South Korean multirole fighter, developed in the 21st century, deployment and operational history yet to be written.
| Length | 16.8 m (55.1 ft) |
| Wingspan | 11.2 m (36.7 ft) |
| Height | 4.8 m (15.7 ft) |
| Wing area | 46 m² (495.1 sqft) |
| Empty weight | 11,793 kg (25,999 lbs) |
| Max. takeoff weight | 25,401 kg (56,000 lbs) |
| Powerplant | 2 × turbofans Hanwha F414-KI 9,983 kgf each |
| Ejection seat | Martin-Baker Mk 18 |
| Maximum speed | 2200 km/h (Mach 2.2) |
| Operational range | 1,000 km (621 mi) |
| Service ceiling | 16,764 m (55,000 ft) |
The KAI KF-21 Boramae is a South Korean-led fighter aircraft development program initiated to provide multirole fighters for the Republic of Korea Air Force to replace its aging F-4D/E Phantom II and F-5E/F Tiger II aircraft. Announced in March 2001, the project experienced delays before renewed interest following a 2008 feasibility study led to its progression, driven by the perceived national importance of developing the domestic defense industry. Indonesia joined the program in July 2010, agreeing to provide 20% of the project's funding and cooperate in technological development. While an early program goal included stealth capabilities exceeding certain 4th generation fighters, the project was later focused on developing a 4.5 generation fighter with limited stealth capabilities. The first prototype was completed and unveiled in April 2021 and named the Boramae. The maiden test flight occurred on 19 July 2022, with manufacturing scheduled to commence in 2026.
The KAI KF-21 Boramae is designed as a twin-engine multirole fighter incorporating design features intended to reduce radar cross-section, characteristic of 4.5 generation aircraft. The airframe incorporates modern aerodynamics and avionics, including an active electronically scanned array (AESA) radar developed domestically. Additional integrated systems include an electro-optical targeting pod (EO TGP), an infra-red search and track (IRST) system, and an electronic warfare (EW) suite. Construction involves both domestic and foreign-sourced components. The aircraft is powered by two General Electric F414 engines, manufactured under license by Hanwha Aerospace. Transparency components, including the canopy and windshield, are provided by Texstars and designed for birdstrike resistance. The KF-21 is equipped with ten external hardpoints, six under the wings and four under the fuselage, with an external payload capacity of 7,700 kg (17,000 lb), in addition to an internal fuel capacity of 6,000 kg (13,227 lb). Early airframe versions, such as Block I and Block II, will carry weapons externally. The aircraft is designed to carry a range of air-to-air munitions including MBDA Meteor, Diehl IRIS-T, AIM-120 AMRAAM, AIM-9X Sidewinder, and ASRAAM missiles, with plans to integrate a Korean short-range air-to-air missile (SRAAM-II). For air-to-surface missions, planned armaments include AGM-65 Maverick, Taurus KEPD 350, a Korean Air-Launched Cruise Missile (KALCM) designated Cheonryong, a Korean Anti-Radar Missile (K-ARM), MBDA Brimstone, and SPEAR 3 missiles. The aircraft also supports precision-guided munitions such as JDAM, GBU-54/56 LJDAM, GBU-12 LGB, KGGB, KGGB 2, CBU-105 WCMD, GBU-39 SDB, and cluster bombs CBU-87 CEM and CBU-97 SFW. Close-range firepower is provided by a 20 mm M61A2 Vulcan rotary autocannon with a capacity of 480 rounds.
Initial operational deployment with the Republic of Korea Air Force is scheduled for late 2026. The plan includes the delivery of at least 40 aircraft by 2028, with a total of 120 aircraft expected by 2032. The initial Block I version is designed with a primary focus on air-superiority missions, including limited air-to-ground capabilities. Subsequent development towards the Block II standard will expand the aircraft's capabilities into a swing-role fighter configuration with enhanced attack and reconnaissance functionalities, incorporating further armament integration. The aircraft is intended for export, with several countries expressing interest.
Main Variants:
KF-21 Block I: This initial version focuses on air-superiority capabilities, with some air-to-ground functionality.
KF-21 Block II: This advanced variant evolves into a swing-role fighter, incorporating attack and reconnaissance capabilities, and Block I aircraft can be upgraded to this standard via software updates.
KF-21N: This is a carrier-based version with 20% larger folding wings designed for increased margin during take-offs/landings and more compact storage.
KF-21EA: This is an electronic warfare aircraft comparable to the EA-18G Growler, based on the two-seat KF-21B airframe, incorporating provisions for an electronic warfare officer station in the rear cockpit.
KF-21EX: This is a planned future variant projected to feature a reduced radar cross-section for increased stealth, internal weapons carriage, and integration with the Next Air Combat System (NACS).
South Korea's Defense Acquisition Program Administration declared the KF-21 Boramae fighter program complete at a ceremony in Sacheon on July 29, 2026, ten years and seven months after system development began, with the first production aircraft due in September.
