The US Department of Defense has awarded Lockheed Martin a $328.5 million Foreign Military Sales contract to equip Taiwan’s Air Force with Legion-ES IRST21 infrared search-and-track sensors.
The systems will provide Taiwan’s F-16 fighters with the ability to passively detect and track airborne threats using long-wave infrared technology, allowing pilots to identify targets at extended ranges without revealing their position through radar emissions.
According to the contract, Lockheed Martin will produce the IRST21 Legion-ES sensors at its facilities in Orlando, Florida, with work expected to conclude by mid-2031. More than $157 million was obligated at the time of award.
This agreement represents the first export of the Legion-ES configuration, marking a milestone in US-Taiwan defense cooperation and signaling increased trust in Taiwan’s operational integration of advanced sensor technologies.
With a legacy exceeding 300,000 flight hours, Lockheed Martin’s IRST21 technology is regarded as a key force-multiplying capability, particularly as regional air defense environments grow more contested and complex.
The contract adds to a series of major US arms sales to Taiwan in recent years. In December 2025, Congress was notified of an $11.1 billion package including HIMARS launchers, self-propelled artillery, loitering munitions, anti-armor weapons, and networked mission systems.
Earlier notifications included $330 million for aircraft spares and repairs in November 2025, and the October 2024 approval of NASAMS air defense batteries with 123 AMRAAM-ER interceptors, deliveries of which are ongoing.
