737 max's crash issues don't come from inherent instability in the design. Rather they come from too much stability. The larger engines shifted the center of gravity forward, which creates a more stable airplane. As an aside, aerodynamic instability is actually beneficial to efficiency in certain regards. This is due to a stable aircraft's tendency to nose down, which requires downward pressure on the tail to keep it level. This downward pressure robs the airplane of some of the lift it generates. On the other hand, an unstable (or rather relaxed stability) airplane has a tendency to nose up, which requires an upward pressure on the tail to correct. This adds lift instead of taking it away. Anyways, 737 max's forward shifted center of gravity caused a change in how the airplane handles. Rather than adjusting the design to compensate or requiring pilot retraining for the new type, Boeing decided to throw in a half baked program that pitched the nose up automatically to make it feel more like the older airplane. The issue came from bad sensors feeding erroneous data to the computers, which started pitching the airplane up automatically. The pilots were uninformed about this new system, and even if they knew it existed they couldn't override it. There's so many layers of incompetence to the 737 max story that it makes me upset, but it wasn't due to an unstable design.