South Korea's homegrown supersonic fighter KF-21 "Boramae," whose first mass-production unit was recently unveiled, is drawing attention after receiving high marks from a foreign military publication. The jet has been named among aircraft capable of competing for global air superiority alongside fifth-generation stealth fighters such as the U.S. F-35, China's J-20 and Russia's Su-57. While the KF-21 is not a full stealth fighter, it was recognized as a 4.5-generation-plus platform with room to evolve further.
Army Recognition, a U.S. military publication, analyzed the major fighters competing for air dominance, citing the U.S. F-35 "Lightning II" and F-22 "Raptor," China's J-20 "Weilong," and Russia's Su-57 (NATO codename "Felon") as representative fifth-generation stealth fighters.
The outlet also listed aircraft currently under development or classified as future-generation platforms as contenders in the global air superiority race, including Turkey's KAAN, South Korea's KF-21 Boramae, the U.S. next-generation F-47 Next Generation Air Dominance (NGAD) fighter, Europe's Future Combat Air System (FCAS), and the sixth-generation "Tempest" being jointly developed by the United Kingdom and Italy.
In particular, the publication noted that while the KF-21 is not yet a full stealth fighter on par with the F-35, attention should be paid to its low-observable design, active electronically scanned array (AESA) radar and modern datalinks. It suggested that with future upgrades including internal weapons bays and enhanced stealth performance, the aircraft could evolve to a higher tier.
The KF-21's inclusion in the global fighter competition stems from the fact that the publication's criteria were not limited to "full stealth capability."
Modern air combat requires not only low observability but also sensor fusion, long-range detection, real-time data sharing and network-centric warfare capabilities. The KF-21 already incorporates some of these features, and with phased upgrades to the rest, it is likely to reach a comparable tier.
Above all, the analysis appears to view the KF-21 as delivering modern combat capabilities at relatively low cost while possessing unlimited upgrade potential.
The KF-21's greatest strength lies in its airframe, which is shaped to reduce radar reflection. Its resemblance to the U.S. F-22 "Raptor," currently the world's most advanced stealth fighter, has earned it the nickname "Baby Raptor." Combined with its low-observable design and AESA radar, the aircraft's strong performance places it in the 4.5-generation category.
Although it is not a full stealth platform like the F-35, its advanced capabilities at lower price and operating costs make it a realistic option for countries that cannot afford full stealth fighters. With superior detection, engagement and information-sharing capabilities compared with existing fourth-generation jets, as well as high scalability for future upgrades and weapons integration, it offers the advantage of being a high-performance platform suitable for mass deployment.
What draws the most interest is that the KF-21 is still evolving. The South Korean Air Force is set to field the Block-I variant, focused on air-to-air missions. The Block-II will add air-to-ground capabilities. Integration of precision-guided munitions and long-range air-to-ground missiles will significantly expand its mission range.
"The KF-21 is a cutting-edge platform capable of evolving to the next stage, and South Korea has reached a technological level where it can mass-produce its own fighter and build on it with enhanced stealth variants and unmanned aircraft integration," Army Recognition said. "In particular, the KF-21EX is evolving to meet the strategic needs of the South Korean Air Force with enhanced stealth performance and the internal carriage of bunker-buster-class weapons, making it a strong option in the next-generation fighter market."
The high marks given to the KF-21 Boramae largely reflect expectations for its final upgraded version, the "KF-21EX." Most notably, the addition of internal weapons bays will elevate stealth performance to full fifth-generation fighter level.
Official renderings released by Korea Aerospace Industries (KAI) show the KF-21EX equipped with internal weapons bays on both sides of the lower fuselage, carrying guided bombs in the 2,000-pound (about 907-kilogram) class. The internal bay system minimizes radar cross-section, allowing the aircraft to leap forward as a stealth platform capable of high-intensity strategic strikes.
The jet is also expected to evolve toward sixth-generation fighter status by combining sensor fusion, AI-based combat support and manned-unmanned teaming (MUM-T). KAI has already presented a concept for the "CCAA," a collaborative combat unmanned aircraft (Loyal Wingman) designed to operate alongside the fighter. The Loyal Wingman, flying ahead of the manned aircraft and bearing all risks, will be tasked with reconnaissance, jamming and strike missions.
Analysts say the combat effectiveness of the KF-21 paired with unmanned platforms could be dozens of times greater than that of a standalone aircraft. This presence is why the KF-21 Boramae is included among candidates competing for global air superiority.
The KF-21 is larger than the U.S. F-16 or F-35 stealth fighter but smaller than the F-15 and F-22. It measures 16.9 meters in length, 4.7 meters in height and 11.2 meters in wingspan. Its maximum payload is 7,700 kilograms, maximum speed is Mach 1.81 (2,200 kilometers per hour) and maximum range reaches 2,900 kilometers.
