South Korea - Indonesia's less-expensive alternative to the F-35 jet takes off

South Korea declared the first successful test flight of its indigenous fighter jet, joining a limited group of countries demonstrating such technology in an effort to lessen its reliance on the United States.

The KF-21, also known as the Boramae, jointly-developed by South Korea and Indonesia, flew for 30 minutes from an airport in the southern city of Sacheon on Tuesday, according to South Korea's Defense Acquisition Program Administration. The aircraft, manufactured by Korea Aerospace Industries, will need more testing before going into mass production in 2026.

South Korea intends to create the next-generation aircraft as a less expensive alternative to Lockheed Martin Corp.'s F-35 Lightning II, both for its own military and for export. Seoul, as one of the United States' closest security partners, has already purchased F-35s.

The $6.7 billion KF-21 project is funded by Indonesia, which has promised to cover 20% of the expenditures. In 2014, the two governments decided to collaborate on the development of the jet. South Korea is planning to deploy 40 KF-21s by 2028 and a total of 120 by 2032 to replace the service’s aging F-4 Phantoms, while 50 should be deployed by Indonesia. For this reason, the aircraft sported the Indonesian flag along with the Korean one during the first flight.

South Korea announced the KF-21 design in April of last year as part of a larger plan to demonstrate its ability to stay up with neighbors such as China, Japan, and North Korea. South Korea has recently invested in military modernization, successfully launching its first submarine-launched ballistic missile and its first rocket to bolster its domestic space program.

The aircraft type would be verified as a potentially combat-capable asset at the end of 2023, and additional ordnance tests for KF-21 Block-2 will be conducted in 2026.

Forty Block-1 jets are envisioned to be capable of air-to-air battles while 80 Block-2 jets that will be deployed as of 2028 are meant to also perform air-to-ground engagements.