KF-21 Boramae 4.5 generation fighter prototypes are currently undergoing various ground tests at KAI facility in Sacheon prior to next month’s maiden flight.
As the interesting photos in this post show, KF-21 Boramae (Hawk) 4.5 generation fighter prototypes are currently undergoing various ground tests at Korea Aerospace Industries (KAI) facility in Sacheon prior to next month’s maiden flight.
According to KAI, 95% of pre-flight ground tests have been completed. Total of 6 flyable prototype aircraft and 2 ground-testing models are undergoing tests at KAI. As reported by Korea Defense Blog Facebook Page, the 6 flyable prototypes will conduct over 2,000 test flight sorties before KF-21 is declared operational.
As already reported, since the roll-out the first prototype aircraft last year, several KF-21 prototypes have been undergoing various ground tests.
Lockheed Martin is an official partner of the KF-X program. When the Republic of Korea Air Force acquired 40 F-35A jet fighters from LM, one of the major clauses in the contract included technology transfers, four of which were categorized as “core technologies” necessary for KF-21’s development.

The four “core technologies” were: Active Electronically-Scanned (AESA) Radar, Radio Frequency (RF) Jammer, Electro-Optical Targeting Pod (EO-TGP), and Infrared Search and Track (IRST).
However, since the US Congress deemed them to be too sensitive, and the technology transfer did not push through, these technologies are being developed indigenously.
Because these core technologies are considered extremely sensitive and are intellectual properties of South Korea, any exported systems will be maintained by South Korean engineers. For example, KF-21 exported to Indonesia will have to be overseen by South Korean engineers when radars and other sensitive subsystems need to be maintained.
This is not unique to the KF-21. Most, if not all, major defense manufacturers impose similar requirements to safeguard sensitive technology. Users of the F-15E and F-35 variants cannot freely maintain their aircraft without Boeing or Lockheed Martin engineers, for example.

The KF-21 Boramae supersonic stealth jet fighter was unveiled on Apr. 9, 2021.
According to KAI, the aircraft is designed to be able to fly at a maximum speed of Mach 1.81, with its flying range reaching 2,900 kilometers.
Featuring dimension of 16.9m x 4.7m x 11.2m, KF-X is larger than F-16 and is of similar size as F-18. Development of KF-21 began in earnest on January 2016 and the assembly process began in 2019 after Critical Design Review (CDR) was completed in 2018. The KF-21 is expected to replace Republic of Korea Air Force (ROKAF) F-4 and F-5 (and eventually even F-15K and KF-16) fighters and will operate alongside the more advanced F-35A in ROKAF inventory.
The KF-21 is a joint project between South Korea and Indonesia in which Seoul holds 80% of shares while Jakarta seeks 20%.
Photo credit: Republic of Korea Armed Forces
