The KAI KF-21 Boramae (formerly known as KF-X), is a fighter aircraft development program between the South Korean and Indonesian air forces with an 80:20 split between Seoul and Jakarta.
The fighter craft derives its name from the historical term describing one-year-old hunting hawks specifically trained for traditional falconry and is projected to form the future backbone of the Republic of Korea Air Force (ROKAF) and the Indonesian air force (TNI-AU).
Touted to be a 4.5-generation fighter, the airframe is reportedly stealthier than any fourth-generation fighter. However, it does not carry any weapons in internal bays like fifth-generation fighters although internal bays could be introduced later in development.
From the vault
First announced in March 2001, the KF-X advanced multi-role jet fighter project was initially intended to replace South Korea’s ageing F-4D/E Phantom II and F-5E/F TIGER II aircraft.
After weathering numerous delays and postponements, on 15 July 2010, a partnership was made with Indonesia, which would provide 20% of the funding for the KF-X project and cooperate with technological development through state-owned Indonesian Aerospace.
In April 2021, the first prototype was completed and unveiled during a rollout ceremony at the headquarters of KAI (Korean Aerospace Industries) in Sacheon.
Tech and specs
The initial goal for the program was to develop a single-seat twin-engine multirole fighter with stealth capabilities exceeding both the Dassault Rafale and Eurofighter Typhoon but less than those of the Lockheed Martin F-35 Lightning II.
Despite its apparent similarities to the F-35, it is not designed to be as low-observable as the F-35 and the overall design architecture features fuselage shaping, canted tails and edge alignment that is touted to reduce radar cross-section (RCS)- which is reported to be down to 1-.1 square meters.
The radar is the culmination of a decade-long effort and a three-year development program by the R&D. It involved operating a test radar from the open rear ramp of a C-130 Hercules, as well as using a South African-registered Boeing 737-55S (ZS-TFJ), which had a KF-21 radome grafted onto its nose.
The fighter bird features an active electronically scanned array radar (AESA), developed in collaboration between Hanwha Systems and Israel’s Elta Systems. Israel’s Elbit Systems is supplying the terrain-following/terrain-avoidance system to Hanwha, who is also developing the nose-mounted infrared search and track sensor based on Leonardo’s SkyWard system.
Powered by two General Electric F414-400K engines, each producing 22,000 pounds of afterburning thrust, they feature axisymmetric nozzles.
In comparison to the later F-35s that feature more stealthy, driverless supersonic inlets, the KF-21 features F-22 style caret inlets with boundary-layer diverters.
KF-21’s integrated electronic warfare suit is being developed by S.Korea’s LIG Nex1, which includes radar jamming, warning and flare systems. Additionally, it is also developing the digital flight computer and the low-profile heads-up display (HUD) building on waveguide-optics technology by BAE.
South Korea is reportedly acquiring air-to-air missiles from European companies MBDA and Diehl BGT for the first batch of KF-21s, which will carry its weapons externally. The Block 2 variant is proposed to carry precision-guided munitions and indigenously developed stand-off cruise missiles.
The KF-21 being the most advanced aircraft program for the country to date has six flight prototypes and two rescue prototypes of the KF-21 is currently used for ground tests-according to an official publication of the South Korean Ministry of National Defense.
Serial production is slated to commence by 2026 while the program aims to deploy 40 and 120 aircraft by 2028 and 2032 respectively.
With 50% of the ground tests completed, the remaining tests are expected to be completed soon and the first flight is tentatively set for July 2022.