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art
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 9:35 am

Something positive as a result of the MAX tragedies:

The US Department of Transportation is seeking applicants for an independent special committee to review the Federal Aviation Administration's certification process of new aircraft including the Boeing 737 Max following two fatal crashes of that aircraft type within five months.


https://www.flightglobal.com/news/artic ... if-456889/
 
Amiga500
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 9:48 am

Interested wrote:
https://www.bbc.com/news/business-47655115

Airlines keeping safety training to an absolute minimum


Wait a sec.

Do people honestly think that 20 quid flights don't come with strings attached?


If we need mandated training time and quality to be stepped up, then its up to the regulators to do that. Most airlines are never voluntarily going to fork out extra.
 
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scbriml
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 12:41 pm

Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a
WASHINGTON—FAA does not want to be the first regulator to lift its 737 MAX operations ban and is working with other agencies to find consensus on joint approval of the model’s return to service, but the agency is prepared to act alone if the authorities cannot agree, sources with knowledge of the agency’s thinking tell Aviation Daily.

“The world thinks FAA is in Boeing’s pocket,” said one source, who requested anonymity due to the issue’s sensitivity. “FAA does not want to be first to lift the grounding.”


Quite telling, IMHO.
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.
 
art
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 12:46 pm

Amiga500 wrote:
Interested wrote:
https://www.bbc.com/news/business-47655115

Airlines keeping safety training to an absolute minimum


Wait a sec.

Do people honestly think that 20 quid flights don't come with strings attached?


If we need mandated training time and quality to be stepped up, then its up to the regulators to do that. Most airlines are never voluntarily going to fork out extra.


Not talking about extra training but I get the impression that pilots have come to spend less time actually flying the aircraft by hand and more time monitoring, with the automatic pilot flying the aircraft. Wouldn't it be an idea to increase the hours spent flying by hand + landing by hand? I would think that would maintain a higher level of proficiency, even if it might be at the cost of somewhat higher fuel burn.
 
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Revelation
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 12:51 pm

scbriml wrote:
Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a
WASHINGTON—FAA does not want to be the first regulator to lift its 737 MAX operations ban and is working with other agencies to find consensus on joint approval of the model’s return to service, but the agency is prepared to act alone if the authorities cannot agree, sources with knowledge of the agency’s thinking tell Aviation Daily.

“The world thinks FAA is in Boeing’s pocket,” said one source, who requested anonymity due to the issue’s sensitivity. “FAA does not want to be first to lift the grounding.”


Quite telling, IMHO.

Welcome to the world where perception is reality, Steve.

Seems many corporate and governmental leaders are going to have to try to cope with the new rules of the game moving forward.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
BlackCat
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 1:00 pm

bgm wrote:
MSPNWA wrote:
Interested wrote:
Can you answer me now as I have no idea on the crashes you refer to?


My point exactly.

Nice try on the red herring to distract from the fact that the A320 had a worse crash/in-service airframe ratio.


The 737 is on the same certificate since 1965. The A320 was a brand new design. Red herring indeed.

Failures of Boeing and FAA:

1) FAA allowing Boeing to certify their own plane. WTF?
2) Boeing only using ONE AoA sensor for MCAS. Again, WTF?
3) Not informing pilots about this feature until after the Lion Air crash. Once again, WTF.

What Boeing did was criminal. You think given that the FAA's reputation is now garbage, other regulatory agencies around the world are going to believe them if they certify it as airworthy? :rotfl:

boeing still test and Fly the New max8 at their fasility today....
 
phollingsworth
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 1:05 pm

scbriml wrote:
Bradin wrote:
Also of interest, it reads like there is a logic error in the software.

In the current design, the system engages for 10 seconds at a time, with five-second pauses in between. Under conditions similar to the Lion Air flight, three engagements over just 40 seconds, including pauses, would send the plane into an unrecoverable dive, the two people involved in the testing said.


We knew this shortly after the Lion crash when Boeing fessed up about MCAS. Boeing's original 'reminder' said something to the effect (can't find exact wording just now) "left unchecked, MCAS can render the plane uncontrollable" (may have said unrecoverable).

The article is pointing out that just three full cycles of MCAS activity (10s trim down, 5s pause, 10s trim down, 5s pause, 10s trim down) without any pilot counter action will leave the plane unrecoverable.

It was shocking when we found out about it. It's still absolutely shocking that Boeing would design such a system, have it rely on a single sensor, have it certified and not tell pilots about it. :banghead:


There are lots of aircraft where 40 uncorrected seconds of a 'runaway' action at certain points in the flight envelope can cause an accident. If you know how to react 40 seconds is a long time, if you don't it is a very short time. Pilots have a lot less than 40 seconds to make a decision on what to do during an engine failure on take-off. Keep in mind to counter the action of the MCAS requires one of the following
[list=]Manual activation of nose-up trip every 5 second period countering any nose down trim for the entire flight (not something a pilot wants to do)
Engaging the trim cutouts and manually trimming the aircraft[/list]
Now pilots who were well versed in the stab trim runaway scenario would be able to either. However, it is increasingly obvious pilots are not well versed in the overall procedure as in most prior cases or runaway it could be stopped by either disconnecting the autopilot or pulling on the yoke in the opposite direction. Therefore, they only practice the first few steps in the overall process and are likely to forget the ultimate mode of engaging the stabiliser cutouts. If you remember all of these no problem; however, if you never get to the third action you will tend to forget that part.

While I think not making use of the second AoA vane in the MCAS system is very poor design it isn't, by itself, a catastrophic failure point. There should be enough potential checks that it shouldn't be an issue. Unfortunately, these were also removed over the years in the way Boing/airlines trained and airlines flew their NGs. This is where mentioning the MCAS system to pilots, specifically that it takes using the cutouts might have helped. Unfortunately, unless the cutout part was regularly practiced it might have had no effect. The Lion Air pilots never tried the cutout even though it has been in the FCTM for a number of years.

This is the inherent problem with any 'differences' training, it has to overcome all of the preconceived biases/shortcuts that pilots use from the prior models. These accidents bear a surprising similarity to British Midland Flight 92. The system changed, even with the differences training, the pilots reverted back to what they had done over and over. Note: I don't think having the AoA disagree light on LNI610 would have solved the problem. However, having it for the prior flight might have helped. The reason why is that the prior crews reported IAS disagree, but the MTC logs had AoA disagree, this caused confusion that helped lead to the problem not being properly addressed.
 
mjoelnir
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 1:19 pm

phollingsworth wrote:
scbriml wrote:
Bradin wrote:
Also of interest, it reads like there is a logic error in the software.



We knew this shortly after the Lion crash when Boeing fessed up about MCAS. Boeing's original 'reminder' said something to the effect (can't find exact wording just now) "left unchecked, MCAS can render the plane uncontrollable" (may have said unrecoverable).

The article is pointing out that just three full cycles of MCAS activity (10s trim down, 5s pause, 10s trim down, 5s pause, 10s trim down) without any pilot counter action will leave the plane unrecoverable.

It was shocking when we found out about it. It's still absolutely shocking that Boeing would design such a system, have it rely on a single sensor, have it certified and not tell pilots about it. :banghead:


There are lots of aircraft where 40 uncorrected seconds of a 'runaway' action at certain points in the flight envelope can cause an accident. If you know how to react 40 seconds is a long time, if you don't it is a very short time. Pilots have a lot less than 40 seconds to make a decision on what to do during an engine failure on take-off. Keep in mind to counter the action of the MCAS requires one of the following
[list=]Manual activation of nose-up trip every 5 second period countering any nose down trim for the entire flight (not something a pilot wants to do)
Engaging the trim cutouts and manually trimming the aircraft[/list]
Now pilots who were well versed in the stab trim runaway scenario would be able to either. However, it is increasingly obvious pilots are not well versed in the overall procedure as in most prior cases or runaway it could be stopped by either disconnecting the autopilot or pulling on the yoke in the opposite direction. Therefore, they only practice the first few steps in the overall process and are likely to forget the ultimate mode of engaging the stabiliser cutouts. If you remember all of these no problem; however, if you never get to the third action you will tend to forget that part.

While I think not making use of the second AoA vane in the MCAS system is very poor design it isn't, by itself, a catastrophic failure point. There should be enough potential checks that it shouldn't be an issue. Unfortunately, these were also removed over the years in the way Boing/airlines trained and airlines flew their NGs. This is where mentioning the MCAS system to pilots, specifically that it takes using the cutouts might have helped. Unfortunately, unless the cutout part was regularly practiced it might have had no effect. The Lion Air pilots never tried the cutout even though it has been in the FCTM for a number of years.

This is the inherent problem with any 'differences' training, it has to overcome all of the preconceived biases/shortcuts that pilots use from the prior models. These accidents bear a surprising similarity to British Midland Flight 92. The system changed, even with the differences training, the pilots reverted back to what they had done over and over. Note: I don't think having the AoA disagree light on LNI610 would have solved the problem. However, having it for the prior flight might have helped. The reason why is that the prior crews reported IAS disagree, but the MTC logs had AoA disagree, this caused confusion that helped lead to the problem not being properly addressed.


The same old defense of Boeing.

A runaway trim diagnostic ends with the trim answering the trim switches on the column. You have STS trimming anyway, so you expect not by the pilot commanded trim movements to happen. You have not been told about MCAS, but you have to diagnose that the automatic does something very strange in manual flight mode. You have stall warning, the stick shaker and unreliable airspeed. So you have to work down a tree of errors and find out what part of your instruments you can trust.

Boeing did lay a trap for pilots.

MCAS explained and a big sign MCAS active when it is active, would have been a sensible arrangement.
 
boerje
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 1:24 pm

scbriml wrote:
Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a
WASHINGTON—FAA does not want to be the first regulator to lift its 737 MAX operations ban and is working with other agencies to find consensus on joint approval of the model’s return to service, but the agency is prepared to act alone if the authorities cannot agree, sources with knowledge of the agency’s thinking tell Aviation Daily.

“The world thinks FAA is in Boeing’s pocket,” said one source, who requested anonymity due to the issue’s sensitivity. “FAA does not want to be first to lift the grounding.”


Quite telling, IMHO.


So FAA does not want to be the first to lift the grounding but if no other regulator joins them FAA will anyway be the first to lift the grounding. :scratchchin:
 
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Carlos01
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 1:31 pm

scbriml wrote:
Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a
WASHINGTON—FAA does not want to be the first regulator to lift its 737 MAX operations ban and is working with other agencies to find consensus on joint approval of the model’s return to service, but the agency is prepared to act alone if the authorities cannot agree, sources with knowledge of the agency’s thinking tell Aviation Daily.

“The world thinks FAA is in Boeing’s pocket,” said one source, who requested anonymity due to the issue’s sensitivity. “FAA does not want to be first to lift the grounding.”


Quite telling, IMHO.


Oh, that's telling indeed a lot. It's telling that absolutely nothing has changed. They are worried about how to approve the MAX for flying again. IMHO they should first focus on if the plane can be approved at all, only then should they worry about the "how" and "with who". So the rubber-stamp mentality prevails, just rush through the process, don't even question if what you are reviewing ticks all the boxes or not.

Nice going. :banghead: :airplane: :alert:
 
HaulSudson
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 1:38 pm

The FAA can always delegate the authority to Boeing, can't they.

Never change a winning team.
 
majano
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 1:50 pm

Chemist wrote:
majano wrote:
Chemist wrote:
People tend to be binary with statements like "Boeing made no mistakes, it's all the pilots" or "The 737 MAX is a flawed kludge, it should be scrapped".
Unfortunately for binary thinkers, reality is almost always somewhere in the middle.

IMHO:
1 - Boeing royally F'd up MCAS, perhaps criminally, and they ought to be penalized. This is what happens when beancounters get too powerful in a company.

What do beancounters have to do with this? Isn't Muilenburg an engineer anyway?


Design solutions likely were restricted because of corporate goals for rapidity of product release, or need for maintaining type certificate. That's a management/cost/beancounter decision.

I am not in the aviation industry, but I sincerely doubt that the accounting department could have a major say, let alone decide, on the type rating of the MAX. I know beancounters are an easy target, but in this case we are stretching it somewhat. .
 
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SheikhDjibouti
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 2:19 pm

boerje wrote:
scbriml wrote:
Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a
WASHINGTON—FAA does not want to be the first regulator to lift its 737 MAX operations ban and is working with other agencies to find consensus on joint approval of the model’s return to service, but the agency is prepared to act alone if the authorities cannot agree, sources with knowledge of the agency’s thinking tell Aviation Daily.

“The world thinks FAA is in Boeing’s pocket,” said one source, who requested anonymity due to the issue’s sensitivity. “FAA does not want to be first to lift the grounding.”

Quite telling, IMHO.

So FAA does not want to be the first to lift the grounding but if no other regulator joins them FAA will anyway be the first to lift the grounding. :scratchchin:
Ok, I'll mention the elephant in the room;
Why would the FAA be the first to lift the grounding order?
Why not EASA? Or any of the other agencies?

They have all got access to the same data - haven't they?
They have all got safety as their #1 priority - haven't they?

It is almost as if the FAA have already made up their minds what will happen next. :scratchchin:

Just imagine if EASA had lain down the gauntlet and warned the FAA that whilst it would be awfully nice if everybody else dropped into line behind them, they would proceed with their own findings anyway?

So is this an invitation to agree, or a veiled threat? You decide. :spin:
Nothing to see here; move along please.
 
maint123
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 2:25 pm

Jouhou wrote:
SheikhDjibouti wrote:
Jouhou wrote:
It doesn't matter what you asked. Most engineers I know are complete morons, the whole having a degree thing is meaningless when it comes to good design, evaluation, and safety.

Bless you!
My partner used to work in a research lab with more PhD's than windows.
Often quite brilliant at what they did, but you wouldn't want to put your life in their hands. :lol:


Heh, my statement might have been a bit abrasive but I'm frequently stunned at how often I need props or visual aids to convey really basic concepts to certain engineers out there. I had to make a guy look up PTFE/Teflon on Wikipedia one day because I couldn't get him to understand that the hard plastic I was holding was not teflon, it was some other plastic that had been misordered, and how it was not acceptable for its intended use.

Ptfe for raised temp usage, around 300 deg C if I remember, But not suitable for abrasion. All engineers learn on the job.
And some never learn, except how to manage and they reach senior levels of authority.
Hope Boeing and FAA are not going in this direction. Because in spite of all the flak I have given them for max, they are one of 2 manufacturers of more or less reliable civilian planes.
 
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casinterest
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 2:29 pm

SheikhDjibouti wrote:
boerje wrote:
scbriml wrote:
Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a

Quite telling, IMHO.

So FAA does not want to be the first to lift the grounding but if no other regulator joins them FAA will anyway be the first to lift the grounding. :scratchchin:
Ok, I'll mention the elephant in the room;
Why would the FAA be the first to lift the grounding order?
Why not EASA? Or any of the other agencies?

They have all got access to the same data - haven't they?
They have all got safety as their #1 priority - haven't they?

It is almost as if the FAA have already made up their minds what will happen next. :scratchchin:

Just imagine if EASA had lain down the gauntlet and warned the FAA that whilst it would be awfully nice if everybody else dropped into line behind them, they would proceed with their own findings anyway?

So is this an invitation to agree, or a veiled threat? You decide. :spin:


The FAA is working to find a consensus amongs all parties on when to lift the ban. The plane has a software fix in test to resolve the issue tied to the crashes. At what point do all agencies agree to the fix?
If the rest of the agencies throw up their hands, and don't care, then the FAA will go it alone. However since all have said they want to re-certify, I would imagine they have some criteria that they would like to discuss with the FAA about bringing the issue to a close. The FAA is open to it.


Will people come up with bullshit tests for systems unaffected?

Or will they all work to re-certify based on what is known?

Multiple fixes documentation changes, and training requirements have been made for faulty sensors data, with no redundancy, feeding an automated system that if left undiagnosed by pilots for 30-50 seconds can result in a crash?
Where ever you go, there you are.
 
mandala499
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 2:42 pm

="phollingsworth"]Unfortunately, unless the cutout part was regularly practiced it might have had no effect. The Lion Air pilots never tried the cutout even though it has been in the FCTM for a number of years.

It would be interesting to see if the pilots involved has gone through the runway stabilizer trim procedure. AFAIK, and from what I am told by trainee NG pilots at Lion Air group, the runaway stabilizer procedure is on their type rating training, and also since beginning of 2018 (yes, 2018, not 2019) on the recurrent training too, because they've had a messy runaway stabilizer incident if I remember correctly in 2017 or 2016.

="phollingsworth"] Note: I don't think having the AoA disagree light on LNI610 would have solved the problem. However, having it for the prior flight might have helped. The reason why is that the prior crews reported IAS disagree, but the MTC logs had AoA disagree, this caused confusion that helped lead to the problem not being properly addressed.

In my opinion, the AOA disagree light would be useless without knowledge of the MCAS, but would be damn useful if pilots knew about it.
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
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hilram
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 2:46 pm

So... If I understand the MCAS fix correctly, it will now rely on two AOA sensors instead of one. So Boeing will still have to retrofit every MAX delivered with only one AOA with the extra AOA. And all MAX planes on the book, I suppose Boeing will have to give that second sensor away for free. That is $100k in revenue lost per plane. And then the compensations for the groundings. And settlements for the families of those lost. And then the massive loss of face for Boeing and the FAA.

I guess some Execs are thinking to themselves "we shouldn't have rushed it like this".
Flown on: A319, 320, 321, 332, 333, 343 | B732, 734, 735, 736, 73G, 738, 743, 744, 772, 77W | CRJ9 | BAe-146 | DHC-6, 7, 8 | F50 | E195 | MD DC-9 41, MD-82, MD-87
 
maint123
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 2:52 pm

oschkosch wrote:
speedking wrote:
StarAC17 wrote:

Oh I agree 100% and it looks horrible for Boeing that they offered extra safety features at an additional cost.
That is like a car manufacturer charging extra for airbags and seat belts


Or build a car with an ABS system with only one speed sensor in one wheel. If it breaks, the ABS will brake the car hard every fifteen seconds. And no warning light. You would need to read the manual to know to switch the ABS off from a separate switch to disable the brakes and then use the hand brake to stop the car.
It still would make the already safe car more safe!
Actually no. When the abs aka speed sensor is defective the brakes don't brake every few seconds. A defective sensor would mean that you can still use your brakes as normal, just you might face blocking brakes instead of the stuttered braking which is from the abs system. That's why abs means anti blocking system :-)

The sensor itself is not defined as being safety relevant, as the brakes still work without the sensor.

Gesendet von meinem SM-G950F mit Tapatalk

ABS is antilock braking system.
A defective sensor - suppose the sensor which senses the wheel rotation stops sending feedback, the abs would get disabled and you work the brakes without abs help. you have to pump the brakes not jam them like with a working abs.
Must be a continuous feedback loop between the rotation sensor and the control unit, like motors have between their encoders and drives. Though I have seen a dc motor go to full speed when the encoder coupling - ahem broke - and the motor went to full speed since the encoder stopped giving rpm feedback. Some safeties disabled.
 
9Patch
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 2:58 pm

scbriml wrote:
Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a
WASHINGTON—FAA does not want to be the first regulator to lift its 737 MAX operations ban and is working with other agencies to find consensus on joint approval of the model’s return to service, but the agency is prepared to act alone if the authorities cannot agree, sources with knowledge of the agency’s thinking tell Aviation Daily.

“The world thinks FAA is in Boeing’s pocket,” said one source, who requested anonymity due to the issue’s sensitivity. “FAA does not want to be first to lift the grounding.”


Quite telling, IMHO.


Quite expected, IMHO.
 
ArgentoSystems
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:02 pm

maint123 wrote:
Though I have seen a dc motor go to full speed when the encoder coupling - ahem broke - and the motor went to full speed since the encoder stopped giving rpm feedback. Some safeties disabled.

Poor engineering... The s/w should have sanity checks. If the power is applied to the motor but you see no input from encoder, then something is broken. Ideally I would like to see a window, for any given power applied, what is the acceptable speed reported by the encoder.
 
mandala499
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:03 pm

hilram wrote:
So... If I understand the MCAS fix correctly, it will now rely on two AOA sensors instead of one. So Boeing will still have to retrofit every MAX delivered with only one AOA with the extra AOA.

ALL 737s come with 2 AOA vanes.
All the Max 8 & 9 to date has MCAS that relies on ONE of the 2 AOA vanes onboard.

This is what Boeing is going to fix, to get the MCAS to use data from 2 AOA vanes... This is a software fix, not a sensor fix or sensor addition.

The Execs should be thinking "we shouldn't have rushed it like this"... they should be thinking, "how the heck did we miss that and made ourselves look like idiots."
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
bob75013
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:09 pm

hilram wrote:
So... If I understand the MCAS fix correctly, it will now rely on two AOA sensors instead of one. So Boeing will still have to retrofit every MAX delivered with only one AOA with the extra AOA. And all MAX planes on the book, I suppose Boeing will have to give that second sensor away for free. That is $100k in revenue lost per plane. And then the compensations for the groundings. And settlements for the families of those lost. And then the massive loss of face for Boeing and the FAA.

I guess some Execs are thinking to themselves "we shouldn't have rushed it like this".



Your understanding is incorrect. MAXs come with two AOA sensors -- that don't currently talk with each other.
 
Wags69
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:10 pm

With this sudden rush to lift the grounding, everything had better be perfect.
With the scrutiny around MAX, all it will take is just one incident,MCAS related or not, and MAX will probably never fly again,
Boeing will be known as a builder whose planes are unsafe, and the FAA will have zero credibility worldwide.
Last edited by Wags69 on Tue Mar 26, 2019 3:14 pm, edited 2 times in total.
 
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smittythepirate
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:11 pm

scbriml wrote:
Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a
WASHINGTON—FAA does not want to be the first regulator to lift its 737 MAX operations ban and is working with other agencies to find consensus on joint approval of the model’s return to service, but the agency is prepared to act alone if the authorities cannot agree, sources with knowledge of the agency’s thinking tell Aviation Daily.

“The world thinks FAA is in Boeing’s pocket,” said one source, who requested anonymity due to the issue’s sensitivity. “FAA does not want to be first to lift the grounding.”


Quite telling, IMHO.



As people have mentioned the FAA should do their job and determine if this has fixed the MAX and whether it should fly again over US soil. Other agencies will follow when their requirements have been fulfilled.
www.jbweather.com
 
Bradin
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:24 pm

hilram wrote:
So... If I understand the MCAS fix correctly, it will now rely on two AOA sensors instead of one. So Boeing will still have to retrofit every MAX delivered with only one AOA with the extra AOA. And all MAX planes on the book, I suppose Boeing will have to give that second sensor away for free. That is $100k in revenue lost per plane. And then the compensations for the groundings. And settlements for the families of those lost. And then the massive loss of face for Boeing and the FAA.

I guess some Execs are thinking to themselves "we shouldn't have rushed it like this".


I believe it’s been mentioned several times in this thread that all 737 Max ship with multiple AOAs by default.
 
kalvado
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:36 pm

smittythepirate wrote:
As people have mentioned the FAA should do their job and determine if this has fixed the MAX and whether it should fly again over US soil. Other agencies will follow when their requirements have been fulfilled.

Except that some will not. EASA announced they will be certifying fix independently, and there are indications that may require full certification review.
I fully envision FAA being the only agency permitting MAX revenue service for some time, and I understand FAA will do their best to avoid such scenario.
 
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GEUltraFan9XGTF
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:42 pm

The "add-on" options were, to my knowledge, a third AOA sensor plus an "AOA disagree" light. The latter is now being offered, free of charge.

IMO, the fix needs to...

-AOA disagree light. If one or both AOA sensors does not read "level" on the ground, perhaps a Master Caution Alarm before take off?
-AOA disagree light: illuminates at any time the two (or three) sensors disagree.
-Boeing should ALSO offer a third AOA sensor for free and feed this into the computer.
-MCAS active light. (Something new.)
-MCAS only activates if 2 (or 3) AOA sensors agree at a certain performance envelope that is indicative of a pre-stall condition.
-MCAS level of activation is known, certain, and communicated in all training manuals. Is it 0.6 or 2.5? Or something else? It is continuous? Does it reset with the yoke switches? What do the yoke trim level switches do?
-MCAS deactivation process is clear and added to all training manuals.
-All the above changes are certified under a microscope.
-MAX planes can only begin flying again AFTER each receives all changes and upgrades have been made.
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GEUltraFan9XGTF
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 3:44 pm

Wags69 wrote:
With this sudden rush to lift the grounding, everything had better be perfect.
With the scrutiny around MAX, all it will take is just one incident,MCAS related or not, and MAX will probably never fly again,
Boeing will be known as a builder whose planes are unsafe, and the FAA will have zero credibility worldwide.


What rush? There is a rush? I think it's the opposite.

How are the two accident investigations going? When can we expect more information?
© 2020. All statements are my own. The use of my statements, including by journalists, YouTube vloggers like "DJ's Aviation", etc. without my written consent is strictly prohibited.
 
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scbriml
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 4:06 pm

GEUltraFan9XGTF wrote:
The "add-on" options were, to my knowledge, a third AOA sensor plus an "AOA disagree" light.


This mythunderstanding is persisting across all three MAX threads. It needs to go away.

There is no option for a third AOA sensor on the MAX. Full stop. Or Period if you're American.
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phollingsworth
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 4:22 pm

SheikhDjibouti wrote:
boerje wrote:
scbriml wrote:
Aviation Week is reporting that the FAA is seeking consensus on lifting the MAX ban.

https://aviationweek.com/commercial-avi ... f4fd51701a

Quite telling, IMHO.

So FAA does not want to be the first to lift the grounding but if no other regulator joins them FAA will anyway be the first to lift the grounding. :scratchchin:
Ok, I'll mention the elephant in the room;
Why would the FAA be the first to lift the grounding order?
Why not EASA? Or any of the other agencies?

They have all got access to the same data - haven't they?
They have all got safety as their #1 priority - haven't they?

It is almost as if the FAA have already made up their minds what will happen next. :scratchchin:

Just imagine if EASA had lain down the gauntlet and warned the FAA that whilst it would be awfully nice if everybody else dropped into line behind them, they would proceed with their own findings anyway?

So is this an invitation to agree, or a veiled threat? You decide. :spin:


The reason the FAA has to be first is because of the way that the Type Certs are done across multiple regulators. As all of the changes to the 737 from NG onwards have been done through the validation process it requires that the FAA certify the aircraft and the others validate the process and results. The FAA would like the validation to come at the same time as the changes are certified. However, given the increased level of scrutiny on the validation process there is a likelihood that other regulators are going to require more information, additional changes, etc. The FAA is hoping that they feed this info to the FAA sooner rather than later so that everything can be handled at once.
 
phollingsworth
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 4:31 pm

mjoelnir wrote:
phollingsworth wrote:
scbriml wrote:

We knew this shortly after the Lion crash when Boeing fessed up about MCAS. Boeing's original 'reminder' said something to the effect (can't find exact wording just now) "left unchecked, MCAS can render the plane uncontrollable" (may have said unrecoverable).

The article is pointing out that just three full cycles of MCAS activity (10s trim down, 5s pause, 10s trim down, 5s pause, 10s trim down) without any pilot counter action will leave the plane unrecoverable.

It was shocking when we found out about it. It's still absolutely shocking that Boeing would design such a system, have it rely on a single sensor, have it certified and not tell pilots about it. :banghead:


There are lots of aircraft where 40 uncorrected seconds of a 'runaway' action at certain points in the flight envelope can cause an accident. If you know how to react 40 seconds is a long time, if you don't it is a very short time. Pilots have a lot less than 40 seconds to make a decision on what to do during an engine failure on take-off. Keep in mind to counter the action of the MCAS requires one of the following
[list=]Manual activation of nose-up trip every 5 second period countering any nose down trim for the entire flight (not something a pilot wants to do)
Engaging the trim cutouts and manually trimming the aircraft[/list]
Now pilots who were well versed in the stab trim runaway scenario would be able to either. However, it is increasingly obvious pilots are not well versed in the overall procedure as in most prior cases or runaway it could be stopped by either disconnecting the autopilot or pulling on the yoke in the opposite direction. Therefore, they only practice the first few steps in the overall process and are likely to forget the ultimate mode of engaging the stabiliser cutouts. If you remember all of these no problem; however, if you never get to the third action you will tend to forget that part.

While I think not making use of the second AoA vane in the MCAS system is very poor design it isn't, by itself, a catastrophic failure point. There should be enough potential checks that it shouldn't be an issue. Unfortunately, these were also removed over the years in the way Boing/airlines trained and airlines flew their NGs. This is where mentioning the MCAS system to pilots, specifically that it takes using the cutouts might have helped. Unfortunately, unless the cutout part was regularly practiced it might have had no effect. The Lion Air pilots never tried the cutout even though it has been in the FCTM for a number of years.

This is the inherent problem with any 'differences' training, it has to overcome all of the preconceived biases/shortcuts that pilots use from the prior models. These accidents bear a surprising similarity to British Midland Flight 92. The system changed, even with the differences training, the pilots reverted back to what they had done over and over. Note: I don't think having the AoA disagree light on LNI610 would have solved the problem. However, having it for the prior flight might have helped. The reason why is that the prior crews reported IAS disagree, but the MTC logs had AoA disagree, this caused confusion that helped lead to the problem not being properly addressed.


The same old defense of Boeing.

A runaway trim diagnostic ends with the trim answering the trim switches on the column. You have STS trimming anyway, so you expect not by the pilot commanded trim movements to happen. You have not been told about MCAS, but you have to diagnose that the automatic does something very strange in manual flight mode. You have stall warning, the stick shaker and unreliable airspeed. So you have to work down a tree of errors and find out what part of your instruments you can trust.

Boeing did lay a trap for pilots.

MCAS explained and a big sign MCAS active when it is active, would have been a sensible arrangement.


Actually, not a defence of Boeing, though a window into the possible thought processes. There have always been corner cases of stabiliser runaway on 737s that could not be fixed by simply disconnecting the autopilots or pulling on the yoke. These tend to include electrical shorts and the like. However, these basically never happen in reality. Hence pilots will not always follow to the last step. I also think the wording in the NG's training manuals is pretty crappy as it breaks sections when the actions actually cross sections. What the poor design of the MCAS software did was make the failures where the trim switches and yoke don't fix the problem much more likely. As such I think that even if the MCAS had been called out in the short differences training there is a high probability that this would not have been sufficient. In the case of BM92 the differences training, which did point out the changes, was clearly insufficient to avert the accident.
 
markalot
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 4:31 pm

maint123 wrote:
ABS is antilock braking system.
A defective sensor - suppose the sensor which senses the wheel rotation stops sending feedback, the abs would get disabled and you work the brakes without abs help. you have to pump the brakes not jam them like with a working abs.
Must be a continuous feedback loop between the rotation sensor and the control unit, like motors have between their encoders and drives. Though I have seen a dc motor go to full speed when the encoder coupling - ahem broke - and the motor went to full speed since the encoder stopped giving rpm feedback. Some safeties disabled.


Using your quote here but not the context of the discussion.

ABS failure means ABS does not work, in this case the plane flew itself into the ground, twice. I'd liken it to if ABS fails then you have no brakes unless you find the ABS off switch under the dash (only available on LS and higher models).

In my opinion this technology should NOT be in a plane until it's proven to be as reliable as a human. If I walk up to someone and put my hand over their eyes each of us know we can no longer rely on our eyes because they're covered. Seems simple enough, yet these sensors do not know when they have failed. The primary controls should always react to a pilots input. I have yet to here a convincing argument against this.

It's maddening to think something like this can make it into production. Someday we'll have sensor technology with the smarts to detect failure and at that point then we can discuss how these "safety" features can save lives.

Right now Boeing has a lot more issues than looking like idiots, they look culpable.
M a r k
 
phollingsworth
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 4:38 pm

kalvado wrote:
smittythepirate wrote:
As people have mentioned the FAA should do their job and determine if this has fixed the MAX and whether it should fly again over US soil. Other agencies will follow when their requirements have been fulfilled.

Except that some will not. EASA announced they will be certifying fix independently, and there are indications that may require full certification review.
I fully envision FAA being the only agency permitting MAX revenue service for some time, and I understand FAA will do their best to avoid such scenario.


EASA are not certifying the fix independently, mainly because to do so would require going back to the original certification. What they are doing, and have said they are doing, is that they will fully review the fix and the proposed certification of it and quite possible mandate additional data and actions as part of the validation. This is actually a standard part of the validation process. However, as time has gone on and regulators have become more familiar with the processes at their counterparts they have been less likely to make these requirements.

EASA will not walk away from the validation process as a whole (Note: they cannot pick and choose which manufacturer) because they have too much vested in it already. The only major manufacture who doesn't (or didn't) use the certification-validation route is/was CFMI. The US is so intricately linked into all Western aircraft that all manufactures would be in trouble if they walked away. However, I would expect a lot more reviews of variances and AMOCs in the future.
 
ODwyerPW
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 4:41 pm

scbriml wrote:
GEUltraFan9XGTF wrote:
The "add-on" options were, to my knowledge, a third AOA sensor plus an "AOA disagree" light.


This mythunderstanding is persisting across all three MAX threads. It needs to go away.

There is no option for a third AOA sensor on the MAX. Full stop. Or Period if you're American.


I was one of those. I read it an article and mentioned it here. Indeed, it was false information. A fellow poster corrected me.
learning never stops.
 
phollingsworth
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 4:48 pm

mandala499 wrote:
="phollingsworth"]Unfortunately, unless the cutout part was regularly practiced it might have had no effect. The Lion Air pilots never tried the cutout even though it has been in the FCTM for a number of years.

It would be interesting to see if the pilots involved has gone through the runway stabilizer trim procedure. AFAIK, and from what I am told by trainee NG pilots at Lion Air group, the runaway stabilizer procedure is on their type rating training, and also since beginning of 2018 (yes, 2018, not 2019) on the recurrent training too, because they've had a messy runaway stabilizer incident if I remember correctly in 2017 or 2016.

="phollingsworth"] Note: I don't think having the AoA disagree light on LNI610 would have solved the problem. However, having it for the prior flight might have helped. The reason why is that the prior crews reported IAS disagree, but the MTC logs had AoA disagree, this caused confusion that helped lead to the problem not being properly addressed.

In my opinion, the AOA disagree light would be useless without knowledge of the MCAS, but would be damn useful if pilots knew about it.


Definitely would be interesting to see, especially what is the period of reoccurrence training and what level it goes to. I am concerned that just putting MCAS in the differences doesn't actually fix the underlying problem. I also agree that AOA disagree fairly useless on the flight without MCAS knowledge (though it might hint why the stick shaker was firing), but reporting to MTC that an IAS Disagree flags, but having the computer say AoA Disagree causes unneeded confusion.
 
Heinkel
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 4:53 pm

SheikhDjibouti wrote:
Ok, I'll mention the elephant in the room;
Why would the FAA be the first to lift the grounding order?
Why not EASA? Or any of the other agencies?


Quite simple: Because the FAA was the leading certification agency for the MAX. And for Boeing in general.

They've made the first certification, all others came later and were are based on the FAA certification.

So the FAA has the obligation to redo the certification and they should be the first to lift the ban.
If they don't and cover now, they are simply cowards.

They should do their job properly and the must stand for it. Otherwise, they should close their business and retire.
 
WIederling
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 5:10 pm

majano wrote:
I am not in the aviation industry, but I sincerely doubt that the accounting department could have a major say, let alone decide, on the type rating of the MAX. I know beancounters are an easy target, but in this case we are stretching it somewhat. .


Afaics the "ZERO transition training" was required by PR, marketing and for Randy to boast about.
<prissy voice of R.B.>... again Airbus is just catching up, the MAX transition requires zero transition training, just a short youtube video and you are all set. </prissy voice>
Murphy is an optimist
 
AvFanNJ
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 5:58 pm

phollingsworth wrote:
kalvado wrote:
smittythepirate wrote:
Except that some will not. EASA announced they will be certifying fix independently, and there are indications that may require full certification review.
I fully envision FAA being the only agency permitting MAX revenue service for some time, and I understand FAA will do their best to avoid such scenario.


EASA are not certifying the fix independently, mainly because to do so would require going back to the original certification. What they are doing, and have said they are doing, is that they will fully review the fix and the proposed certification of it and quite possible mandate additional data and actions as part of the validation. This is actually a standard part of the validation process. However, as time has gone on and regulators have become more familiar with the processes at their counterparts they have been less likely to make these requirements.

Thanks for pointing this out. It adds a bit of rationality to yet another thread with posts bordering on hysterical. Claims like EASA will review the aircraft from the bottom up, inferring that it will review unchanged aspects of the basic 737 NG design it signed off on long ago are simply not credible. Some posters seem to think that EASA will require major a physical redesign of the MLG and engine wing placement. NO! These aspects were reviewed and approved when the MAX was first certified by the regulators. What's now in question (aside from separate questions about the FAA's lack of oversight and Boeing's lack of proactivity and candor) is mainly the implementation of the MCAS enhancement and its flawed behavior and reliance on a single AOA vane. That's what the regulators will independently review, along with Boeing's software fix and no doubt, will all eventually recertify the MAX when their questions have been answered and their requirements have been met. No doubt it will take awhile to satisfy all of them but I'm willing to bet they will be and no changes to the basic MAX airframe will be mandated. The opinions of many in here that the MAX is a fundamentally unsound design are irrelevant; the regulators will look at the facts and fixes fairly and rule accordingly.
 
superbizzy73
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:10 pm

Help me out here (and, yes, I'm definitely ready to get flamed in this a.net world)...so, United Airlines has the exact same setup as the MAX's that crashed, and they have 23,000 +/- flight hours with the type...and they didn't crash a one of them (yes, I know they have the -9, and the aircraft that crashed were -8...they all have the same flight system. As far as I can understand, United's MCAS is set up the exact same way, with none of the extras that have been mentioned.) I wonder why United hasn't crashed a MAX? If your going to be a pilot, first and foremost you must be able to fly the aircraft, even if systems go haywire on you, right? And, as a PIC, your situational awareness has to be focused on the overall performance on the aircraft, including emergency procedures, and not letting automation ultimately control the situation, correct? Look, I'm not trying to kick dirt on the graves of those who died, but I seriously think that none of the passengers or crew needed to die. Maybe the MCAS system is flawed, but there is a very distinct procedure to get the aircraft to fly properly if a system seems to not be working right as far as I understand, and it's unfortunately pretty obvious that the procedures were not followed. I'd be interested to see if any United or Southwest or Air Canada or Iceland Air or LOT or American Airlines or Air China or Norwegian Air (or any other MAX customers) pilots had issues with the MCAS at any time, and what their response was if the system did indeed have an issue.
 
ltbewr
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:14 pm

Norwegian has announced today it has suspended some sales of tickets to/from SWF (NY) per reports in SWF (Newburgh, NY) area newspaper due to the 737MAX grounding. https://www.usnews.com/news/best-states ... cket-sales
 
trex8
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:22 pm

superbizzy73 wrote:
Help me out here (and, yes, I'm definitely ready to get flamed in this a.net world)...so, United Airlines has the exact same setup as the MAX's that crashed, and they have 23,000 +/- flight hours with the type...and they didn't crash a one of them (yes, I know they have the -9, and the aircraft that crashed were -8...they all have the same flight system. As far as I can understand, United's MCAS is set up the exact same way, with none of the extras that have been mentioned.) I wonder why United hasn't crashed a MAX? If your going to be a pilot, first and foremost you must be able to fly the aircraft, even if systems go haywire on you, right? And, as a PIC, your situational awareness has to be focused on the overall performance on the aircraft, including emergency procedures, and not letting automation ultimately control the situation, correct? Look, I'm not trying to kick dirt on the graves of those who died, but I seriously think that none of the passengers or crew needed to die. Maybe the MCAS system is flawed, but there is a very distinct procedure to get the aircraft to fly properly if a system seems to not be working right as far as I understand, and it's unfortunately pretty obvious that the procedures were not followed. I'd be interested to see if any United or Southwest or Air Canada or Iceland Air or LOT or American Airlines or Air China or Norwegian Air (or any other MAX customers) pilots had issues with the MCAS at any time, and what their response was if the system did indeed have an issue.

Well we know the LionAr crash had AoA sensor issues. If no UA plane had one maybe none ever had the Mcas kick in.

40 seconds to fix the problem with likely speed, altitude, terrain warnings blaring away? And the Lionair crew had no knowledge of the existence of Mcas. Yes an excellent pilot may well have been able to sort it out (or if you had a 3rd pilot on hand like flight of the Lionair plane the evening before to probably notice that trim wheel turning like crazy and help stop it). But OEMs of mass produced commercial airliners should not be building aircraft which can only be handled by test pilots! My Honda sedan shouldnt need Formula1 skills to drive on a public road.
https://www.nytimes.com/2019/03/25/busi ... error.html
 
ILNFlyer
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:35 pm

This has certainly left both the FAA and Boeing with black eyes, and if guilty, rightly so. I would be interested in knowing how Airbus handles a similar system.
 
superbizzy73
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:42 pm

trex8 wrote:
superbizzy73 wrote:
Help me out here (and, yes, I'm definitely ready to get flamed in this a.net world)...so, United Airlines has the exact same setup as the MAX's that crashed, and they have 23,000 +/- flight hours with the type...and they didn't crash a one of them (yes, I know they have the -9, and the aircraft that crashed were -8...they all have the same flight system. As far as I can understand, United's MCAS is set up the exact same way, with none of the extras that have been mentioned.) I wonder why United hasn't crashed a MAX? If your going to be a pilot, first and foremost you must be able to fly the aircraft, even if systems go haywire on you, right? And, as a PIC, your situational awareness has to be focused on the overall performance on the aircraft, including emergency procedures, and not letting automation ultimately control the situation, correct? Look, I'm not trying to kick dirt on the graves of those who died, but I seriously think that none of the passengers or crew needed to die. Maybe the MCAS system is flawed, but there is a very distinct procedure to get the aircraft to fly properly if a system seems to not be working right as far as I understand, and it's unfortunately pretty obvious that the procedures were not followed. I'd be interested to see if any United or Southwest or Air Canada or Iceland Air or LOT or American Airlines or Air China or Norwegian Air (or any other MAX customers) pilots had issues with the MCAS at any time, and what their response was if the system did indeed have an issue.

Well we know the LionAr crash had AoA sensor issues. If no UA plane had one maybe none ever had the Mcas kick in.

40 seconds to fix the problem with likely speed, altitude, terrain warnings blaring away? And the Lionair crew had no knowledge of the existence of Mcas. Yes an excellent pilot may well have been able to sort it out (or if you had a 3rd pilot on hand like flight of the Lionair plane the evening before to probably notice that trim wheel turning like crazy and help stop it). But OEMs of mass produced commercial airliners should not be building aircraft which can only be handled by test pilots! My Honda sedan shouldnt need Formula1 skills to drive on a public road.
https://www.nytimes.com/2019/03/25/busi ... error.html


Thank you for the reply. I agree with you 100% about the Honda comment. It seems to me that we are unfortunately becoming more and more dependent on technology, and it looks like it's a crutch that won't go away anytime soon. I guess I can say I'm old enough to miss that analog world.
 
rheinwaldner
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:42 pm

Boof02671 wrote:
And yet two of the largest airline WN with 34 and AA with 24 and over 100,000 hours had zero incidents.

100000 hours is like nothing. You loose all credibility if you want to make any conclusions about the safety of an aircraft based on 100k hrs operation.
Many things are difficult, all things are possible!
 
rheinwaldner
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:43 pm

Boof02671 wrote:
You can’t make that claim. Total speculation with no data to back it up.

100k hours is also no relevant data.
Many things are difficult, all things are possible!
 
rheinwaldner
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:47 pm

MSPNWA wrote:
mjoelnir wrote:
No other frame had in the last 30 years this rate of accidents to number of operating frames or operating hours.

False. The A320 had its first, second, and third crashes with fewer frames in service than the MAX did with its second (maybe first).

The difference is that these crashes had unrelated reasons. The MAX could be the first jet airliner ever, that crashed two times due to the same technical reason (as main contributing factor) at all.
Many things are difficult, all things are possible!
 
rheinwaldner
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 6:49 pm

MSPNWA wrote:
Interested wrote:
Can you answer me now as I have no idea on the crashes you refer to?


My point exactly.

Nice try on the red herring to distract from the fact that the A320 had a worse crash/in-service airframe ratio.

That ratio is not relevant. E.g. the grounding of the MAX was done for other reasons (similarity).
Many things are difficult, all things are possible!
 
ClubCX
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 7:23 pm

I can't believe the FAA is talking about letting these planes fly again before we even have a preliminary report from Ethiopia. Zero credibility.
 
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767333ER
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 7:25 pm

superbizzy73 wrote:
trex8 wrote:
superbizzy73 wrote:
Help me out here (and, yes, I'm definitely ready to get flamed in this a.net world)...so, United Airlines has the exact same setup as the MAX's that crashed, and they have 23,000 +/- flight hours with the type...and they didn't crash a one of them (yes, I know they have the -9, and the aircraft that crashed were -8...they all have the same flight system. As far as I can understand, United's MCAS is set up the exact same way, with none of the extras that have been mentioned.) I wonder why United hasn't crashed a MAX? If your going to be a pilot, first and foremost you must be able to fly the aircraft, even if systems go haywire on you, right? And, as a PIC, your situational awareness has to be focused on the overall performance on the aircraft, including emergency procedures, and not letting automation ultimately control the situation, correct? Look, I'm not trying to kick dirt on the graves of those who died, but I seriously think that none of the passengers or crew needed to die. Maybe the MCAS system is flawed, but there is a very distinct procedure to get the aircraft to fly properly if a system seems to not be working right as far as I understand, and it's unfortunately pretty obvious that the procedures were not followed. I'd be interested to see if any United or Southwest or Air Canada or Iceland Air or LOT or American Airlines or Air China or Norwegian Air (or any other MAX customers) pilots had issues with the MCAS at any time, and what their response was if the system did indeed have an issue.

Well we know the LionAr crash had AoA sensor issues. If no UA plane had one maybe none ever had the Mcas kick in.

40 seconds to fix the problem with likely speed, altitude, terrain warnings blaring away? And the Lionair crew had no knowledge of the existence of Mcas. Yes an excellent pilot may well have been able to sort it out (or if you had a 3rd pilot on hand like flight of the Lionair plane the evening before to probably notice that trim wheel turning like crazy and help stop it). But OEMs of mass produced commercial airliners should not be building aircraft which can only be handled by test pilots! My Honda sedan shouldnt need Formula1 skills to drive on a public road.
https://www.nytimes.com/2019/03/25/busi ... error.html


Thank you for the reply. I agree with you 100% about the Honda comment. It seems to me that we are unfortunately becoming more and more dependent on technology, and it looks like it's a crutch that won't go away anytime soon. I guess I can say I'm old enough to miss that analog world.

2 things you’re missing:

First, you’re essentially arguing as many do that rogue MCAS and and should be treated like runaway trim and yet that’s a general assumption that is not true. The MCAS trim can be interrupted and overridden, but as soon as you stop counteracting it, unlike STS, it resumes. Totally different animal than runaway trim. Even if it is to be considered as runaway trim, I don’t myself remember any instance of runaway trim happening that low to the ground. Rogue MCAS is a risk and a factor beyond what a 2 pilot crew should be required to handle. By the time you identify it, shut it off, and crank the trim back you’re probably in bad shape anyway.

Second issue is calling technology a crutch when ironically the 737’s lack of technological advancement causes this problem.
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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zckls04
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Re: B737MAX Grounded Worldwide

Tue Mar 26, 2019 7:55 pm

superbizzy73 wrote:
Help me out here (and, yes, I'm definitely ready to get flamed in this a.net world)...so, United Airlines has the exact same setup as the MAX's that crashed, and they have 23,000 +/- flight hours with the type...and they didn't crash a one of them (yes, I know they have the -9, and the aircraft that crashed were -8...they all have the same flight system. As far as I can understand, United's MCAS is set up the exact same way, with none of the extras that have been mentioned.) I wonder why United hasn't crashed a MAX?


Events don't usually happen in a uniform manner. Once you start talking about an event that happens with a very small probability, as in the case of a plane crash, you simply can't infer that because the event didn't happen in a particular subset of the sample (US flights), it is proof, or even evidence of it being meaningful in some way. That's absolutely statistically invalid. In fact in general, statistics are not that useful for gleaning information about extremely rare events; they only become useful with a large sample size of events.

Now, it may yet transpire that the circumstances of the Lion Air and Ethiopian crashes could not happen in the US, and perhaps further information will come to light that proves that. However looking purely at the statistics, there is no evidence that the MAX crashes were not US airlines is in any way significant. That's simply not what the evidence shows.

Maybe the MCAS system is flawed, but there is a very distinct procedure to get the aircraft to fly properly if a system seems to not be working right as far as I understand, and it's unfortunately pretty obvious that the procedures were not followed.


Indeed. The question is whether that procedure is comprehensive enough, whether it was communicated properly to the pilots, and whether the problem ought to arise in the first place.
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