By Jun Ji-hye



The U.S. refusal to hand over four core technologies used in making F-35 stealth fighters to Korea has put its indigenous fighter jet development program, KF-X, in jeopardy.



The government said it can develop the technologies on its own, but questions remain about whether this is possible and whether it can achieve its goal of developing the jets by 2025.



With this in mind, Defense Minister Han Min-koo accompanied President Park Geun-hye on her U.S. trip and asked Washington to retract its earlier decision and allow Lockheed Martin to transfer the technologies.



The four technologies ― the active electronically scanned array (AESA) radar, infrared search and track (IRST), electronic optics targeting pod (EOTGP) and RF jammer ― are crucial for air warfare.



The AESA radar is essential equipment that helps a pilot identify friend or foe in battle and finds targets on the ground.



Its strength lies in determining and detecting multiple targets simultaneously. It also has advantages with its information processing speed and combat capability.



The nation's Agency for Defense Development has been leading the development of the radar since 2006 with defense firm LIG Nex1, but has yet to devise cooling technology to counter the heat the equipment generates.



IRST detects and traces infrared signals from engines or missiles, letting a pilot know if an enemy aircraft has fired missiles.



EOTGP, which detects and traces targets, helps a pilot's pinpoint strikes against ground targets.



The RF jammer shoots out high-powered electromagnetic waves to freeze an enemy's electronic equipment. It helps increase aircraft survival.



In April, the U.S. government refused to allow the transfer of the technologies to Korea for security reasons, dealing a serious blow to the KF-X project that calls for developing and producing 120 fighter jets by 2025 to replace an aging fleet of F-4s and F-5s.



Defense observers say there is little chance of the U.S. reversing its decision, even if Han asks U.S. Defense Secretary Ash Carter for this.



The Defense Acquisition Program Administration (DAPA) said the government is pushing for domestic development and cooperation with other foreign companies to produce its own technologies.



But experts remain skeptical, saying it will not be easy to domestically develop the cutting-edge technologies within 10 years.



When DAPA signed a deal with the U.S. defense giant in September last year to buy 40 F-35s, the agency said Seoul would receive 25 technologies from Lockheed, including the four core ones as part of an offset program.



The U.S. is yet to decide whether it will allow Lockheed to transfer the remaining 21 technologies to Korea, with DAPA expecting the decision as early as next month.



