Boeing 737 MAX MCAS System

Boeing's Maneuvering Characteristics Augmentation System (MCAS) on the 737 MAX — designed to compensate for engine placement that made the plane prone to stalling — caused two crashes (Lion Air 610 and Ethiopian Airlines 302) that killed 346 people. Investigations revealed Boeing concealed MCAS from pilots and regulators to avoid costly retraining requirements. The 737 MAX was grounded worldwide for 20 months. It remains the most devastating example of prioritising profit over safety in modern aviation.