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1989worstyear
Posts: 887
Joined: Sun Dec 04, 2016 6:53 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 4:37 am

Strato2 wrote:
scbriml wrote:
The total cost to Boeing though will be a lot more than just the $$$s ("designed by clowns who are managed by monkeys" comes to mind).


This was the latest blurb to come out and it's a catchy phrase that was plastered all over the news media. The flying public will remember this because it's like an ad only in reverse. I would not be surprised if it led to 737 MAX memes to come out.


It has already started:

https://imgflip.com/i/35wlky
Stuck at age 15 thanks to the certification date of the A320-200 and my parents' decision to postpone having a kid by 3 years. At least there's Dignitas...
 
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PixelFlight
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 4:44 am

patrickjp93 wrote:
PixelFlight wrote:
patrickjp93 wrote:
As the guy who's been going on and on about mathematically proving things, that's just insulting. No, boeing could not have done that without giving up the 737 type rating. That's been made abundantly clear in the JATR report as well. It's only NOW that the FAA and EASA will allow it, if they even do. If it's forced to become a new type, that means full sim training as if it were a clean sheet. That's utterly ridiculous. the regulators made MCAS 2.0 impossible to grandfather and made the taller landing gear impossible to grandfather. The one was a multi-input, redundant, fault-tolerant system. You can read that one up for yourself Leeham and others have covered it extensively. The other breaks the lack of evacuation slides which was also a strictly grandfathered requirement of the 737 type. It's not like Boeing kept that for kicks. Ground equipment is ridiculously cheap compared to pilot retraining. If they hadn't been forced to keep both, we wouldn't be here. It's a failure of regulators. If you applied the same safety-critical analysis to the regulation framework you'd realize how asinine it is.

New type rating don't imply "full sim training as if it were a clean sheet". Airbus successfully use "Common Type Rating" to take the new aircraft controls by undergoing “differences training” only. And for sure, going from a A330 to a A350 is way more different that what Boeing tried to avoid between the 737 NG and a 737 MAX with redundant MCAS.

That option wasn't on the table in the case of either modification. You're free to read the JATR report's findings on the motivations behind Boeing's actions.

JATR chapter R9, I know:

"Observation O9.1-B: Boeing submitted to the FAA’s AEG a list of features of the
B7378 MAX cockpit which were changed from the base model B737-800. In
Issue Paper O-1, Type Rating Determination and 14 CFR Training Requirements,
the FAA raised concerns about cumulative effects of system changes from the
B737 NG to the B737 MAX that may cause greater than level B differences
training. Boeing’s response to this concern was that there was no precedent in
prior Boeing amended type certification projects and that AC 120-53B did not
require the cumulative effects on system changes to be considered. The FAA
accepted Boeing’s response on 26 January 2016."

If the FAA did not accept the response (as there should have), the consequence will be simply a level C difference training, required sim training. But Boeing promised to the operators that no sim training would be required. Now we know that many pilots, even before JT610, was frustrated about the level B difference training on a ipad and requested sim training because there feel that the MAX was much different than expected. Boeing actively refused that point of view to keep there impossible promise. The safety was already suffering when pilots did not fell to be trained enough on a new machine.
:stirthepot: 737-8 MAX: "For all speeds higher than 220 Kts and trim set at a value of 2.5 units, the difficulity level of turning the manual trim wheel was level A (trim wheel not movable)." :stirthepot:
 
rheinwaldner
Posts: 1865
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 6:52 am

patrickjp93 wrote:
In terms of the AoA calculation, well, a 3D angle can be represented by 3 floats. That's simple math. Go thumb through a physics textbook and look at vectors. I'm assuming use of 64-bit floats since 32 would probably be too noisy for use in avionics. If it's actually 128-bit, fine, but still 3 floats. Gyroscope gives you an angle of orientation vs. the ground (gravity being the activating force), and a 3D angle is 3 floats. Now radar is the interesting bit. You would want to give a series of angles for how the air is moving in front of the nose, but air is more than just 1 item (vs. the whole plane in terms of the gyroscope), so you'd want to calculate a set of angles for a given area in front of the nose. That's an angle field. Each is 3 floats, and the distance is fixed, so you don't need to transmit the distance to the computer. That's a known quantity by the computer, just like the time to transmit the data to the computer is known (network hardware calculates this on the fly). So let's just say the field is represented by 36 angles, or a 6x6 square matrix. 36*3 = 108. Given the short distance ahead, the air currents will not change significantly before they reach the AoA vanes, so now you know the angle the air is moving vs. the radar, you know the plane's angle vs. the Earth, you know which "squares" in the matrix (your air current angles) are most likely to be passed through by the vanes, and you know your airspeed. Therefore, as long as the vane position is fixed at a known angle as well, those calculations are very, very simple. It's basic multiplication and you have a tolerance factor. You repeat this calculation for several increments of time and you can show which AoA is giving you highly likely data and which is not. This, paired with the historical data of the AoAs paired with the historical of the gyroscope, makes that check very simple. You wouldn't need more than a megaflop or two of performance.

The 737 has a radar, that can measure air flow direction?

Further issues:
- Are you aware, that the airspeed indication depends on the AoA in an aircraft? So how can your "you know your airspeed"-condition be helpful to find a failed AoA sensor?
- As good as "you know your airspeed" you "knew your AoA" too. You are picking a number of input values to find your flawed AoA sensor by calculation but ignore the fact, that these input values could be based on failed sensors too. So complexity increases a lot because your validation logic now must be able to find broken sensors not in isolation but among many sensors or input values, which in many cases interfere with each other. This is much more a physical problem than a computational problem. If fact, you demonstrate correctly, that the computational problem is small. And at the same time, you make beginner mistakes how to treat the physics of an aircraft.
Many things are difficult, all things are possible!
 
bennett123
Posts: 9794
Joined: Sun Aug 15, 2004 12:49 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 7:00 am

According to www.737.org.uk the D Check interval for the B737NG is 24-40K hours or 9-12 years.

First question is the wide range.

Secondly, this means that roughly 25 extra D Checks have been needed. How much spare capacity exists?.

Thirdly, how many parked B737NG are able to RTS and would D Checks be needed on them?.
 
Danny
Posts: 3752
Joined: Thu Apr 25, 2002 3:44 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 8:31 am

So Mr Muilenburg walks away with USD 80 million golden parachute. Meanwile almost 3 thousand people at Spirit Aerosystems loose their jobs.
https://www.ft.com/content/58152562-33f ... a0cae3f0de
https://www.cnbc.com/2020/01/10/boeing- ... -jobs.html
 
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enzo011
Posts: 1905
Joined: Tue Jun 21, 2011 8:12 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 9:01 am

Danny wrote:
So Mr Muilenburg walks away with USD 80 million golden parachute. Meanwile almost 3 thousand people at Spirit Aerosystems loose their jobs.
https://www.ft.com/content/58152562-33f ... a0cae3f0de
https://www.cnbc.com/2020/01/10/boeing- ... -jobs.html



This is on the Boeing Board who appointed him and offered him the salary. I believe he is not getting a severance package but this is only his entitlements of his contract. His successor will be on a similar pay package you think and will have the same incentives to keep the share price high for his own personal gain, even if it means screwing 3000 supplier jobs.
 
phollingsworth
Posts: 759
Joined: Sat Mar 06, 2004 6:05 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 9:01 am

shmerik wrote:
morrisond wrote:
What evidence do you have that is anything other than stick lightening?

Please provide a source that says that.

When EASA does get to fly it's tests hopefully later this week hopefully we will know for sure.


I think the reason so many of us are skeptical of the extent of the lightening claims is that Boeing had to drastically increase the authority of MCAS later on in development. That suggests that the pitch up behavior is at least greater than what the engineers initially expected. Obviously no one has any hard proof either way, unless you're willing to trust the story about "the slightest lightening" that you wouldn't notice had you not been briefed on its existence. B has given many reasons for people to be hesitant to trust claims about the MAX's performance.

I'm looking forward to the results of the testing too, it will be nice to have this cleared up finally.


I am not privilege to insider knowledge. However, one possible reason that the authority was expanded so significantly is Boeing's expectation of EASA's requests for additional testing in the validation programme. EASA is very keen on clear stall identification in aircraft without hard envelope protection (I would argue evidence suggests it might be reasonable to expand this to aircraft wit hard envelope protection). This stems partly from the UK CAA's history with deep-stall. The FAA has always been more sanguine about it. Many aircraft that were cleared to fly in the US required stick pushers to be certified in the UK, and later would have required them under JAA/EASA certification. This includes the 727 and MD-90. The JAA also mandated that Boeing make changes to the 737NG to make stall more clearly identifiable. They felt the stick shakers were not enough to ensure that an aircraft would not be held in stall. Boeing did this by expanding the authority of the original Speed Trim System.

The original MCAS0.9 is a good example of a system that was designed for an outside the normal flight envelope to provide control feel that meets the regulator requirement. In the wind-up turn the change in AoA will be slow, so the miss trim rate can be slow. However, this will not give a noticeable pitch down tendency as the pilot pulls back in 1g flight. So Boeing increased the rate in hopes of making the nose drop more noticeable. Had they done this on a schedule similar to speed trim, ie with a constant input vs an intermittent one, it might have presented the same way to pilots as a speed trim failure and the amount of out of trim that happened in all three flights might have been avoided. However, it still might have been too much.
 
Checklist787
Posts: 566
Joined: Sat Jun 01, 2019 2:37 am

Re: Boeing 737MAX Grounding News and Reference Thread 2020

Tue Jan 14, 2020 10:58 am

Revelation wrote:
David Calhoun installed as CEO of Boeing, pointing out one area of opportunity is greater transparency and accountability:

Calhoun kicked off his new job with a 13 January letter to all Boeing staff in which he lays out priorities and promises to improve the company’s transparency and commitment to safety.

“We have work to do to uphold our values and to build on our strengths. I see greatness in this company, but I also see opportunities to be better,” Calhoun’s letter says. “That includes engaging one another and our stakeholders with greater transparency, holding ourselves accountable to the highest standards of safety and quality and incorporating outside-in perspective on what we do and how we do it.”

Ref: https://www.flightglobal.com/aerospace/ ... 22.article


From this article in French

D. Calhoun also reportedly spoke of "humility".

It is wishful thinking on his part. How ironic, a person coming "directly" from GE and who sits on the board of directors since 2009 who will clean up with karsher the decisions which go back at least for 15 years, in other words the arrival of J. Mc Nerney including D. Muilenburg is the "worthy" heir but also victim, because after disclosure of shocking mails, prove that this deleterious atmosphere of the employees has been done since that time under Mc Nerney.
We remember that the battery problems that occurred on the 787 Dreamliner's in 2013 occurred under Mc Nerney.

The latter was very lucky, he was CEO for 10 years (2005-2015) it's long to have enough time to gangrene an industry but not enough to get caught in the bag because he left before MAX's 1st flight.

Muilenburg (2015-2019) wanted to go in the same direction but in worse still, we feel that stupidity has reached its climax. These emails arise the next day when he was urged to leave without delay for the good of the company ...

Where Muillenburg fell while dragging Boeing to hell is that he wanted to hide all this cultivated arrogance by pressing on the FAA and putting MAX back into service as quickly as possible as a priority absolutely rather than cleaning from the inside

It was not good for him, it illustrates well the arrogance and the gangrene which gnaws at him cause he knew his time was running out

Despite was a young prodigy by integrating the company very young...

I think is a good news for the industry, the passengers and the airlines.

Boeing is changing now and D. Calhoun, elected by the board of directors understood that it cannot and should not last

A few days ago, Boeing said that there would be sanctions against those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!

This is the legacy that Mc Nerney and Muillenburg left behind, and it could have lasted longer. But the bad acquisition turned against Muillenburg so that fate would allow Boeing to reform and change its culture ...

It is a human problem but when arrogant people who indulge in their excess it should not be surprising to see them exchange shocking mails end up getting burned too...

Anyway, this one reflects well the world "hyper capitalist" of which we live, because many companies are corrupt.

Watch Ghosn in the Renault-Toyota case (2018-2020), the Volkswagen Diesel gate in 2015. But in aeronautics it is much more delicate because there are always dead when a crash occurs at high altitude ...

This will certainly serve as a lesson for Airbus too who was lucky not to fall into this spiral of exaggerated arrogance

The success of its narrowbody A320 has assured it serenity and "eternal" stability ...

https://www.latribune.fr/entreprises-fi ... 37041.html

https://boeing.mediaroom.com/news-relea ... tem=130600
"No limit to my poooWer!!!
Do it! "...
 
kalvado
Posts: 2896
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounding News and Reference Thread 2020

Tue Jan 14, 2020 11:28 am

Checklist787 wrote:
Revelation wrote:
David Calhoun installed as CEO of Boeing, pointing out one area of opportunity is greater transparency and accountability:

Calhoun kicked off his new job with a 13 January letter to all Boeing staff in which he lays out priorities and promises to improve the company’s transparency and commitment to safety.

“We have work to do to uphold our values and to build on our strengths. I see greatness in this company, but I also see opportunities to be better,” Calhoun’s letter says. “That includes engaging one another and our stakeholders with greater transparency, holding ourselves accountable to the highest standards of safety and quality and incorporating outside-in perspective on what we do and how we do it.”

Ref: https://www.flightglobal.com/aerospace/ ... 22.article


From this article in French

D. Calhoun also reportedly spoke of "humility".

It is wishful thinking on his part. How ironic, a person coming "directly" from GE and who sits on the board of directors since 2009 who will clean up with karsher the decisions which go back at least for 15 years, in other words the arrival of J. Mc Nerney including D. Muilenburg is the "worthy" heir but also victim, because after disclosure of shocking mails, prove that this deleterious atmosphere of the employees has been done since that time under Mc Nerney.
We remember that the battery problems that occurred on the 787 Dreamliner's in 2013 occurred under Mc Nerney.

The latter was very lucky, he was CEO for 10 years (2005-2015) it's long to have enough time to gangrene an industry but not enough to get caught in the bag because he left before MAX's 1st flight.

Muilenburg (2015-2019) wanted to go in the same direction but in worse still, we feel that stupidity has reached its climax. These emails arise the next day when he was urged to leave without delay for the good of the company ...

Where Muillenburg fell while dragging Boeing to hell is that he wanted to hide all this cultivated arrogance by pressing on the FAA and putting MAX back into service as quickly as possible as a priority absolutely rather than cleaning from the inside

It was not good for him, it illustrates well the arrogance and the gangrene which gnaws at him cause he knew his time was running out

Despite was a young prodigy by integrating the company very young...

I think is a good news for the industry, the passengers and the airlines.

Boeing is changing now and D. Calhoun, elected by the board of directors understood that it cannot and should not last

A few days ago, Boeing said that there would be sanctions against those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!

This is the legacy that Mc Nerney and Muillenburg left behind, and it could have lasted longer. But the bad acquisition turned against Muillenburg so that fate would allow Boeing to reform and change its culture ...

It is a human problem but when arrogant people who indulge in their excess it should not be surprising to see them exchange shocking mails end up getting burned too...

Anyway, this one reflects well the world "hyper capitalist" of which we live, because many companies are corrupt.

Watch Ghosn in the Renault-Toyota case (2018-2020), the Volkswagen Diesel gate in 2015. But in aeronautics it is much more delicate because there are always dead when a crash occurs at high altitude ...

This will certainly serve as a lesson for Airbus too who was lucky not to fall into this spiral of exaggerated arrogance

The success of its narrowbody A320 has assured it serenity and "eternal" stability ...

https://www.latribune.fr/entreprises-fi ... 37041.html

https://boeing.mediaroom.com/news-relea ... tem=130600

Hunt for the guilty, punishment of the innocent, and reward for the uninvolved.
 
Checklist787
Posts: 566
Joined: Sat Jun 01, 2019 2:37 am

Re: Boeing 737MAX Grounding News and Reference Thread 2020

Tue Jan 14, 2020 11:43 am

kalvado wrote:
Checklist787 wrote:
Revelation wrote:
David Calhoun installed as CEO of Boeing, pointing out one area of opportunity is greater transparency and accountability:


Ref: https://www.flightglobal.com/aerospace/ ... 22.article


From this article in French

D. Calhoun also reportedly spoke of "humility".

It is wishful thinking on his part. How ironic, a person coming "directly" from GE and who sits on the board of directors since 2009 who will clean up with karsher the decisions which go back at least for 15 years, in other words the arrival of J. Mc Nerney including D. Muilenburg is the "worthy" heir but also victim, because after disclosure of shocking mails, prove that this deleterious atmosphere of the employees has been done since that time under Mc Nerney.
We remember that the battery problems that occurred on the 787 Dreamliner's in 2013 occurred under Mc Nerney.

The latter was very lucky, he was CEO for 10 years (2005-2015) it's long to have enough time to gangrene an industry but not enough to get caught in the bag because he left before MAX's 1st flight.

Muilenburg (2015-2019) wanted to go in the same direction but in worse still, we feel that stupidity has reached its climax. These emails arise the next day when he was urged to leave without delay for the good of the company ...

Where Muillenburg fell while dragging Boeing to hell is that he wanted to hide all this cultivated arrogance by pressing on the FAA and putting MAX back into service as quickly as possible as a priority absolutely rather than cleaning from the inside

It was not good for him, it illustrates well the arrogance and the gangrene which gnaws at him cause he knew his time was running out

Despite was a young prodigy by integrating the company very young...

I think is a good news for the industry, the passengers and the airlines.

Boeing is changing now and D. Calhoun, elected by the board of directors understood that it cannot and should not last

A few days ago, Boeing said that there would be sanctions against those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!

This is the legacy that Mc Nerney and Muillenburg left behind, and it could have lasted longer. But the bad acquisition turned against Muillenburg so that fate would allow Boeing to reform and change its culture ...

It is a human problem but when arrogant people who indulge in their excess it should not be surprising to see them exchange shocking mails end up getting burned too...

Anyway, this one reflects well the world "hyper capitalist" of which we live, because many companies are corrupt.

Watch Ghosn in the Renault-Toyota case (2018-2020), the Volkswagen Diesel gate in 2015. But in aeronautics it is much more delicate because there are always dead when a crash occurs at high altitude ...

This will certainly serve as a lesson for Airbus too who was lucky not to fall into this spiral of exaggerated arrogance

The success of its narrowbody A320 has assured it serenity and "eternal" stability ...

https://www.latribune.fr/entreprises-fi ... 37041.html

https://boeing.mediaroom.com/news-relea ... tem=130600

Hunt for the guilty, punishment of the innocent, and reward for the uninvolved.


Develop with rationality and factuality if you tell the truth ...

Boeing has changed and no more Popcorn and sensational articles for those who hate it.

The thriller is finished, wake up...
Last edited by Checklist787 on Tue Jan 14, 2020 11:55 am, edited 3 times in total.
"No limit to my poooWer!!!
Do it! "...
 
StTim
Posts: 3730
Joined: Thu Aug 08, 2013 7:39 am

Re: Boeing 737MAX Grounding News and Reference Thread 2020

Tue Jan 14, 2020 11:47 am

Checklist787 wrote:
A few days ago, Boeing said that there would be sanctions against those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!


Yes without doubt the mails/messages were unprofessional and irresponsible BUT did the writers have a reasonable and safe way to report the concerns? If not then they too were victims of the corrosive culture.

I read another quote, which of course I cannot find now, where they introduced shaming meetings where people were shamed for missing milestones. This is not a way to improve quality - or openness.

Who would want to work in such an environment?
 
dtw2hyd
Posts: 8411
Joined: Wed Jan 09, 2013 12:11 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 11:55 am

patrickjp93 wrote:
...
No, I can assure you it isn't any less complex. Oh, and the kernel is certified for safety-critical use just as it's certified for PCI-DSS and it's certified for use in mainframes for financial transactions. It's far more robust and fault-tolerant than Linux. IBM's Z mainframes no longer run Linux either.

JATR's conclusions can be incorrect. I can mathematically prove you don't need a single regulation to build a safe product. It's not about the process or regulatory compliance. It's about good engineering. You can do rule-compliant work without ever reading the rules. I've done it many times. And in some cases the rules can be a hindrance to safety and good engineering. In this case the strictness around grandfathering was an impediment to good design rather than an enabler of good design.


A hardened kernel helps against virus,malware,hacks or against bloated hardware interrupts unlike a general kernel.
A hardened processor protects against radiation
A reliable chip/hardware is measured in terms of mean time between failure

Here the discussion is about flight safety, and you are mixing it with kernel safety. Apples and oranges. Please don't muddle the discussion.
All posts are just opinions.
 
patrickjp93
Posts: 648
Joined: Thu Aug 22, 2019 12:00 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:09 pm

PixelFlight wrote:
patrickjp93 wrote:
PixelFlight wrote:
Ok, you are now maybe ready to understand that Boeing did no want any sim training for the 737 MAX, not because of the regulators, but because Boeing promised to the operators that there will not require sim training time to the pilots flying the MAX and, even agree to pay 1M$ per aircraft in case that promise will be broken. Really, it's not the regulator that enforced that impossible goal, but Boeing itself !

The goal WAS possible, if the FAA hadn't been incompetent rubes with shoddy regulatory frameworks. There's no scientifically/mathematically sound reason the 737 MAX shouldn't be grandfathered just because of a new redundant sensor system or because it gets tall enough to not need it.

It was Boeing impossible promise to the operators. The regulator did not force Boeing to set that goal.

It wasn't impossible or unreasonable. The rules were wrong. They should have been changed.
 
Thorkel
Posts: 26
Joined: Mon Dec 15, 2014 2:38 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:10 pm

Not sure if this has been posted before - just came across this paper, written by somebody from Boeing surprisingly (although on their own dime), on the performance of pilots from a US airline when completing memory line items. It includes how well they did at executing the runaway stabiliser checklist in a non stressful situation.

http://www.code7700.com/pdfs/line_pilot ... _items.pdf
 
patrickjp93
Posts: 648
Joined: Thu Aug 22, 2019 12:00 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:11 pm

dtw2hyd wrote:
patrickjp93 wrote:
...
No, I can assure you it isn't any less complex. Oh, and the kernel is certified for safety-critical use just as it's certified for PCI-DSS and it's certified for use in mainframes for financial transactions. It's far more robust and fault-tolerant than Linux. IBM's Z mainframes no longer run Linux either.

JATR's conclusions can be incorrect. I can mathematically prove you don't need a single regulation to build a safe product. It's not about the process or regulatory compliance. It's about good engineering. You can do rule-compliant work without ever reading the rules. I've done it many times. And in some cases the rules can be a hindrance to safety and good engineering. In this case the strictness around grandfathering was an impediment to good design rather than an enabler of good design.


A hardened kernel helps against virus,malware,hacks or against bloated hardware interrupts unlike a general kernel.
A hardened processor protects against radiation
A reliable chip/hardware is measured in terms of mean time between failure

Here the discussion is about flight safety, and you are mixing it with kernel safety. Apples and oranges. Please don't muddle the discussion.

I'm not muddling the discussion. Most of the differences at the OS level for safety criticality come down to deterministic completion times for all operations, in addition to being able to run on fault-tolerant, hardened hardware. BSD and some flavors of Linux have been used for medical safety purposes for decades. That said, they've never been used for aerospace despite being used in satellites where the engineering constraints are even tighter.
 
kalvado
Posts: 2896
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounding News and Reference Thread 2020

Tue Jan 14, 2020 12:12 pm

StTim wrote:
Checklist787 wrote:
A few days ago, Boeing said that there would be sanctions against those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!


Yes without doubt the mails/messages were unprofessional and irresponsible BUT did the writers have a reasonable and safe way to report the concerns? If not then they too were victims of the corrosive culture.

I read another quote, which of course I cannot find now, where they introduced shaming meetings where people were shamed for missing milestones. This is not a way to improve quality - or openness.

Who would want to work in such an environment?

I suspect this is exactly why MAX takes so long to be ungrounded.
 
Thorkel
Posts: 26
Joined: Mon Dec 15, 2014 2:38 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:27 pm

patrickjp93 wrote:
dtw2hyd wrote:
patrickjp93 wrote:
...
No, I can assure you it isn't any less complex. Oh, and the kernel is certified for safety-critical use just as it's certified for PCI-DSS and it's certified for use in mainframes for financial transactions. It's far more robust and fault-tolerant than Linux. IBM's Z mainframes no longer run Linux either.

JATR's conclusions can be incorrect. I can mathematically prove you don't need a single regulation to build a safe product. It's not about the process or regulatory compliance. It's about good engineering. You can do rule-compliant work without ever reading the rules. I've done it many times. And in some cases the rules can be a hindrance to safety and good engineering. In this case the strictness around grandfathering was an impediment to good design rather than an enabler of good design.


A hardened kernel helps against virus,malware,hacks or against bloated hardware interrupts unlike a general kernel.
A hardened processor protects against radiation
A reliable chip/hardware is measured in terms of mean time between failure

Here the discussion is about flight safety, and you are mixing it with kernel safety. Apples and oranges. Please don't muddle the discussion.

I'm not muddling the discussion. Most of the differences at the OS level for safety criticality come down to deterministic completion times for all operations, in addition to being able to run on fault-tolerant, hardened hardware. BSD and some flavors of Linux have been used for medical safety purposes for decades. That said, they've never been used for aerospace despite being used in satellites where the engineering constraints are even tighter.


It’s not just timing predictability. Safety Critical OSs and languages are designed to essentially remove most causes of dynamism. Dynamic allocation of memory - nope. Recursion - nope, risk you might blow the stack. OpenBSD doesn’t run on most of the processor types usually used for avionics, and software written in C (with all the problematic practices that allows) typically won’t be allowed a Safety Integrity Level (SIL) above 0. You need appropriate languages for that - either restricted C/C++ (the MISRA variants) or purpose built languages (such as ADA, and the variants that allow mathematical specification of pre/post conditions like SPARK). Retrospectively refactoring existing applications for this is hard.

And that’s before you get to the issue that many safety critical problems are not in the implementation, but in the requirements definition in the first place (which likely applies to MCAS).

It’s also worth stressing that engineers write these standards - not lawyers. There are a lot of engineers, with a lot of experience writing safety critical systems, that have put a lot of time into these standards. It requires a distinct set of skills, expertise and behaviours. If you think you know better, then that pretty much demonstrates why the standards were written in the first place.
 
patrickjp93
Posts: 648
Joined: Thu Aug 22, 2019 12:00 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:43 pm

rheinwaldner wrote:
patrickjp93 wrote:
In terms of the AoA calculation, well, a 3D angle can be represented by 3 floats. That's simple math. Go thumb through a physics textbook and look at vectors. I'm assuming use of 64-bit floats since 32 would probably be too noisy for use in avionics. If it's actually 128-bit, fine, but still 3 floats. Gyroscope gives you an angle of orientation vs. the ground (gravity being the activating force), and a 3D angle is 3 floats. Now radar is the interesting bit. You would want to give a series of angles for how the air is moving in front of the nose, but air is more than just 1 item (vs. the whole plane in terms of the gyroscope), so you'd want to calculate a set of angles for a given area in front of the nose. That's an angle field. Each is 3 floats, and the distance is fixed, so you don't need to transmit the distance to the computer. That's a known quantity by the computer, just like the time to transmit the data to the computer is known (network hardware calculates this on the fly). So let's just say the field is represented by 36 angles, or a 6x6 square matrix. 36*3 = 108. Given the short distance ahead, the air currents will not change significantly before they reach the AoA vanes, so now you know the angle the air is moving vs. the radar, you know the plane's angle vs. the Earth, you know which "squares" in the matrix (your air current angles) are most likely to be passed through by the vanes, and you know your airspeed. Therefore, as long as the vane position is fixed at a known angle as well, those calculations are very, very simple. It's basic multiplication and you have a tolerance factor. You repeat this calculation for several increments of time and you can show which AoA is giving you highly likely data and which is not. This, paired with the historical data of the AoAs paired with the historical of the gyroscope, makes that check very simple. You wouldn't need more than a megaflop or two of performance.

The 737 has a radar, that can measure air flow direction?

Further issues:
- Are you aware, that the airspeed indication depends on the AoA in an aircraft? So how can your "you know your airspeed"-condition be helpful to find a failed AoA sensor?
- As good as "you know your airspeed" you "knew your AoA" too. You are picking a number of input values to find your flawed AoA sensor by calculation but ignore the fact, that these input values could be based on failed sensors too. So complexity increases a lot because your validation logic now must be able to find broken sensors not in isolation but among many sensors or input values, which in many cases interfere with each other. This is much more a physical problem than a computational problem. If fact, you demonstrate correctly, that the computational problem is small. And at the same time, you make beginner mistakes how to treat the physics of an aircraft.

Bear in mind I've been saying what you CAN do with other sensors. I know this back and forth is a mile long, but you'll have to be careful separating my blue-sky engineering thoughts from anything that's speaking specifically to current 737 systems and grandfathering. And you don't need the AoA to get your air speed. Using triangulation from the radar sensors or Boeing's upcoming Lidar implementation, you can derive craft speed based on the bounce time of reflected beams at a given distance ahead since Special Relativity is a well-understood scheme at this point. Or if you're happy with a dirtier approximation, if you know the outside air temperature and pressure and have historical altimeter data you can get within a few percent of the real speed. It wouldn't have the same precision, but bearing in mind the speed you have to be flying to gain/lose/maintain altitude at a given drag (we know the overall drag of the craft after we've done flight testing +/- 1% for natural frame variability). That estimation, of course, is only in a completely reliable form when you have an undamaged frame, but it's usable if your AoA goes AWOL. And if the sensors fail (which is also detectable or assignable by the pilots) then that estimation goes away too. By the time you're having that many failures simultaneously, chances are you've got a fire in your flight computer or electrical system and you're going into manual control law anyway which is more based on visual than system readings when you know the system is bogus.
I believe all of the sensors I said I'd use for that secondary calculation have failure rates of e-12 or better, and they definitely don't interfere with the AoA itself, not a one. The most difficult part of the problem is the wiring. I don't envy the hardware installers/maintainers.
 
patrickjp93
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:46 pm

Thorkel wrote:
patrickjp93 wrote:
dtw2hyd wrote:

A hardened kernel helps against virus,malware,hacks or against bloated hardware interrupts unlike a general kernel.
A hardened processor protects against radiation
A reliable chip/hardware is measured in terms of mean time between failure

Here the discussion is about flight safety, and you are mixing it with kernel safety. Apples and oranges. Please don't muddle the discussion.

I'm not muddling the discussion. Most of the differences at the OS level for safety criticality come down to deterministic completion times for all operations, in addition to being able to run on fault-tolerant, hardened hardware. BSD and some flavors of Linux have been used for medical safety purposes for decades. That said, they've never been used for aerospace despite being used in satellites where the engineering constraints are even tighter.


It’s not just timing predictability. Safety Critical OSs and languages are designed to essentially remove most causes of dynamism. Dynamic allocation of memory - nope. Recursion - nope, risk you might blow the stack. OpenBSD doesn’t run on most of the processor types usually used for avionics, and software written in C (with all the problematic practices that allows) typically won’t be allowed a Safety Integrity Level (SIL) above 0. You need appropriate languages for that - either restricted C/C++ (the MISRA variants) or purpose built languages (such as ADA, and the variants that allow mathematical specification of pre/post conditions like SPARK). Retrospectively refactoring existing applications for this is hard.

And that’s before you get to the issue that many safety critical problems are not in the implementation, but in the requirements definition in the first place (which likely applies to MCAS).

It’s also worth stressing that engineers write these standards - not lawyers. There are a lot of engineers, with a lot of experience writing safety critical systems, that have put a lot of time into these standards. It requires a distinct set of skills, expertise and behaviours. If you think you know better, then that pretty much demonstrates why the standards were written in the first place.

Being a language geek myself, your dynamic memory allocation problem stopped being an issue with C/C++ in 2009 and 2014 respectfully. And as for recursion, it depends. Tail recursion produces no stack frames, and these days the optimizers can usually rewrite recursive functions into loop forms and will if you know the right flags.
 
patrickjp93
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:48 pm

PixelFlight wrote:
patrickjp93 wrote:
PixelFlight wrote:
New type rating don't imply "full sim training as if it were a clean sheet". Airbus successfully use "Common Type Rating" to take the new aircraft controls by undergoing “differences training” only. And for sure, going from a A330 to a A350 is way more different that what Boeing tried to avoid between the 737 NG and a 737 MAX with redundant MCAS.

That option wasn't on the table in the case of either modification. You're free to read the JATR report's findings on the motivations behind Boeing's actions.

JATR chapter R9, I know:

"Observation O9.1-B: Boeing submitted to the FAA’s AEG a list of features of the
B7378 MAX cockpit which were changed from the base model B737-800. In
Issue Paper O-1, Type Rating Determination and 14 CFR Training Requirements,
the FAA raised concerns about cumulative effects of system changes from the
B737 NG to the B737 MAX that may cause greater than level B differences
training. Boeing’s response to this concern was that there was no precedent in
prior Boeing amended type certification projects and that AC 120-53B did not
require the cumulative effects on system changes to be considered. The FAA
accepted Boeing’s response on 26 January 2016."

If the FAA did not accept the response (as there should have), the consequence will be simply a level C difference training, required sim training. But Boeing promised to the operators that no sim training would be required. Now we know that many pilots, even before JT610, was frustrated about the level B difference training on a ipad and requested sim training because there feel that the MAX was much different than expected. Boeing actively refused that point of view to keep there impossible promise. The safety was already suffering when pilots did not fell to be trained enough on a new machine.

Apart from MCAS missing from the differences training altogether, truth is no pilots struggled making the transition, so I'd say your B vs. C training didn't have an impact.
 
patrickjp93
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:51 pm

PixelFlight wrote:
patrickjp93 wrote:
PixelFlight wrote:
You are wrong on this. The training requirement is a simple table listing the difference with the previous model and for each difference the level of training is evaluated. A proper MCAS design would have probably be a single line in that table that would require a relatively small simulator training session.
Sorry, but I don't usually speak English.

In this case that's not true, because the change in architecture would break grandfathering altogether. The 737 MAX would have been an all-new type. It's no longer about differences training at that point. It's the full gauntlet sim training as if it's a brand new pilot on a brand new plane. That was a requirement Boeing had. Surely the FAA could have worked together with Boeing to find a proper compromise solution where grandfathering rigidity was relaxed to allow either MCAS 2.0 or increased landing gear height without nullifying the common type rating.

I wish I'd known English was your 2nd or 3rd+ language. Your use of it is very good, but I'm sure some of your ideas aren't translating perfectly.

Again, regulators are ok with “differences training” between new type rating, as proved by the "common type rating" set by Airbus since many years already. It was Boeing promise to the operators that was impossible. The solution would have required either more development time, and/or sim training.

The FAA was not going to allow it if the new version of the plane added a redundant sensor control system. This has been fleshed out here on the forum by more senior people than me quite a few times now. It would have been full-blown sim training as if it were a new plane. This would not be like the 787 and 777X sharing a common type rating where pilots can simply run differences training. No, it would have been as though a cutting edge, brand new design hit the market.
 
Thorkel
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 12:58 pm

patrickjp93 wrote:
Thorkel wrote:
patrickjp93 wrote:
I'm not muddling the discussion. Most of the differences at the OS level for safety criticality come down to deterministic completion times for all operations, in addition to being able to run on fault-tolerant, hardened hardware. BSD and some flavors of Linux have been used for medical safety purposes for decades. That said, they've never been used for aerospace despite being used in satellites where the engineering constraints are even tighter.


It’s not just timing predictability. Safety Critical OSs and languages are designed to essentially remove most causes of dynamism. Dynamic allocation of memory - nope. Recursion - nope, risk you might blow the stack. OpenBSD doesn’t run on most of the processor types usually used for avionics, and software written in C (with all the problematic practices that allows) typically won’t be allowed a Safety Integrity Level (SIL) above 0. You need appropriate languages for that - either restricted C/C++ (the MISRA variants) or purpose built languages (such as ADA, and the variants that allow mathematical specification of pre/post conditions like SPARK). Retrospectively refactoring existing applications for this is hard.

And that’s before you get to the issue that many safety critical problems are not in the implementation, but in the requirements definition in the first place (which likely applies to MCAS).

It’s also worth stressing that engineers write these standards - not lawyers. There are a lot of engineers, with a lot of experience writing safety critical systems, that have put a lot of time into these standards. It requires a distinct set of skills, expertise and behaviours. If you think you know better, then that pretty much demonstrates why the standards were written in the first place.

Being a language geek myself, your dynamic memory allocation problem stopped being an issue with C/C++ in 2009 and 2014 respectfully. And as for recursion, it depends. Tail recursion produces no stack frames, and these days the optimizers can usually rewrite recursive functions into loop forms and will if you know the right flags.


Yep - and for a high integrity application, guess what you can’t use. Compiler optimisations, particularly when they make significant transformations of the code. I’ve known circumstances where engineers have had to take the original source code and the compiler output and trace the two to demonstrate the compiler isn’t doing anything funky, and the original intent of the code is maintained - this needed to be presented to the regulator. You need to be able to trust and demonstrate that the code outputted from the compiler represents the code you wrote, particularly when you get to the high SILs/PLs.

Writing this sort of code is boring and expensive. But it also results in reliable, analysable, predictable and above all safe systems.

I also don’t think you really understand what I meant around dynamic memory. I simply mean - you can’t do it for a high SIL/PL application. No malloc(). No new(). No derivative of those functions.. At all. Memory usage needs, for high integrity applications, needs to be statically analysable and utterly predictable. You allocate it all up front, and leave it be.

I’m going to stop here, as this sub-discussion is off-topic. You clearly have technical knowledge, but you clearly also haven’t developed high integrity systems of this type, using these languages or these standards. They are a big reason why modern avionics (and similar systems) are as safe as they are.
 
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keesje
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Tue Jan 14, 2020 1:00 pm

Checklist787 wrote:
Revelation wrote:
David Calhoun installed as CEO of Boeing, pointing out one area of opportunity is greater transparency and accountability:

Calhoun kicked off his new job with a 13 January letter to all Boeing staff in which he lays out priorities and promises to improve the company’s transparency and commitment to safety.

“We have work to do to uphold our values and to build on our strengths. I see greatness in this company, but I also see opportunities to be better,” Calhoun’s letter says. “That includes engaging one another and our stakeholders with greater transparency, holding ourselves accountable to the highest standards of safety and quality and incorporating outside-in perspective on what we do and how we do it.”

Ref: https://www.flightglobal.com/aerospace/ ... 22.article


....
Boeing is changing now and D. Calhoun, elected by the board of directors understood that it cannot and should not last

A few days ago, Boeing said that there would be sanctions against those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!

This is the legacy that Mc Nerney and Muillenburg left behind, and it could have lasted longer. But the bad acquisition turned against Muillenburg so that fate would allow Boeing to reform and change its culture



While we see a hunt for scapegoats, including those in the Boeing board, the problem is bigger. There has been a longer term tendency to position the FAA as bureaucracy, weakening US Aerospace Industry development, wasting money.

Over the last decade, and before, there was industry wide support for reducing FAA certification oversight, influence and stronger delegation.

Image Image

https://gama.aero/wp-content/uploads/AIA_GAMA_Senate_Leadership_Letter_FAA_Reauthorization.pdf

Congress did a review not long ago & applauded the FAA for decentralisation, delegation and asked to side EASA where possible.
https://www.gao.gov/assets/690/683649.pdf

As evidenced by the latests mails releases, it gave Boeing engineering the feeling they could push FAA around at their liking.
They clearly had back up from Boeing leadership & Capitol Hill.

https://www.seattletimes.com/business/b ... f-737-max/

Congress, Senators and GAMA and AIA camera lovers, these days keep a low profile, lost interest, did 180s or try divert attention, try blame anyone else.

Long live Google for making it harder to re-write history. Firing the Boeing board isn’t solving the bigger system issue.
"Never mistake motion for action." Ernest Hemingway
 
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scbriml
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:02 pm

Checklist787 wrote:
A few days ago, Boeing said that there would be sanctions against those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!


Fire the workers and reward the bosses. That should help change the culture. :banghead:

Checklist787 wrote:
Boeing has changed and no more Popcorn and sensational articles for those who hate it.


Changed? It requires someone looking through some special glasses to think the company has changed one day after a new CEO starts. :spin:

It's far too soon to declare that Boeing has changed. Having Calhoun at the top is just more of the same. Changing a culture that has seeped through the company over many years cannot be changed overnight by a new CEO. It will take a lot of effort for Boeing to change and more changes at the upper end will be required before anyone outside Boeing starts to believe that change is actually happening.

StTim wrote:
Yes without doubt the mails/messages were unprofessional and irresponsible BUT did the writers have a reasonable and safe way to report the concerns? If not then they too were victims of the corrosive culture.


It's apparent from the leaked emails and messages that the behaviours were driven from the top down. These are employees put under unreasonable pressure by their managers to meet specific goals. It seems doubtful that any complaints or concerns passed up the chain were given the consideration they should have been.

StTim wrote:
I read another quote, which of course I cannot find now, where they introduced shaming meetings where people were shamed for missing milestones. This is not a way to improve quality - or openness.


Yes, it was reported somewhere in one of these very fast moving threads. It reminded me of the old satirical office poster - "The beatings will only stop when morale improves." or one of those sarcastic motivational posters - "It's hard to soar like an eagle when you're surrounded by turkeys."
Time flies like an arrow. Fruit flies like a banana!
There are 10 types of people in the World - those that understand binary and those that don't.
 
dtw2hyd
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:11 pm

patrickjp93 wrote:
I'm not muddling the discussion. Most of the differences at the OS level for safety criticality come down to deterministic completion times for all operations, in addition to being able to run on fault-tolerant, hardened hardware. BSD and some flavors of Linux have been used for medical safety purposes for decades. That said, they've never been used for aerospace despite being used in satellites where the engineering constraints are even tighter.


OS kernel hardening is not exclusive to any OS. Traditionally UNIX based operating systems allowed compilation of minimal kernels from get go, now even Microsoft allows it to certain level.

Back to the topic, There is no evidence any of the operating systems on MAX are compromised. A hardware based on 8088/386/68K runs very limited number of instructions. Unless there is evidence that crew have the ability to browse internet or watch videos on FCCs, OS kernel is not an issue.

AFAIK, Bit flip is related to radiation, not OS kernel hardness. It was just a concern raised by FAA during MAX re-certification review, they may have already ruled out the possibility, otherwise there would have been an AD for NGs.
Last edited by dtw2hyd on Tue Jan 14, 2020 1:14 pm, edited 1 time in total.
All posts are just opinions.
 
mjoelnir
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:13 pm

patrickjp93 wrote:
PixelFlight wrote:
patrickjp93 wrote:
In this case that's not true, because the change in architecture would break grandfathering altogether. The 737 MAX would have been an all-new type. It's no longer about differences training at that point. It's the full gauntlet sim training as if it's a brand new pilot on a brand new plane. That was a requirement Boeing had. Surely the FAA could have worked together with Boeing to find a proper compromise solution where grandfathering rigidity was relaxed to allow either MCAS 2.0 or increased landing gear height without nullifying the common type rating.

I wish I'd known English was your 2nd or 3rd+ language. Your use of it is very good, but I'm sure some of your ideas aren't translating perfectly.

Again, regulators are ok with “differences training” between new type rating, as proved by the "common type rating" set by Airbus since many years already. It was Boeing promise to the operators that was impossible. The solution would have required either more development time, and/or sim training.

The FAA was not going to allow it if the new version of the plane added a redundant sensor control system. This has been fleshed out here on the forum by more senior people than me quite a few times now. It would have been full-blown sim training as if it were a new plane. This would not be like the 787 and 777X sharing a common type rating where pilots can simply run differences training. No, it would have been as though a cutting edge, brand new design hit the market.


Do you think you know what you are talking about?
You can have different level of difference training between different variants of frames of the same aircraft family.
The highest level includes simulator training.
It is not the same as a cutting edge brand new design hits the market. It is still just a difference training between variants, with limited time on a simulator.

If it is moving over to a brand new design, you would look at several days or weeks of training.
 
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scbriml
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:14 pm

patrickjp93 wrote:
It wasn't impossible or unreasonable. The rules were wrong. They should have been changed.


So we need to add "The rules were wrong" to the list of reasons why it's not Boeing's fault?
Time flies like an arrow. Fruit flies like a banana!
There are 10 types of people in the World - those that understand binary and those that don't.
 
Checklist787
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Tue Jan 14, 2020 1:16 pm

keesje wrote:
Checklist787 wrote:
Revelation wrote:
David Calhoun installed as CEO of Boeing, pointing out one area of opportunity is greater transparency and accountability:


Ref: https://www.flightglobal.com/aerospace/ ... 22.article


....
Boeing is changing now and D. Calhoun, elected by the board of directors understood that it cannot and should not last

A few days ago, Boeing said that there would be sanctions against those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!

This is the legacy that Mc Nerney and Muillenburg left behind, and it could have lasted longer. But the bad acquisition turned against Muillenburg so that fate would allow Boeing to reform and change its culture



While we see a hunt for scapegoats, including those in the Boeing board, the problem is bigger. There has been a longer term tendency to position the FAA as bureaucracy, weakening US Aerospace Industry development, wasting money.

Over the last decade, and before, there was industry wide support for reducing FAA certification oversight, influence and stronger delegation.

Image Image

https://gama.aero/wp-content/uploads/AIA_GAMA_Senate_Leadership_Letter_FAA_Reauthorization.pdf

Congress did a review not long ago & applauded the FAA for decentralisation, delegation and asked to side EASA where possible.
https://www.gao.gov/assets/690/683649.pdf

As evidenced by the latests mails releases, it gave Boeing engineering the feeling they could push FAA around at their liking.
They clearly had back up from Boeing leadership & Capitol Hill.

https://www.seattletimes.com/business/b ... f-737-max/

Congress, Senators and GAMA and AIA camera lovers, these days keep a low profile, lost interest, did 180s or try divert attention, try blame anyone else.

Long live Google for making it harder to re-write history. Firing the Boeing board isn’t solving the bigger system issue.


Keesje we know that.

Why give me an article from D. Gates when my analysis is based in part on these emails?

Your PDF dates from 2015 and the article from Seattle times dates from 3 days before D. Calhoun takes office as president and CEO with new resolutions

Are you trying to DECONSTRUCT my analysis as false?
Last edited by Checklist787 on Tue Jan 14, 2020 1:43 pm, edited 4 times in total.
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Do it! "...
 
Checklist787
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:25 pm

scbriml wrote:
Checklist787 wrote:
A few days ago, Boeing saidagainst that there would be sanctions those who have exchanged these irresponsible emails. These employees deserve to be fired without notice and I hope so, because from an ethical, human and industrial point of view it is inadmissible and unacceptable!


Fire the workers and reward the bosses. That should help change the culture. :banghead:

Checklist787 wrote:
Boeing has changed and no more Popcorn and sensational articles for those who hate it.


Changed? It requires someone looking through some special glasses to think the company has changed one day after a new CEO starts. :spin:

It's far too soon to declare that Boeing has changed. Having Calhoun at the top is just more of the same. Changing a culture that has seeped through the company over many years cannot be changed overnight by a new CEO. It will take a lot of effort for Boeing to change and more changes at the upper end will be required before anyone outside Boeing starts to believe that change is actually happening.

StTim wrote:
Yes without doubt the mails/messages were unprofessional and irresponsible BUT did the writers have a reasonable and safe way to report the concerns? If not then they too were victims of the corrosive culture.


It's apparent from the leaked emails and messages that the behaviours were driven from the top down. These are employees put under unreasonable pressure by their managers to meet specific goals. It seems doubtful that any complaints or concerns passed up the chain were given the consideration they should have been.

StTim wrote:
I read another quote, which of course I cannot find now, where they introduced shaming meetings where people were shamed for missing milestones. This is not a way to improve quality - or openness.


Yes, it was reported somewhere in one of these very fast moving threads. It reminded me of the old satirical office poster - "The beatings will only stop when morale improves." or one of those sarcastic motivational posters - "It's hard to soar like an eagle when you're surrounded by turkeys."


Scbriml, are you sure to have readen D. Calhoun's email?...

https://www.boeing.com/features/2020/01 ... oyees.page
Last edited by Checklist787 on Tue Jan 14, 2020 1:53 pm, edited 3 times in total.
"No limit to my poooWer!!!
Do it! "...
 
patrickjp93
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:26 pm

dtw2hyd wrote:
patrickjp93 wrote:
I'm not muddling the discussion. Most of the differences at the OS level for safety criticality come down to deterministic completion times for all operations, in addition to being able to run on fault-tolerant, hardened hardware. BSD and some flavors of Linux have been used for medical safety purposes for decades. That said, they've never been used for aerospace despite being used in satellites where the engineering constraints are even tighter.


OS kernel hardening is not exclusive to any OS. Traditionally UNIX based operating systems allowed compilation of minimal kernels from get go, now even Microsoft allows it to certain level.

Back to the topic, There is no evidence any of the operating systems on MAX are compromised. A hardware based on 8088/386/68K runs very limited number of instructions. Unless there is evidence that crew have the ability to browse internet or watch videos on FCCs, OS kernel is not an issue.

AFAIK, Bit flip is related to radiation, not OS kernel hardness. It was just a concern raised by FAA during MAX re-certification review, they may have already ruled out the possibility, otherwise there would have been an AD for NGs.

One technical correction for you. Bit flipping can't entirely be addressed by hardware (well, it can if you build an ASIC that is the OS binary made into Silicon, but that's EXPEEEEEEENSIVE to do and not viable for making a few hundred to a few thousand chips). Bit flipping at the software level is handled through multiple parity checks. Probably the best place to read on it would be the engineering documents behind ZFS that Joyent and Sun Microsystems published. Think of Bit Rot and Bit Flip as synonymous for the purposes of education here. The same techniques are used, except in memory, in real time on every critical operation, to ensure the data remains pristine exactly as designed. This is part of kernel hardening for operation in high-radiation environments. Hardening isn't only used as a technical term in security.
Last edited by patrickjp93 on Tue Jan 14, 2020 1:32 pm, edited 1 time in total.
 
patrickjp93
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:28 pm

scbriml wrote:
patrickjp93 wrote:
It wasn't impossible or unreasonable. The rules were wrong. They should have been changed.


So we need to add "The rules were wrong" to the list of reasons why it's not Boeing's fault?

We need to add it to the list of things to address to fix problems across the industry. I gave a perfectly reasonable explanation of what is wrong with the rigid framework of grandfathering. It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.
 
patrickjp93
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:30 pm

mjoelnir wrote:
patrickjp93 wrote:
PixelFlight wrote:
Again, regulators are ok with “differences training” between new type rating, as proved by the "common type rating" set by Airbus since many years already. It was Boeing promise to the operators that was impossible. The solution would have required either more development time, and/or sim training.

The FAA was not going to allow it if the new version of the plane added a redundant sensor control system. This has been fleshed out here on the forum by more senior people than me quite a few times now. It would have been full-blown sim training as if it were a new plane. This would not be like the 787 and 777X sharing a common type rating where pilots can simply run differences training. No, it would have been as though a cutting edge, brand new design hit the market.


Do you think you know what you are talking about?
You can have different level of difference training between different variants of frames of the same aircraft family.
The highest level includes simulator training.
It is not the same as a cutting edge brand new design hits the market. It is still just a difference training between variants, with limited time on a simulator.

If it is moving over to a brand new design, you would look at several days or weeks of training.

That's exactly what the FAA was going to treat the MAX as if the landing gear was raised, because the grandfathering of the 737 is a warped mess that somehow hinges on wing height above the ground. That's why I'm saying this is partly a failure of the regulatory framework too.
 
FluidFlow
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:37 pm

patrickjp93 wrote:
scbriml wrote:
patrickjp93 wrote:
It wasn't impossible or unreasonable. The rules were wrong. They should have been changed.


So we need to add "The rules were wrong" to the list of reasons why it's not Boeing's fault?

We need to add it to the list of things to address to fix problems across the industry. I gave a perfectly reasonable explanation of what is wrong with the rigid framework of grandfathering. It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.


Besides the rules: Boeing was not able to just raise the ground clearance because it would have changed the wing and fuselage a lot: taller gear means bigger bay, means changes to the wing and fuselage. Also the front gear would have needed an extension and triggered changes at the fuselage there.

It was not only the slides that would have had to be installed, the wing and probably the wing box would have need redesign due to changes needed to accommodate the taller landing gear. So the regulations are just an excuse here.
 
kalvado
Posts: 2896
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:39 pm

patrickjp93 wrote:
scbriml wrote:
patrickjp93 wrote:
It wasn't impossible or unreasonable. The rules were wrong. They should have been changed.


So we need to add "The rules were wrong" to the list of reasons why it's not Boeing's fault?

We need to add it to the list of things to address to fix problems across the industry. I gave a perfectly reasonable explanation of what is wrong with the rigid framework of grandfathering. It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.

Is it actually a failure?
Grandfathering is about small changes to previous design, so that there is no need to certify new type once you change color of cockpit paint.
Question is what "small" actually means, drawing a bright line between can and cannot do.
The manufacturer has an incentive to game the system, and grandfather as much as possible. Once you loosen the requirement, you'll quickly get 737SUPER (previously known as 777) and 707PRIME (formerly 787). After all, it is just a new control system, new wing, new cockpit, new engine, new landing gear - and a few similar minor changes.
I don't know how to draw the line, but getting the line drift to infinity to ignore modern requirements is definitely a bad idea
 
patrickjp93
Posts: 648
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:42 pm

FluidFlow wrote:
patrickjp93 wrote:
scbriml wrote:

So we need to add "The rules were wrong" to the list of reasons why it's not Boeing's fault?

We need to add it to the list of things to address to fix problems across the industry. I gave a perfectly reasonable explanation of what is wrong with the rigid framework of grandfathering. It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.


Besides the rules: Boeing was not able to just raise the ground clearance because it would have changed the wing and fuselage a lot: taller gear means bigger bay, means changes to the wing and fuselage. Also the front gear would have needed an extension and triggered changes at the fuselage there.

It was not only the slides that would have had to be installed, the wing and probably the wing box would have need redesign due to changes needed to accommodate the taller landing gear. So the regulations are just an excuse here.

There's plenty of room to expand the gear. Remember the 737's landing gear doesn't raise into a closed bay. It's just flush with the underside of the fuselage. It's fairly trivial to expand it. Yes, some geometry would change a little, but given the turbulent flow the landing gear causes anyway, I'm not convinced it would change the handling in the slightest.
 
FluidFlow
Posts: 723
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:48 pm

patrickjp93 wrote:
FluidFlow wrote:
patrickjp93 wrote:
We need to add it to the list of things to address to fix problems across the industry. I gave a perfectly reasonable explanation of what is wrong with the rigid framework of grandfathering. It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.


Besides the rules: Boeing was not able to just raise the ground clearance because it would have changed the wing and fuselage a lot: taller gear means bigger bay, means changes to the wing and fuselage. Also the front gear would have needed an extension and triggered changes at the fuselage there.

It was not only the slides that would have had to be installed, the wing and probably the wing box would have need redesign due to changes needed to accommodate the taller landing gear. So the regulations are just an excuse here.

There's plenty of room to expand the gear. Remember the 737's landing gear doesn't raise into a closed bay. It's just flush with the underside of the fuselage. It's fairly trivial to expand it. Yes, some geometry would change a little, but given the turbulent flow the landing gear causes anyway, I'm not convinced it would change the handling in the slightest.


If you check out the following picture you can see, there is not a lot of space left until the wheels touch, so not a lot of possibilities and a major redesign if you stretch the gear:

https://sunvair.com/
 
patrickjp93
Posts: 648
Joined: Thu Aug 22, 2019 12:00 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:50 pm

kalvado wrote:
patrickjp93 wrote:
scbriml wrote:

So we need to add "The rules were wrong" to the list of reasons why it's not Boeing's fault?

We need to add it to the list of things to address to fix problems across the industry. I gave a perfectly reasonable explanation of what is wrong with the rigid framework of grandfathering. It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.

Is it actually a failure?
Grandfathering is about small changes to previous design, so that there is no need to certify new type once you change color of cockpit paint.
Question is what "small" actually means, drawing a bright line between can and cannot do.
The manufacturer has an incentive to game the system, and grandfather as much as possible. Once you loosen the requirement, you'll quickly get 737SUPER (previously known as 777) and 707PRIME (formerly 787). After all, it is just a new control system, new wing, new cockpit, new engine, new landing gear - and a few similar minor changes.
I don't know how to draw the line, but getting the line drift to infinity to ignore modern requirements is definitely a bad idea

Changing avionics architecture would be too big, certainly. Moving from cables to FBW would be too big. Moving from Bleed Air to Bleedless would be too big. Extending landing gear and the minimal geometry changes required while not impacting the handling of the plane should be sufficiently small. The other point to consider is small enough between generations, and probably providing a sunset on common type ratings to be within one generation. In other words, if you hold training on the NG, you can move up to the MAX or down to the Classic with differences training, but if you train for the MAX and have to move to the Classic, you do the full training regimen instead of just differences training as you would for the NG, and your pilot type certificate for the MAX is revoked and replaced with the Classic.

There are easy, sensible ways to manage all of this together. Despite what many on here might consider hubris or paradigm-changing thought on my part, this is simple stuff to think through, analyze, and validate. I'm not a genius, so seriously, think through what I propose and argue on the merits/demerits. It's not like we on here are too stupid to go work at the highest levels of the FAA. The entire structure is based on seniority rather than skill anyway.
 
patrickjp93
Posts: 648
Joined: Thu Aug 22, 2019 12:00 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:51 pm

FluidFlow wrote:
patrickjp93 wrote:
FluidFlow wrote:

Besides the rules: Boeing was not able to just raise the ground clearance because it would have changed the wing and fuselage a lot: taller gear means bigger bay, means changes to the wing and fuselage. Also the front gear would have needed an extension and triggered changes at the fuselage there.

It was not only the slides that would have had to be installed, the wing and probably the wing box would have need redesign due to changes needed to accommodate the taller landing gear. So the regulations are just an excuse here.

There's plenty of room to expand the gear. Remember the 737's landing gear doesn't raise into a closed bay. It's just flush with the underside of the fuselage. It's fairly trivial to expand it. Yes, some geometry would change a little, but given the turbulent flow the landing gear causes anyway, I'm not convinced it would change the handling in the slightest.


If you check out the following picture you can see, there is not a lot of space left until the wheels touch, so not a lot of possibilities and a major redesign if you stretch the gear:

https://sunvair.com/

Telescoping gear that retract before being stowed. Good lord they already know how to do that for the MAX 10 just for takeoff to prevent tail strikes.
 
dtw2hyd
Posts: 8411
Joined: Wed Jan 09, 2013 12:11 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 1:58 pm

patrickjp93 wrote:
dtw2hyd wrote:
...
One technical correction for you. Bit flipping can't entirely be addressed by hardware (well, it can if you build an ASIC that is the OS binary made into Silicon, but that's EXPEEEEEEENSIVE to do and not viable for making a few hundred to a few thousand chips). Bit flipping at the software level is handled through multiple parity checks. Probably the best place to read on it would be the engineering documents behind ZFS that Joyent and Sun Microsystems published. Think of Bit Rot and Bit Flip as synonymous for the purposes of education here. The same techniques are used, except in memory, in real time on every critical operation, to ensure the data remains pristine exactly as designed. This is part of kernel hardening for operation in high-radiation environments. Hardening isn't only used as a technical term in security.


Are you randomly googling keywords are pasting here? From IBM Z-Series running Linux now moved on to SUN/ZFS a file system.

Limit the discussion to MAX and explain your take on bit flip issue on MAX.
All posts are just opinions.
 
morrisond
Posts: 2772
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 2:03 pm

FluidFlow wrote:
patrickjp93 wrote:
scbriml wrote:

So we need to add "The rules were wrong" to the list of reasons why it's not Boeing's fault?

We need to add it to the list of things to address to fix problems across the industry. I gave a perfectly reasonable explanation of what is wrong with the rigid framework of grandfathering. It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.


Besides the rules: Boeing was not able to just raise the ground clearance because it would have changed the wing and fuselage a lot: taller gear means bigger bay, means changes to the wing and fuselage. Also the front gear would have needed an extension and triggered changes at the fuselage there.

It was not only the slides that would have had to be installed, the wing and probably the wing box would have need redesign due to changes needed to accommodate the taller landing gear. So the regulations are just an excuse here.


I believe the 777X got a new wing box and gear - no idea if it's higher clearance though.

https://www.flightglobal.com/systems-an ... 38.article
 
patrickjp93
Posts: 648
Joined: Thu Aug 22, 2019 12:00 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 2:07 pm

dtw2hyd wrote:
patrickjp93 wrote:
dtw2hyd wrote:
...
One technical correction for you. Bit flipping can't entirely be addressed by hardware (well, it can if you build an ASIC that is the OS binary made into Silicon, but that's EXPEEEEEEENSIVE to do and not viable for making a few hundred to a few thousand chips). Bit flipping at the software level is handled through multiple parity checks. Probably the best place to read on it would be the engineering documents behind ZFS that Joyent and Sun Microsystems published. Think of Bit Rot and Bit Flip as synonymous for the purposes of education here. The same techniques are used, except in memory, in real time on every critical operation, to ensure the data remains pristine exactly as designed. This is part of kernel hardening for operation in high-radiation environments. Hardening isn't only used as a technical term in security.


Are you randomly googling keywords are pasting here? From IBM Z-Series running Linux now moved on to SUN/ZFS a file system.

Limit the discussion to MAX and explain your take on bit flip issue on MAX.

No I just have a very eclectic knowledge base from the computing world having been in the darkest bowels of banking transaction systems (mainframes) to web development (standard x86 servers) in the last three years, not to mention I was pursuing a masters in computer science before my professor left to work for Google. Aviation would be my second knowledge hobby.

Bit flipping, or bit rot, is when a bit is changed unintentionally to the programmer and system maintainer. This can happen in storage (which ZFS was built to mitigate), in memory (which ECC DRAM was designed to mitigate), and even in-CPU when it comes to avionics. That's where very exotic microarchitectures come into play to run multiple copies of a calculation simultaneously and then take the majority vote result. Now, even this is not full-proof, so secondary parity checks are run to ensure the inputs and outputs are possible matches to each other rather than just relying on an uninformed electorate (which dives very deep into binary mathematics and is outside the scope of this discussion).
 
kalvado
Posts: 2896
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 2:12 pm

patrickjp93 wrote:
kalvado wrote:
patrickjp93 wrote:
We need to add it to the list of things to address to fix problems across the industry. I gave a perfectly reasonable explanation of what is wrong with the rigid framework of grandfathering. It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.

Is it actually a failure?
Grandfathering is about small changes to previous design, so that there is no need to certify new type once you change color of cockpit paint.
Question is what "small" actually means, drawing a bright line between can and cannot do.
The manufacturer has an incentive to game the system, and grandfather as much as possible. Once you loosen the requirement, you'll quickly get 737SUPER (previously known as 777) and 707PRIME (formerly 787). After all, it is just a new control system, new wing, new cockpit, new engine, new landing gear - and a few similar minor changes.
I don't know how to draw the line, but getting the line drift to infinity to ignore modern requirements is definitely a bad idea

Changing avionics architecture would be too big, certainly. Moving from cables to FBW would be too big. Moving from Bleed Air to Bleedless would be too big. Extending landing gear and the minimal geometry changes required while not impacting the handling of the plane should be sufficiently small. The other point to consider is small enough between generations, and probably providing a sunset on common type ratings to be within one generation. In other words, if you hold training on the NG, you can move up to the MAX or down to the Classic with differences training, but if you train for the MAX and have to move to the Classic, you do the full training regimen instead of just differences training as you would for the NG, and your pilot type certificate for the MAX is revoked and replaced with the Classic.

There are easy, sensible ways to manage all of this together. Despite what many on here might consider hubris or paradigm-changing thought on my part, this is simple stuff to think through, analyze, and validate. I'm not a genius, so seriously, think through what I propose and argue on the merits/demerits. It's not like we on here are too stupid to go work at the highest levels of the FAA. The entire structure is based on seniority rather than skill anyway.

Each complex question has a great answer - simple, obvious and wrong.
Let's see how well your position holds water.
From your perspective, how floor strength rating question should be addressed? Modern rules require higer impact strength of cabin floor than what is available on 737 family, and that would be a major redesign. It is not piloting related, it is structural redesign. Cost may approach - or exceed - that of pilot retraining, though. The weaker floor is grandfathered in on MAX as it is only a small change of 737-100.

What kind of changes you think should trigger enforcing that change?
 
Exeiowa
Posts: 347
Joined: Fri Jul 06, 2018 4:49 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 2:23 pm

Blame can be passed around, but the consequences seem to be sitting on Boeing. It's there aircraft it ultimately there problem. Regulations are designed to prevent these issues arising in the first place. People complain about red tape up until the moment there was not enough to prevent killing people. Making a design which technically complies but is unsafe is dealt with by compliance option 2, having your pants sued off you. They made their bed now they have to lie in it. I feel bad for the people caught in the crossfire who just want to work and make a decent living. I commented a few days ago about how whenever we hear of a whistleblower for some safety related item their actions never get a sympathetic view in these forums, like the oxygen bottle incident or the paperwork issues on 787s so I doubt any MAX whistleblowing earlier would have sympathetic viewing here. And it seems that information here gets disseminated into a wider audience.
 
dtw2hyd
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Joined: Wed Jan 09, 2013 12:11 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 2:26 pm

patrickjp93 wrote:
dtw2hyd wrote:
patrickjp93 wrote:


Are you randomly googling keywords are pasting here? From IBM Z-Series running Linux now moved on to SUN/ZFS a file system.

Limit the discussion to MAX and explain your take on bit flip issue on MAX.

No I just have a very eclectic knowledge base from the computing world having been in the darkest bowels of banking transaction systems (mainframes) to web development (standard x86 servers) in the last three years, not to mention I was pursuing a masters in computer science before my professor left to work for Google. Aviation would be my second knowledge hobby.

Bit flipping, or bit rot, is when a bit is changed unintentionally to the programmer and system maintainer. This can happen in storage (which ZFS was built to mitigate), in memory (which ECC DRAM was designed to mitigate), and even in-CPU when it comes to avionics. That's where very exotic microarchitectures come into play to run multiple copies of a calculation simultaneously and then take the majority vote result. Now, even this is not full-proof, so secondary parity checks are run to ensure the inputs and outputs are possible matches to each other rather than just relying on an uninformed electorate (which dives very deep into binary mathematics and is outside the scope of this discussion).


I can debate all day long your computer science academics picked up verbatim from internet.

But at some point moderators will realize we are off-topic deep into the woods and delete all posts. I type my thoughts, not copy and paste. Not going to waste my keystrokes.
All posts are just opinions.
 
User avatar
zkojq
Posts: 4346
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 2:54 pm

morrisond wrote:
ET though knew if they had intermittent trim issues treat it as Runaway Trim and run the appropriate checklist - there is just a lot of debate of how well or did they even get that information to their pilots.


and yet each and every single time I've pressed you on this and asked you to provide a source for your allegation you've either brushed it off and provided nothing or completely ignored me all together.
First to fly the 787-9
 
phollingsworth
Posts: 759
Joined: Sat Mar 06, 2004 6:05 am

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 3:03 pm

asdf wrote:
phollingsworth wrote:
....Without having access to Boeing's specific tech trades it is really impossible to know where they would have sited the engines on a clean sheet design; and therefore, how much augmentation they would need.


so unbelivable ...
what are you guys writing of here?

one never ever needed augmentation of stickforce in any manual controlled airplane before the clown&monkey 737MAX


Except the A300/A310. Peter Lemming presented a whole blog post on that system. Also, the 757 and 767 were borderline on needing them and ultimately the 767-2C has stick force augmentation. Further, elevator feel mechanisms and stick nudgers are all about stick force modification.
 
patrickjp93
Posts: 648
Joined: Thu Aug 22, 2019 12:00 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 3:07 pm

kalvado wrote:
patrickjp93 wrote:
kalvado wrote:
Is it actually a failure?
Grandfathering is about small changes to previous design, so that there is no need to certify new type once you change color of cockpit paint.
Question is what "small" actually means, drawing a bright line between can and cannot do.
The manufacturer has an incentive to game the system, and grandfather as much as possible. Once you loosen the requirement, you'll quickly get 737SUPER (previously known as 777) and 707PRIME (formerly 787). After all, it is just a new control system, new wing, new cockpit, new engine, new landing gear - and a few similar minor changes.
I don't know how to draw the line, but getting the line drift to infinity to ignore modern requirements is definitely a bad idea

Changing avionics architecture would be too big, certainly. Moving from cables to FBW would be too big. Moving from Bleed Air to Bleedless would be too big. Extending landing gear and the minimal geometry changes required while not impacting the handling of the plane should be sufficiently small. The other point to consider is small enough between generations, and probably providing a sunset on common type ratings to be within one generation. In other words, if you hold training on the NG, you can move up to the MAX or down to the Classic with differences training, but if you train for the MAX and have to move to the Classic, you do the full training regimen instead of just differences training as you would for the NG, and your pilot type certificate for the MAX is revoked and replaced with the Classic.

There are easy, sensible ways to manage all of this together. Despite what many on here might consider hubris or paradigm-changing thought on my part, this is simple stuff to think through, analyze, and validate. I'm not a genius, so seriously, think through what I propose and argue on the merits/demerits. It's not like we on here are too stupid to go work at the highest levels of the FAA. The entire structure is based on seniority rather than skill anyway.

Each complex question has a great answer - simple, obvious and wrong.
Let's see how well your position holds water.
From your perspective, how floor strength rating question should be addressed? Modern rules require higer impact strength of cabin floor than what is available on 737 family, and that would be a major redesign. It is not piloting related, it is structural redesign. Cost may approach - or exceed - that of pilot retraining, though. The weaker floor is grandfathered in on MAX as it is only a small change of 737-100.

What kind of changes you think should trigger enforcing that change?

The cost would not exceed pilot retraining and the $1 billion it's now going to cost Boeing in compensating airlines for 1000+ frames at 1 million a pop. Second, this is where regulators and OEMs can work together to improve a grandfathered design without foisting undue secondary consequences from that improvement. Reinforcing the floor beams does not materially change the aerodynamic handling. It may change some rotation inertial moments to a tiny degree, but it uniformly adds weight throughout the fuselage. If that means the wing has to move back one inch to retain CoG over the wing box and thus the handling, fine, but you can still grandfather the common type just fine. It's not much more of a modification than a stretched variant.
 
patrickjp93
Posts: 648
Joined: Thu Aug 22, 2019 12:00 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 3:10 pm

dtw2hyd wrote:
patrickjp93 wrote:
dtw2hyd wrote:

Are you randomly googling keywords are pasting here? From IBM Z-Series running Linux now moved on to SUN/ZFS a file system.

Limit the discussion to MAX and explain your take on bit flip issue on MAX.

No I just have a very eclectic knowledge base from the computing world having been in the darkest bowels of banking transaction systems (mainframes) to web development (standard x86 servers) in the last three years, not to mention I was pursuing a masters in computer science before my professor left to work for Google. Aviation would be my second knowledge hobby.

Bit flipping, or bit rot, is when a bit is changed unintentionally to the programmer and system maintainer. This can happen in storage (which ZFS was built to mitigate), in memory (which ECC DRAM was designed to mitigate), and even in-CPU when it comes to avionics. That's where very exotic microarchitectures come into play to run multiple copies of a calculation simultaneously and then take the majority vote result. Now, even this is not full-proof, so secondary parity checks are run to ensure the inputs and outputs are possible matches to each other rather than just relying on an uninformed electorate (which dives very deep into binary mathematics and is outside the scope of this discussion).


I can debate all day long your computer science academics picked up verbatim from internet.

But at some point moderators will realize we are off-topic deep into the woods and delete all posts. I type my thoughts, not copy and paste. Not going to waste my keystrokes.

The internet is largely going to displace universities when it comes to churning out decent programmers and developers, especially given all the information from all of those textbooks and lectures is online now, but really, you're just going around calling people liars and hacks? Debate on the merits of the arguments.
 
User avatar
scbriml
Posts: 19172
Joined: Wed Jul 02, 2003 10:37 pm

Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 3:16 pm

patrickjp93 wrote:
It was more expensive to develop MCAS and move the engines forward than it would have been to raise the landing gear, but raising the gear was made off-limits under grandfathering for the type. That's a failure of the regulation framework, simple as that. Iterative improvement has to be allowed.


How much did it cost to develop MCAS and the LEAP pylons?

All those were Boeing choices. Choices taken to try and shoehorn the MAX into the "it's just another 737" category so as to not require additional training. We have been told many times that replacing the 737's training wheels represents a very significant engineering exercise because there simply isn't the space there for longer gear. So you'd probably be looking at an entirely new winbox and associated structures. I'm struggling to believe writing some bad software was more expensive than engineering a new wing box (new pylons would have to be developed anyway).

patrickjp93 wrote:
There's plenty of room to expand the gear. Remember the 737's landing gear doesn't raise into a closed bay. It's just flush with the underside of the fuselage. It's fairly trivial to expand it.


It simply isn't "fairly trivial". We've had 737 engineers tell us before that there is no spare space for enlarged gear without a significant re-engineering of the wingbox. This topic was discussed many times during the gestation of the MAX, not least when it became clear that Boeing was using a physically smaller version of LEAP than Airbus.
Time flies like an arrow. Fruit flies like a banana!
There are 10 types of people in the World - those that understand binary and those that don't.
 
Exeiowa
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Tue Jan 14, 2020 3:16 pm

I remember when I thought after 3 years in my profession I knew everything.....

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