BAE Systems has been awarded an US$11 million contract by Korea Aerospace Industries (KAI) to integrate the AN/APX-127(V)1 Combined Interrogator Transponder (CIT) on the KF-21 Boramae aircraft.
The latest Identification Friend or Foe (IFF) system enhances decision-making by enabling pilots to more effectively distinguish allied forces from potential threats in contested operational environments.
Designed for tactical aircraft, the CIT offers the flexibility required to meet both current and future mission demands, supporting operators in an increasingly complex battlespace. Its open-system architecture allows for software upgrades, reducing the cost and risk associated with hardware changes, while delivering advanced multi-function capability and meeting the latest requirements for cryptography, anti-jam performance and cyber resilience.
BAE Systems noted that the APX-127 Combined Interrogator Transponder will equip the KF-21 with state-of-the-art IFF capability, strengthening the Republic of Korea’s national defence posture. The company added that the system provides fifth-generation fighter pilots with an advantage in air superiority missions, while ensuring continued interoperability with US and coalition partners.
With the same form factor, the AN/APX-127(V)1 is a drop-in replacement for the AN/APX-126(V) CIT currently fielded on the KF-21. It is Mark XIIB IFF certified, supporting Mode S and Mode 5 for secure, encrypted data exchange. The upgraded system improves situational awareness through additional receive channels for passive acquisition of Mode 5 Level 2 and Automatic Dependent Surveillance–Broadcast In (ADS-B In), enabling the detection and identification of friendly aircraft in complex and dynamic environments.
Through advanced technology and system architecture, BAE Systems’ next-generation IFF solutions address obsolescence and increase processing capacity to support future capability growth. With more than 80 years of experience, the company has delivered over 1,500 interrogators, 6,000 combined interrogator transponder systems and 16,000 transponders. Its IFF products support all service branches and are used by US and coalition forces across air defence, weapon systems, air traffic control and range instrumentation.
Work on the AN/APX-127(V)1 CIT will be carried out at BAE Systems’ facilities in Greenlawn, New York, and Austin, Texas. Delivery of the KF-21 CIT units to KAI for integration and certification is expected in 2026.

























