There was no redundancy on the sensors,
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There’s two AOA sensors on the plane, but only one at a time is read by the MCAS. If both were hooked up, how would the MCAS determine which is correct? Boeing and airlines rely on competent pilots to handle the problem.
The Airbus 321 has three AOA sensors. The computers vote for which is correct if there are different readings. They still get it wrong sometimes.
I understand your comment. The enhanced Boeing system supposedly had some sensor validation, or at least a disagreement warning light. In any event, the rumor (and of course I don’t know if it is true) is that the enhanced system was helpful but optional.