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seahawk
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 3:45 pm

Too much gloom and doom imho. If there is one firm on the globe that can fix this quickly it is Boeing.
 
LDRA
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 3:51 pm

The rudder cable issue is serious! FAA really has some explaining to do. How did they let that one slide. Now that max is in production it is going to cause Boeing a lot of disruption to correct the issue
 
StTim
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 4:00 pm

seahawk wrote:
Too much gloom and doom imho. If there is one firm on the globe that can fix this quickly it is Boeing.



To be honest this is not getting better for Boeing. I originally expected them to have resolved the issues by now and even with the long lead times in aviation be flying or close to flying again.

The problem has been a constant drip feed of new issues and these then each have their own lead time.

I thought it ill advised of Boeing to state that it would be flying again in October. Boeing is no longer in control of the time line for certification.
 
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JerseyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 4:04 pm

The rudder cable issue is an example where grandfathering is not appropriate.

The debris from the new engines follows a different path from the NG and I guess is more energetic.
 
Virtual737
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 4:05 pm

PITingres wrote:
the Lion Air crash -- given what we know externally -- is likely to be written up just as 2175301 has stated.


2175301 wrote that a main reason he (I'm assuming he) doesn't feel that MCAS is the main cause (although he used the term root cause almost exclusively) is because the previous Lion Air crew were able to land the plane.

As far as I know, we are only aware of 3 flights in total that experienced the MCAS dive at relatively low altitude (or at all) and, in 2 out of those 3 instances, the plane crashed with the loss of all on board.

Are you able to elaborate how this single successful landing discounts MCAS as being the main factor? I ask because I'm interested.

Many thanks.
 
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PITingres
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 4:30 pm

Virtual737 wrote:
PITingres wrote:
the Lion Air crash -- given what we know externally -- is likely to be written up just as 2175301 has stated.


2175301 wrote that a main reason he (I'm assuming he) doesn't feel that MCAS is the main cause (although he used the term root cause almost exclusively) is because the previous Lion Air crew were able to land the plane.

As far as I know, we are only aware of 3 flights in total that experienced the MCAS dive at relatively low altitude (or at all) and, in 2 out of those 3 instances, the plane crashed with the loss of all on board.

Are you able to elaborate how this single successful landing discounts MCAS as being the main factor? I ask because I'm interested.

Many thanks.


We're mixing up semantics here. First, let me state, yet again, that I, and I believe 2175301, are only talking about the Lion Air crash. Accident reports are written up in isolation and as a rule don't take trends into account, that is for a different kind of paper. Second, as I understand it, the formal probable cause (not "main cause", nor "root cause", whatever those might be) is the most proximal and immediate cause of the accident. Other causes are contributing. Since two pilots were able to control the Lion Air plane, the probable cause seems to me to be the apparent failure to communicate the situation and cure to the third pilot, leaving him to figure it out on his own. Or not, as the unfortunate case turned out to be.

I think you and others are confusing the formal "probable cause" of a specific accident, with the "thing(s) that if we fix this will make the other contributing or probable causes moot or at least less serious". (or, less wordily, "thing(s) that most needs fixed".) They are not the same! The latter of course is MCAS 1.0.
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seat1a
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 4:43 pm

Can Boeing go back to making 737-800s?
 
Virtual737
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 4:44 pm

PITingres wrote:

We're mixing up semantics here. First, let me state, yet again, that I (and I believe 2175301) are only talking about the Lion Air crash. Accident reports are written up in isolation and as a rule don't take trends into account, that is for a different kind of paper. Second, as I understand it, the formal probable cause (not "main cause", nor "root cause", whatever those might be) is the most proximal and immediate cause of the accident. Other causes are contributing. Since two pilots were able to control the Lion Air plane, the probable cause seems to me to be the apparent failure to communicate the situation and cure to the third pilot, leaving him to figure it out on his own. Or not, as the unfortunate case turned out to be.

I think you and others are confusing the formal "probable cause" of a specific accident, with the "thing(s) that if we fix this will make the other contributing or probable causes moot or at least less serious". (or, less wordily, "thing(s) that most needs fixed".) They are not the same! The latter of course is MCAS 1.0.


Thanks for the reply. I'm almost with you. Taking the Lion Air crash in isolation, I'm still not sure how one set of pilots (with a 3rd pilot in the cockpit) being able to land the plane and one set (without the 3rd pilot) not being able to can lead to the probably cause being directed to the latters actions, training, lack of info etc. If there were 10 previous flights with a failed AoA sensor and misbehaving MCAS and all 10 of those managed to land successfully, but only the last crew didn't then I would understand. 1 failure and 1 success doesn't lead to any meaningful conclusion in my humble opinion.

Thanks again.
 
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PITingres
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 4:53 pm

Keep in mind that the NTSB is required by US law to find a (singular) probable cause, and "probable cause" is not formally defined as far as I know. My understanding of the usage over time is that the probable cause is generally deemed to be the last link in the chain(*), and other causes are contributing. The confusion and angst here seems to be caused by assuming "probable cause" is "most important cause", and that is not at all the case! At least as far as NTSB reports are concerned, the arguably more important bits are the Safety Recommendations, and if the NTSB were writing up the Lion Air accident, there's no doubt in my mind that there would be a Safety Recommendation aimed at MCAS. (It would not be the only Safety Recommendation.)

Other nations' investigative bodies follow their own national laws, of course. I'm no expert by any means, but the ones I know about tend to follow something quite similar to the NTSB model.

(*) or something like that. Obviously the last link could always end up being "pilot failed to control the aircraft" and that's not useful. If you read a handful of NTSB AAR's, you'll get a feeling for how "probable cause" is selected; I'm not sure I can verbalize it exactly, and I bet the NTSB can't either.
Last edited by PITingres on Tue Jul 30, 2019 4:56 pm, edited 1 time in total.
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 4:56 pm

LDRA wrote:
The rudder cable issue is serious! FAA really has some explaining to do. How did they let that one slide.

It's impossible for you know this to be a serious issue without being a trained engineer with access to lots of restricted data.

In reality we have a media report of some anonymous engineers saying they're upset because management didn't act on their concerns.

We don't know if the managers had solid technical grounds to do so, or not.
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LDRA
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 5:05 pm

Revelation wrote:
LDRA wrote:
The rudder cable issue is serious! FAA really has some explaining to do. How did they let that one slide.

It's impossible for you know this to be a serious issue without being a trained engineer with access to lots of restricted data.

In reality we have a media report of some anonymous engineers saying they're upset because management didn't act on their concerns.

We don't know if the managers had solid technical grounds to do so, or not.


It is impossible for YOU to know if I am qualified to know this is a serious issue or not

I will leave at that
 
IADFCO
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 5:23 pm

Revelation wrote:
LDRA wrote:
The rudder cable issue is serious! FAA really has some explaining to do. How did they let that one slide.

It's impossible for you know this to be a serious issue without being a trained engineer with access to lots of restricted data.

In reality we have a media report of some anonymous engineers saying they're upset because management didn't act on their concerns.

We don't know if the managers had solid technical grounds to do so, or not.


Why these personal attacks? And how do *you* know that LDRA is not a trained engineer with access to lots of restricted data?

OK, then I'll reword LDRA's concern. There are very serious allegations in the press that the rudder control system does not comply with FAA's own criteria for uncontained engine failures, and that concerns expressed by FAA personnel have been dismissed by FAA management on the grounds that the proposed fixes were financially inconvenient for the manufacturer.

Just for the record, the Office of Inspector General of the U.S. Department of Transportation has already at least two FAA audits in progress, one is of FAA’s Oversight of Open-Door Helicopter Operations, the other of its Airport Improvement Program’s State Block Grant Program. Source is the DOT OIG own web site: https://www.oig.dot.gov/. So there are ways to convert concerns into official investigations "by trained engineers with access to lots of restricted data".
 
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 5:50 pm

IADFCO wrote:
There are very serious allegations in the press that the rudder control system does not comply with FAA's own criteria for uncontained engine failures, and that concerns expressed by FAA personnel have been dismissed by FAA management on the grounds that the proposed fixes were financially inconvenient for the manufacturer.

Anyone can say anything hiding behind the shield of anonymity.

You would think if an a.net member had such a "hot potato" item they were willing to drop, they would do so before the NYT report, no?

Basically, if you are posting something that's a fact, forum rules require a link, otherwise it's just an opinion.

All the post said was it's a serious issue but no basis for why, so the natural assumption is we're all going on the same media reports.

IADFCO wrote:
Just for the record, the Office of Inspector General of the U.S. Department of Transportation has already at least two FAA audits in progress, one is of FAA’s Oversight of Open-Door Helicopter Operations, the other of its Airport Improvement Program’s State Block Grant Program. Source is the DOT OIG own web site: https://www.oig.dot.gov/. So there are ways to convert concerns into official investigations "by trained engineers with access to lots of restricted data".

Indeed, and when one of the many ongoing official investigations start telling us there's reason to believe that FAA evaluated the risk with regard to uncontained engine failures incorrectly, I'll take it seriously.

Right now all we have is a media report quoting engineers that were unhappy about being overruled by their bosses.

For the record, I take all the investigations you cite seriously.

I also take the FBI/DoT probe very seriously because they have subpoena power, whereas the other agencies do not.

I take anonymous complaints to the NYT and anonymous internet posts much less seriously.
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DenverTed
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 5:56 pm

What's the deal with the rudder cables? Is it the same on the NG? Or is something different on the NG in terms of cable routing away or more armoring?

This sounds like the trim wheel, low probability, but if they fix it on the MAX, they have to fix it on the NG. Unless they can prove some rationale that the probability is higher on the MAX, and that is the demarcation between fixing it or not. Which sounds to me like forcing the data to fit the desired result. Which is the kind of fuzzy thinking that led to this to begin with.
 
Nils75cz
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 6:03 pm

The way I understand it, the bigger and differently mounted engines expose a bigger probability of debris destroying crucial rudder cables in case of a failure.
 
Vladex
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 6:09 pm

Maybe in the end only FAA will approve the airplane and UA,AA and Southwest can fly them in the USA only?
 
Agrajag
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 6:20 pm

Nils75cz wrote:
The way I understand it, the bigger and differently mounted engines expose a bigger probability of debris destroying crucial rudder cables in case of a failure.



Yep, and ive read that the cables need to be shrouded in titanium tubes for protection but i cant imagine that would make much of a difference if the hp turbine let go. Thats a lot of energy and short of armour plate, whats going to stop it going where it wants to go.?
The plural of anecdote is anecdotes, not data.
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flyingphil
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 6:26 pm

As the engines on the 737MAX are mounted so far forward more of the fuselage is at risk from flying debris including the rudder cables.

With the 737NG less of the fuselage is at risk as the engines are tucked more underneath wing, so the wing would take more of the debris.

Wether this is a showstopper I have no idea. I assume the cables could be shielded somehow.
 
Canuck600
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 6:39 pm

qf789 wrote:
A couple of things regarding the 737MAX from Air Canada's Q2 earning update

Most impacted market due to grounding is Hawaii

https://twitter.com/e_russell/status/11 ... 77186?s=20

Current 737MAX pilots are sitting idle as carrier does not operate 737NG, not hiring new pilots atm

https://twitter.com/e_russell/status/11 ... 51969?s=20

Will take Air Canada up to a year to take delivery of other 737MAX's once recertified as need to hire more pilots before they can take delivery of them

https://twitter.com/e_russell/status/11 ... 01539?s=20


I believe Longhauler said that pilots are still being hired but being trained/assigned to other aircraft.
 
inkjet7
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 6:51 pm

MartijnNL wrote:
factsonly wrote:
A B737MAX is flying today!

Today Saturday 27 July, TUI Netherlands is ferrying a stranded B737MAX from Sofia back to base in Amsterdam.

Thank you for the heads up. I saw it gliding through the sky this afternoon. Apparently the entire flight was done at 20,000 feet and 300 knots.


Flaps 1 to keep MCAS out.
 
Natflyer
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 7:11 pm

inkjet7 wrote:
MartijnNL wrote:
factsonly wrote:
A B737MAX is flying today!

Today Saturday 27 July, TUI Netherlands is ferrying a stranded B737MAX from Sofia back to base in Amsterdam.

Thank you for the heads up. I saw it gliding through the sky this afternoon. Apparently the entire flight was done at 20,000 feet and 300 knots.


Flaps 1 to keep MCAS out.


With Flaps 1 it would not have been at 300 kts.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 7:44 pm

flyingphil wrote:
As the engines on the 737MAX are mounted so far forward more of the fuselage is at risk from flying debris including the rudder cables.

With the 737NG less of the fuselage is at risk as the engines are tucked more underneath wing, so the wing would take more of the debris.

Wether this is a showstopper I have no idea. I assume the cables could be shielded somehow.


They aren't mounted that much further forward than the NG. The issue that those FAA engineers brought up seemed to be based on larger engines with bigger parts that have more mass. This makes it more likely for a part to depart the engine with enough energy to cut through the fuselage and cables.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 7:46 pm

Vladex wrote:
Maybe in the end only FAA will approve the airplane and UA,AA and Southwest can fly them in the USA only?

That will not happen. Either it will be approved by the FAA and international regulators (with the possible exception of China) or it won't be approved.
 
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DocLightning
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 7:56 pm

seat1a wrote:
Can Boeing go back to making 737-800s?


Depends on whether CFM wants to keep making CFM56-7 engines. But even if they did, will airlines want to buy an airplane that burns 20% more fuel than the competition? And Boeing has already lost billions of dollars on the -MAX.
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par13del
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 8:04 pm

planecane wrote:
flyingphil wrote:
As the engines on the 737MAX are mounted so far forward more of the fuselage is at risk from flying debris including the rudder cables.

With the 737NG less of the fuselage is at risk as the engines are tucked more underneath wing, so the wing would take more of the debris.

Wether this is a showstopper I have no idea. I assume the cables could be shielded somehow.


They aren't mounted that much further forward than the NG. The issue that those FAA engineers brought up seemed to be based on larger engines with bigger parts that have more mass. This makes it more likely for a part to depart the engine with enough energy to cut through the fuselage and cables.

So the engine makers did not beef up their containment, they also have a requirement to ensure that failures are contained right?
 
hivue
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 8:26 pm

par13del wrote:
planecane wrote:
they also have a requirement to ensure that failures are contained right?


I doubt if there is any regulation which requires that. In many cases it would be physically impossible to contain a turbine rotor that has come apart.

See post 1148 above.
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BravoOne
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 8:42 pm

I seem to recall that the MD11 had a new design on the flap control cables that reduced the possibility of an unwanted slat retraction in the event of an uncontained catostrophic rotor burst on the #3 engine. If so, it was probably driven by FAA design criteria.
 
889091
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 8:52 pm

Sure, Boeing brought the spotlight upon themselves, but I get the impression that the the FAA is in CYA mode and scrutinizing everything to the n-th degree. How would they even test/simulate that the Ti shielding on the rudder cables can withstand the impact of a HP turbine that has let go? Do something for the sake of being seen to be doing something?....

Is the FAA going to now revoke the certification for the 772LR? Afterall, Boeing slapped on a larger diameter GE90-115B (that produces more thrust, ergo more energy, should a HP turbine fail) on the same wing....

Boeing better add a lot of padding to their 777X certification timeframe.
 
smartplane
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 9:07 pm

JetBuddy wrote:
I was under the impression there were only two problems facing the MAX. But according to these articles there are now six issues.

In simplified terms:

- MCAS issue (well known)
- Trim wheel issue (too rigid, impossible to move in certain scenarios)
- Lack of training (a few slides on an ipad / no simulator training)
- Flight control computer (the lagging microprocessor)
- Autopilot disengage not working in some emergencies (likely related to the above one)
- Vulnerable rudder cables / if engine disintegration (larger fan blades, different position, vulnerable rudder cables)

Several of these may be related to the others.

https://www.moonofalabama.org/2019/07/7 ... ified.html
https://www.moonofalabama.org/2019/07/e ... sues-.html

The longer resolution of these issues takes, the more will be found, because multiple agencies inside and outside the USA are still looking.

Every Boeing and FAA hand that 'touched', and even eyes that 'viewed' the MAX are now being tracked back to the NG, X and 787
 
Paulotd
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 9:14 pm

Whats the possibility Boeing back the production of 737 NG?
 
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 9:20 pm

Paulotd wrote:
Whats the possibility Boeing back the production of 737 NG?

Read #1274 and numerous similar posts above.
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PW100
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 9:47 pm

par13del wrote:
planecane wrote:
flyingphil wrote:
As the engines on the 737MAX are mounted so far forward more of the fuselage is at risk from flying debris including the rudder cables.

With the 737NG less of the fuselage is at risk as the engines are tucked more underneath wing, so the wing would take more of the debris.

Wether this is a showstopper I have no idea. I assume the cables could be shielded somehow.


They aren't mounted that much further forward than the NG. The issue that those FAA engineers brought up seemed to be based on larger engines with bigger parts that have more mass. This makes it more likely for a part to depart the engine with enough energy to cut through the fuselage and cables.

So the engine makers did not beef up their containment, they also have a requirement to ensure that failures are contained right?


We should distinguish between disk failure and (individual) blade failure.

Regulations require containment of individual blades (fan, compressor, turbine), and such must also be demonstrated. We all have seen the fan blade off containment test videos, many can be found on YouTube. Less known are the compressor and turbine blade off tests. These are not done on a running engine, but in a test spin bunker, by individual stage or a combination of stages (compressor drum), depending on design characteristics.
So all engines are able to contain the high energy release of single blades. Usually the containment is strong enough to contain multiple blade failures, but this is not a hard requirement.

The amount of energy released by a disk fracture is so large, that there is no reasonable way to contain that. Flight safety for these parts is regulated in a different way, by defining hard life limits for these critical parts (LLP = Life Limited Part, or LCF = Low Cycle Fatigue). Life limits in terms of engine cycles (sort of engine starts). Most common is 15000 / 18000 / 30000 cycle limit. Once the component has reached its limit, it must be replaced. Meaning the engine has to go to the shop.

Life limits are set very conservatively, especially at initial certification (say 5000 cycles). Parts that are replaced for life limits will be returned to the OEM and deep analysis is performed on these parts. Once a sufficient amount of parts have been tested successfully, the life limit of the said part can be increased/escalated. It can take 10 - 15 years of service time for the fleet to build up sufficient life to reach final life limit.
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sillystrings
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 9:54 pm

889091 wrote:
Sure, Boeing brought the spotlight upon themselves, but I get the impression that the the FAA is in CYA mode and scrutinizing everything to the n-th degree. How would they even test/simulate that the Ti shielding on the rudder cables can withstand the impact of a HP turbine that has let go? Do something for the sake of being seen to be doing something?....

Is the FAA going to now revoke the certification for the 772LR? Afterall, Boeing slapped on a larger diameter GE90-115B (that produces more thrust, ergo more energy, should a HP turbine fail) on the same wing....

Boeing better add a lot of padding to their 777X certification timeframe.

If I understand the timeline correctly, this issue with the cables was brought up by the FAA before the MAX was even certified.
 
TTailedTiger
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 9:57 pm

The problem appears to be the FAA. Not Boeing. As far as I have seen Boeing has been compliant and done everything in their power to to get the Max back in the air. The FAA is dragging their feet and now they are going back on systems they already approved? It sounds like the president needs to cut a few people at the FAA down to size. Bring in some real professionals who can make sure the plane is safe and get it back on the air in a timely manner.

This is the same FAA that doesn't even require all aircraft to have transponders or mandate that they be on at all times. It is quite frightening to know that ATC or TCAS can't see a potential threat. That tells me everything I need to know. They are not really concerned with safety. Just posturing.
 
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flyingphil
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 10:05 pm

On PBS an interview with the NY Times journalist..
“In this case, there was a dispute over these cables, which FAA engineers, most of them who are working on this issue wanted the company to make these cables safer. Boeing pushed back. And the FAA managers sided with Boeing over the engineers in the FAA, and then gave Boeing the ability to approve these cables.

An engineer inside the FAA filed a safety complaint about this issue. But, again, managers were deferring to Boeing and specifically cited Boeing's timeline as one of the reasons.“..

https://www.pbs.org/newshour/show/did-t ... of-737-max
 
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JetBuddy
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 10:07 pm

XRAYretired wrote:
Been somewhere nice I hope!

You missed the 'AOA reliability' one from the EASA list (don't know what this is really about).

Oh and, the 'Flaps System' problem (no detail but declared catastrophic by FAA).

Oh and, MAX simulator did not simulate MCAS and, whilst on the subject, MAX nor NG simulators did not adequately simulate manual trim wheel loads.


I wish!

I've not heard about the Flaps system problem yet. Will be interesting to see what that means.

That's two more on the list then. Wow.

Revelation wrote:
I'm impressed by that site's close tracking of the events, but the suggested implications always seem to be the worst case scenario.

The original report of the first five issues suggest some of them may be resolved by, for instance, making a convincing argument that iPad training is sufficient rather than needing to have simulator training just because the training issue is on the list.

We don't know if the sixth item was already known to EASA before it made its list.

For all we know, EASA could have decided that the evaluation of risk that Boeing made was proper with respect to the regulations and the concerns of the FAA engineers raised by the NYT were not. Or, of course, the opposite. The issue is we don't know which is true, so we don't know if the issue is now on EASA's list.

And yes, there are other items that some feel are important, but they too weren't on EASA's list.


Yes, I'm quite impressed by them too. I discovered them through this thread today. Agreed about the "worst case scenario", but so far there has been a few of those regarding everything MAX. So I think it's legitimate speculation, at least for now.

smartplane wrote:
The longer resolution of these issues takes, the more will be found, because multiple agencies inside and outside the USA are still looking.

Every Boeing and FAA hand that 'touched', and even eyes that 'viewed' the MAX are now being tracked back to the NG, X and 787


That's certainly what has happened so far. I think it's a good thing that all of these issues are discovered - but there's a balancing act between what absolutely needs fixing, what should be rectified and redesigned, and what is not possible to do anything about without redesigning and recertifying the whole airplane.

If all of the listed issues are fixed, the 737 MAX will probably be the safest passenger aircraft to ever fly - post accidents that is.

What worries me most about this whole situation is the "fox guarding the henhouse" situation between Boeing and FAA.
 
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flyingphil
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 10:28 pm

Worth a read.
I forgot Nikki Haley is on the Boeing board, maybe she will get Trump to put pressure on the FAA?

https://www.palisadeshudson.com/2019/07 ... llion-man/
 
smartplane
Posts: 1024
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 10:30 pm

JetBuddy wrote:
smartplane wrote:
The longer resolution of these issues takes, the more will be found, because multiple agencies inside and outside the USA are still looking.

Every Boeing and FAA hand that 'touched', and even eyes that 'viewed' the MAX are now being tracked back to the NG, X and 787


That's certainly what has happened so far. I think it's a good thing that all of these issues are discovered - but there's a balancing act between what absolutely needs fixing, what should be rectified and redesigned, and what is not possible to do anything about without redesigning and recertifying the whole airplane.

If all of the listed issues are fixed, the 737 MAX will probably be the safest passenger aircraft to ever fly - post accidents that is.

What worries me most about this whole situation is the "fox guarding the henhouse" situation between Boeing and FAA.

Spirited dialogue between Boeing and the FAA, regarding what needs to be fixed for flights and deliveries to resume, versus what can be covered by AD's and rectified later.

Until Boeing / FAA resolve, fix now / fix later consensus between the FAA and EASA will be deferred (latter appears to be representing other airworthiness authority interests).

Longer this debate takes, the more issues will surface. And the less open Boeing is, or appears to be, the greater the suspicion the OEM is aware of other issues.
 
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par13del
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 10:39 pm

Well when Boeing were working on the initial MCAS fix they did discover and included a undisclosed flap problem (I believe it was flap) but they did include a fix for something not MCAS.
I have been searching but all articles found are in the May timeline prior to submission, I still want to know if the FAA & EASA accepted the
MCAS fix which was submitted.
 
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 10:43 pm

flyingphil wrote:
On PBS an interview with the NY Times journalist..
“In this case, there was a dispute over these cables, which FAA engineers, most of them who are working on this issue wanted the company to make these cables safer. Boeing pushed back. And the FAA managers sided with Boeing over the engineers in the FAA, and then gave Boeing the ability to approve these cables.

An engineer inside the FAA filed a safety complaint about this issue. But, again, managers were deferring to Boeing and specifically cited Boeing's timeline as one of the reasons.“..

The unanswered question is if the managers had sufficient evidence to justify overruling their underlings or not.
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planecane
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Tue Jul 30, 2019 11:41 pm

flyingphil wrote:
Worth a read.
I forgot Nikki Haley is on the Boeing board, maybe she will get Trump to put pressure on the FAA?

https://www.palisadeshudson.com/2019/07 ... llion-man/


Enough of this TV/movie story line creation. If President Trump was going to pressure the FAA he would have done it already. He also probably wouldn't have been part of the grounding order in the first place. Although he is a political outsider, he wants to be reelected. Pressuring the FAA to unground the MAX and then a crash happening would give powerful ammunition to his opponent. Even if he wanted to step in, he's not that stupid.
 
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BoeingVista
Posts: 2004
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 12:49 am

Revelation wrote:
flyingphil wrote:
On PBS an interview with the NY Times journalist..
“In this case, there was a dispute over these cables, which FAA engineers, most of them who are working on this issue wanted the company to make these cables safer. Boeing pushed back. And the FAA managers sided with Boeing over the engineers in the FAA, and then gave Boeing the ability to approve these cables.

An engineer inside the FAA filed a safety complaint about this issue. But, again, managers were deferring to Boeing and specifically cited Boeing's timeline as one of the reasons.“..

The unanswered question is if the managers had sufficient evidence to justify overruling their underlings or not.


Its not an unanswered question, the result of the safety complaint was a decision against the FAA managers so they did not sufficient evidence to rule against their engineers but by then it was too late as the delegation had already happened. But today is a new dawn and the FAA must now rectify this safety issue, the MAX is not compliant.
BV
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 3:56 am

BoeingVista wrote:
Revelation wrote:
flyingphil wrote:
On PBS an interview with the NY Times journalist..
“In this case, there was a dispute over these cables, which FAA engineers, most of them who are working on this issue wanted the company to make these cables safer. Boeing pushed back. And the FAA managers sided with Boeing over the engineers in the FAA, and then gave Boeing the ability to approve these cables.

An engineer inside the FAA filed a safety complaint about this issue. But, again, managers were deferring to Boeing and specifically cited Boeing's timeline as one of the reasons.“..

The unanswered question is if the managers had sufficient evidence to justify overruling their underlings or not.


Its not an unanswered question, the result of the safety complaint was a decision against the FAA managers so they did not sufficient evidence to rule against their engineers but by then it was too late as the delegation had already happened. But today is a new dawn and the FAA must now rectify this safety issue, the MAX is not compliant.


I think a more important question is how many uncontained engine failures have occurred in the last 20 years where parts flew out that could cut through the fuselage and rudder cables?

Since it is accepted that you can't economically design a plane that is 100% safe, does this failure occur frequently enough that it really is a safety issue? Then add that at least from the report the concern is that it happens just after takeoff.

I also don't understand why the issue is only with the rudder cables. Are the elevator and aileron cables routed differently and redundant? I always assumed that all the control cables were close to each other.
 
prebennorholm
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 3:56 am

DenverTed wrote:
What's the deal with the rudder cables? Is it the same on the NG? Or is something different on the NG in terms of cable routing away or more armoring?

"The deal" is lack of redundancy. And yes, it is the same on the NG, but it should have been corrected on the NG 20+ years ago. Non-redundant rudder control was pretty much standard in the early days of air travel. It was allowed to live on in the NG, and now also on the MAX. Both decisions were.... aeh, we can apply many different adjectives here, but I will be polite and mention only "old-fashioned".

On other planes multiple routing - hydraulic, electric, steel cables, or a combination - has been the norm for half a century or more. That is the way to do business in modern time. Anything less is just too cheap.

An uncontained engine disk failure will normally mean that two or a few parts leave perpendicularly to the rotation axis in opposite directions. No two parts will escape at identical or nearly identical path. Having two routings pretty close to each other therefore offers a vastly reduced risk of failure (= many more zeroes behind the all important numbers).

Luckily the CFM56-7B has not been prone to uncontained failures, and we can hope that the LEAP-1B will prove as good in this respect. But non-redundant rudder control routing is simply not the way to build airliners in the 21st century. Grandfathering and no accident (yet) are not valid excuses.
Always keep your number of landings equal to your number of take-offs
 
RickNRoll
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Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 4:12 am

StTim wrote:
seahawk wrote:
Too much gloom and doom imho. If there is one firm on the globe that can fix this quickly it is Boeing.



To be honest this is not getting better for Boeing. I originally expected them to have resolved the issues by now and even with the long lead times in aviation be flying or close to flying again.

The problem has been a constant drip feed of new issues and these then each have their own lead time.

I thought it ill advised of Boeing to state that it would be flying again in October. Boeing is no longer in control of the time line for certification.


The reason for that appears to be that Boeing has been pushing the limits for years. Just a bit each time. Now that it has caught up with them, multiple years of slight compromises of safety are being revealed all at once. The FAA has been deliberately comprised as a part of this process. Anyone with the most basic training in quality processes would recognise that what has happened to the FAA is not the fault of the FAA, it is by design. The political power of Boeing has allowed it to ask for and get control over supervising itself. There are plenty of examples of 'self regulation' in business failing.
 
RickNRoll
Posts: 1789
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 4:14 am

prebennorholm wrote:
DenverTed wrote:
What's the deal with the rudder cables? Is it the same on the NG? Or is something different on the NG in terms of cable routing away or more armoring?

"The deal" is lack of redundancy. And yes, it is the same on the NG, but it should have been corrected on the NG 20+ years ago. Non-redundant rudder control was pretty much standard in the early days of air travel. It was allowed to live on in the NG, and now also on the MAX. Both decisions were.... aeh, we can apply many different adjectives here, but I will be polite and mention only "old-fashioned".

On other planes multiple routing - hydraulic, electric, steel cables, or a combination - has been the norm for half a century or more. That is the way to do business in modern time. Anything less is just too cheap.

An uncontained engine disk failure will normally mean that two or a few parts leave perpendicularly to the rotation axis in opposite directions. No two parts will escape at identical or nearly identical path. Having two routings pretty close to each other therefore offers a vastly reduced risk of failure (= many more zeroes behind the all important numbers).

Luckily the CFM56-7B has not been prone to uncontained failures, and we can hope that the LEAP-1B will prove as good in this respect. But non-redundant rudder control routing is simply not the way to build airliners in the 21st century. Grandfathering and no accident (yet) are not valid excuses.


There would have been some significant crashes if not for redundancy. QF32 comes to mind. Despite massive damage to vital systems the plane still landed safely.
 
RickNRoll
Posts: 1789
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 4:16 am

Revelation wrote:
flyingphil wrote:
On PBS an interview with the NY Times journalist..
“In this case, there was a dispute over these cables, which FAA engineers, most of them who are working on this issue wanted the company to make these cables safer. Boeing pushed back. And the FAA managers sided with Boeing over the engineers in the FAA, and then gave Boeing the ability to approve these cables.

An engineer inside the FAA filed a safety complaint about this issue. But, again, managers were deferring to Boeing and specifically cited Boeing's timeline as one of the reasons.“..

The unanswered question is if the managers had sufficient evidence to justify overruling their underlings or not.


The funny thing is that the cockpit evironment is way ahead of Boeing as a company. CRM is now taken very seriously. Out of the cockpit, not so much.
 
RickNRoll
Posts: 1789
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 4:18 am

TTailedTiger wrote:
The problem appears to be the FAA. Not Boeing. As far as I have seen Boeing has been compliant and done everything in their power to to get the Max back in the air. The FAA is dragging their feet and now they are going back on systems they already approved? It sounds like the president needs to cut a few people at the FAA down to size. Bring in some real professionals who can make sure the plane is safe and get it back on the air in a timely manner.

This is the same FAA that doesn't even require all aircraft to have transponders or mandate that they be on at all times. It is quite frightening to know that ATC or TCAS can't see a potential threat. That tells me everything I need to know. They are not really concerned with safety. Just posturing.


The FAA has been compromised by politics. The 'get rid of red tape and let business get on with making money' mantra is very popular politically.
 
RickNRoll
Posts: 1789
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 4:22 am

hivue wrote:
Revelation wrote:
NYT suggests that Boeing management is pressuring engineers to keep costs low to keep the stock price high, presumably because management bonuses are often stock grants or options.


Management remuneration (not just bonuses) often is heavily influenced by stock price period. If the (major, at any rate) stockholders ain't happy ain't nobody happy. The tyranny of the stockholder has contributed significantly to this mess (and a number of other corporate messes as well).


It is common practice for bonuses to include share options. They are directly benefitting from a higher stock price. This is not the only company to have it's integrity weakened by this practice.
 
prebennorholm
Posts: 6977
Joined: Tue Mar 21, 2000 6:25 am

Re: Boeing 737MAX Grounded Worldwide Q3 2019

Wed Jul 31, 2019 4:44 am

Natflyer wrote:
inkjet7 wrote:
MartijnNL wrote:
Thank you for the heads up. I saw it gliding through the sky this afternoon. Apparently the entire flight was done at 20,000 feet and 300 knots.


Flaps 1 to keep MCAS out.


With Flaps 1 it would not have been at 300 kts.

Flap 1 and IAS 200 kts, at FL200, and add the southerly wind bringing today's heatwave to Europe from Africa, then ground speed 300 kts seems spot on.
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