South Korea has embarked on a campaign that will expand the operational modes of the active electronically scanned array (AESA) radar that equips the Korea Aerospace Industries (KAI) KF-21 fighter.

The programme was initiated by the Agency for Defense Development (ADD) and involves other parties, including the Republic of Korea Air Force, involved with the radar, according to South Korea’s Defense Acquisition Program Administration (DAPA).

[Photo4] AESA radar mounted on a platform simulator for ground-based functional and performance testing before flight trials

Source: Hanwha Systems

The KF-21’s AESA radar was developed locally by South Korea

The work will focus on the air-to-ground and air-to-sea modes. The AESA’s air-to-air capabilities have been validated in tests over the last decade.

Hanwha Systems, which produces the radar, rolled out the first mass-produced AESA set in August 2025, and will deliver 40 sets between 2025-2028.

Following the work, the AESA will be able to detect and track air, ground, and sea targets, giving the fighter a multi-role capability in all weather, says the DAPA.

“Through this project, we plan to secure operational capabilities for the overall modes of the KF-21 AESA radar, thereby dramatically improving the operational capabilities of the KF-21 in future battlefields,” says ADD senior researcher Jeong Seong-tae.

“Through this, we will contribute to independently improving the performance of domestically developed equipment and securing the ability to mount our own weapons, and it will also have a positive effect on expanding defence exports.”

The KF-21 is set to enter South Korean service at the end of 2026.

Separately, on 28 January KAI announced that Saudi Arabia’s air force chief, General Turki Al Saud, visited the company’s headquarters in Sacheon, South Korea.

Al Saud, according to KAI, “showed great interest” in KAI programmes such as the KF-21. He also received a briefing about the type.

Saudi Arabia is in the process of considering a fighter order. Contenders include the Eurofighter Typhoon, Boeing F-15EX, and Dassault Aviation Rafale. In November 2025, US President Donald Trump said he would approve the sale of Lockheed Martin F-35s to the kingdom.