BAE Systems Wins $11M Contract for KF-21 Fighter Avionics Upgrade

BAE Systems Secures $11 Million Contract to Upgrade KF-21 Fighter Avionics

BAE Systems has officially announced an $11 million contract award from Korea Aerospace Industries (KAI) to supply advanced Identification Friend or Foe (IFF) systems for the KF-21 Boramae fighter aircraft. According to the company’s statement released on December 15, 2025, the agreement involves the integration of the AN/APX-127(V)1 Combined Interrogator Transponder (CIT), a critical avionics component designed to enhance the indigenous fighter’s interoperability and situational awareness.

The contract underscores the deepening industrial cooperation between the British multinational defense contractor and South Korea’s aerospace sector. As the KF-21 program moves through its production phases, the integration of NATO-standard identification systems ensures the aircraft can operate seamlessly alongside U.S. and coalition forces. BAE Systems confirmed that production and delivery of the units are scheduled for 2026, with work being performed at its facilities in Greenlawn, New York, and Austin, Texas.

Technical Specifications and Capabilities

The centerpiece of this contract is the AN/APX-127(V)1 CIT, which BAE Systems describes as a “drop-in” replacement for the AN/APX-126(V) currently used on KF-21 prototypes. This compatibility allows KAI to upgrade the aircraft’s avionics suite without requiring significant structural modifications, streamlining the integration process for the production block.

Advanced Identification Standards

According to the press release, the new system is Mark XIIB certified, meeting the latest U.S. Department of Defense and NATO standards. The system features Mode 5 and Mode S capabilities:

• Mode 5: This standard utilizes modern cryptographic techniques to provide secure, encrypted identification, significantly reducing the risk of friendly fire (fratricide) and improving resistance to jamming or spoofing in contested electronic warfare environments.
• Mode S: This mode facilitates interoperability with civil air traffic control systems, allowing for selective interrogation and reducing radio frequency congestion in crowded airspace.

Situational Awareness Upgrades

Beyond basic identification, the AN/APX-127(V)1 includes Automatic Dependent Surveillance–Broadcast (ADS-B) “In” capability. This feature allows the KF-21 to passively receive position and flight data from other aircraft, thereby enhancing the pilot’s situational awareness without the need to emit active signals that could compromise the aircraft’s location. The system also utilizes multi-channel reception to passively acquire Mode 5 Level 2 data, further aiding in the rapid classification of friendly forces.

“The APX-127 Combined Interrogator Transponder will equip the KF-21 aircraft with state-of-the-art IFF to help bolster the Republic of Korea’s national defense strategy. This new system gives fifth-generation fighter pilots an edge in air superiority missions and allows them to maintain interoperability with U.S. and coalition partners.”

— Seth Guanu, Combat Identification Products Program Area Director, BAE Systems

Strategic Context: The KF-21 Program

The KF-21 Boramae is South Korea’s 4.5-generation multirole fighter, developed to replace the Republic of Korea Air Force’s (ROKAF) aging fleet of F-4 Phantom II and F-5 Tiger II aircraft. While the aircraft is indigenous, it relies on select international partnerships for critical subsystems, such as the IFF technology provided by BAE Systems.

With mass production reportedly beginning in mid-2024, the delivery of these upgraded IFF systems in 2026 aligns with the operational fielding of the initial production blocks. The adoption of an open-system architecture in the AN/APX-127(V)1 is intended to facilitate future software upgrades, mitigating obsolescence risks and reducing long-term lifecycle costs for the ROKAF.

AirPro News Analysis

The selection of the AN/APX-127(V)1 highlights a critical requirement for modern non-stealth and semi-stealth fighters: coalition interoperability. While the KF-21 is a South Korean platform, its primary strategic utility lies in its ability to integrate into a broader defensive network involving U.S. assets. By securing Mark XIIB and Mode 5 certification, KAI is ensuring that the KF-21 can participate in complex joint operations without being a liability in the identification chain.

Furthermore, the “drop-in” nature of this upgrade illustrates a prudent engineering approach. Avoiding airframe modifications to accommodate new avionics preserves the program’s schedule and budget, both of which are often volatile in domestic fighter programs. This contract reinforces BAE Systems’ foothold in the Asian defense market, positioning it as a key supplier for the region’s growing fleet of indigenous platforms.

Sources

Sources: BAE Systems Press Release