[Buddahaid]

Originally Posted by Catfish

When the Aoa vane or some data transfer on one side was indeed damaged why did the MCAS system take this input for real, when there was the second one working?
The vane or some part of the one Aoa sensor on one side is damaged, the control system gets strange readings and sops, handing control to the pilots - autopilot off - ok.

In the second the autopilot is off, the MCAS system counts to 5 seconds and then 'adjusts' the pitch down because of the one wrong one Aoa reading, but what is with the second one?

That's the part where Boeing offered a reduced price MCAS system that used only one AOA sensor at a time selected by the PIC. The MCAS system that optionally used both AOA sensors and alerted the crew when they didn't agree is what Boeing is now installing at no charge and treating as standard equipment now. The PIC should have recognized the AOA sensor he was using was giving erratic readings and switched to the other sensor.

One might make a similar argument that if you back over a kid on a tricycle in your car, and didn't buy the back up camera with a proximity sensor, that it's the auto manufacturers fault for not making the equipment standard in the first place.