South Korea’s first homegrown fighter jet just flew wingtip-to-wingtip with the Americans — and the plane next to it was a Cold War spy legend.
On October 23, a KF-21 Boramae from the Republic of Korea Air Force’s 156th Fighter Squadron (16th Fighter Wing) flew in formation with U.S. Air Force aircraft over the Yellow Sea, Seoul officials said Friday. The U.S. side brought a U-2S Dragon Lady high-altitude reconnaissance aircraft, plus F-35 and F-16 fighters. South Korea added F-35s, F-15Ks and FA-50s to the lineup.
Why this is a first
It was the first time the KF-21 has flown in formation with U.S. air force assets. The timing was deliberate: the flight came just days before the allies opened Freedom Flag, their twice-yearly combined air exercise, on Monday, October 26 at Kunsan Air Base. A Korean Air Force official said the point was to build up the KF-21’s experience ahead of the drills.
The U.S. Seventh Air Force described the “Friendship Flight” as a demonstration of how the two air forces integrate directly during flying operations.
What the KF-21 actually is
The KF-21 is South Korea’s first domestically developed fighter. Development wrapped up in July 2026, and the first production aircraft entered service with the 156th Fighter Squadron on September 22. The Air Force plans to field more than 100 of them in stages by early 2030, eventually replacing the aging F-4 and F-5 fleets.
Korea-watchers sometimes call it a “4.5-generation” fighter: it borrows a stealth-like shape from the F-35 but is not a full stealth aircraft, which is why it was flying with F-35s rather than instead of them.
Freedom Flag, briefly
Freedom Flag launched in 2024, replacing two older exercises, and runs for two weeks. This round focuses on counter-air and air interdiction missions, and on testing whether South Korea can plan and run a combined exercise on its own — a rehearsal for Seoul’s goal of taking wartime operational control (OPCON) of its forces by 2030.
For a program that spent years in the “still in testing” column, a month-old operational jet flying alongside a U-2 is a tidy way to announce it has arrived.
Sources
- The Korea Herald — S. Korea’s indigenous KF-21 fighter jet conducts 1st formation flight with US aircraft
- Korea JoongAng Daily — Korea’s indigenous KF-21 fighter jet conducts first formation flight with U.S. aircraft
- The Korea Times — Korea, US kick off combined air drills this week
- Kunsan Air Base — Setting the Tempo: Exercise Freedom Flag Underway at Kunsan