The Gen III TacIRST distributed infrared threat‑warning system will equip the F-22 Raptor, with an evaluation planned in 2026.
Lockheed Martin has announced the first flight of the latest iteration of its TacIRST sensor, or Gen III TacIRST. The flight was conducted in October by a Rockwell Sabreliner 65 testbed equipped with a pod carrying the sensor.
In an emailed statement, the company says it is “demonstrating capability readiness before the scheduled customer‑evaluation window in 2026.” In January 2025 Lockheed Martin was awarded a contract to equip the F-22 Raptor with TacIRST, and the company confirmed to us that the initial customer integration will indeed be with the F‑22.
TacIRST
TacIRST, or Tactical Infrared Search and Track, is a next-generation sensor developed by Lockheed Martin which allows to detect and track airborne threats with weapon-quality accuracy, says the company. The system provides 360‑degree situational awareness, passively detecting and tracking both surface‑to‑air and air‑to‑air threats.
The company told us the Gen III TacIRST builds on the proven architecture of earlier TacIRST prototypes while incorporating a suite of SWAP‑C (Size, Weight, Power, and Cost) improvements. Improving SWAP-C allows to obtain a more compact, less power-hungry system which can easily be integrated on aircraft without requiring extensive modification.
Additionally, the system is designed with open mission standards to integrate seamlessly with existing host platforms and enhance missile‑warning capability. This ensures compatibility with a range of platforms, including fixed‑wing fighters and large aircraft, says Lockheed Martin.
Compared to traditional IRST which features round windows, TacIRST is based on a smaller staring sensor much more similar to the windows of the F-35’s Distributed Aperture System. Similarly to DAS, TacIRST supports integration with Helmet-Mounted Displays (HMS) to provide pilots with rapid threat indication, as well as targeting functions to support beyond‑visual‑range missile engagements.
Lockheed Martin further says TacIRST builds on the hardware and software expertise gained from fielding IRST‑21 and the AN/AAR-56 F‑22 Missile Launch Detector (MLD) system. The former is itself the evolution of the company’s legacy AN/AAS-42 IRST sensor system, which accumulated over 300,000 flight hours on F-14 and international F-15 platforms.
TacIRST and F-22
Lockheed Martin announced on Jan. 22, 2025, that it has been awarded a $270 million contract from the U.S. Air Force to integrate a system of next-generation infrared defensive sensors on the F-22 Raptor. The system, known as the Infrared Defensive System (IRDS), will add a distributed set of embedded TacIRST sensors to enhance the F-22’s survivability and lethality.
“We understand the need for advanced and versatile infrared systems like IRDS that will make pilots’ missions more survivable and lethal against current and future adversaries,” said on that occasion Hank Tucker, Vice President of Missions Systems at Lockheed Martin. “We’re committed to supporting the Air Force through continuous innovation of capabilities to deter and defeat evolving threats.”
It is unclear if TacIRST will be integrated directly in the Raptor’s airframe, although the description as a distributed set of embedded sensors and the SWAP-C improvements appear to suggest so. The fact that TacIRST uses small staring sensors would make it ideal for installation on the F-22 as the sensors would be flush with the surfaces of the aircraft.
In the past, there were unconfirmed reports about the technology behind TacIRST possibly being related to upgrades to the F-22’s current AN/AAR-56 Missile Launch Detector (MLD). Given the sensitivity of the F-22 program, the statement released in January did not delve into details, so it is unclear if the IRDS will completely replace the AAR-56 or just its sensors.
The F-22 is receiving a plethora of upgrades as part of an improvement campaign that calls for $7.8 billion in investments before 2030, which includes $3.1 billion for research and development and $4.7 billion in procurement. While the Air Force previously planned to retire the oldest Raptors, the service now appears to be reconsidering that plan and focusing on sustaining an air superiority combat capability for a highly contested environment.
As part of the upgrades, an F-22 has been spotted at the Air Force’s Plant 42 facility in Palmdale, California, with two pods installed under the outer underwing hardpoints in February 2022. Budget documents mentioned an InfraRed Search and Track (IRST) sensor being developed for the F-22, which appears now confirmed to be the type of sensor housed inside the two pods.
It is unclear if these pods might have any relation with TacIRST, although they could host the sensors distributed around the aircraft to provide a 360-degrees cover. However, the pods could also host a more powerful IRST specifically for long-range targeting or other capabilities.
In July 2024 we got an up-close look at one of the pods installed under a Rockwell Sabreliner 65 testbed after a test campaign at Nellis AFB, Nevada. It would have been expected to see some kind of transparent surface associated with the IRST, however the surfaces on the nose of the pod appeared to be opaque. We still cannot exclude that there are two different variants of the pod, depending on the equipment inside.
