South Korea and Indonesia have signed an agreement to jointly develop a 4.5-generation fighter to act as an improved version the KF-16 combat aircraft.

Indonesia will pay 20% of the KF-X programme development costs, and purchase about 50 fighter jets when mass production begins, accordiing to

The KF-X programme will secure the need for multipurpose fighter jets and replace the South Korean Air Force’s aging F-4 and F-5 fighters.

The KF-X aircraft will include an active electronically scanned array radar, an electronic warfare suite and an infrared search-and-track system.

It will have super-velocity intercept and supercruise capabilities, along with air-to-air, air-to-ground and air-to-sea capabilities.

The agreement was decided following a KF-X letter of intent signed in March 2009 by South Korean President Lee Myung-bak during a visit to Indonesia.