[DiogenesLamp]

Nope. The extra sensor was part of an options package. When ti should have been standard and required for obvious reasons. And that is just the tip of iceberg on the stupidity Boeing design on that aircraft. I believe that one of the design flaws still exists. The “STAB” switch does not have a position to cancel all computer control and still have Electric control from the yoke.

You sound like you know more about it than I do, so I will bow to your superior knowledge on the matter.

And yes, it is stupid to cut off electronic control from manual adjustment of the trim.

[Revel]

Well I don’t know, I think you were right. There were all kinds of articles at the time talking about the 2nd sensor being optional. Now when I go reading around, it seems that they did have a 2nd sensor but the software was not using it.

It seems they were talking about a 3rd sensor that was an option.

https://arstechnica.com/information-technology/2019/03/boeing-sold-safety-feature-that-could-have-prevented-737-max-crashes-as-an-option/