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-   -   B737MAX Recertification - Archive (https://www.flyertalk.com/forum/united-airlines-mileageplus/2031779-b737max-recertification-archive.html)

LarryJ Apr 8, 2019 9:59 pm

I don't see the point in dividing the blame.

There is a failure of design which allowed the problem to occur. No doubt about that. It's quite clear that the MCAS logic should not have relied on a single data input without cross-checking for disagreement.

Once the failure occurs, us pilots have to deal with it and land the airplane safely.

These are two separate issues. They are both separately and independently at fault.

BF263533 Apr 8, 2019 11:13 pm

"Boeing’s 737 Max: 1960s Design, 1990s Computing Power and Paper Manuals"
 
“We all rolled our eyes. The idea that, ‘Here we go. The 737 again, ' " said Mr. Ludtke, the former 737 Max cockpit designer who spent 19 years at Boeing.

"Nobody was quite perhaps willing to say it was unsafe, but we really felt like the limits were being bumped up against," he added.

https://www.nytimes.com/2019/04/08/b...-737-max-.html

worldclubber Apr 8, 2019 11:51 pm


Originally Posted by LarryJ (Post 30980437)
I don't see the point in dividing the blame.

There is a failure of design which allowed the problem to occur. No doubt about that. It's quite clear that the MCAS logic should not have relied on a single data input without cross-checking for disagreement.

Once the failure occurs, us pilots have to deal with it and land the airplane safely.

These are two separate issues. They are both separately and independently at fault.

I agree with most of what you said. But it is, of course, also part of the responsibilities of the manufacturer to anticipate failures and give the pilots the tools to deal with them and suggest a solution that is as easy and safe as possible.

ExplorerWannabe Apr 9, 2019 7:34 am


Originally Posted by worldclubber (Post 30980597)
But it is, of course, also part of the responsibilities of the manufacturer to anticipate failures and give the pilots the tools to deal with them and suggest a solution that is as easy and safe as possible.

Anticipate common failures yes but they can't anticipate everything or you end up with checklists that look like a 1970s-era Encyclopedia Britannica and are impossible to use. Should automakers have to build a car that is able to stop from 50-70 mph in 5 feet because some drivers don't pay attention to the traffic in front of them? Why did the pilots let trim get so out of control before turning off the electrics? Would a different captain and FO have made a difference in that situation by not even letting it develop to the point it did? Why was the plane pitching downward in the first place?

When the investigation completes -- despite the interests of Ethiopia in protecting ET and its national pride, despite the US interests in not smearing Boeing, despite a LOT of other agendas -- the professionals will hopefully have data and provide information on both the primary causative factors and any secondary and tertiary contributing factors. In the meantime, the plane is grounded and Boeing is trying to remove unnecessary stress from the cockpit.

DenverBrian Apr 9, 2019 7:45 am


Originally Posted by ExplorerWannabe (Post 30981469)
Should automakers have to build a car that is able to stop from 50-70 mph in 5 feet because some drivers don't pay attention to the traffic in front of them?

No, for two main reasons: 1) Because 50-0 in five feet is way too much G force on the occupants of the car; and 2) because cars don't kill 150-450 people at a time, after first terrorizing them for 30 seconds or more. @:-)

(The attempts to analogize to cars are extremely weak tea.)

What aircraft makers should do is design and build passenger jets that fly as safely and easily as possible. We shouldn't be putting fighter jet-style computer systems on an unstable passenger jet just to make it flyable.

worldclubber Apr 9, 2019 8:24 am


Originally Posted by DenverBrian (Post 30981496)
What aircraft makers should do is design and build passenger jets that fly as safely and easily as possible.

And if they decide to put in a system that has the capability to pitch the nose down and fly the plane into the ground, they should make it double/triple safe. There are EGPWS systems and the like to alert the pilots, but the system can cause a CFIT without any issues?

PS: Congrats DenverBrian on your 20,000 posts.

DenverBrian Apr 9, 2019 9:11 am


Originally Posted by worldclubber (Post 30981614)
And if they decide to put in a system that has the capability to pitch the nose down and fly the plane into the ground, they should make it double/triple safe. There are EGPWS systems and the like to alert the pilots, but the system can cause a CFIT without any issues?

PS: Congrats DenverBrian on your 20,000 posts.

I didn't even notice! Thanks!

fly18725 Apr 9, 2019 9:37 am


Originally Posted by DenverBrian (Post 30981496)
What aircraft makers should do is design and build passenger jets that fly as safely and easily as possible. We shouldn't be putting fighter jet-style computer systems on an unstable passenger jet just to make it flyable.

Good news. Both Airbus and Boeing are doing what you suggest.

DenverBrian Apr 9, 2019 10:01 am


Originally Posted by fly18725 (Post 30981876)


Good news. Both Airbus and Boeing are doing what you suggest.

350 dead passengers might disagree with you. But they're unable to. Because they're dead.

BF263533 Apr 9, 2019 11:02 am


Originally Posted by DenverBrian (Post 30981496)
......What aircraft makers should do is design and build passenger jets that fly as safely and easily as possible. We shouldn't be putting fighter jet-style computer systems on an unstable passenger jet just to make it flyable.


Originally Posted by fly18725 (Post 30981876)
Good news. Both Airbus and Boeing are doing what you suggest.


The New York Times Article referenced above states: "Boeing’s 737 Max: 1960s Design, 1990s Computing Power and Paper Manuals." So even if MCAS is a jet-style computer system then it is working with the MAX's 1990s overall computing power, if the New York times article is correct..

Boeing says :" less...stability [for] fuel efficiency. "

https://www.boeing.com/commercial/ae...y/fo01txt.html

"2 Flight Control Computers and Stability Augmentation
The trend in the design of modern airplanes is to have less static longitudinal stability--frequently referred to as relaxed static stability (RSS)--to capture the benefit of improved fuel efficiency. Simply stated, some airplanes are now designed to be aerodynamically efficient, and stability is augmented electronically so that stick force gradients will meet certification requirements. Many methods exist for augmenting stability. For example, the Boeing 777 and MD-11 use flight control computers that adjust the elevator actuator positions to give the appearance of more longitudinal stability than the airplane actually has. In other words, computers absorb the extra workload caused by flying with RSS."

I saw an article that stated Airbus agrees with this concept.

MAX apparently maximizes the The trend in the design of modern airplanes is to have less static longitudinal stability.

TravellingMan Apr 9, 2019 11:14 am

Wonder how long the current Boeing CEO is going to last? I feel he is probably going to be canned before end of Q2 2019 as the "quick fix" to the MAX does not seem to be "quick". Based on airlines planning their schedule, I think it could be Q4 2019 before they are back in the air again or maybe Q1 2020.

Where is the 777X in the approval process? Have they started?


Originally Posted by username (Post 30976156)
Article in USA Today - probably not very informative [for us] but it is bringing up more doubts and questions to the general public: https://www.usatoday.com/story/news/...em/3378703002/

This could delay the re-introduction of the MAX, probably delay future model launches as blogs and papers are going to make an issue of the approval process for public consumption (high potential for scare)

JimInOhio Apr 9, 2019 9:36 pm


Originally Posted by TravellingMan (Post 30982246)
Wonder how long the current Boeing CEO is going to last? I feel he is probably going to be canned before end of Q2 2019 as the "quick fix" to the MAX does not seem to be "quick". Based on airlines planning their schedule, I think it could be Q4 2019 before they are back in the air again or maybe Q1 2020.

Where is the 777X in the approval process? Have they started?



This could delay the re-introduction of the MAX, probably delay future model launches as blogs and papers are going to make an issue of the approval process for public consumption (high potential for scare)

I have doubts we'll ever see the MAX10.

BF263533 Apr 9, 2019 11:01 pm


Originally Posted by JimInOhio (Post 30983980)
I have doubts we'll ever see the MAX10.

The first MAX -10 fuselage, l/n 7644, arrived at Renton in early April 2019. http://www.b737.org.uk/737max10.htm

Regarding the 777x there are a few news stories out there that the 737 MAX design decision process raises questions about the 777x.
"Given the questions raised by Boeing's design decisions on its 737 Max aircraft, will the folding wing tips on its new 777-X line of planes be safe?"

https://interestingengineering.com/t...-are-they-safe

Top stories
Boeing shareholders file class-action lawsuit over 737 Max plane crashes
NBC News·4 hours ago

Airlines have completely stopped ordering the 737 Max
CNN.com·12 hours ago

nnn Apr 11, 2019 11:01 am


None of those changes to the anti-stall system, known as MCAS, were fully examined by the Federal Aviation Administration.

Although officials were aware of the changes, the modifications didn’t require a new safety review, according to three people with knowledge of the process. It wasn’t necessary under F.A.A. rules since the changes didn’t affect what the agency considers an especially critical or risky phase of flight.
If even the FAA didn't think through MCAS long enough to realize that it could theoretically activate near the ground based on a single erroneous sensor reading, it seems like balls were dropped all over.

https://www.nytimes.com/2019/04/11/b...-faa-mcas.html

spin88 Apr 11, 2019 12:55 pm


Originally Posted by JimInOhio (Post 30983980)
I have doubts we'll ever see the MAX10.

I have the same doubts. The MAX10 pushes the airframe even further, more weight, longer, and a new telescoping landing gear. Lots that can go wrong. And given that Boeing is already pushing safety with the landing gear and landing speeds on the MAX9, can you imagine what will happen the first time a MAX10 goes off the runway or has a tire issue? And what if they have issues with the new landing grear?

Sorry, Boeing, the 737 is not, and will never be, a 757.


Originally Posted by BF263533 (Post 30984117)
The first MAX -10 fuselage, l/n 7644, arrived at Renton in early April 2019. 737 MAX-10

Regarding the 777x there are a few news stories out there that the 737 MAX design decision process raises questions about the 777x.
"Given the questions raised by Boeing's design decisions on its 737 Max aircraft, will the folding wing tips on its new 777-X line of planes be safe?"

https://interestingengineering.com/t...-are-they-safe

My guess is (a) airlines have to be thinking carefully about the MAX10, and (b) the FAA is unlikely to roll-over on certification like they did with the MAX8/9. This said, I think airlines would need to bail, until they do, it is full speed ahead for Boeing. Giving up on the MAX10 would be basically handing orders to Airbus for the A321neo.


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