OK, The $64Bn Question - 737 MAX. Root cause?

[meleagertoo]

We all know - or think we know most of the whys, wherefores, ifs and maybes of MCAS.
But as far as I know it wasn't actually MCAS that initiated these accidents.
What was it that tripped MCAS into action, because surely that is the root of the events?
Was it a common event between Indonesia and Ethiopia, or did they somehow manage to trigger MCASinto a similar response in different ways?
To date the lack of discussion on this apparently fundamental subject appears to be deafening.

[tdracer]

Indonesia was due to the installation of a defective AOA sensor - plus apparently poor maintenance that didn't do a proper functional test after the AOA sensor replacement (not to mention dispatching the aircraft after the previous flight had reported the problem without corrective action). Lots of blame to go around but that doesn't excuse the lousy design by Boeing.
Ethiopia was reportedly due to a birdstrike which corrupted the AOA sensor.

[DaveReidUK]

Might be worth a read of what's been posted previously. Plenty of explanation of the sequence of events there.

[keesje]

"OK, The $64Bn Question - 737 MAX. Root cause?"

The Aircraft Certification Process Review and Reform ARC - FAA of 2012.https://www.faa.gov/regulations_policies/rulemaking/committees/documents/media/acprrarc-4202012.pdf

Pushed by the 787 development & certification drama's, the A320NEO sales boom, Industry & Congress closely worked together to Streamline aircraft certification processes, delegate responsibilities to OE's, to improve competitiveness of the US Aerospace Industry.

Congress and Industry representations made sure in the years after set Congressional directives & KPI's were met using FAA budget Reauthorizations.

2016 “Aviation manufacturing is our nation’s top export and general aviation alone contributes approximately $80 billion and 400,000 jobs to our economy,” said U.S. Transportation Secretary Anthony Foxx. “The FAA’s rule replaces prescriptive design requirements with performance-based standards, which will reduce costs and leverage innovation without sacrificing safety.” https://www.faa.gov/newsroom/faa-issues-final-rule-small-airplane-safety-certification-standards

A root cause everybody has been trying hard to ignore / forget. Because most key actors are still around.

It allowed short cuts & aggressive grandfathering of design and requirements for the 737MAX (& 777x) 2012-2018. Saving costs & time.

During 2012 - 2018, "Efficiency goals" beat "maintaining the highest level of safety".​

Bureaucratic, slow FAA didn't stand a chance against Industry (Booming Boeing) + Congress + Public opinion.
​​​​​​

[keesje]

Hmm, it seems this isn't over yet...

Passengers in fatal Boeing 737 MAX crashes are ‘crime victims,’ US judge says

A US judge in Texas ruled on Friday that people killed in two Boeing (BA) (https://money.cnn.com/quote/quote.html?symb=BA&source=story_quote_link) 737 MAX crashes are legally considered “crime victims,” a designation that will determine what remedies should be imposed.

In December, some crash victims’ relatives said the US Justice Department violated their legal rights when it struck a January 2021 deferred prosecution agreement with the planemaker over two crashes that killed 346 people (https://www.cnn.com/2019/03/10/africa/ethiopian-airlines-crash-boeing-max-8-intl/index.html).

The families argued the government “lied and violated their rights through a secret process” and asked US District Judge Reed O’Connor (https://www.txnd.uscourts.gov/judge/district-judge-reed-oconnor) to rescind Boeing’s immunity from criminal prosecution – which was part of the $2.5 billion agreement – and order the planemaker publicly arraigned on felony charges.

https://edition.cnn.com/2022/10/22/business/boeing-737-max-crime-victims/index.html

[DaveReidUK]

Already being discussed in the R&N thread.

[Bergerie1]

And neither should it be. To design such a powerful control system using only one source of AoA information at a time, and with no comparitor warning, and with no training or information in the manuals seems to me to be a negligent way of working. Nothing wrong with the MCAS as such, similar systems hsve been used elsewhere.