Someone check my sanity here. From the Seattle Times article:
According to a detailed FAA briefing to legislators, Boeing will change the MCAS software to give the system input from both angle-of-attack sensors.
Good, good.
It will also limit how much MCAS can move the horizontal tail in response to an erroneous signal. And when activated, the system will kick in only for one cycle, rather than multiple times.
First, that sentence doesn't make sense; if a signal is known to be "erroneous", surely MCAS shouldn't act at all?! More significantly, my understanding is that MCAS was given the greater control authority because, when the system with the original intended control authority was tested, it was found to be inadequate and still produced handling characteristics that were
not certifiable; Boeing had to significantly increase MCAS authority (without properly informing the FAA of the design change!) in order to get the high AoA handling certifiable. So how can they now reduce MCAS authority and retain certification?
I'm starting to wonder if Boeing are going to have to change the airframe, not the software, to produce an acceptable solution.