China’s first 3D-printed mini turbojet engine hits Mach 0.75 in tests

China’s state-owned Aero Engine Corporation of China (AECC) has successfully tested its first fully 3D-printed miniature turbojet engine in a solo flight, marking a significant milestone in the country’s independent aviation propulsion development. The ultra-lightweight engine, producing 353 pounds of thrust, powered a target drone to an altitude of 6,000 meters (about 20,000 feet) and reached speeds of Mach 0.75 during a 30-minute flight. The engine operated stably throughout, validating its design, reliability at higher altitudes, and integration with aircraft systems. This test follows an earlier captive-carry flight at 4,000 meters and represents a transition from controlled testing to operational application. The engine’s design leverages a combination of 3D printing and multi-disciplinary topology optimization (TO), a computational method that optimizes material distribution for performance and weight reduction. This approach enables the creation of complex, lightweight structures that traditional manufacturing cannot easily produce. Over three-