> There's no fundamental design flaw, the aircraft is sound.

From what I have read, the new aircraft design had a habit of raising it's nose when engine power was applied, which put the plane into a situation where it might stall.

The MCAS was added to automatically detect this behaviour and stop the nose lifting.

So basically, without the MCAS, under certain scenarios the plane had a tendency to want to stall.

That does suggest the aerodynamic design of the plane is less than ideal and this could even be considered a design fault.