Korea's KF-21 Fighter Makes First Successful Supersonic Flight

The Korean Defense Acquisition Program Administration (DAPA) announced on Jan. 17 that the KF-21 Boramae, a Korean-made fighter jet, has successfully completed its first supersonic flight.

According to DAPA, the first KF-21 prototype broke Mach 1.0 for the first time at an altitude of about 40,000 feet over the South Sea at 3:15 p.m. on Jan. 17 after taking off at the Third Training Wing of the Korean Air Force in Sacheon, South Gyeongsang Province at 2:58 p.m.

The KF-21 is a 4.5th-generation high-tech fighter developed by Korea Aerospace Industries (KAI) with funding from Korea and Indonesia. Since its first test flight in July last year, the three prototypes of the fighter jet have made more than 80 flights to date. 

The supersonic flight confirms that the KF-21 has structural stability at supersonic speeds. When an aircraft exceeds Mach 1.0, shock waves are generated in the aircraft such as wings due to air resistance, and the surrounding air flow becomes unstable. This change can have a significant impact on the structural integrity of the aircraft.

In addition, DAPA said the supersonic flight is meaningful in that an aircraft with a unique shape developed with Korea’s own technology has surpassed the speed of sound for the first time. The T-50 Golden Eagle, a Korean supersonic advanced trainer, broke through the speed of sound in 2003. But the T-50 was developed through technical cooperation with the United States. The KF-21’s successful supersonic flight has made Korea one of the few countries with a supersonic aircraft developed with their own technology.

The KF-21 will go through a process of verifying flight stability in the supersonic range while increasing its altitude and speed in the sonic range down the road.