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

Sat Jan 18, 2020 11:42 am

PixelFlight wrote:
https://www.airliners.net/forum/viewtopic.php?f=3&t=1437865#p21944881
Oykie wrote:
Aviation week reports that the FAA certification needs tweaks, but not a complete overhaul. The 737MAX was used as a case study.
https://aviationweek.com/air-transport/ ... ittee-says

"FAA certification as a whole ... is safe. It’s effective,” Moak said. "
"Even if Boeing was required to certify the MAX as a new design, it “would not have produced more rigorous scrutiny ... and would not have produced a safer airplane,” the report added. "

A bit disappointing. If I remember correctly, the EASA was confident that there way of doing certification would have detected the 737-8/9 MAX problem. So why not the FAA ? The FAA will not recover his leadership with such report and recommendations.


I believe that is where the tweaks comes in. To look at more aspects of the human-machine interaction in different failure scenarios.
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planecane
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 11:47 am

[*]
ACATROYAL wrote:
It appears that the latest software issue was discovered by auditors and not Boeing!!!! Thats it Im 100% officially done with the Max and 100% done with Boeing! Enough of this never ending Max Saga. The Max is an absolute Disaster and will go down in aviation history as the worst plane ever.
Now I'm 100% done with this thread. This is a dead end topic and thread...Lets all move on to happier topics...

Source? The Reuters article said it was discovered during a technical review in Iowa. The FCC vendor, Collins Aerospace (formerly Rockwell Collins) is located in Cedar Rapids, IA.

The technical review could have been internal or Boeing doing an audit. Nowhere that I've seen had reported that it was an audit by the FAA or any other regulator.
 
889091
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 2:06 pm

Firstly, to all the Boeing employees who may be reading this thread - hang in there! I cannot even start to imagine the stress that this management induced debacle has caused you, but hopefully there is light at the end of the tunnel.

Now, I hate to flog a dead horse to death, but desperate times calls for desperate measures....

Many have said that the tooling for the 757 has been destroyed, but in one of the more recent and recursive 757 thread, someone mentioned that the tooling is still there and that it has been stored.

Assuming that it hasn't been destroyed and because the 757 sits higher off the ground, the LEAP engine should be able to fit under the wing without needing the gears to be lengthened - should Boeing consider resurrecting the 757 (re-engined with LEAP), seeing how much 'merde' they are currently under?

- and yes, I know it only took 27 pages of posts before this came up.... :stirthepot:
 
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Revelation
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 2:09 pm

Dieuwer wrote:
I suppose we also are rapidly approaching the point of “no return”: airlines are not going to wait forever for a permanent MAX fix to be implemented. At a certain point, they have the duty to their shareholders and their customers to move on and find a new plane to replace their grounded MAX.

That's where the duopoly effect causes problems. There really is no source to replace Boeing, neither the Chinese nor Russian attempts are sufficient nor can Airbus make more capacity available since the A32x family is booked solid through 2024 and Airbus is somewhat behind current production targets.

astuteman wrote:
It has always been my experience that climbing out of the great big hole is way harder, and takes way longer, than falling into it.

The reason why everything about the MAX has slowed to a crawl is because of lack of trust, not for any other reason.
Everything that Boeing do now is being examined with a microscope.
And this will bring things out, small things maybe, that otherwise would have stayed below the radar.
And there is NO shortcut to be had in rebuilding trust :shakehead:

Trust me, the HARDEST part is NOT behind - it is ahead - fixing the damage.

I agree. As I wrote earlier in the crisis, playing hardball and being evasive was a risky strategy, and we see the old CEO was made to walk the plank and the relationship with the regulators and legislators is in tatters because of the message dump showing how Boeing had a deliberate strategy of misleading the regulators. Now we have a new CEO but no evidence of how he will repair the relationships and prevent similar things from happening in the future, and not much hope of such because he's a former BoD member and a career capitalist. The main problem is that even though many of the key individuals have moved on, we don't see any steps to replace or retrain the cadre of middle management raised in a culture of putting concerns about profits above concerns about safety.
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lhrnue
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 2:14 pm

planecane wrote:
Dieuwer wrote:
Indeed. As I predicted March last year the MAX would NOT be flying by the end of 2019.
And here we are. ANOTHER software "issue". Not to mention the trove of emails leaked recently that imply a major criminal cover up. Mark my words: the MAX ain't gonna fly for a LONG time, if EVER.

Would you have reminded us of your prediction of it was flying last year? You didn't make a "prediction," you made a "guess." A prediction is based on facts and analysis, neither of which existed in significant quantity in March of last year.


Her is an updated guess. It won't fly by this time next year.
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 4:03 pm

My only half humorous suggestion last year: Plead with Buffet to the rescue. Berkshire would like a company making 10-15% gross profit, 20% not necessary. And willing to spend money for capital projects that might wreck the next few quarters. But ensure profits for years. The formidable downside is that Berkshire buys companies with great management. Boeing is sadly lacking.

Look at BNSF slowly pulling away from UP.
Buffet: the airline business...has eaten up capital...like..no other (business)
 
MrBretz
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 4:49 pm

Here’s a good summary of how Boeing has moved from an engineering company to what it has become today. It’s summarizes the history in one short article as the upper management has moved from a engineering to stock price above all mentality.

https://enewspaper.latimes.com/infinity ... 6bf740270e
 
xmp125a
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 5:16 pm

aw70 wrote:
Totally left field question, and apologies for the fact that this has certainly been asked (and answered) before. In addition to being inane and impractical - but I'm just curious whether this would be at all doable.

It's not like the -800 series of the 737 is a completely terrible aircraft. Wouldn't it be a solution to simply hang -800 engines off the existing MAX frames (at least some of them), remove MCAS on these planes, and call it a day? Or is the MAX too different in other aspects, so that a hybrid 800/MAX with old engines and pylons (which avoids the stability issue entirely) would need a completely new certification as well


Even if it could be done technically, the airlines crave higher fuel efficiency of modern engines with high bypass ratios. I wonder how many of them you could sell (airlines then having a choice between the new hybrid you propose or waiting until 2024 for Airbus to deliver Neo). Are that desperate for new capacity to accept 800-like plane now, while the competitors will be flying 10% more fuel efficient planes?
 
Chrisba320
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 6:42 pm

seahawk wrote:
Less drama would be fine. There is no big difference between both products and the grandfathering is also not the root cause of the problem. The root cause is the management and work culture at Boeing. A newly designed plane made under the same pressure and with the same goals and strategies would be worse.


No big difference between the two products? I beg to differ. The difference in passenger experience between the two is enormous.
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sat Jan 18, 2020 6:58 pm

889091 wrote:
Firstly, to all the Boeing employees who may be reading this thread - hang in there! I cannot even start to imagine the stress that this management induced debacle has caused you, but hopefully there is light at the end of the tunnel.

Don't forget that many employees are part of the problem as well as we've learned from the revealed messages. They might not have been in a position to overrule higher management but many of the employees featured in those messages had a moral obligation to blow the whistle. At least one is even pleading the 5th!
 
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LX015
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sat Jan 18, 2020 7:32 pm

How many faulty issues are on this aircraft??? Every week it seems like something new! Not beating up on Boeing, but level of irresponsibility is beyond belief.

https://simpleflying.com/boeing-737-max-startup-issue/
 
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sat Jan 18, 2020 7:52 pm

LX015 wrote:
How many faulty issues are on this aircraft??? Every week it seems like something new! Not beating up on Boeing, but level of irresponsibility is beyond belief.

https://simpleflying.com/boeing-737-max-startup-issue/

I would say this is a by product of the aircraft being inspected almost microscopically head to tail, some issues that any other plane may face after EIS and corrected with ADs may have been discovered through this intense examination. Ironically, this probably reduces the possibility of the Max being affected by ADs after re-EIS.
 
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sat Jan 18, 2020 8:25 pm

jeffrey0032j wrote:
LX015 wrote:
How many faulty issues are on this aircraft??? Every week it seems like something new! Not beating up on Boeing, but level of irresponsibility is beyond belief.

https://simpleflying.com/boeing-737-max-startup-issue/

I would say this is a by product of the aircraft being inspected almost microscopically head to tail, some issues that any other plane may face after EIS and corrected with ADs may have been discovered through this intense examination. Ironically, this probably reduces the possibility of the Max being affected by ADs after re-EIS.


I would hope so, but if issues continue to pop up I wonder how many customers will just decide to buy a different aircraft that doesn't come with this many issues.
 
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Stitch
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sat Jan 18, 2020 8:32 pm

LX015 wrote:
How many faulty issues are on this aircraft??? Every week it seems like something new! Not beating up on Boeing, but level of irresponsibility is beyond belief.


Every aircraft family has ADs issued against them over their production life as issues appear over time. With the MAX, since they're going over the entire thing with a fine-toothed comb, all those issues are cropping up in a short period as opposed to over years.


LX015 wrote:
I would hope so, but if issues continue to pop up I wonder how many customers will just decide to buy a different aircraft that doesn't come with this many issues.


One might think that a frame that has been so thoroughly examined for issues and had them addressed before (second) EIS might very well be the one that airlines (and passengers, financiers and insurers) choose because the chances of an unknown issue happening would be statistically far lower.
 
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LX015
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sat Jan 18, 2020 8:42 pm

LX015 wrote:
I would hope so, but if issues continue to pop up I wonder how many customers will just decide to buy a different aircraft that doesn't come with this many issues.


One might think that a frame that has been so thoroughly examined for issues and had them addressed before (second) EIS might very well be the one that airlines (and passengers, financiers and insurers) choose because the chances of an unknown issue happening would be statistically far lower.[/quote]

I see your point, but after hearing negative press on the MAX so often that its burned into our memories isn't a good thing. Just the same way many people undoubtedly has negative memories whenever they hear about the DC -10.
 
smartplane
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sat Jan 18, 2020 8:54 pm

Stitch wrote:
One might think that a frame that has been so thoroughly examined for issues and had them addressed before (second) EIS might very well be the one that airlines (and passengers, financiers and insurers) choose because the chances of an unknown issue happening would be statistically far lower.

Agreed. Should be a very safe plane when modified, and all identified urgent and non-urgent AD's identified are actioned.

The debate now, is should new builds from the re-start of production, built but not yet delivered, and already delivered but grounded, incorporate ALL urgent AD's before RTS, and how much time is given to action non-urgent AD's? Modifications to regain certification are a given.

Boeing will want to re-start production, and not incorporate some non-urgent AD's, because there are supply and resource issues (priority to already built / delivered aircraft). Already built fuselages and other structures is almost a 4th category.

The question for airworthiness authorities are the potential interactions / issues created by actioning some AD's, and deferring others.
 
XRAYretired
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sat Jan 18, 2020 9:03 pm

jeffrey0032j wrote:
LX015 wrote:
How many faulty issues are on this aircraft??? Every week it seems like something new! Not beating up on Boeing, but level of irresponsibility is beyond belief.

https://simpleflying.com/boeing-737-max-startup-issue/

I would say this is a by product of the aircraft being inspected almost microscopically head to tail, some issues that any other plane may face after EIS and corrected with ADs may have been discovered through this intense examination. Ironically, this probably reduces the possibility of the Max being affected by ADs after re-EIS.

Failure to complete power up checks would result in no despatch. So nothing flies unless you fix it.

There is no microscopic inspection, the regulator activities are all in relation to flight controls and are directly related to the MCAS debacle. FAA/EASA are just not delegating cert tasks to Boeing.

Mr Markos leaked emails imply there is a post RTS plan of actions/activities that may well involve ADs.

Boeing are not being hard done to. It is the 346 and the bereaved who have been hard done to.

Ray
 
2175301
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sun Jan 19, 2020 12:01 am

XRAYretired wrote:
jeffrey0032j wrote:
LX015 wrote:
How many faulty issues are on this aircraft??? Every week it seems like something new! Not beating up on Boeing, but level of irresponsibility is beyond belief.

https://simpleflying.com/boeing-737-max-startup-issue/

I would say this is a by product of the aircraft being inspected almost microscopically head to tail, some issues that any other plane may face after EIS and corrected with ADs may have been discovered through this intense examination. Ironically, this probably reduces the possibility of the Max being affected by ADs after re-EIS.

Failure to complete power up checks would result in no despatch. So nothing flies unless you fix it.

There is no microscopic inspection, the regulator activities are all in relation to flight controls and are directly related to the MCAS debacle. FAA/EASA are just not delegating cert tasks to Boeing.

Mr Markos leaked emails imply there is a post RTS plan of actions/activities that may well involve ADs.

Boeing are not being hard done to. It is the 346 and the bereaved who have been hard done to.

Ray


I disagree on the extent of the FAA & International Regulator interest. While it started as just MCAS (and everything I have heard was that the FAA flight testing in June found no problems with MCAS R2); but the bit flip issue expanded the revision and review to the flight control computers.

All changes to the flight control computers, all the software within them, and how they interact with other systems become included with the review at that point as the change is driven by the FAA identified bit flip issue - and the FAA said in June that this area must be fully resolved before they will approve (and now the International Regulators are apparently involved in a joint acceptance with the FAA). This is vastly more complicated and involved than just the changes between MCAS V1 and MCAS V2. Also, coming up with documentation to "current" standards for all those old software programs would not be easy (which is where I believe that Boeing was most cited for inadequate information that caused significant delay: I can easily see Boeing initially submitting that this and that software program is grandfathered, and the international regulators saying that no, you need to submit paperwork to current standards for each and every program).

Thus, the power up of those computers and their displays are now part of the review package. It is also in my opinion more likely than not that the failure to power up is related to the software changes (communication timing) between the computers and other things implemented to have independent co-checking computers as the fix to the bit flip issue.

Have a great day,
 
MrBretz
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sun Jan 19, 2020 1:05 am

2175301 said:

“Thus, the power up of those computers and their displays are now part of the review package. It is also in my opinion more likely than not that the failure to power up is related to the software changes (communication timing) between the computers and other things implemented to have independent co-checking computers as the fix to the bit flip issue.”



I agree completely and have been saying this all along having been involved with multiple computers controlling systems. It is especially true when both computers are doing the same thing. Testing all the failure cases, and failure of one at startup is a case I can imagine is easy to forget, is extensive.
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sun Jan 19, 2020 1:25 am

planecane wrote:
Dieuwer wrote:
Indeed. As I predicted March last year the MAX would NOT be flying by the end of 2019.
And here we are. ANOTHER software "issue". Not to mention the trove of emails leaked recently that imply a major criminal cover up. Mark my words: the MAX ain't gonna fly for a LONG time, if EVER.

Would you have reminded us of your prediction of it was flying last year? You didn't make a "prediction," you made a "guess." A prediction is based on facts and analysis, neither of which existed in significant quantity in March of last year.


I don't think predictions are based on facts, more like they're made on "feelings" and past knowledge.
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sun Jan 19, 2020 2:06 am

2175301 wrote:
I disagree on the extent of the FAA & International Regulator interest. While it started as just MCAS (and everything I have heard was that the FAA flight testing in June found no problems with MCAS R2); but the bit flip issue expanded the revision and review to the flight control computers.

Then why that Canadian leaked emails in the autumn about the neverending headache of MCAS algorithms?
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sun Jan 19, 2020 9:53 am

BBC with a new story:


https://www.bbc.com/news/business-51153286

Victims' families slam report into 737 Max crashes

Relatives of a man killed in one of two crashes involving a Boeing 737 Max have condemned a report into the disasters.
The expert panel behind the report concluded the system used to certify the aircraft as safe was "effective".
But the family of Joseph Waithaka has described the report as "an extremely appalling and disappointing attempt to defend a flawed system".

The report also had a lukewarm reception from the chair of the Transportation Committee in the US House of Representatives, which has been holding a lengthy inquiry into the 737 Max. In a statement, Democrat congressman, Peter De Fazio, said: "Our investigation has already revealed multiple junctures at which the current certification process failed." He added that 346 people had died "because the system failed".

"Not addressing the failures head on would be a grave mistake," he said.
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sun Jan 19, 2020 1:58 pm

How quickly could Airbus increase the production rate of the A320NEO? if they could push the rate higher, could Boeing's customers cancel their orders considering that Boeing has not met its contractual obligations? or are the sale contracts too tightly worded?
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sun Jan 19, 2020 2:01 pm

Please forgive me if this has already been asked in this LONG thread, but wouldn't fixing the MAX's MCAS issue boil down to a matter of testing and writing new code (or vice-versa)?
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par13del
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sun Jan 19, 2020 2:24 pm

GSPSPOT wrote:
Please forgive me if this has already been asked in this LONG thread, but wouldn't fixing the MAX's MCAS issue boil down to a matter of testing and writing new code (or vice-versa)?

...which is what Boeing and the FAA was doing after March 2019 when it was announced worldwide that MCAS was the cause of almost 400 deaths.
Boeing submitted MCAS 2.0 to the FAA for testing in June 2019, we have since moved on to bit flip, dual computer redundancy being too slow, disrespectful e-mails now the computers that was previously working on alternate flights and must now do so simultaneously is slow starting up, so more testing and software updates.

Time will tell if Boeing knew that the FAA would be going for the maximum amount of automation and redundancy that they could get away with on a non-FBW a/c, if the better financial decision would have been to cancel and start over. I suspect those numbers will be hidden but the penalties paid and cost to Boeing will be fully revealed to show that they were hurt, but someone will look at the cost to make the 400+ grounded frames, the savings that could have been achieved and the damage across the industry in terms of lost jobs and production and compare the two.
 
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Sun Jan 19, 2020 2:31 pm

LX015 wrote:
I would hope so, but if issues continue to pop up I wonder how many customers will just decide to buy a different aircraft that doesn't come with this many issues.

Theoretically they would, but in the real world there are no other different aircraft available to be bought that fit the customer's requirements.

GSPSPOT wrote:
Please forgive me if this has already been asked in this LONG thread, but wouldn't fixing the MAX's MCAS issue boil down to a matter of testing and writing new code (or vice-versa)?

Yes, but we know the regulators are not just requiring MCAS's code to be fixed, but to also add more code to allow both flight computers to be online at the same time and for their outputs to be compared and to turn off automation if the outputs differ. This second part is what people are referring to as the 'bit flip fix' because testing to simulate computer memory bits flipping due to cosmic rays was what found the problem needing to be fixed. And there may be even more issues found as the testing continues, that is the nature of these things.
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767333ER
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sun Jan 19, 2020 2:51 pm

planecane wrote:
Dieuwer wrote:
Indeed. As I predicted March last year the MAX would NOT be flying by the end of 2019.
And here we are. ANOTHER software "issue". Not to mention the trove of emails leaked recently that imply a major criminal cover up. Mark my words: the MAX ain't gonna fly for a LONG time, if EVER.

Would you have reminded us of your prediction of it was flying last year? You didn't make a "prediction," you made a "guess." A prediction is based on facts and analysis, neither of which existed in significant quantity in March of last year.

Not exactly. A prediction can be based off of observation and fact, but they don’t have to be. If those were requirements for making a prediction, predictions would have a much higher success rate than they do. More appropriate for what you describe would by hypothesis, but I don’t see anyone conducting an experiment here.
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CPHGuard
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Sun Jan 19, 2020 7:33 pm

Would it be possible for Boeing to do a MAX 2.0, where they use the same components as now such as fuselage, landing gear, engines, etc, but add the 787 avionics/FBW?

It would be a huge amount of work, but still probably less than a clean sheet design.
 
benbeny
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 4:10 am

767333ER wrote:
planecane wrote:
Dieuwer wrote:
Indeed. As I predicted March last year the MAX would NOT be flying by the end of 2019.
And here we are. ANOTHER software "issue". Not to mention the trove of emails leaked recently that imply a major criminal cover up. Mark my words: the MAX ain't gonna fly for a LONG time, if EVER.

Would you have reminded us of your prediction of it was flying last year? You didn't make a "prediction," you made a "guess." A prediction is based on facts and analysis, neither of which existed in significant quantity in March of last year.

Not exactly. A prediction can be based off of observation and fact, but they don’t have to be. If those were requirements for making a prediction, predictions would have a much higher success rate than they do. More appropriate for what you describe would by hypothesis, but I don’t see anyone conducting an experiment here.

At least in my field, observational studies may have hypotheses.

Semantics aside, what makes FAA take a long time? It's almost a year already. Did Boeing screw up so badly during their initial certification process till FAA/EASA find so many faults in this re-certification?
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 5:26 am

CPHGuard wrote:
Would it be possible for Boeing to do a MAX 2.0, where they use the same components as now such as fuselage, landing gear, engines, etc, but add the 787 avionics/FBW?

I don’t think they need a full FBW system, but just a FBW trim (stabilizer) and maybe elevator.

CRJ-1000 got a FBW rudder - and it was significant work.
 
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seahawk
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Re: Boeing 737MAX Grounding News and Reference Thread 2020

Mon Jan 20, 2020 6:15 am

Revelation wrote:
LX015 wrote:
I would hope so, but if issues continue to pop up I wonder how many customers will just decide to buy a different aircraft that doesn't come with this many issues.

Theoretically they would, but in the real world there are no other different aircraft available to be bought that fit the customer's requirements.

GSPSPOT wrote:
Please forgive me if this has already been asked in this LONG thread, but wouldn't fixing the MAX's MCAS issue boil down to a matter of testing and writing new code (or vice-versa)?

Yes, but we know the regulators are not just requiring MCAS's code to be fixed, but to also add more code to allow both flight computers to be online at the same time and for their outputs to be compared and to turn off automation if the outputs differ. This second part is what people are referring to as the 'bit flip fix' because testing to simulate computer memory bits flipping due to cosmic rays was what found the problem needing to be fixed. And there may be even more issues found as the testing continues, that is the nature of these things.


Bit flip is a required test caused by the fact that they now have a catastrophic failure mode in the former STS system through adding MCAS. Before the 737 was rather laxed when it came to this, as the 2 flight control computers were not connected
 
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767333ER
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 6:56 am

CPHGuard wrote:
Would it be possible for Boeing to do a MAX 2.0, where they use the same components as now such as fuselage, landing gear, engines, etc, but add the 787 avionics/FBW?

It would be a huge amount of work, but still probably less than a clean sheet design.

If they do that only for the FAA to decide it’s no longer certifiable as a modified variant of the 737-100 all the grandfathering privileges are gone and they design becomes uncertifiable due to many parts of the design no longer being compliant with regulation and then all that money was wasted. Even if it did pass certification the common type rating would be gone and they would still have to plan for a replacement in 15-20 years time.

The only way this whole disaster could really fixed is if they could go back in time and elect to do the NSA over the MAX. Now they are stuck with this thing.
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PixelFlight
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 8:09 am

ADent wrote:
CPHGuard wrote:
Would it be possible for Boeing to do a MAX 2.0, where they use the same components as now such as fuselage, landing gear, engines, etc, but add the 787 avionics/FBW?

I don’t think they need a full FBW system, but just a FBW trim (stabilizer) and maybe elevator.

CRJ-1000 got a FBW rudder - and it was significant work.

The 737-8/9 MAX is in fact close to a FBW stab trim, but without the safety of a FBW system, and this is the origin of the problem. In AP flight mode, the 737-8/9 MAX already operate the elevators and stab trim from as in a FBW aircraft. In manual flight mode, the aerodynamic of the 737-8/9 MAX require the MCAS to comply with the regulation, and MCAS is a kind of borderline near FBW system in the sens that it's a computer that activate with high authority a primary control surface from a sensor, but with a discrete signal and without redundancy. Now the MCAS V2 will get a bare minimum of redundancy, but not to increase his availability as in a FBW system, but to disable it in case of disagreement from the sensors and/or computers. A change of the avionic could certainly add the required redundancy to increase the availability to the level of a FBW system, at least for the stab trim, but this would also require a redundant actuator and a redundant power for that actuator. At this point there could remove the manual trim wheels as in the A350.
: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:
 
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InsideMan
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 9:00 am

889091 wrote:
Firstly, to all the Boeing employees who may be reading this thread - hang in there! I cannot even start to imagine the stress that this management induced debacle has caused you, but hopefully there is light at the end of the tunnel.


nice warm words of comfort but you do realize that many many Boeing employees not only had to be in the know but also in the do?
While management rightfully bears the responsibility it's not like everyone else is innocent.....
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 9:30 am

InsideMan wrote:
889091 wrote:
Firstly, to all the Boeing employees who may be reading this thread - hang in there! I cannot even start to imagine the stress that this management induced debacle has caused you, but hopefully there is light at the end of the tunnel.


nice warm words of comfort but you do realize that many many Boeing employees not only had to be in the know but also in the do?
While management rightfully bears the responsibility it's not like everyone else is innocent.....


But not the 'average Joe' who's working on the production line (at Boeing and suppliers). They're the ones who's jobs are being put at most risk by the MAX production stop.
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.
 
Scotron12
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 10:23 am

scbriml wrote:
InsideMan wrote:
889091 wrote:
Firstly, to all the Boeing employees who may be reading this thread - hang in there! I cannot even start to imagine the stress that this management induced debacle has caused you, but hopefully there is light at the end of the tunnel.


nice warm words of comfort but you do realize that many many Boeing employees not only had to be in the know but also in the do?
While management rightfully bears the responsibility it's not like everyone else is innocent.....


But not the 'average Joe' who's working on the production line (at Boeing and suppliers). They're the ones who's jobs are being put at most risk by the MAX production stop.



For sure! No "average Joe" is walking away with over $60M in severance pay for doing a fu*ked up job. Not just Muilenberg but that whole Board of Duds!
 
phollingsworth
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 10:57 am

PixelFlight wrote:
ADent wrote:
CPHGuard wrote:
Would it be possible for Boeing to do a MAX 2.0, where they use the same components as now such as fuselage, landing gear, engines, etc, but add the 787 avionics/FBW?

I don’t think they need a full FBW system, but just a FBW trim (stabilizer) and maybe elevator.

CRJ-1000 got a FBW rudder - and it was significant work.

The 737-8/9 MAX is in fact close to a FBW stab trim, but without the safety of a FBW system, and this is the origin of the problem. In AP flight mode, the 737-8/9 MAX already operate the elevators and stab trim from as in a FBW aircraft. In manual flight mode, the aerodynamic of the 737-8/9 MAX require the MCAS to comply with the regulation, and MCAS is a kind of borderline near FBW system in the sens that it's a computer that activate with high authority a primary control surface from a sensor, but with a discrete signal and without redundancy. Now the MCAS V2 will get a bare minimum of redundancy, but not to increase his availability as in a FBW system, but to disable it in case of disagreement from the sensors and/or computers. A change of the avionic could certainly add the required redundancy to increase the availability to the level of a FBW system, at least for the stab trim, but this would also require a redundant actuator and a redundant power for that actuator. At this point there could remove the manual trim wheels as in the A350.


The 737MAX's trim is nowhere near that of an FBW system it is still very much a mechanical system with electrical augmentation. While MCAS increased the rate and range that the autopilot could actuate the stab trim, it didn't increase the force authority. As such a human can still physically stop the autopilot trim by grabbing the trim wheel. This is not the case on the 757/767 or any of the Boeing or Airbus FBW aircraft. Further, FBW systems can be simplex, duplex, triplex, etc. The reason that we see Duplex and Triplex in aircraft with irreversible controls is that there is no means for the human being to actually fly the aircraft without those systems operating. If you loose all the hydraulics and electrics on a 757 or 767 they are deemed to be basically un-flyable, even though they are not FBW, where as a 737 can still be flown by cables alone. MCAS, because of the combination of the rates/range, and the identification and countering of the failure mode introduces a reasonable likelihood that some failures will make the aircraft un-flyable. Hence the switch to duplex. Keep in mind that the 777 which is fully FBW only has duplex sensing on all of its AoA based actions. Even the A320 with Triplex AoA sensors can be dispatched with only 2 operating, without significant restrictions in operations. As long as the regulators are satisfied that the duplex system with the associated reduction in availability meets or exceeds the required performance then it is good to go.

Boeing is currently paying the price for trying to retrofit safety criticality into an avionics suite that is not design to be safety critical. It is something that can be done, but basically requires rewriting the entire software stack to accomplish. Had Boeing gone for a rebuild of the underlying avionics on 737MAX in the first instance this would have been a much larger task upfront but would have made RTS a much simpler prospect, FBW or no FBW.
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 11:11 am

phollingsworth wrote:
PixelFlight wrote:
ADent wrote:
I don’t think they need a full FBW system, but just a FBW trim (stabilizer) and maybe elevator.

CRJ-1000 got a FBW rudder - and it was significant work.

The 737-8/9 MAX is in fact close to a FBW stab trim, but without the safety of a FBW system, and this is the origin of the problem. In AP flight mode, the 737-8/9 MAX already operate the elevators and stab trim from as in a FBW aircraft. In manual flight mode, the aerodynamic of the 737-8/9 MAX require the MCAS to comply with the regulation, and MCAS is a kind of borderline near FBW system in the sens that it's a computer that activate with high authority a primary control surface from a sensor, but with a discrete signal and without redundancy. Now the MCAS V2 will get a bare minimum of redundancy, but not to increase his availability as in a FBW system, but to disable it in case of disagreement from the sensors and/or computers. A change of the avionic could certainly add the required redundancy to increase the availability to the level of a FBW system, at least for the stab trim, but this would also require a redundant actuator and a redundant power for that actuator. At this point there could remove the manual trim wheels as in the A350.


The 737MAX's trim is nowhere near that of an FBW system it is still very much a mechanical system with electrical augmentation. While MCAS increased the rate and range that the autopilot could actuate the stab trim, it didn't increase the force authority. As such a human can still physically stop the autopilot trim by grabbing the trim wheel. This is not the case on the 757/767 or any of the Boeing or Airbus FBW aircraft. Further, FBW systems can be simplex, duplex, triplex, etc. The reason that we see Duplex and Triplex in aircraft with irreversible controls is that there is no means for the human being to actually fly the aircraft without those systems operating. If you loose all the hydraulics and electrics on a 757 or 767 they are deemed to be basically un-flyable, even though they are not FBW, where as a 737 can still be flown by cables alone. MCAS, because of the combination of the rates/range, and the identification and countering of the failure mode introduces a reasonable likelihood that some failures will make the aircraft un-flyable. Hence the switch to duplex. Keep in mind that the 777 which is fully FBW only has duplex sensing on all of its AoA based actions. Even the A320 with Triplex AoA sensors can be dispatched with only 2 operating, without significant restrictions in operations. As long as the regulators are satisfied that the duplex system with the associated reduction in availability meets or exceeds the required performance then it is good to go.

Boeing is currently paying the price for trying to retrofit safety criticality into an avionics suite that is not design to be safety critical. It is something that can be done, but basically requires rewriting the entire software stack to accomplish. Had Boeing gone for a rebuild of the underlying avionics on 737MAX in the first instance this would have been a much larger task upfront but would have made RTS a much simpler prospect, FBW or no FBW.

I think that we vastly agree. From a technical point of view only, what a 737-8/9 MAX need to have a FBW stab trim ? I think it require more redundant ADIRU and flight computer (not necessarily 3 sensors as the 777 demonstrate) to increase availability, a redundant actuator (a second electrical motor like in the 737 classic), and a redundant power supply. This last point is maybe the most challenging, but certainly doable.
: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:
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 11:11 am

767333ER wrote:
CPHGuard wrote:
Would it be possible for Boeing to do a MAX 2.0, where they use the same components as now such as fuselage, landing gear, engines, etc, but add the 787 avionics/FBW?

It would be a huge amount of work, but still probably less than a clean sheet design.

If they do that only for the FAA to decide it’s no longer certifiable as a modified variant of the 737-100 all the grandfathering privileges are gone and they design becomes uncertifiable due to many parts of the design no longer being compliant with regulation and then all that money was wasted. Even if it did pass certification the common type rating would be gone and they would still have to plan for a replacement in 15-20 years time.

The only way this whole disaster could really fixed is if they could go back in time and elect to do the NSA over the MAX. Now they are stuck with this thing.


Given that the FAA has certified as big or bigger relative changes on the same TC before, especially on the power-plant side there is no reason to believe the FAA would have automatically said no. Though things will be different now. Of course any changes brought on by an FBW conversion would have necessitated bringing those parts of the aircraft up to current rules or ELS findings. Further, Boeing could have achieved a common type rating with an FBW aircraft, but it would probably no have made sense to take the penalties of making a fully irreversible aircraft fly like an aircraft with reversible flight controls plus all the added weight of the required extra redundancy.
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 11:25 am

PixelFlight wrote:
phollingsworth wrote:
PixelFlight wrote:
The 737-8/9 MAX is in fact close to a FBW stab trim, but without the safety of a FBW system, and this is the origin of the problem. In AP flight mode, the 737-8/9 MAX already operate the elevators and stab trim from as in a FBW aircraft. In manual flight mode, the aerodynamic of the 737-8/9 MAX require the MCAS to comply with the regulation, and MCAS is a kind of borderline near FBW system in the sens that it's a computer that activate with high authority a primary control surface from a sensor, but with a discrete signal and without redundancy. Now the MCAS V2 will get a bare minimum of redundancy, but not to increase his availability as in a FBW system, but to disable it in case of disagreement from the sensors and/or computers. A change of the avionic could certainly add the required redundancy to increase the availability to the level of a FBW system, at least for the stab trim, but this would also require a redundant actuator and a redundant power for that actuator. At this point there could remove the manual trim wheels as in the A350.


The 737MAX's trim is nowhere near that of an FBW system it is still very much a mechanical system with electrical augmentation. While MCAS increased the rate and range that the autopilot could actuate the stab trim, it didn't increase the force authority. As such a human can still physically stop the autopilot trim by grabbing the trim wheel. This is not the case on the 757/767 or any of the Boeing or Airbus FBW aircraft. Further, FBW systems can be simplex, duplex, triplex, etc. The reason that we see Duplex and Triplex in aircraft with irreversible controls is that there is no means for the human being to actually fly the aircraft without those systems operating. If you loose all the hydraulics and electrics on a 757 or 767 they are deemed to be basically un-flyable, even though they are not FBW, where as a 737 can still be flown by cables alone. MCAS, because of the combination of the rates/range, and the identification and countering of the failure mode introduces a reasonable likelihood that some failures will make the aircraft un-flyable. Hence the switch to duplex. Keep in mind that the 777 which is fully FBW only has duplex sensing on all of its AoA based actions. Even the A320 with Triplex AoA sensors can be dispatched with only 2 operating, without significant restrictions in operations. As long as the regulators are satisfied that the duplex system with the associated reduction in availability meets or exceeds the required performance then it is good to go.

Boeing is currently paying the price for trying to retrofit safety criticality into an avionics suite that is not design to be safety critical. It is something that can be done, but basically requires rewriting the entire software stack to accomplish. Had Boeing gone for a rebuild of the underlying avionics on 737MAX in the first instance this would have been a much larger task upfront but would have made RTS a much simpler prospect, FBW or no FBW.

I think that we vastly agree. From a technical point of view only, what a 737-8/9 MAX need to have a FBW stab trim ? I think it require more redundant ADIRU and flight computer (not necessarily 3 sensors as the 777 demonstrate) to increase availability, a redundant actuator (a second electrical motor like in the 737 classic), and a redundant power supply. This last point is maybe the most challenging, but certainly doable.


We do agree on a fair amount. However, based on my observations there is no need to add a second electric actuator to the 737 trim system, at least at this point. The reason for this is that there is already a redundant actuation system, the Mk1 human arm. You can disagree on wether or not this is sufficient for the flight enveloped on the 737MAX; however, unless you greatly increase the force authority of the electric motor it would also be insufficient for the vast majority of areas where human is insufficient. If you increase the force authority I would agree that a second motor and power supply would be needed. The power supply is already present; however, adding the motor and linking it too said power supply would required significant modification of existing frames. It would also require significantly more differences training between the 2 aircraft. This is because the failure modes would be even more different, and more importantly the way the flight crew would counter them would be totally different. With the current system the failure mode countering that is needed for the MAX works perfectly well on the NG. There is little reason to go to an FBW trim system on the 737 unless there is a significant benefit in MTC burden or weight. We saw the MAX go to FBW spoilers as this saved quite a bit of weight and etc costs. However, the spoilers were already irreversible so the change in behaviour to the flight crew is nearly zero.
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 11:56 am

phollingsworth wrote:
PixelFlight wrote:
ADent wrote:
I don’t think they need a full FBW system, but just a FBW trim (stabilizer) and maybe elevator.

CRJ-1000 got a FBW rudder - and it was significant work.

The 737-8/9 MAX is in fact close to a FBW stab trim, but without the safety of a FBW system, and this is the origin of the problem. In AP flight mode, the 737-8/9 MAX already operate the elevators and stab trim from as in a FBW aircraft. In manual flight mode, the aerodynamic of the 737-8/9 MAX require the MCAS to comply with the regulation, and MCAS is a kind of borderline near FBW system in the sens that it's a computer that activate with high authority a primary control surface from a sensor, but with a discrete signal and without redundancy. Now the MCAS V2 will get a bare minimum of redundancy, but not to increase his availability as in a FBW system, but to disable it in case of disagreement from the sensors and/or computers. A change of the avionic could certainly add the required redundancy to increase the availability to the level of a FBW system, at least for the stab trim, but this would also require a redundant actuator and a redundant power for that actuator. At this point there could remove the manual trim wheels as in the A350.


The 737MAX's trim is nowhere near that of an FBW system it is still very much a mechanical system with electrical augmentation. While MCAS increased the rate and range that the autopilot could actuate the stab trim, it didn't increase the force authority. As such a human can still physically stop the autopilot trim by grabbing the trim wheel. This is not the case on the 757/767 or any of the Boeing or Airbus FBW aircraft. Further, FBW systems can be simplex, duplex, triplex, etc. The reason that we see Duplex and Triplex in aircraft with irreversible controls is that there is no means for the human being to actually fly the aircraft without those systems operating. If you loose all the hydraulics and electrics on a 757 or 767 they are deemed to be basically un-flyable, even though they are not FBW, where as a 737 can still be flown by cables alone. MCAS, because of the combination of the rates/range, and the identification and countering of the failure mode introduces a reasonable likelihood that some failures will make the aircraft un-flyable. Hence the switch to duplex. Keep in mind that the 777 which is fully FBW only has duplex sensing on all of its AoA based actions. Even the A320 with Triplex AoA sensors can be dispatched with only 2 operating, without significant restrictions in operations. As long as the regulators are satisfied that the duplex system with the associated reduction in availability meets or exceeds the required performance then it is good to go.

Boeing is currently paying the price for trying to retrofit safety criticality into an avionics suite that is not design to be safety critical. It is something that can be done, but basically requires rewriting the entire software stack to accomplish. Had Boeing gone for a rebuild of the underlying avionics on 737MAX in the first instance this would have been a much larger task upfront but would have made RTS a much simpler prospect, FBW or no FBW.


Isn't the reason grabbing the trim wheel stops the stabilizer movement because it is designed that way with clutches that disengage? I don't think a human grip could physically overpower the electric motor.

The primary trim is technically "fly by wire" as there is electrical control of the trim motor. I guess you could say it is FBW with a manual/physical backup system.
 
rheinwaldner
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 1:29 pm

Total cost for the grounding is now estimated more than 20 billions:
https://aviationweek.com/air-transport/aerospace-analysts-see-growing-737-max-costs-boeing?utm_rid=CPEN1000014909485&utm_campaign=22889&utm_medium=email&elq2=46e264cf54a449d99b58b0f6dab1f440

And this 20 billion figure does not even yet include the settlements from lawsuits.

For that money Boeing maybe could have gotten NSA and NMA meanwhile (if e.g. the two would have share considerable development efforts)...
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 1:40 pm

phollingsworth wrote:
We do agree on a fair amount. However, based on my observations there is no need to add a second electric actuator to the 737 trim system, at least at this point. The reason for this is that there is already a redundant actuation system, the Mk1 human arm. You can disagree on wether or not this is sufficient for the flight enveloped on the 737MAX; however, unless you greatly increase the force authority of the electric motor it would also be insufficient for the vast majority of areas where human is insufficient. If you increase the force authority I would agree that a second motor and power supply would be needed. The power supply is already present; however, adding the motor and linking it too said power supply would required significant modification of existing frames. It would also require significantly more differences training between the 2 aircraft. This is because the failure modes would be even more different, and more importantly the way the flight crew would counter them would be totally different. With the current system the failure mode countering that is needed for the MAX works perfectly well on the NG. There is little reason to go to an FBW trim system on the 737 unless there is a significant benefit in MTC burden or weight. We saw the MAX go to FBW spoilers as this saved quite a bit of weight and etc costs. However, the spoilers were already irreversible so the change in behaviour to the flight crew is nearly zero.

I my opinion, getting ride of the manual trim wheels is a desirable goal given the limitations that ET302 faced trying to using them. Or at least to have manual trim wheels with force not depending on the speed, like on the A320. But the A320 trim stab is an hydraulic motor with electric actuators, something I think is more difficult to install on a 737 frame compared to the 2 electrical motors like in the A350 and that was already installed in the 737 classic. There already have bluerprint for it, even if it probably require update.
: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:
 
phollingsworth
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 2:25 pm

rheinwaldner wrote:
Total cost for the grounding is now estimated more than 20 billions:
https://aviationweek.com/air-transport/aerospace-analysts-see-growing-737-max-costs-boeing?utm_rid=CPEN1000014909485&utm_campaign=22889&utm_medium=email&elq2=46e264cf54a449d99b58b0f6dab1f440

And this 20 billion figure does not even yet include the settlements from lawsuits.

For that money Boeing maybe could have gotten NSA and NMA meanwhile (if e.g. the two would have share considerable development efforts)...


That requires two things. 1. you knew at the start this chain of events would happen and it is precluded by a new design and not replaced by another similar chain. 2. You believe Boeing could execute a clean sheet design for much less than $20 billion and have done it in a competitive timeframe. Keep in mind that walking away from the MAX and starting a clean-sheet design after Nov 2018 or March 2019 would cost substantially more than $20 billion.

Also, the costs assume that compensation is cumulative in that Boeing will have to pay $8 billion for being out of service/late and another $5 billion for additional training. However, in many cases the full amount of the two combined wouldn't be realised. Additionally, we have no idea what exposure to the £1 million per airframe discount that WN received Boeing will have on the full order book. For instance I doubt this discount applies to AC as they were not an operator of 737NGs.

What is obvious, in hindsight, is that spending a bit more on the programme upfront and properly designing the MCAS avionics and assessing the safety would have saved Boeing a large amount of money. The sad thing is that Boeing had similar programme control issues on the 787 and doesn't seem to have learned.
 
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767333ER
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 2:38 pm

phollingsworth wrote:
767333ER wrote:
CPHGuard wrote:
Would it be possible for Boeing to do a MAX 2.0, where they use the same components as now such as fuselage, landing gear, engines, etc, but add the 787 avionics/FBW?

It would be a huge amount of work, but still probably less than a clean sheet design.

If they do that only for the FAA to decide it’s no longer certifiable as a modified variant of the 737-100 all the grandfathering privileges are gone and they design becomes uncertifiable due to many parts of the design no longer being compliant with regulation and then all that money was wasted. Even if it did pass certification the common type rating would be gone and they would still have to plan for a replacement in 15-20 years time.

The only way this whole disaster could really fixed is if they could go back in time and elect to do the NSA over the MAX. Now they are stuck with this thing.


Given that the FAA has certified as big or bigger relative changes on the same TC before, especially on the power-plant side there is no reason to believe the FAA would have automatically said no. Though things will be different now. Of course any changes brought on by an FBW conversion would have necessitated bringing those parts of the aircraft up to current rules or ELS findings. Further, Boeing could have achieved a common type rating with an FBW aircraft, but it would probably no have made sense to take the penalties of making a fully irreversible aircraft fly like an aircraft with reversible flight controls plus all the added weight of the required extra redundancy.

To do a full FBW and avionics conversion would change a lot of the plane, the latter readily doing so. In order to convert to a 787 style FBW system all the cables would need to be removed, an extra hydraulic system added, the other two hydraulic systems changed, all the control “computers” changed (including that old hydraulic computer the thing has). Most of that is an undertaking they’ve never had to do before. There could be a chance the TC could stay the same, but then again what about it would be a 737 anymore? The fuselage and maybe the wings? It then becomes nearly as much 737 as the 737 is 707.
Been on: 732 733 734 73G 738 752 763 A319 A320 A321 CRJ CR7 CRA/CR9 E145 E175 E190 F28 MD-82 MD-83 C172R C172S P2006T PA-28-180

2 ears for spatial hearing, 2 eyes for depth perception, 2 ears for balance... How did Boeing think 1 sensor was good enough?!
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 2:40 pm

phollingsworth wrote:
Boeing is currently paying the price for trying to retrofit safety criticality into an avionics suite that is not design to be safety critical. It is something that can be done, but basically requires rewriting the entire software stack to accomplish. Had Boeing gone for a rebuild of the underlying avionics on 737MAX in the first instance this would have been a much larger task upfront but would have made RTS a much simpler prospect, FBW or no FBW.

As per earlier posts, the stuff Boeing is doing now (going from active-standby pair to active-active pair) is not a rewrite of the entire stack, it's largely done so you do not have to rewrite the entire stack! The software stack itself is largely preserved, just some comparators are added around the edges, and just some more triggers for disengagement are added. In theory since you already have an active-standby pair the software already has some robustness with respect to rapid failover. The main issue becomes one of testing, and as we've seen with the issue reported last week about activating displays at start up time you often find some places where the software needs more hardening.

It's interesting to see the software audits being held in Cedar Rapids. It's as clear an indication one can get that the center of expertise with regard to the flight control software is at a vendor's site, which IMHO is an absurd position for Boeing to have put itself into.
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trini81
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 2:59 pm

https://www.msn.com/en-us/money/compani ... ar-BBZ8Saf

Interesting article on Boeing's history on dealing with accidents... "How Boeing’s Responsibility in a Deadly Crash ‘Got Buried’"
 
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 3:24 pm

767333ER wrote:
Now they are stuck with this thing.


I have to believe this is the nightmare haunting the dreams of the BoD, astute Boeing shareholders, and BCA employees. They are stuck with this thing for the next quarter century or so. Boeing (and its airline customers as well) has tried to extract more golden eggs from this goose than it could deliver. But what options do they have for this market for the foreseeable future? Nothing.

Now they are stuck with this thing.
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 3:26 pm

trini81 wrote:
https://www.msn.com/en-us/money/companies/how-boeings-responsibility-in-a-deadly-crash-got-buried/ar-BBZ8Saf

Interesting article on Boeing's history on dealing with accidents... "How Boeing’s Responsibility in a Deadly Crash ‘Got Buried’"

TK1951: Different systems but the same principle: primary flight control depending on a single sensor.
Redundancy is the key to improve safety.
Last edited by PixelFlight on Mon Jan 20, 2020 3:30 pm, edited 1 time in total.
: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:
 
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PixelFlight
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Re: Boeing 737MAX Grounding, General Discussion Thread, January 2020

Mon Jan 20, 2020 3:29 pm

767333ER wrote:
To do a full FBW and avionics conversion would change a lot of the plane, the latter readily doing so. In order to convert to a 787 style FBW system all the cables would need to be removed, an extra hydraulic system added, the other two hydraulic systems changed, all the control “computers” changed (including that old hydraulic computer the thing has). Most of that is an undertaking they’ve never had to do before. There could be a chance the TC could stay the same, but then again what about it would be a 737 anymore? The fuselage and maybe the wings? It then becomes nearly as much 737 as the 737 is 707.

But what about converting only the stab trim to FBW first, possibly the 737-8/9 MAX already ?
: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:

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