Boeing have grounded the MAX reluctantly,acting under "extreme caution".FCENG84 has outlined very succintly why MCAS is there and why stick input cant inhibit it.I dont think they're going to install a third AoA and they wont be fitting a stick shaker
inhibit switch on the column.What if 2 faulty AoA indicators rule out the 3rd good one?
I think they will stick with two and have them activate MCAS only when they both agree.If they disagree MCAS wont activate which will make unwanted MCAS activation
far more unlikely.
In these accidents,the crew were facing unreliable airspeed and a flight control problem(perceived though it may be) simultaneously compounded of course by the cacophony of the stick shaker.Thats cognitive overload for some crews,especially if unfamiliar with MCAS in the first place(Lionair).
But we know that some crews can handle this,even without MCAS knowledge.Call it airmanship.
If the AoA fix is done then IMO they have to supplement it with some additional precautions;
-------->No Captain can go direct to MAX without significant classic/NG time as Captain
-------->this 100 hour limitation in some companies where a Captain is deemed "experienced" and can fly with a new co-pilot out of flight school....this has to be looked at again.
-------->MAX simulators have to represent the MAX faithfully.....100%.....an MCAS event(unwanted and genuine) must be programmable
-------->new MAX pilots have to have these scenarios demonstrated and they have to perform them....every 6 months
Of course it might help if the Captains were not 28 years old but thats another topic...for another day.