[dotancohen]

The airplane could have a dozen AoA sensors, but if the software is ignoring 11 of them then there is only one actual AoA sensor for purpose of discussion. Even if the sensors are used for other aspects, such as pilot instrumentation.

And yes, I understand perfectly well that this invalidates the idea that the second sensor was "eliminated" to save cost - but if I remember correctly there was a paid option to have the MCAS consider both sensors. So there was a financial aspect to the decision. Someone please correct me if I'm wrong.

[salawat]

Close! AoA disagree hazard light was an optional feature. In the original implementation, the Flight computer in command, either the one on the pilot's side, or the one on the copilot's side (alternated on power up), were fed input from only the AoA sensor they shared a physical link with.

The optional feature was essentially networking the two ststems such that the data would be fed to the FCIC for warning light activation, so that pilot's could start running the right checklists.

[dotancohen]

Thank you.