KAI KF-21 Boramae

The KAI KF-21 Boramae (Korean: KF-21 보라매, romanized: KF-21 Fighting Hawk; formerly KF-X; commonly KF-21) is a South Korean twin-engine fighter aircraft. The initial goal of the program was to develop an indigenous multirole fighter for the Republic of Korea Air Force (ROKAF). The airframe of Blocks I and II adopts semi-stealth technology with partially embedded external weapons and MUM-T (Manned-Unmanned Teaming) capabilities, while full stealth—including internal weapons bays—is planned for the Block III or KF-21EX variant. As South Korea's second domestic fighter jet development program following the FA-50 series, the KF-21 makes the nation the fourth in the world—joining the United States, China, and Russia—to produce an aircraft featuring stealth avionic architecture.

The Block I program is led by the South Korean government, which holds 60% of the shares. An additional 20% is held by the manufacturer Korea Aerospace Industries (KAI), with Indonesia holding the final 20% stake. Later, in August 2024, Indonesia's stake was reduced to 7.5% due to Indonesian government request. The Block II program, which focuses primarily on the serial integration of air-to-ground and air-to-ship armaments, will be executed solely by South Korea through early 2027. The Block III, or KF-21EX, program will be carried out with newly formed international partners.

In April 2021, the first prototype was completed and unveiled during a rollout ceremony at the headquarters of KAI at Sacheon Airport. It was named the Boramae. The first test flight was on 19 July 2022. The serial production started in July 2024. 40 Block I units are scheduled for delivery beginning in September 2026; the ROKAF expects to complete additional 80 Block II units deployment by 2032. It will also be available for export. The ROKAF will initially begin replacing its F-4D/E Phantom II and F-5E/F Tiger II jets with KF-21s, which will eventually also replace the aging KF-16s and F-15Ks in service.