The ROKAF said goodbye with a special retirement the official retirement of the venerable F-4 Phantom II fighter jets. Just days earlier, this marked the end of active weapons deployment for the F-4 Phantom II, a mainstay in South Korea’s military, after more than five decades of service.
For this historic event, the ROKAF mobilized four F-4E fighters, two of them in classic paint schemes, one in camouflage, the other in a light gray finish. Alongside these vintage aircraft flew two prototypes of the new generation of South Korean fighters, the KF-21 Boramae, which is slated to replace the aging F-4s and F-5 Tiger IIs. A three-hour flight meticulously recorded from a two-seat F-15K Slam Eagle retraced 55 years of legacy by the F-4 Phantom II over the Korean Peninsula: over the provinces of Gyeonggi, Jeolla, and Gyeongsang.
The F-4 Phantom II first took to the skies in 1958 and was originally developed as an interceptor for the United States Navy. It started to be developed little by little into a multi-mission fighter bomber, capable of carrying out both air-to-air and air-to-ground missions. Its versatility also extended to performing reconnaissance and electronic warfare tasks, turning it into the most iconic aircraft of the Vietnam War epoch. Up to 1981, McDonnell Douglas built more than 5,000 units in total, where twelve countries included various versions of the F-4 in their fleets. Today, only Iran, Turkey, Greece, and South Korea still fly this iconic jet.
As South Korea says its final goodbye to the F-4 Phantom II, it also celebrates an important achievement in its KF-21 Boramae program. The KF-21 has just completed its first air-to-air refueling tests, some 18 months after the prototype first took to the skies. The DAPA confirmed the fifth prototype of the KF-21, in a test flight over the South Sea, hooked up with an Airbus A330 Multi-Role Tanker Transport (MRTT), locally known as the KC-330 Cygnus.
DAPA underscored this very achievement, saying that aerial refueling could enable the KF-21 to extend its operational radius and lengthen operational time, thus greatly bolstering the ROKAF’s long-distance operation capabilities. The flight test was conducted to check the turbulence behind the tanker, the safety of connection and separation, and the total refueling function.
The KF-21 program, officially started in 2016, has been moving at a fast clip. Of these, six prototypes – including a two-seater – have been completed so far, with the first production model scheduled to be delivered to the ROKAF during the second half of 2026. It has been referred to as a “4.5-generation fighter jet” with advanced features such as AESA radar and IRST, without placing the main emphasis on stealth, as with the fifth generation of fighters, such as the F-35 family.
South Korea’s strategy in developing the KF-21 strikes a balance between rapid deployment and advanced capability. The KF-21 may not be as capable across the board as the F-35; however, it is a cost-effective and timely means for replacing its fleets of F-4s and F-5s. The success of the program would also open up the prospect of the KF-21 becoming an export solution that would not be caught by many of the export controls affecting foreign-developed avionics.
The transition of South Korea from the storied F-4 Phantom II to the very modern KF-21 Boramae speaks for a big evolution in its air combat capability, ensuring ROKAF would be a formidable force in the region.