The Republic of Korea Air Force (ROKAF) originally planned to buy 120 advanced, high-end fighters as its next-generation platform, in order to replace its existing fleet of F-4 Phantom IIs and other aircraft. So far, it has bought 60 fighters in 2 phases. Back in 2002, the South Koreans picked the advanced F-15K derivative of the F-15E Strike Eagle for its F-X Next Generation Fighter Program, and bought 40. In 2008, a 2nd F-X Phase II contract was signed for 20 more F-15ks, with slight modifications.
As the 3rd phase loomed, the question was whether it will be a variant of their existing fleet, or something new. While the Defense Acquisition Program Administration (DAPA) dreamed of developing their own “5th generation” aircraft for Phase 3, reality eventually had its say. Now, foreign manufacturers are offering the ROKAF a number of off-the-shelf options. But throughout 2013 DAPA couldn’t seem to be able to reconcile the air force’s desire for advanced technology with its budget constraints. Boeing seemed on the edge of winning with its F15-SEs as the sole contender within budget, only to be rejected by the end of September 2013. This reopened the tender with Lockheed Martin’s F-35 as the likely favorite.