On 29 October 2018, Lion Air Flight 610 plunged into the Java Sea after a rogue flight control system—MCAS—reacted to a single faulty angle-of-attack sensor and pushed the nose down repeatedly. Four months later, Ethiopian 302 suffered the same fatal sequence. The FAA grounded the global MAX fleet on 13 March 2019, launching a 20-month reckoning that forced the industry to rethink how regulators delegate safety oversight to manufacturers. The crashes claimed 346 lives and rewrote the rules on pilot training, software transparency, and certification rigor.