I think there is a certain amount of hindsight in your response to scenario 1. While there is a good case to be made that Boeing was wrong to minimize the diffe

I think there is a certain amount of hindsight in your response to scenario 1. While there is a good case to be made that Boeing was wrong to minimize the differences between the latest models and their predecessors, the Lion Air crash investigation did not produce any evidence that an MCAS fault could not be remedied by following the published procedure, and as far as I can tell, no other incidents prior to the Ethiopian Airlines crash have suggested that that, either. Up until possibly this crash, there has been no evidence that an MCAS fault presents any more risk, with a properly informed pilot at the controls, than would a trim runaway in the prior models. That is considered to be an acceptable risk, and the issue with properly informing pilots seemed to have been addressed. They should have reacted faster after the latest crash, but fortunately this delay has had no consequences. One would hope that the question of MCAS not being triply redundant will be reassessed, but the argument that it could do no more harm than a fault in the existing trim mechanism is not an unreasonable one, again if considered without hindsight.