South Korea's KF-21 stealth fighter is under development shares similarities with India's AMCA

by Paul Iddon

The Turkish Air Force is paying a heavy price for Ankara’s purchase of Russian S-400 air defence missile systems. It has missed out on the chance to acquire fifth-generation F-35 Lightning II stealth fighters as a direct result of this procurement. Consequently, it will not likely field a capable fifth-generation aircraft, either homegrown or imported, for at least a decade.

But that’s not all. Ankara may also not even be authorized to buy the 40 new Block 70 F-16s and 80 modernization kits it requested from the United States in October to modernize its enormous F-16 fleet, the backbone of its air force, and keep it up-to-date for the next decade or so until it can finally acquire a fifth-generation replacement, or even a 4.5-generation stopgap fighter.

Turkey has repeatedly suggested that if the U.S. refuses this request, it will turn to Russia for Su-35 Flanker-E jets. However, such a move would certainly trigger additional U.S. sanctions under the Countering America’s Adversaries Through Sanctions Act (CAATSA) on Turkey for buying advanced Russian military hardware and further antagonize NATO, which could further limit Ankara’s European options for modern fighters.

Turkey’s European options are already very limited. Britain is unlikely to sell Eurofighter Typhoons for the time being, as it has sanctions on Ankara over its cross-border military offensives in Syria. France will not likely sell Ankara any Dassault Rafales anytime soon as it is selling those jets to Turkey’s neighbour and rival Greece. That may mean Turkey’s only potential option for a European-built 4.5-generation jet could be Sweden’s Saab Gripen E.

If Turkey continually refuses to compromise with the U.S. and NATO on the S-400, its fir force will inevitably suffer the consequences.

Are There Any Other Viable Options For Ankara?


Turkey and Pakistan are close allies that welcome expanded and stronger military cooperation with each other.

Also, both Ankara and Islamabad are trying to develop and build their own stealthy fifth-generation fighter jets. Turkey has the TAI TF-X project, while Pakistan is working on the Project AZM PAC PF-X. However, neither of these projects is likely to produce a full-fledged fifth-generation fighter jet any time soon if at all, especially without extensive external assistance.

Nevertheless, defence cooperation with Pakistan could potentially help Turkey acquire capable 4.5-generation jets to supplement its F-16 fleet and replace its older jets. Author, analyst, and former air force pilot Kaiser Tufail suggested in 2018 that Turkey and Pakistan could build an interim jet “rather than jumping straight to a full-capability fifth generation fighter.” He even suggested that cooperation “could well take the shape of a ‘Block-4’ JF-17 Thunder developed by Turkey and Pakistan.”

The JF-17 was jointly developed by China and Pakistan. The first of 50 new JF-17 Thunder Block 3 jets will enter service in the Pakistani Air Force (PAF) this year. The new variant is a major improvement over its Block 1 and 2 predecessors, which lacks some basic capabilities, and has been described as the PAF’s first 4.5-generation fighter. The version includes an actively electronically scanned array (AESA), a key feature for any advanced 4.5-generation jet.

If Turkey and Pakistan work on a more advanced variant of this JF-17, as Tufail suggested, then Turkey could acquire a capable and formidable 4.5-generation fighter by the end of the decade.


Ankara could also turn to China for the Chengdu J-10C ‘Firebird’. Pakistan recently received the first J-10Cs that it ordered in response to India’s acquisition of Rafale F3R jets – although experts say the Rafale remains a considerably more advanced and capable 4.5-generation jet than the J-10C.

Turkey’s neighbour and rival Greece has also recently begun acquiring Rafales, much to Ankara’s frustration. Turkey recently reached a deal with Qatar, under which Doha will temporarily base some of its new Rafale jets in the country. There is speculation that Turkey won’t pass up the chance to inspect these jets and perhaps even train against them.

Buying J-10Cs would make a lot of sense for Turkey if it has no other Western alternatives. Justin Bronk, the Research Fellow for Airpower and Technology in the Military Sciences team at the Royal United Services Institute (RUSI) in London, said as much in an interview with Ahval News last year.

He said that Turkey could do a lot worse than the J-10C if it wants a cheap “multi-role and relatively capable modern replacement” for its F-16s and couldn’t get that from the West. He also said China is much more competitive in the sale of fighter jets than Russia.

“You’d be mad to look at Russia when the J-10C is on offer,” he said.

The J-10C is a considerably cheaper and arguably more advanced 4.5-generation jet than the Russian Sukhoi Su-35 since it has AESA radar. The Su-35 still relies on less advanced passive electronically scanned array (PESA) radar. The J-10C is also compatible with China’s PL-15 long-range beyond-visual-range air-to-air missile. In addition to costing more, procuring Su-35s would also undoubtedly incur more serious CAATSA sanctions.

With that being said, the U.S. and NATO would certainly not be pleased with Turkey fielding Chinese fighter jets. In the first half of the 2010s, years before CAATSA existed, Turkey sought FD-2000 air defence missile systems from China. U.S. and European defence companies warned Ankara at the time that “their partnerships in certain fields would not be able to continue if Turkey buys missiles from China.”

Still, to paraphrase Bronk, the J-10C wouldn’t be the worst alternative in the world if Turkey is denied modernized F-16s.


South Korea is developing a new national fighter called the KF-21 Boramae. While still a prototype, the KF-21 will likely become a cutting-edge 4.5-generation fighter jet.

Ankara initially expressed strong interest in the project a decade ago and already has extensive defence ties with South Korea. Turkey has several license-built variants of South Korean systems, such as the T-155 Fırtına howitzer, based on the K9 Thunder. The Altay main battle tank Turkey is developing is also heavily based on the South Korean K2 Black Panther tank design.

In other words, defence ties between Ankara and Seoul are nothing new.

Additionally, the U.S. and NATO would hardly object to Turkey expanding defence ties with South Korea. And Seoul will undoubtedly welcome as many customers for the jet as possible, which it plans to begin exporting in 2028 for $65 million per unit.

If Seoul can rollout and begin exporting the KF-21 for that competitive price, which is cheaper than the current price for Rafales and Typhoons, by the end of this decade, then Turkey could become a customer and begin replacing its older F-16s, especially its already aged Block 30s.

The KF-21 will be stealthy, but, unlike the F-35 or F-22, its initial versions will carry its weaponry on external hardpoints rather than internal bays, making them much more detectable to radar than fifth-generation aircraft. The Block 1 variants will be built solely for air-to-air combat, while the Block 2 variant will also have ground attack capabilities. Perhaps sometime in the 2030s, a Block 3 variant with internal weapons bays and other improvements will be developed, making the KF-21 a genuinely fifth-generation aircraft.

Unlike its Russian and Chinese counterparts, the KF-21 will also be compatible with American and European missiles such as the AIM-120 AMRAAM, AIM-9X Sidewinder, and MBDA Meteor.

Military analyst Abraham Ait has high hopes for the upcoming Korean jet. He even went so far as to predict that it could become the most successful fifth-generation fighter program outside the United States and China.

“With Russia’s Su-57 program stymied by a very small production run, Turkey’s seemingly overly ambitious TF-X program heavily reliant on foreign technologies and coming from a country with a much more limited domestic technological base, and the Pakistani Project AZM fighter expected to be built around Chinese rather than indigenous technologies and plus a heavy emphasis on cost reduction much like the preceding JF-17, this leaves the KF-X as a leader among indigenous fifth generation programs outside China and the United States,” Ait wrote in The Diplomat.