South Korea and Indonesia have agreed to jointly develop a new fighter, the KFX. This would be an aircraft with capabilities somewhat beyond the top-line American F-16 Block 60. The best example of this is a special version of the Block 60 developed for the UAE (United Arab Emirates). The UAE bought 80 "Desert Falcons" (the F-16E) which is optimized for air combat. It is a 22 ton aircraft based on the Block 52 model, but with an AESA (phased array) radar and lots of other additional goodies.
KFX development is expected to take ten years and cost $2 billion. South Korea hopes to build on the work it did to develop its T-50 jet trainer. This is a 13 ton, two seat, single engine aircraft that is also available as a combat model (the F-50), which carries a 20mm autocannon and up to three tons of bombs and missiles. The KFX would weigh twice as much, have one or two engines, a single seat and the ability to carry twice as much weight in weapons. The KFX is expected to look more like the Eurofighter Typhoon, than the T-50 or F-16. The KFX is also expected to cost $50 million each, have advanced electronics (including an AESA radar). Indonesia will provide 20 percent of the development costs and buy fifty of the KFXs. South Korea will buy 150-250 of the new aircraft, to replace its current fleet of elderly American F-4s and F-5s. This is an ambitious undertaking, and success is not certain, especially when the timeline, budget and aircraft performance are concerned.
The competition remains the U.S. F-16, which is one of the most modified jet fighters in service. While most are still called the F-16C, there are actually six major mods, identified by block number (32, 40, 42, 50, 52, 60), plus the Israeli F-16I, which is a major modification of the Block 52. The F-16D is a two seat trainer version of F-16Cs. The various block mods included a large variety of new components (five engines, four sets of avionics, five generations of electronic warfare gear, five radars and many other mechanical, software, cockpit and electrical mods.)