No. The original MCAS version also had an accelerometer input, in addition to the AoA input, as the MCAS was only needed when the aircraft went into "ballistic" mode. The AoA option was for a 3rd AoA as all aircraft have 2 as stated above. FYI: the air carriers dictate the market not the other way around. The Airbus A320 NEO was serving that market and the MAX was Boeing's response. As to a "cheaper version," if that was the case then there would only be Airbus aircraft flying as everything built by Airbus is always cheaper dollar wise when compared to like aircraft. They make their money on the support side. Technically yes. However, if it were to say a single AoA vane could lead to a catastrophic failure risk then it would be closer to being correct. To pick up from the answer above and without getting into the complexity of risk analysis, the pilot's interaction to a system failure is one of the first items addressed in determining it's failure risk. There is actually FAA approve guidance on how the aircrew reacts right down to the length of time it takes to react. If I recall during the original risk assessment of the MCAS it was determined the aircrew would react with the 3 second limit, which along with the rest of the original assessment requirements, kept an MCAS failure below the catastrophic risk and the major risk categories. So there's more than a simple "assumption" if the crew can intervene, it's actually part of the certification guidance. Hence the ongoing regulatory review of cockpit data saturation levels and pilot training to see if the 3 second rule and other guidance is still valid. Another cherry-picked item. The forces were calculated back when the manual trim system was certified years ago. There was zero requirement to recalculate for MCAS install. In the Ethiopia case, it's my understanding there are other issues involved outside the MCAS involvement. And if you had to build a web server under an equal level of regulatory oversight it would be interesting to see if that backup would still be there or simply offered as an option especially if your customer picked the price point it would buy at.