The AoA Disagree Alert was "standard", the indicator was always (stupidly!) extra, and the Alert in fact (accidentally) was only active with the indicator add-o

The AoA Disagree Alert was "standard", the indicator was always (stupidly!) extra, and the Alert in fact (accidentally) was only active with the indicator add-on. https://boeing.mediaroom.com/news-releases-statements?item=130431 https://boeing.mediaroom.com/news-releases-statements?item=1... Both planes that crashed didn't have the optional add-on, so ended up not having the Alert either. https://arstechnica.com/information-technology/2019/03/boeing-sold-safety-feature-that-could-have-prevented-737-max-crashes-as-an-option/ https://arstechnica.com/information-technology/2019/03/boein...