The KF-21 Has Very High Hopes

Asia’s newest fixed wing combat aircraft enjoyed a lot of hype in April when no less than President Moon Jae-In attended its official launch. The KF-21 Doramae is a twin engine “4.5 generation” multirole fighter that was hailed as a triumph of South Korean technology–the initial press coverage emphasized how its development was a departure from reliance on US-made combat aircraft. The ROK Air Force (ROKAF) in its current structure is a formidable mix of Cold War vintage fighters. Older F-4J’s an F-5E’s are still in service alongside the combat proven KF-16 and F-15K. With the KF-21, however, Seoul is determined to beat the naysayers and shift its military strength to complete and total self-reliance.

But indigenous aircraft are always a challenge to manufacture regardless of the budget and expertise poured into them. The KF-21 had a difficult upbringing that began in 2000 when the Defense Acquisition Program Agency (DAPA) was tasked with conceptualizing a modern fighter jet to advance the state of national aerospace. Of course, Korea Aerospace Industries (KAI) was the natural choice as the main contractor. At the time KAI established its reputation with a propeller-driven trainer and a jet trainer called the T-50 Golden Eagle. But the aspirational fighter jet program languished for years until 2009-2010 when DAPA found a willing investor to underwrite as much as 20% of the costs involved. It turned out Indonesia was eager to contribute funding since the program, which was named “KF-X,” promised to enhance its own national aerospace sector. Prestige mattered too at a time when China and Russia were openly flight testing their own stealth fighters.

Remarkably, KAI had no direct involvement with the KF-X’ completion until it received the government’s marching orders in 2015. It also turned out Indonesia failed to cover its promised share of development costs. This year’s unveiling of a single model–itself a prototype that won’t enter production for a few more years–has effectively revived the newly named KF-21’s prospects. At the ceremony on April 9 the KF-21 model had the South Korean and Indonesia flags printed below its cockpit. The gesture matters because the entire program may be scaled down without the financing of a long-term foreign operator–South Korea’s media claim the Indonesian air force are receiving as many as 50 KF-21’s by the 2030s. Meanwhile, should everything go according to plan, the KF-21 enters service with the ROKAF once the branch sheds its older models, leaving the fourth-generation fighters and the F-35A to complete a very intimidating aerial fleet.

According to KAI, the KF-21 offers three advantages over legacy aircraft flown by regional air forces. First, being a twin engine multirole fighter, its payload is formidable with ten hardpoints; there are three on each wing and four on its belly. Tabletop models of the KF-21 have been shown loaded with external fuel tanks plus four anti-radiation missiles and four beyond-visual-range missiles. Quite the lethal combination. The second advantage is data linking with other KF-21’s and US Air Force fighters when these are operating together with the ROKAF. The data link allows seamless communications and battlespace awareness if KF-21’s are tasked with defeating external adversaries over national airspace.

The third advantage of the KF-21 is beyond visual range or BVR targeting. When up against different models of earlier generation fighters, whether these are J-7’s or MiG-29’s, the KF-21 will have detected and locked on them before these can visualize their opponents. The KF-21’s ability to conduct BVR engagements makes it a perfect escort for strike missions across the DMZ if the ROKAF must neutralize North Korean missiles and sensitive infrastructure during a hypothetical conflict that takes place in the near future. It bears mentioning that for such an advanced multirole fighter the KAI KF-21 isn’t comparable to the Boeing F-22 Raptor. The KF-21’s airframe features specific geometries for reducing its radar cross-section (RCS) and the pilots have electronic warfare tools for countering radar detection. Having external hardpoints for its weapon payload is another sure sign the KF-21 was intended as a non-stealthy strike aircraft.

As with other national efforts at military aircraft the KF-21 is celebrated as a wonder of domestic technological innovation but is reliant on imported engines and, not surprisingly, these are supplied by General Electric. There’s no word yet if KAI is planning to make its own engines at some point along the KF-21’s production cycle. With the exception of China, whose state-owned aerospace giant CATIC sells a twin engine stealth fighter called the FC-31, other Asian countries with ambitions to roll out stealth fighter aircraft are bedeviled by the steep costs and the critical access to a foreign-made engine. This is apparent with Japan’s own stealth fighter program and is a severe hurdle for India and Turkey.

India ad Turkey, by the way, have mockups of stealth airframes designed by state-owned aerospace manufacturers but updates on their progress are scarce. Neither country are eligible as operators of Lockheed Martin’s F-35A, which means a locally made stealth fighter is tied with their self-image as emerging world powers. Even the KF-21’s success is far from assured. The challenges of manufacturing stealth aircraft at scale and at an acceptable cost are serious enough that an alternate trend in contemporary multirole fighters is improving them to an extreme for lucrative exports. KAI’s push for the KF-21 looks like an optimal bet on a “heavy” fighter that’s affordable and effective at defeating its peers.