we're talking about a warning device in one case and active movement of controls, snd for a good fraction of full travel of control, in the other.
It may be about force in some very narrow sense - but, as a matter of fact, MCAS is doing a controls movement which has direct and immediate effect of trajectory.
 
Agrajag
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 2:56 pm

If you are a pilot weighing 50kg and of below average strength, what then?
The plural of anecdote is anecdotes, not data.
Slartibartfast had a point
 
kalvado
Posts: 2025
Joined: Wed Mar 01, 2006 4:29 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 3:04 pm

morrisond wrote:

Yes MCAS was bad.

However I don't agree that the basic design of the MAX was bad or unsafe without MCAS.

In retrospect a better approach may have been to try to get around the FAR that said no-no to stick forces getting light at full AFT COG and very light weights by getting an exception (if that is even possible) and requiring pilots to do training on that scenario on what to expect.

Even with my ranting on about Pilot training standards - I don't think that there is a pilot in the world who would be bad enough to allow a MAX to get into an actual stall due to the too light controls. The stick shaker, audio warnings and frame buffeting would have been more than enough information for any Pilot to know they need to reduce the AOA.

Well well intended - Over regulation could be at fault in this case as well.

It is not unsafe. It is uncertifiable. And likely for a good reason:
even in my prime days I didn't know these things well enough to talk about how change of second derivative sign translates into poles of Nyquist diagram, but from a very basic perspective this may have some very interesting consequences for things like return to steady state.
 
kalvado
Posts: 2025
Joined: Wed Mar 01, 2006 4:29 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 3:06 pm

Agrajag wrote:
If you are a pilot weighing 50kg and of below average strength, what then?

Request a transfer to FBW plane. From OSHA logic, this should be treated as a limitation requiring reasonable accommodation by employer - and transfer to another type is definitely a reasonable one. Free upgrade from 737 to widebody, yehoo!
 
Interested
Posts: 647
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 3:40 pm

morrisond wrote:
Interested wrote:
morrisond wrote:

That's like saying we should totally focus on eradicating all forms of cancer and Doctors don't need to go Med School to learn how to manage cancer until we have a cure. Screw the people that already have cancer - if we lose a few so what that's wasted resources.

We will eventually be able to build the perfect airplane and be able to take the Pilot out of the equation with AI - which should be better than an Pilot as they should have perfect memory. But until the perfect airplane can be built - training is needed.

Find me a fatal crash in the last 20 years where the pilots did everything right and the plane still crashed.

You are also not accounting for the fact that parts can fail in a perfectly designed aircraft or Metal Fatigue leading to loss of control surfaces, dual flameouts due to bird strikes or all out engine failure, Uncontained Engine failures leading to control surface damage. The list goes on and on.

Certain procedures need to be understood, practiced and memorized as the time to respond to most emergencies is not long enough to go look up the proper procedure in the manuals.

If you are comfortable with the current state of training fine. How confident would you be of being on a flight with 150 Hour Wonder pilots out of the current training system and an uncontained engine failure caused the loss of some control surfaces on one side of the plane? It has almost happened a few times in the past few years.

Due to automation Piloting has gotten a lot simpler in the past 30 years. They should have the time to practice unusual situations for when things happen - for even in a perfectly designed airplane parts can fail.

Yes - Boeing's botched design were responsible for these terrible tragedies. But you cannot blame them 100% and ignore the other factors.

Would you let the FAA off the hook or the other Safety agencies worldwide who rubber stamped the FAA's certification of the MAX?

There are always multiple factors to crashes and shame on us if we don't look at all of them and do what we can to improve every part.

Is it boring not just bashing on Boeing 100% - yes I can see that as People are always looking for that one thing to pin it on.

Airplane crashes however a lot more complicated.


The design of this plane is leading to more "cancers" to cure

With better design we could have actually reduced the amount of "cancers" to cure

Without even discussing training - surely you can accept the above?

Once you accept that I'm more than happy to agree more training would be great as well. I do have to remind you it's Boeing who promised no sim training would be needed to fly these planes.

I'm sure that may have been the case with a better design.


I have never said it wasn't a totally screwed up design. It was terrible. I totally accept that - but errors will always be made and parts in perfectly made airplanes can fail as well which is why better training is needed.

No SIM training should have been needed with a better design - you are right.

That is what I'm advocating for - more frequent recurrent training with a larger focus on Non-Normal procedures. The Worldwide standard really seems to be lacking in this regard.


But this is what I'm finding hard to accept

We both agree this is a terribly designed plane. A screw up in your words.

We know that how the plane came to be certified safe to fly is under review as we speak

I just can't accept that the solution to a totally screwed up plane design is we just accept it now and try and train pilots to deal with it when it goes wrong

That's nowhere near putting safety first for the future

It's accepting failure and trying to deal with it with a software patch

So frustrating we end up in this situation. The 737 Max can never be the safe plane it could have been with better design

But we just have to accept it??
 
Interested
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 3:42 pm

GalaxyFlyer wrote:
Interested wrote:
seahawk wrote:

Imagine all 737MAX would have the AoA disagree warning and would automatically disable MCAS in the case. There would be no problems at all flying the planes. It is a problem of the documentation of MCAS, how it is programmed, the man to machine interface and how crews were not trained to identify and handle the problem correctly.


You think any member of the public wants to fly on a plane where their safety relies on pilots being able to turn those trim wheels at the right time

Boeing have designed planes that have software patches that make that more likely to be needed

No thank you. I would rather stay in the UK thanks.


Well, the traveling public world-wide has done exactly that since about 1959. I’d bet the n7mber of times the manual trim has been used in all those flights is under a 100.

GF


It's terrifying
 
planecane
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 3:45 pm

Interested wrote:
morrisond wrote:
Interested wrote:

The design of this plane is leading to more "cancers" to cure

With better design we could have actually reduced the amount of "cancers" to cure

Without even discussing training - surely you can accept the above?

Once you accept that I'm more than happy to agree more training would be great as well. I do have to remind you it's Boeing who promised no sim training would be needed to fly these planes.

I'm sure that may have been the case with a better design.


I have never said it wasn't a totally screwed up design. It was terrible. I totally accept that - but errors will always be made and parts in perfectly made airplanes can fail as well which is why better training is needed.

No SIM training should have been needed with a better design - you are right.

That is what I'm advocating for - more frequent recurrent training with a larger focus on Non-Normal procedures. The Worldwide standard really seems to be lacking in this regard.


But this is what I'm finding hard to accept

We both agree this is a terribly designed plane. A screw up in your words.

We know that how the plane came to be certified safe to fly is under review as we speak

I just can't accept that the solution to a totally screwed up plane design is we just accept it now and try and train pilots to deal with it when it goes wrong

That's nowhere near putting safety first for the future

It's accepting failure and trying to deal with it with a software patch

So frustrating we end up in this situation. The 737 Max can never be the safe plane it could have been with better design

But we just have to accept it??


MCAS was terribly designed, NOT THE PLANE. You refuse to believe that these same types of "fixes" may very well be implemented in other re-engined models such as the A320NEO, A330NEO and 777-200LR and -300ER. Just because the fix in contained within FBW software instead of an autopilot function operating during manual flight doesn't mean the designs are less terrible. Do you actually believe that there was no aerodynamic difference hanging significantly larger engines on those models vs. the base models?
 
dakota123
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 3:52 pm

kalvado wrote:
zeke wrote:
SomebodyInTLS wrote:
It does seem like people are mentally twisting to avoid having the word "stall" associated with MCAS, despite it being right there in the very regulations MCAS was created to address!


MCAS does not prevent a stall any more than a stick shaker does.

The idea behind MCAS is to have consistent control force up to a stall. If the control forces got lighter, the humans operating the aircraft would continue to pull at the same pressure, and as a result would unknowingly increase the rate of change as they applied constant pressure.

MCAS is there to try and overcome predictable human performance issues.

Very hard to buy such a statement when we're talking about a warning device in one case and active movement of controls, snd for a good fraction of full travel of control, in the other.
It may be about force in some very narrow sense - but, as a matter of fact, MCAS is doing a controls movement which has direct and immediate effect of trajectory.


Look up the difference between a nudger and a pusher. A nudger (unless resisted) does a control movement also, but is most definitely an augmentation system and will not prevent a stall since it can be overcome. A pusher gives an ~80 lb nose-down tug on the column instantaneously (more or less) and is much less likely to be overcome. It is intended to prevent stalls, not merely guide a pilot away from the regime in question. Yes, there is gray area.
“And If I claim to be a wise man, well surely it means that I don’t know”
 
OldAeroGuy
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 4:02 pm

Interested wrote:

But this is all just a result of a badly designed plane to start with. That's the HUGE mistake in all of this. The initial plane design. Everything leads from that. And it's all bad following after bad.


The 747, 727, HS Trident, VC-10 and the BAC 1-11 were all "clean sheet of paper" designs. All had stick nudgers or stick pushers fitted after initial flight tests to meet UK-CAA handling characteristics issues and/or prevent deep stalls.

Were these all "bad" airplanes?

Listen to Captain Davies, a legendary UK-CAA certification pilot describe his experiences with all these models.

https://www.aerosociety.com/news/audio- ... oeing-727/

Stall handling certification requirements have moved on since Captain Davies days. The 727 would not have passed today's FAA regulations. It would have required a stick pusher or greater authority MCAS like system for FAA certification.

MCAS functionality on the MAX is very much like the stick nudger described for UK registered 747's.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
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PixelFlight
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 4:29 pm

zeke wrote:
MCAS is there to try and overcome predictable human performance issues.

MCAS is designed as a unpredictable device.
No one can predict when it will start and stop nose down commands.
Even the full conditions when it will possibly fire is a ongoing hot debate.
It confuse human as two deadly crashes have show.
And it has been hidden to the pilots...
Last edited by PixelFlight on Tue Apr 23, 2019 4:52 pm, edited 3 times in total.
 
Interested
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 4:34 pm

planecane wrote:
Interested wrote:
morrisond wrote:

I have never said it wasn't a totally screwed up design. It was terrible. I totally accept that - but errors will always be made and parts in perfectly made airplanes can fail as well which is why better training is needed.

No SIM training should have been needed with a better design - you are right.

That is what I'm advocating for - more frequent recurrent training with a larger focus on Non-Normal procedures. The Worldwide standard really seems to be lacking in this regard.


But this is what I'm finding hard to accept

We both agree this is a terribly designed plane. A screw up in your words.

We know that how the plane came to be certified safe to fly is under review as we speak

I just can't accept that the solution to a totally screwed up plane design is we just accept it now and try and train pilots to deal with it when it goes wrong

That's nowhere near putting safety first for the future

It's accepting failure and trying to deal with it with a software patch

So frustrating we end up in this situation. The 737 Max can never be the safe plane it could have been with better design

But we just have to accept it??


MCAS was terribly designed, NOT THE PLANE. You refuse to believe that these same types of "fixes" may very well be implemented in other re-engined models such as the A320NEO, A330NEO and 777-200LR and -300ER. Just because the fix in contained within FBW software instead of an autopilot function operating during manual flight doesn't mean the designs are less terrible. Do you actually believe that there was no aerodynamic difference hanging significantly larger engines on those models vs. the base models?


I'm not interested in those planes

And I didnt ask for larger engines!

This plane was grandfathered from the 737 NG

A plane I believe we all believe to be very safe. I certainly felt safe on them. Those planes didn't need software patches to make it safe. This plane does. And it's a traversty that this has happened IMO

A safe plane made unsafe

And it's supposed to be grandfathered from it and an improvement!!!
 
planecane
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 4:43 pm

Interested wrote:
planecane wrote:
Interested wrote:

But this is what I'm finding hard to accept

We both agree this is a terribly designed plane. A screw up in your words.

We know that how the plane came to be certified safe to fly is under review as we speak

I just can't accept that the solution to a totally screwed up plane design is we just accept it now and try and train pilots to deal with it when it goes wrong

That's nowhere near putting safety first for the future

It's accepting failure and trying to deal with it with a software patch

So frustrating we end up in this situation. The 737 Max can never be the safe plane it could have been with better design

But we just have to accept it??


MCAS was terribly designed, NOT THE PLANE. You refuse to believe that these same types of "fixes" may very well be implemented in other re-engined models such as the A320NEO, A330NEO and 777-200LR and -300ER. Just because the fix in contained within FBW software instead of an autopilot function operating during manual flight doesn't mean the designs are less terrible. Do you actually believe that there was no aerodynamic difference hanging significantly larger engines on those models vs. the base models?


I'm not interested in those planes

And I didnt ask for larger engines!

This plane was grandfathered from the 737 NG

A plane I believe we all believe to be very safe. I certainly felt safe on them. Those planes didn't need software patches to make it safe. This plane does. And it's a traversty that this has happened IMO

A safe plane made unsafe

And it's supposed to be grandfathered from it and an improvement!!!


You don't know if those planes needed software patches or not (neither do I). That is my whole point. You are railing against "poor design" of the MAX but any re-engined plane could have just as poor design and have a software "patch" to keep it flying. The only difference is that for those other models, the "patch" would be contained within the FBW software and for the MAX they added a new algorithm to the FCC.

You didn't ask for bigger engines on the A320NEO either but they are there. The only thing that made the 737MAX less safe than the 737NG is very poorly thought out software design logic. If MCAS had been designed properly, the MAX would be just as safe as the NG.
 
OldAeroGuy
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 4:44 pm

kalvado wrote:
OldAeroGuy wrote:
zeke wrote:

There is via the elevator shift, that’s how control force is added for STS.


Hi Zeke

In answer to your earlier question, I don't know why STS wasn't utilized to incorporate the column force part of MCAS.

What I can say is that for MCAS to have the desired function, it must be activated by AoA and not Speed. That's why MCAS will increase Stick Force required for a straight ahead 1G stall at 120 kts or for a 2G, 60 deg banked turn at 180 kts.

Perhaps it was easier to incorporate an AoA based column force system separately.

Which again brings MCAS desired function into question. As far as I understand, STS operates within certain speed window. MCAS is active throughout, with last actuation on ET flight in overspeed condition.
So either MCAS is designed for situations beyond low speed stall, as we discussed - or it is designed without understanding design goals.


To be clear:

- MCAS was designed to be active if AoA > X
- On JT043, JT610 & ET303, an erroneous AoA vane signal indicated AoA > X
- On JT043, JT610 & ET303, correct AoA < X
- Therefore, on JT043, JT610 & ET303, MCAS was active in a flight region where it was not intended to function.

MCAS.v2 will eliminate this type of error by shutting down the MCAS function if Left and Right AoA signals are different by more than 5 deg.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
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PixelFlight
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 4:48 pm

planecane wrote:
MCAS was terribly designed, NOT THE PLANE. You refuse to believe that these same types of "fixes" may very well be implemented in other re-engined models such as the A320NEO, A330NEO and 777-200LR and -300ER. Just because the fix in contained within FBW software instead of an autopilot function operating during manual flight doesn't mean the designs are less terrible. Do you actually believe that there was no aerodynamic difference hanging significantly larger engines on those models vs. the base models?

I agree. But does the unusual engines position on the MAX increase the aerodynamic difference with the base model (on some edges of the flight domain) compared to the aerodynamic difference on others similar commercial civil aircrafts changes like the A320NEO, A330NEO and 777-200LR and -300ER ?

If Boeing design decision for the MAX was to increase the fuselage/wings clearance (for ex. longer gears, or by any others methods) and to place the larger engines at a aerodynamically ideal position, would the MCAS ever exists today on the MAX ?
Last edited by PixelFlight on Tue Apr 23, 2019 5:07 pm, edited 1 time in total.
 
kalvado
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 4:49 pm

dakota123 wrote:
kalvado wrote:
zeke wrote:

MCAS does not prevent a stall any more than a stick shaker does.

The idea behind MCAS is to have consistent control force up to a stall. If the control forces got lighter, the humans operating the aircraft would continue to pull at the same pressure, and as a result would unknowingly increase the rate of change as they applied constant pressure.

MCAS is there to try and overcome predictable human performance issues.

Very hard to buy such a statement when we're talking about a warning device in one case and active movement of controls, snd for a good fraction of full travel of control, in the other.
It may be about force in some very narrow sense - but, as a matter of fact, MCAS is doing a controls movement which has direct and immediate effect of trajectory.


Look up the difference between a nudger and a pusher. A nudger (unless resisted) does a control movement also, but is most definitely an augmentation system and will not prevent a stall since it can be overcome. A pusher gives an ~80 lb nose-down tug on the column instantaneously (more or less) and is much less likely to be overcome. It is intended to prevent stalls, not merely guide a pilot away from the regime in question. Yes, there is gray area.

First of all, thank you for providing a reasonable source for the terminology. It makes quite a bit of sense to differentiate by degree of action. I cannot fully agree with "if he so choses" part, as any protection can be overcome with enough determination. Well, Fort Knox is very well protected so that nobody could overcome that... at least not yet. In a plane, circuit breaker is always there for a truly determined pilot.
However grayscale definition where "prevention" means very high degree of an action is fine, as long as it is understood this is a professional slang, not terminology.
But then, Zeke compares positive action MCAS with stick shaker - which in 737 context is a no-action device. Which means MCAS, in a grayscale world, is much more of preventive thing than a warning thing.
Moreover, even then we didn't see full data for MAXstick force, and it is very well possible that MCAS actuation results in significant forces in at least part of the envelope. As operation window for MCAS seem to be very wide, including highest speeds, it can be seen as prevention device in certain situations even using that slang.
 
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par13del
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 5:08 pm

PixelFlight wrote:
If Boeing design decision for the MAX was to increase the fuselage/wings clearance (for ex. longer gears, or by any others methods) and to place the larger engines at an aerodynamically ideal position, would the MCAS ever exists today on the MAX ?

If not MCAS maybe something else?
To accommodate longer gears the entire wheel well would have to be redesigned, since it was going larger, would they decide to encase the wheels when retracted, would that entail a larger and stronger wing to body connections, would new wings be required, update fuselage with increased weight, how would that affect stall / approach speeds, would it continue to handle like a NG, etc etc.
 
OldAeroGuy
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 5:08 pm

kalvado wrote:
But then, Zeke compares positive action MCAS with stick shaker - which in 737 context is a no-action device.


Where did you get this idea?

On the 737, or any airplane with a stall warning device, a stick shaker prompts an immediate action., no grey area.

The pilots must take action to avoid stalling, by pitching down and increasing speed. Thrust to be added as required.

Pilots only intentionally stall a Part 25 airplane during flight test.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
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PixelFlight
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 5:24 pm

par13del wrote:
PixelFlight wrote:
If Boeing design decision for the MAX was to increase the fuselage/wings clearance (for ex. longer gears, or by any others methods) and to place the larger engines at an aerodynamically ideal position, would the MCAS ever exists today on the MAX ?

If not MCAS maybe something else?
To accommodate longer gears the entire wheel well would have to be redesigned, since it was going larger, would they decide to encase the wheels when retracted, would that entail a larger and stronger wing to body connections, would new wings be required, update fuselage with increased weight, how would that affect stall / approach speeds, would it continue to handle like a NG, etc etc.

I think that the 737 MAX-10 have telescopic gears not requiring stronger wing to body connections, but it look like it will use the extra height only for the rotation. I wonder if a variation of that design could provides the extra height all the time.
 
kalvado
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 5:27 pm

OldAeroGuy wrote:
kalvado wrote:
But then, Zeke compares positive action MCAS with stick shaker - which in 737 context is a no-action device.


Where did you get this idea?

On the 737, or any airplane with a stall warning device, a stick shaker prompts an immediate action., no grey area.

The pilots must take action to avoid stalling, by pitching down and increasing speed. Thrust to be added as required.

Pilots only intentionally stall a Part 25 airplane during flight test.

Once again:
it is about direct action. Stick pusher moves the yoke. MCAS moves stabilizer.
stick shaker prompts immediate action. Buzzer may also prompt an immediate action - but neither acts on its own.
If anything, this is WAY more fundamental distinction compared to "may overcome if desired". Action vs warning.
 
Interested
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 5:34 pm

planecane wrote:
Interested wrote:
planecane wrote:

MCAS was terribly designed, NOT THE PLANE. You refuse to believe that these same types of "fixes" may very well be implemented in other re-engined models such as the A320NEO, A330NEO and 777-200LR and -300ER. Just because the fix in contained within FBW software instead of an autopilot function operating during manual flight doesn't mean the designs are less terrible. Do you actually believe that there was no aerodynamic difference hanging significantly larger engines on those models vs. the base models?


I'm not interested in those planes

And I didnt ask for larger engines!

This plane was grandfathered from the 737 NG

A plane I believe we all believe to be very safe. I certainly felt safe on them. Those planes didn't need software patches to make it safe. This plane does. And it's a traversty that this has happened IMO

A safe plane made unsafe

And it's supposed to be grandfathered from it and an improvement!!!


You don't know if those planes needed software patches or not (neither do I). That is my whole point. You are railing against "poor design" of the MAX but any re-engined plane could have just as poor design and have a software "patch" to keep it flying. The only difference is that for those other models, the "patch" would be contained within the FBW software and for the MAX they added a new algorithm to the FCC.

You didn't ask for bigger engines on the A320NEO either but they are there. The only thing that made the 737MAX less safe than the 737NG is very poorly thought out software design logic. If MCAS had been designed properly, the MAX would be just as safe as the NG.


I'm assuming 737ng does not have a software patch and it's a proven safe plane.

Am I wrong?

The other planes I'm not bothered about. This is about taking the 737ng and supposedly grandfathering it. Which I don't believe they have done myself.

I think they've created an entirely new plane that is unsafe.

The other planes are irrelevant to my argument
 
kalvado
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 5:36 pm

PixelFlight wrote:
par13del wrote:
PixelFlight wrote:
If Boeing design decision for the MAX was to increase the fuselage/wings clearance (for ex. longer gears, or by any others methods) and to place the larger engines at an aerodynamically ideal position, would the MCAS ever exists today on the MAX ?

If not MCAS maybe something else?
To accommodate longer gears the entire wheel well would have to be redesigned, since it was going larger, would they decide to encase the wheels when retracted, would that entail a larger and stronger wing to body connections, would new wings be required, update fuselage with increased weight, how would that affect stall / approach speeds, would it continue to handle like a NG, etc etc.

I think that the 737 MAX-10 have telescopic gears not requiring stronger wing to body connections, but it look like it will use the extra height only for the rotation. I wonder if a variation of that design could provides the extra height all the time.

Nope, as far as I understand: extra height would mean different evacuation scheme. 737 overwing exits go to wing and then pax supposed to jump to the ground. These are at top limit for a no-slide escape, like 6' jump. Changing that means full certification to modern standards, including different door sizes etc. Even if gear could be redesigned, this is a hard stop. Unlike 737, 320 does have overwing slides to accomodate for being higher off the ground.
 
xmp125a
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 6:00 pm

morrisond wrote:
Due to automation Piloting has gotten a lot simpler in the past 30 years. They should have the time to practice unusual situations for when things happen - for even in a perfectly designed airplane parts can fail.


But Boeing actually went along with this, as now it is pretty obvious that botched design was at least partially due to the requirement for no sim time. And I understand that this is what you can sell but the job of engineers is to say "nope it can't be done safely" even if market would like to buy it when safety critical systems are in play! Airlines who wanted no sim time will not be blamed, Boeing will. And even more, Boeing management itself botched up big time because they did not believe Airbus is on track with 320neo. At least three years they were asleep at the wheel and then forced engineers to work in half of the time Airbus had.

So yes I can agree with need for better training, but Boeing actively sought to make it appear unnecessary!
 
kayik
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 6:06 pm

morrisond wrote:
That's like saying we should totally focus on eradicating all forms of cancer and Doctors don't need to go Med School to learn how to manage cancer until we have a cure. Screw the people that already have cancer - if we lose a few so what that's wasted resources.


Terrible analogy. It is not cancer that we know a little about.; it is something Boeing created and supposed to know everything about.

I don't think it is a global training issue, it is more like "Boeing covers up the training needs and FAA stamps" issue. Ethiopians have a MAX sim, I have laid eyes on another MAX sim invoice dated November for $12.4 million in Europe. The invoice clearly says 737MAX simulator, do we now what that means? However, this indicates that training issues are taken seriously outside US where there are no simulators.

If a plane is supposed to behave the same as the old one (with band aid), you expect it to behave the same in catastrophic conditions too. You would not expect the band aid to force you to sky dive.

These two Ethiopian pilots were struggling in a diving plane at full speed several hundred meters above ground and some self declared Sullys are claiming that they could fly that plane by doing everything right.

Another thing I would like to add is, this topic is about 737MAx grounding and maybe ungrounding issues. Not about what is MCAS or what is not; how US pilots would succesfuly fly planes or vocabulary discussions. Could you please show your knowledge in related topis?
 
OldAeroGuy
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 6:12 pm

Interested wrote:
I'm assuming 737ng does not have a software patch and it's a proven safe plane.

Am I wrong?


Depends on your definition of software. The Speed Trim System (STS) could be thought of as a software patch. It make commands to the 737NG flight control system without pilot input.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
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AirlineCritic
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Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 6:20 pm

I have to say I find reading this thread painful. From a number of angles... it does not look pretty. I think it is pretty well established that most accidents (probably including this) are going to have multiple causes. In this case most likely the design of the aircraft (MCAS, sensors, computers, and the manual trim system) and the actions that the crew took. When the investigation process is complete, we usually find that errors were made and learn to correct those, by fixing the machine and training the people better. Often in simulators!

So why is it important for you guys to keep trying to whitewash any of these components or crew actions? Frankly, all I can think of is motives that are ... improper. What I'm hoping we'll conclude is along the lines of:

* unforeseen failure mode was not taken into account in design => better design
* crew actions were difficult or wrong in the given case => better design + better training + better procedures
* process failure allowed the potential failures to escape => better process

Now, instead of trying to prove that "the other guy/machine takes all the blame" and hi-fiving your friends you present the same arguments, could we at least agree that the accident could have been prevented by either better machine or better actions, and that improvements in both are going to be forthcoming? This isn't to blame either side, by the way, it may well be that, for instance, we don't know yet what the right procedure is in different flight regimes to deal with these errors. But we will. And as has been noted by many, it is not in anyone's interest to have a third accident.

However, what I would find more interesting to talk about is what we do NOT yet know. Many of you are taking descriptions that in my eyes are shallow, imprecise and preliminary, and using them to support your favourite outcome. But I think we really don't know everything. For instance:

* we do not know what exact findings lead to the increased authority of MCAS during flight testing
* we do not know exactly what kinds of forces are needed in the manual trim system, and what flight regimes it works well in
* we do not have full transcripts or FDR logs of the two crashes
* we do not fully understand the FDR data that we have
* we do not know whether the initiating event (at least in the Lion Air case) lead to the errors, sensors or something else?

What else?
 
Interested
Posts: 647
Joined: Thu May 19, 2016 12:19 pm

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 6:21 pm

OldAeroGuy wrote:
Interested wrote:
I'm assuming 737ng does not have a software patch and it's a proven safe plane.

Am I wrong?


Depends on your definition of software. The Speed Trim System (STS) could be thought of as a software patch. It make commands to the 737NG flight control system without pilot input.


How often does it go wrong and lead to them having to use manual trim?
 
Interested
Posts: 647
Joined: Thu May 19, 2016 12:19 pm

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 6:23 pm

From the post above:


* we do not know what exact findings lead to the increased authority of MCAS during flight testing

Morrison and OldAeroGuy - we are still waiting for an answer to the above?

Please can you re-assure us it's nothing to worry about and why
 
User avatar
PixelFlight
Posts: 653
Joined: Thu Nov 08, 2018 11:09 pm

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 6:28 pm

kalvado wrote:
PixelFlight wrote:
I think that the 737 MAX-10 have telescopic gears not requiring stronger wing to body connections, but it look like it will use the extra height only for the rotation. I wonder if a variation of that design could provides the extra height all the time.

Nope, as far as I understand: extra height would mean different evacuation scheme. 737 overwing exits go to wing and then pax supposed to jump to the ground. These are at top limit for a no-slide escape, like 6' jump. Changing that means full certification to modern standards, including different door sizes etc. Even if gear could be redesigned, this is a hard stop. Unlike 737, 320 does have overwing slides to accomodate for being higher off the ground.

Ok :checkmark: Thanks for the explanation!
I understand now why the MAX was a shorter path compared to a new design. I still doubt that was a decision "designed to make an already safe aircraft even safer"... "We quickly need to compete the NEO before it start eating our market" was obviously the priority.
 
RandWkop
Posts: 179
Joined: Sat May 05, 2012 10:56 pm

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 6:40 pm

planecane wrote:
Interested wrote:
planecane wrote:

MCAS was terribly designed, NOT THE PLANE. You refuse to believe that these same types of "fixes" may very well be implemented in other re-engined models such as the A320NEO, A330NEO and 777-200LR and -300ER. Just because the fix in contained within FBW software instead of an autopilot function operating during manual flight doesn't mean the designs are less terrible. Do you actually believe that there was no aerodynamic difference hanging significantly larger engines on those models vs. the base models?


I'm not interested in those planes

And I didnt ask for larger engines!

This plane was grandfathered from the 737 NG

A plane I believe we all believe to be very safe. I certainly felt safe on them. Those planes didn't need software patches to make it safe. This plane does. And it's a traversty that this has happened IMO

A safe plane made unsafe

And it's supposed to be grandfathered from it and an improvement!!!


You don't know if those planes needed software patches or not (neither do I). That is my whole point. You are railing against "poor design" of the MAX but any re-engined plane could have just as poor design and have a software "patch" to keep it flying. The only difference is that for those other models, the "patch" would be contained within the FBW software and for the MAX they added a new algorithm to the FCC.

You didn't ask for bigger engines on the A320NEO either but they are there. The only thing that made the 737MAX less safe than the 737NG is very poorly thought out software design logic. If MCAS had been designed properly, the MAX would be just as safe as the NG.


But on the 320NEO, 330NEO and 773ER there was room to hang the larger diameter engines without moving the engines up and forward. The effects of the new engines on these aircraft should be much less than the MAX as the positioning on the MAX is much different than all other re-engines. I shouldn`t be getting into this argument as I don`t have the knowledge, but this thread should concentrate solely on the MAX issues. Dragging other planes into this is just another red herring.
 
OldAeroGuy
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Joined: Sun Dec 05, 2004 6:50 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 7:02 pm

AirlineCritic wrote:
I have to say I find reading this thread painful. From a number of angles... it does not look pretty. I think it is pretty well established that most accidents (probably including this) are going to have multiple causes. In this case most likely the design of the aircraft (MCAS, sensors, computers, and the manual trim system) and the actions that the crew took. When the investigation process is complete, we usually find that errors were made and learn to correct those, by fixing the machine and training the people better. Often in simulators!

So why is it important for you guys to keep trying to whitewash any of these components or crew actions? Frankly, all I can think of is motives that are ... improper. What I'm hoping we'll conclude is along the lines of:

* unforeseen failure mode was not taken into account in design => better design
* crew actions were difficult or wrong in the given case => better design + better training + better procedures
* process failure allowed the potential failures to escape => better process

Now, instead of trying to prove that "the other guy/machine takes all the blame" and hi-fiving your friends you present the same arguments, could we at least agree that the accident could have been prevented by either better machine or better actions, and that improvements in both are going to be forthcoming? This isn't to blame either side, by the way, it may well be that, for instance, we don't know yet what the right procedure is in different flight regimes to deal with these errors. But we will. And as has been noted by many, it is not in anyone's interest to have a third accident.

However, what I would find more interesting to talk about is what we do NOT yet know. Many of you are taking descriptions that in my eyes are shallow, imprecise and preliminary, and using them to support your favourite outcome. But I think we really don't know everything. For instance:

* we do not know what exact findings lead to the increased authority of MCAS during flight testing
* we do not know exactly what kinds of forces are needed in the manual trim system, and what flight regimes it works well in
* we do not have full transcripts or FDR logs of the two crashes
* we do not fully understand the FDR data that we have
* we do not know whether the initiating event (at least in the Lion Air case) lead to the errors, sensors or something else?

What else?


Great comprehensive post. It will most informative when the international review panel has completed its work in 90 days or so.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
Posts: 3886
Joined: Sun Dec 05, 2004 6:50 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 7:04 pm

Interested wrote:
OldAeroGuy wrote:
Interested wrote:
I'm assuming 737ng does not have a software patch and it's a proven safe plane.

Am I wrong?


Depends on your definition of software. The Speed Trim System (STS) could be thought of as a software patch. It make commands to the 737NG flight control system without pilot input.


How often does it go wrong and lead to them having to use manual trim?


Probably about as often as the MAX with MCAS.v2.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
morrisond
Posts: 1402
Joined: Thu Jan 07, 2010 12:22 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 7:04 pm

Interested wrote:
morrisond wrote:
Interested wrote:

The design of this plane is leading to more "cancers" to cure

With better design we could have actually reduced the amount of "cancers" to cure

Without even discussing training - surely you can accept the above?

Once you accept that I'm more than happy to agree more training would be great as well. I do have to remind you it's Boeing who promised no sim training would be needed to fly these planes.

I'm sure that may have been the case with a better design.


I have never said it wasn't a totally screwed up design. It was terrible. I totally accept that - but errors will always be made and parts in perfectly made airplanes can fail as well which is why better training is needed.

No SIM training should have been needed with a better design - you are right.

That is what I'm advocating for - more frequent recurrent training with a larger focus on Non-Normal procedures. The Worldwide standard really seems to be lacking in this regard.


But this is what I'm finding hard to accept

We both agree this is a terribly designed plane. A screw up in your words.

We know that how the plane came to be certified safe to fly is under review as we speak

I just can't accept that the solution to a totally screwed up plane design is we just accept it now and try and train pilots to deal with it when it goes wrong

That's nowhere near putting safety first for the future

It's accepting failure and trying to deal with it with a software patch

So frustrating we end up in this situation. The 737 Max can never be the safe plane it could have been with better design

But we just have to accept it??


I never said the MAX design was totally screwed up - the basic design is fine. However MCAS was totally screwed up and not really needed to improve Safety in any material way.
 
OldAeroGuy
Posts: 3886
Joined: Sun Dec 05, 2004 6:50 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 7:08 pm

Interested wrote:
From the post above:


* we do not know what exact findings lead to the increased authority of MCAS during flight testing

Morrison and OldAeroGuy - we are still waiting for an answer to the above?

Please can you re-assure us it's nothing to worry about and why


Why do you keep asking the same question when you know that no new data has been released?

This is getting to be trolling of the worst sort. Re-read AirlineCritic's post and respect his comments.
Last edited by OldAeroGuy on Tue Apr 23, 2019 7:13 pm, edited 1 time in total.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
morrisond
Posts: 1402
Joined: Thu Jan 07, 2010 12:22 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 7:11 pm

kayik wrote:
morrisond wrote:
That's like saying we should totally focus on eradicating all forms of cancer and Doctors don't need to go Med School to learn how to manage cancer until we have a cure. Screw the people that already have cancer - if we lose a few so what that's wasted resources.


Terrible analogy. It is not cancer that we know a little about.; it is something Boeing created and supposed to know everything about.

I don't think it is a global training issue, it is more like "Boeing covers up the training needs and FAA stamps" issue. Ethiopians have a MAX sim, I have laid eyes on another MAX sim invoice dated November for $12.4 million in Europe. The invoice clearly says 737MAX simulator, do we now what that means? However, this indicates that training issues are taken seriously outside US where there are no simulators.

If a plane is supposed to behave the same as the old one (with band aid), you expect it to behave the same in catastrophic conditions too. You would not expect the band aid to force you to sky dive.

These two Ethiopian pilots were struggling in a diving plane at full speed several hundred meters above ground and some self declared Sullys are claiming that they could fly that plane by doing everything right.

Another thing I would like to add is, this topic is about 737MAx grounding and maybe ungrounding issues. Not about what is MCAS or what is not; how US pilots would succesfuly fly planes or vocabulary discussions. Could you please show your knowledge in related topis?


They were still in a climb at about 6-7000' AGL at a speed in excess of Vmo when they turned Electric trim back on (reactivating MCAS) sending the plane into the nosedive. The plane did not do that by itself.
 
morrisond
Posts: 1402
Joined: Thu Jan 07, 2010 12:22 am

Re: B737MAX Grounded Worldwide

Tue Apr 23, 2019 7:17 pm

AirlineCritic wrote:
I have to say I find reading this thread painful. From a number of angles... it does not look pretty. I think it is pretty well established that most accidents (probably including this) are going to have multiple causes. In this case most likely the design of the aircraft (MCAS, sensors, computers, and the manual trim system) and the actions that the crew took. When the investigation process is complete, we usually find that errors were made and learn to correct those, by fixing the machine and training the people better. Often in simulators!

So why is it important for you guys to keep trying to whitewash any of these components or crew actions? Frankly, all I can think of is motives that are ... improper. What I'm hoping we'll conclude is along the lines of:

* unforeseen failure mode was not taken into account in design => better design
* crew actions were difficult or wrong in the given case => better design + better training + better procedures
* process failure allowed the potential failures to escape => better process

Now, instead of trying to prove that "the other guy/machine takes all the blame" and hi-fiving your friends you present the same arguments, could we at least agree that the accident could have been prevented by either better machine or better actions, and that improvements in both are going to be forthcoming? This isn't to blame either side, by the way, it may well be that, for instance, we don't know yet what the right procedure is in different flight regimes to deal with these errors. But we will. And as has been noted by many, it is not in anyone's interest to have a third accident.

However, what I would find more interesting to talk about is what we do NOT yet know. Many of you are taking descriptions that in my eyes are shallow, imprecise and preliminary, and using them to support your favourite outcome. But I think we really don't know everything. For instance:

* we do not know what exact findings lead to the increased authority of MCAS during flight testing
* we do not know exactly what kinds of forces are needed in the manual trim system, and what flight regimes it works well in
* we do not have full transcripts or FDR logs of the two crashes
* we do not fully understand the FDR data that we have
* we do not know whether the initiating event (at least in the Lion Air case) lead to the errors, sensors or something else?

What else?


Good post

We do not know that Ethiopian actually gave the proper Procedures to it's pilots (See Avherald article)
We do not know that even if the pilots received them whether they were familiar with them.
We do not know if they actually tried the Manual Trim wheels - it could have been them trying to Manually use the Electric Trim

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