South Korea’s fifth-generation stealth fighter KF-21, is likely to outsell US F-35s if exported, although their power may not be comparable.
According to information on Eurasia Times website, the Indonesian side recently reiterated its commitment to participate in the South Korean – led KF-21 stealth fighter project; would provide a cheaper alternative to the US F-35 stealth fighter.
In April this year, South Korea demonstrated the prototype of its first domestically produced, semi-stealth fighter jet as the KF-21. The Indonesian side agreed to invest $7.6 billion in the project, accounting for about 20% of development costs, in exchange for the acquisition of related technologies. It is expected that Indonesia will buy 50 KF-21 stealth fighters.
The KF-21 project, which began research and development in 2015, will eventually replace the aging F-4 and F-5 fighters of the Republic of Korea Air Force. Although Indonesia has a 20% stake in the KF-21 project, its commitment to the KF-21 fighter project has been questioned, due to Indonesia’s late payment due to poor domestic economic conditions; Besides, the opinion of the leader of the Indonesian Army is often “shaken”.

South Korea said that the KF-21 is the first domestically produced stealth fighter, making Korea the 8th country in the world to successfully develop an advanced 4++ generation fighter. above.
Military expert Joseph Chaco, an analyst on military and international affairs of South Korea, told The EurAsian Times: “More than 30 Indonesian aeronautical scientists have traveled to Korea to participate in the project development. Although the investment on KF-21 promised by Indonesia has yet to be a reality.
In the context of China’s increasing military modernization and unreasonable claims on territorial waters in the East and South China Seas. It is China’s military action that will be the factor for Indonesia to decide on such large-scale weapons procurement projects.
Mr. Chaco further explained that the KF-21 also uses many American elements, the key components of the KF-2 all come from the US, including Lockheed Martin and General Electric of the US, and the KF-21 will be subject to control US fighter aircraft export. Although it is reported that around 65% of the KF-21’s parts are manufactured in Korea, Chaco believes that most of the KF-21’s “subsystems” were developed with the assistance of foreign partners or direct use of foreign parts.
When asked about the price of the KF-21 and its competitors, Chaco believes that the unit price of the KF-21 is expected to be around $65 million and the newly launched Russian 5th generation light fighter Su- 75 Checkmate will be its competitor. Currently, Russia has significant influence in the region.

The KF-21 will be used in conjunction with the F-35 that South Korea purchased from the US. Korea can also flexibly configure the aircraft’s payload according to customer requirements. For example, the aircraft has acquired the ability to use the European Meteor missile. Some analysts say that the design of the KF-21 is very similar to the US F-22, although it has been positioned as a replacement for the F-35.
The KF-21 is expected to replace the ROK Air Force’s third generation fighters such as the F-5E/F and F-4, as well as some F-16C/D and F-15K fighters. ; All are about to expire. In addition, the KF-21 fighter will also supplement the 60 US F-35As purchased by South Korea. It is estimated that by 2028, 40 KF-21s are expected to be put into service with the Republic of Korea Air Force.
Although in many respects, the KF-21 resembles the F-35; but the KF-21 is a twin-engine fighter, and the F-35 is a single-engine fighter. The KF-21 prototype uses General Electric’s F414-GE-400K engine and the Company will continue to supply 240 engines for 120 KF-21 fighters.
Similar to the F-35 and F-22, the KF-21 also has a stealth function, but the stealth performance of this aircraft is far from comparable to the US 5th generation stealth fighter. The radar reflectivity area of the KF-21 is considered to be comparable only to the Eurofighter Typhoon generation 4++. What affects the KF-21’s stealth is the 6 under-wing weapon racks and 4 under-fuselage weapon racks. As the KF-21 pursues a more economical price tag and shorter development cycles, this causes the aircraft to forego important internal weapons bays.

The KF-21 is expected to carry a payload of 7.7 tons of weapons and maintain a maximum flight speed of Mach 1.83. The KF-21 seems to have an advantage over the F-35A in some respects, as it has a range of up to 2,900 km. South Korea has also independently developed an active phased array radar (AESA), which can use long-range weapons, such as the European Meteor air-to-air missile.
Although the KF-21 may not be a fifth generation fighter, it is expected to have an export advantage over fighters from China, India, France, Europe and other countries. other, due to cheaper price and faster delivery.
In addition, the KF-21 will also rely on its own unique advantages to create an export advantage over the F-35 and J-10C. Like the export of the US F-35, will have to be tied to political conditions; in addition, customers are also required to accept software updates selected and controlled by US manufacturers.
As for the Chinese fighter J-10CE, an opponent also considered to be the KF-21, also has the problem of insufficient reliability, weak brand and has Chinese origin. However these problems do not exist on the KF-21.
As Korea develops new avionics and related sensors, if they can be used on KF-21 fighters, customers from around the world can have more autonomy, better products and more stable supply.