Watch: Korea’s 4th-gen fighter reaches 40,000 feet and speeds Mach 1
SEOUL, SOUTH KOREA — South Korea’s national fighter jet KF-21 Boramae has successfully completed its first supersonic flight. The supersonic flight took place approximately 6 months after the first flight.
- Bad weather and snowfall stopped F-22s from flying over Korea
- Poland announced its intentions to participate in the KF-21 project
- Top 5 best fifth generation fighter jets in the World
The South Korean-developed KF-21 fighter jet flies at supersonic speed for the first time. This made South Korea one of the few countries to develop and operate supersonic fighter jets with national resources.
The KF-21 that made the supersonic speed test was able to reach supersonic speed without an afterburner thanks to its supercruise function. Thanks to the Supercruise function, fighter jets can reach supersonic speeds with low fuel consumption.
According to the Defense Acquisition Program Administration [DAPA] statement. The first prototype of the KF-21 Boramae fighter jet took off on Tuesday for its first supersonic test flight from Sacheon Air Force Base, South Korea’s Gyeongsang Province. During the flight, which lasted about 1 hour, the KF-21 exceeded a speed of Mach 1 at 40,000 feet and reached supersonic speed.

Emphasizing the importance of achieving supersonic capabilities in the development of the KF-21, DAPA said: “When an aircraft exceeds the speed of sound, shock waves occur in the aircraft due to air friction and other accompanying events. Uneven airflow around the aircraft has a significant adverse effect on the structural strength of the aircraft. But the KF-21 successfully managed to stay on top of the sound. This is a first for South Korea’s own aircraft.”
Test process
South Korea will conduct approximately 2,200 test flights of six KF-21 fighter prototypes by 2026. South Korea has so far successfully conducted test flights of KF-21 prototypes 1, 2, and 3. The KF-21 Boramae made its maiden flight in July 2022.
South Korean Defense Minister Lee Yong-sup said: “The success of the supersonic flight allowed our military to further solidify the foundation for building a strong military based on advanced science and technology.”

The country plans to conduct more intensive supersonic test flights, flying the KF-21 at higher altitudes and at higher speeds to thoroughly study and verify flight stability at supersonic speeds. It is intended to reflect the results of test flights for research and development of the KF-21 fighter.
KF-21 Boramae fighter program
The KF-21 program, called KF-X, is known as the largest defense project ever undertaken by the South Korean government. 8.8 trillion won [$7.1 billion] has been allocated for the development costs of the 4.5-generation KF-21 Boramae, which has very low visibility compared to a fourth-generation fighter, which Indonesia has also committed to contribute 20 percent.
The project consists of two phases over 13 years from 2015 to 2028. The first phase focuses on the development of the aircraft and the development of air-to-air combat capabilities between 2015 and 2026. The air-to-ground capabilities to conduct air-to-ground operations will be developed in the second phase, which will take place between 2026 and 2028.
Korea Aerospace Industries [KAI] aims to deliver 120 KF-21 Boramae fighters to the South Korean Air Force by 2032.
***
Follow us everywhere and at any time. BulgarianMilitary.com has responsive design and you can open the page from any computer, mobile devices or web browsers. For more up-to-date news, follow our Google News, YouTube, Reddit, LinkedIn, Twitter and Facebook pages. Subscribe to our Newsletter and read our stories in News360App in AppStore or GooglePlay or in FeedlyApp in AppStore or GooglePlay. Our standards: Manifesto & ethical princliples.