Adjusting the engine's positioning affected the aircraft's center of gravity which, in turn, affected its handling.

In order to make it behave more like the Next-Generation 737s, the manufacturer installed a system, known as Maneuvering Characteristics Augmentation System, or MCAS, to compensate for the nose's tendency to pitch up by pitching the nose down.

MCAS is a quasi-autopilot feature, operating in the background to help the pilot fly the plane when hand flying. The idea was the Max would fly like a 737 NG, and pilots would be able to fly both planes interchangeably with only a supplemental learning course instead of acquiring a new type rating to fly the aircraft that would require a full-fledged training regimen.