The FS-X later called XF-2A origins can be traced back to the early 1980’s and the highly secretive Laboratory Three division of Japan’s Technical Research and Development Institute (TRDI). There, studies were being carried out to investigate the options for an indigenous design, combining long range with maneuverability, to meet the particular requirements of the Japanese Air Self-Defense Force (JASDF). In 1987, the JASDF selected a variant of the F-16C as the Japanese FS-X aircraft to replace the Mitsubishi F-1 aircraft, and in 1988 Mitsubishi was selected as prime contractor for the aircraft, which became known as the F-2. The program involved technology transfer from the USA to Japan, and responsibility for cost sharing was split 60% by Japan and 40% by the USA. Four flying prototypes were developed, along with two static prototypes for static testing and fatigue tests. Flight trials of the prototypes were successfully completed by 1997. After the F-2s entering service in the 2000s the first (63-8501) and second (63-8502) prototypes now are test aircraft for new technology and equipment and continue to fly to this day.
Around 2018-2019 XF-2A (63-8501) now a test aircraft served as a test bed for next gen F-X fighter technology which I will describe below. The F-X studies have been around for a long time as far as 2010 maybe even older. At the time Japan started the F-X program for a future Japanese gen 5 stealth fighter (now Gen 6). A milestone was the development and first flight of the X-2 Shinshin in 22 April 2016 which boosted research on stealth aircraft. Technically the F-X program is still ongoing today now in collaboration with the U.K, Italy and Japan which has formed the GCAP gen 6 fighter program as of 2023.
New IRST and AESA radar technology
In October 2018 XF-2A (63-8501) was seen with 2 ASM-2 missiles however one of these are not a missile anymore but instead has been converted into a IRST sensor, the warhead removed and seeker changed recognizable by a now black “seeker” which is now an IRST sensor this is one of the new technologies that was being experimented on for the future F-X fighter which is planned to use IRST.
A year later in March 2019 a new radar was installed on the XF-2A no official name I could find but I think “F-X” Radar is appropriate since it was a test for a new more powerful AESA radar which was a upgraded version of J/APG-2 now with more focus on tracking and targeting stealth aircraft much more easy, the radar works together with the IRST sensor. Sadly there is little to no hard numbers on the performance but that is nothing new since J/APG-1 and J/APG-2 also lack such data thus these radars will have to be estimated by Gaijin. After 2019 it is unknown what happened to the IRST sensor and new radar, there are rumors it might be added to late production F-2s but we have yet to see that. Needless to say this is the pinnacle in Japanese fighter domestic AESA radar technology and would be an even bigger boost in radar power compared to the already modern J/APG-2.
In War Thunder this aircraft would be a late gen 4 addition to the game closer to when more stealthy aircraft are being introduced and will be a good transition to the gen 5 era of radar technology for Japan. Other then that this will have similar capabilities to late production F-2s however it will not be as good compared to late F-2s in the CAS role due to lack of AN/AAQ-33 ATP and lack of LJDAMs but will be almost identical in the air to air role and with the IRST and even stronger radar thanks to the new F-X radar it might surpass late F-2s in the fighter role.
Length: 15.52 m (50 ft 11 in)
Wingspan: 11.125 m (36 ft 6 in) over missile launchers
10.8 m (35 ft) without missile launchers
Wing area: 34.84 m2 (375.0 sq ft)
Aspect ratio: 3.3
Empty weight: 9,527 kg (21,003 lb)
Gross weight: 13,459 kg (29,672 lb) clean
Max takeoff weight: 22,100 kg (48,722 lb)
Maximum landing weight: 18,300 kg (40,300 lb)
Fuel capacity: 4,637 l (1,225 US gal; 1,020 imp gal) maximum internal fuel 4,588 l (1,212 US gal; 1,009 imp gal)
Powerplant: 1 × General Electric F110-IHI-129 afterburning turbofan, 76 kN (17,000 lbf) thrust dry, 131 kN (29,500 lbf) with afterburner
Maximum speed: 2,124 km/h (1,320 mph, 1,147 kn)
Maximum speed: Mach 2.0 at high altitude, Mach 1.1 at low altitude
Combat range: 833 km (518 mi, 450 nmi) +
Service ceiling: 18,000 m (59,000 ft)
Wing loading: 634.3 kg/m2 (129.9 lb/sq ft) maximum
- 20 mm M61 cannon: 511 rounds
- 4x AAM-3
- 4x AAM-5A/B
- 4x AAM-4/B
- 4x ASM-1
- 4x ASM-2
- 2x ASM-3/A
- 8x GBU-38 GPS
- GCS-1 kit
- 12x 500Ib Mk.82
- “F-X” AESA radar
- ASM-2 IRST Modified
Mitsubishi F-2 | Thai Military and Asian Region
F-16.net - The ultimate F-16, F-35 and F-22 reference
次期戦闘機・アビオニクス（2-1） : 軍事あれこれとかのblog (credit to this site for a lot of useful information and pictures)
(sadly sources on the radar and IRST itself are lacking besides the original pics I provided which mainly come from the Japanese Mod)