South Korea formally completes development of indigenous KF-21 fighter jet

South Korea officially concluded the development phase of its first indigenous KF-21 fighter jet, marking the culmination of a decade-long project aimed at modernising its air fleet and bolstering its defence industry.

The milestone was commemorated at the headquarters of sole contractor Korea Aerospace Industries (KAI) in Sacheon, located approximately 300 kilometres south of Seoul, according to the Defense Acquisition Program Administration (DAPA), cited by Korean media.

Launched in 2015, the 8.8 trillion-won ($6.04 billion) project was designed to replace the Republic of Korea Air Force’s ageing fleet of U.S.-manufactured F-4 and F-5 fighter jets.

The initiative achieved major progress following the rollout of the first KF-21 prototype in April 2021. In May of this year, the aircraft successfully passed its final combat suitability evaluation, satisfying all operational and performance requirements. Over the course of testing, officials conducted more than 1,600 flight trials without incident.

Speaking at the ceremony, DAPA Minister Lee Yong-cheol praised the collaborative effort behind the aircraft's development.

"The success of the KF-21 is a splendid accomplishment that was possible due to the blood and sweat of technicians, and also the support of the public, who believed in the power of our technical skills," Lee said. "We will promote the excellence of KF-21 jets and once again demonstrate the nation's strength by achieving self-reliant national defence through technological independence."

Following the completion of the development phase, DAPA announced plans to deliver the first operational KF-21 jet to the Air Force in September.

Wednesday’s ceremony was attended by officials from the state-run Agency for Defense Development, KAI, and defence ministry representatives from Indonesia. Jakarta entered the project as a co-development partner, agreeing to share costs in exchange for technology transfers, a prototype aircraft, and other project deliverables.

Under DAPA’s deployment strategy, an initial batch of 40 KF-21 jets — primarily configured for air-to-air combat missions — will be delivered to the South Korean Air Force by 2028. The procurement plan aims to produce an additional 80 aircraft featuring enhanced multi-role capabilities by 2032, eventually bringing the total fleet size to 120 aircraft.

By Tamilla Hasanova