Kristen Smith 
- Two F-16s exchanged sensor data through a pre-production L3Harris data link
- Legion detects and tracks airborne targets in radar-denied environments
- Lockheed is testing the capability under an Air National Guard contract
Lockheed Martin has flown two F-16s carrying networked Legion sensor pods in a test that let the aircraft share targeting data without using radar.
The trials were conducted with the Air National Guard and the Air Force Reserve Test Center, flying from Morris Air National Guard Base in Tucson, Arizona, the company said Wednesday. The pods traded sensor data over HiveLink, a pre-production link built by L3Harris. According to Lockheed, linking the pods lets pilots establish range to multiple airborne targets almost instantly.
What Is the Legion Sensor System?
Legion, formerly IRST21, is a passive infrared search-and-track system that detects and tracks airborne threats at long range, even in radar-denied environments.
The system is housed in a 16-inch-diameter pod built around an IRST21 sensor and processor. Its open architecture accommodates additional sensors without modifications to the host aircraft, and a common interface allows integration without affecting the aircraft’s operational flight program.
Legion is fielded and in production in podded form for the Air Force, operating on F-15 and F-16 aircraft. Lockheed said the system can be integrated into other fighter, non-fighter and uncrewed platforms.
What Comes Next for Legion?
Lockheed is flight testing under an Air National Guard contract to validate performance, transportability and interoperability. Future work covers software-defined radios, multi-waveform gateways and support for crewed-uncrewed teaming.
Cristin Stengel, Legion program director at Lockheed, said the effort is turning infrared search-and-track into a networked passive capability.
What Other Legion Work Does Lockheed Hold?
Lockheed received a $233 million firm-fixed-price contract in October 2025 for full-rate production of IRST21 Block II systems for the Navy and Air National Guard, covering 59 infrared receivers, 20 inertial measurement units and 45 processors. Work is expected to be completed by September 2029.
Lockheed also took a $328.5 million foreign military sales contract in February to produce Legion-ES systems, supporting a U.S. government agreement with the Taiwan Air Force. Taiwan is the first international customer for that configuration.
