IRIA News

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Lockheed Martin received a $328.5 million Foreign Military Sales (FMS) contract by the U.S. government to produce IRST21 Legion-ES sensor systems for the Taiwan Air Force.

The contract supports a recently approved U.S. government FMS agreement with Taiwan and marks the first time the Legion-ES configuration will be delivered to an international partner.

The award comes as Taiwan continues to modernize its air force amid growing regional security pressures and increasing emphasis on improving early warning, situational awareness, and survivability for its fighter fleet.

Under the contract, Lockheed Martin will produce IRST21 Legion-ES infrared search-and-track sensor systems tailored for integration with the F-16 platform.

The system is designed to complement overall aircraft performance by providing passive detection and tracking of airborne targets without emitting radar signals that could reveal an aircraft’s position.

The U.S. government awarded the contract as part of its Foreign Military Sales program, which facilitates defense cooperation with allies and partners through government-to-government agreements.

Lockheed Martin confirmed that the contract directly supports the Taiwan Air Force, making Taiwan the first international ally to receive the Legion-ES version of the IRST21 system.

IRST21 Legion-ES

The IRST21 is Lockheed Martin’s next-generation infrared search-and-track capability. It uses long-wave infrared sensing to passively detect and track airborne targets at extended ranges, allowing pilots to identify and monitor threats without relying solely on active radar systems.

The Legion-ES configuration is a low-profile, embedded, and fully integrated IRST system designed specifically for the F-16. By operating passively, the system enables pilots to maintain situational awareness while reducing the risk of detection by adversaries equipped with electronic warfare or anti-radiation capabilities.

According to Lockheed Martin, the Legion-ES provides high-accuracy detection and tracking of airborne threats, increasing pilot reaction time and enhancing aircraft survivability in contested airspace.

Importance for Taiwan

Taiwan’s selection as the first international recipient of the Legion-ES IRST21 configuration is a notable milestone for the program. The system is expected to significantly strengthen the Taiwan Air Force’s ability to detect and track potential airborne threats, particularly in environments where electronic warfare and radar jamming are major concerns.

Passive sensing technologies such as IRST systems are increasingly valued by air forces facing advanced adversaries with sophisticated radar and electronic countermeasures. By improving situational awareness without increasing electromagnetic emissions, IRST systems offer a critical layer of capability in modern air combat.

The addition of the Legion-ES to Taiwan’s F-16 fleet is expected to support faster decision-making by pilots and improve coordination during air defense and interception missions.

“This award marks an important milestone as Taiwan becomes the first international partner to receive the Legion-ES IRST21 configuration,” said Cristin Stengel, program director for Lockheed Martin IRST21.

“This system will bring advanced passive sensing capability to strengthen situational awareness, accelerate decision-making, and support our allied air forces,” Stengel said.

Building on Proven Technology

The Legion-ES builds on Lockheed Martin’s long-standing experience with infrared search-and-track systems. The company said its legacy IRST systems have accumulated more than 300,000 flight hours combined, providing a mature technological foundation for the new configuration.

The low-profile design of the Legion-ES allows it to be integrated with minimal impact on aircraft aerodynamics while still delivering extended-range detection and tracking capability. This approach reflects a broader trend in air combat toward integrating advanced sensors without compromising performance or stealth characteristics.

Broader Strategic Context

The contract aligns with ongoing U.S. efforts to support Taiwan’s defense capabilities through arms sales and technology transfers approved under the Taiwan Relations Act. While the IRST21 system is a defensive sensor rather than a weapon, it plays a key role in enhancing air defense readiness and resilience.

For Lockheed Martin, the award represents both a program milestone and an expansion of the IRST21’s international footprint. Taiwan’s adoption of the Legion-ES configuration could influence future interest from other F-16 operators seeking to enhance passive sensing and survivability.

As production under the $328.5 million contract moves forward, the delivery of IRST21 Legion-ES systems is expected to deepen defense cooperation between the U.S. and Taiwan while strengthening Taiwan’s ability to monitor and respond to potential airborne threats in a complex regional security environment.