Originally Posted by
cooperplace
is there someone with authority and detailed 737 knowledge who can explain to interested but uninformed nitwits like me whether any consensus as to cause of this tragedy is emerging?
I am not your knowledgeable authority figure but I have read the entire thread from the beginning and will be happy to summarize.
Before November 6th there was not much in the way of consensus as to a possible cause. Unreliable Air Speed (UAS) possibly due to the covers being left on the speed sensors was the talk of the day.
On November 6th Boeing issued a statement that changed the focus to the Angle Of Attack (AOA) sensor. Specifically that bad data from an AOA sensor could cause uncommanded nose down trim on the stabilizer (horizontal part of the tail).
Link to November 6th discussion:
Indonesian aircraft missing off Jakarta
At some point Boeing disclosed the existence of a new feature named MCAS that was evidently not previously disclosed to pilots. MCAS is an anti-stall feature that was not required (or implemented) on older versions of the 737. When working properly with good AOA data MCAS trims the stabilizer to lower the plane's nose in an attempt to mitigate a stall. MCAS could have been a lifesaver under different circumstances, however...
MCAS along with faulty AOA data seems to be prevailing theory as to what might have been at least a contributing factor in the crash. The idea being that bad AOA data fed to MCAS caused the plane to be trimmed more and more nose down, ultimately leading to a crash.
Disclaimer: This is my interpretation of the speculation posted here by others. I could easily have goofed something up.