I saw a documentary about the the new 737s that crashed.
the story is they put new designed engines on the wing but they had to be moved slightly forward to fit.
this in turn destabalysed the weight of the plane and made the nose heavy.
so they installed a yokey bob in the cockpit that constantly works to keep the nose level.
but Boeing did'nt bother to tell anybody outside the factory about it.
was'nt in any of the manuals and no pilots knew about it.
sure the planes fly themselves these days.
you turn it off and the plane nose dives straight down out of the sky.
They installed only ONE AoA sensor to compensate for the fuselage imbalance..
Two would have helped, but weight is everything.
As someone commented here, most aircraft are unflyable without computer management.
As they are are aerodynamically unstable.
Older aircraft were based on gliders, but everyone wants cheap flights...so!!