In 1982, the Japanese government announced that they were seeking a new warplane to succeed the Mitsubishi F-1 fighter support aircraft. This led to a project known as the Next Fighter Support Aircraft, or FS-X. The Japanese government contacted several foreign aircraft manufacturers to see if existing types could meet the FS-X requirement. At the same time, the indigenous Japanese aircraft industry was approached to see if it were practical for them to come up with a solution. Very rapidly, the contenders narrowed down to the F-16 Fighting Falcon, the F/A-18 Hornet, the Panavia Tornado IDS, and a possible indigenous aircraft. An important requirement was the use of a Japanese-built datalink system and the ability to carry the ASM-1 antiship missile.
The formal requirement was issued on November 22, 1985. The aircraft was to have the ability to carry up to four antiship missiles. In addition, the aircraft had to be able to carry 2-4 short-range AAMs and 2-4 medium- range AAMs, although not necessarily at the same time as the antiship missiles were being carried. An important requirement was a minimum combat radius of 450 nautical miles.
After looking over the responses, the Japanese Defense Agency concluded that no existing aircraft was able to meet these requirements. Only an indigenously-developed aircraft would do. The three foreign contenders complained bitterly about being ruled out in favor of an as-yet-nonexistent paper design. In addition, US and European governments became involved because of the large trade inbalances that existed between Japan and the economies of the USA and Europe, and they pressured the Japanese government for a reconsideration. As a result of the controversy, in April of 1986 the Japanese Defense Agency reissued its request, and all three foreign contenders issued revised proposals.
The question now came down to whether a co-development of an existing foreign aircraft would be selected, or if an entirely indigenous aircraft would have to be developed from scratch. The choice of an entirely new indigenous design would of course have pleased the Japanese aviation industry, but the cost would have been quite high and the project might be subject to lengthy delays due to the need to start from scratch. If a foreign design were selected instead, a considerable Japanese contribution to the project would be required. The Tornado development was eliminated at an early stage because of vague and unspecified concerns about a co-development project with European aircraft industries being somehow incompatible with Japanese security concerns. The revised F/A-18 was dropped soon thereafter because of its high cost. On September 11, 1987, it was announced that the choice had narrowed down to an indigenous aircraft, or a development of the F-15 or F-16.
On October 21, 1987, the Japanese government announced that it had ruled out the solely indigenous option, and that it had selected a development of the F-16C/D as the choice for the FS-X. The decision was undoubtedly due to a lot of pressure from the US government. The deal was also rather controversial in the USA at the time, with critics charging that the US was giving away too much technology to a competitor. Japanese Air Self Defense Force (JASDF) announced plans to acquire as many as 130 FS-Xs to replace the Mitsubishi F-1 fighter bomber.
The prime contractor for the FS-X was Mitsubishi Heavy Industries, in collaboration with General Dynamics (now Lockheed Martin). Fuji Heavy Industries and Kawasaki Heavy Industries were important subcontractors. It was agreed that 60 percent of the work would be done in Japan, with the remaining 40 percent of the work being done by American industries.
Mitsubshi was assigned the responsibility for the forward fuselage and for all final assembly, with Kawasaki supplying the central fuselage, the landing gear doors, and the engine access doors. Fuji is responsible for the radome, the air intake, the starboard wing (except for the leading edge flaps), wing root fairings, the starboard wing flaperon, vertical tail surface and horizontal tail surface. General Dynamics (later Lockheed Martin) was given the port wing (with the exception of the flaperon), the starboard wing leading edge flaps, and the rear fuselage.
The increased- performance General Electric F110-GE-129 turbofan was selected as the powerplant, which is the engine used by the F-16C/D Block 50. The engine is to be built under license in Japan by Ishikawajima-Harima Heavy Industries.
Originally, the FS-X was to have had a pair of large foreplane surfaces underneath the air intake, much like those tested on the F-16 CCV and AFTI F-16. However, these were deleted from the design on December 11, 1991, reducing weight and aerodynamic drag.
The FS-X is quite similar in appearance to the F-16C/D, but features a new Japanese-designed wing of greater span and root chord. The wingspan is 36 feet 0 inches, as compared with 32 feet 9 3/8 inches for the standard F-16C. The new wing has 25 percent more area and makes extensive use of co-cured composite technology to cut down on the weight and to reduce the radar signature. The planform of the wing is much the same as that of the F-16, but features a slightly forward-swept trailing edge. As compared to the F-16, the FS-X has an extra stores station underneath each wing, for a total of three plus the wingtip station. The FS-X will be able to carry two or four Mitsubishi ASM-2 anti-shipping missiles. The tailplane surfaces are 20 percent larger in area than those of the standard F-16C.
The fuselage of the FS-X is slightly longer in the midsection than that of the F-16C/D in order to accommodate additional fuel and avionics, and the radome is slightly longer. The FS-X has a length of 50 feet 1 inches, as compared with 49 feet 6 inches for the F-16.
The FS-X features a reinforced canopy with a bow frame because of mission requirements for low-level flight capabilities and the attendant increased risk of bird strikes.
The FS-X features a housing for a drag chute above the engine exhaust.
The estimated maximum take- off weight of the FS-X is 49,000 pounds, as compared with 42,300 pounds for a USAF F-16C.
The primary difference between the FS-X and the F-16 is in the use of Japanese domestic technology for much of the avionics, including a new Mitsubishi Electric active phased-array radar, a Yokogawa LCD multi-function display, a Shimadzu holographic display and Mitsubishi Electric integrated electronic warfare system, plus an indigenous inertial reference system and mission computer.
The control stick and throttle lever have complete Hands On Throttle and Stick (HOTAS) capability, with the weapons release switches being on the stick.
Both single- and two-seat versions were planned. The two seater has all the capabilities of the single seater but has somewhat less internal fuel (1043 US gallons as opposed to 1225 US gallons. The rear seat does not have a holographic heads-up display. The crew members sit on ACES II enector seats.
The primary weapons of the FS-X were to be the AIM-7F/M Sparrow, the AIM-9L Sidewinder, and the Mitsubishi AAM-3 missiles. There are as yet no plans to use the AIM-120 AMRAAM or the Mitsubishi AAM-4 that is currently under development. The primary air-to-ground weapon was to be the Mitsubishi ASM-2 antiship missile. An internal 20-mm JM61A1 rotary cannon is also carried.
The Japanese Defense Agency ordered two single-seat FS-X and two dual- seat TFS-X prototypes, plus two static test aircraft. The prototype FS-X (bearing the temporary serial number 63-0001, befitting aircraft assigned to the Technical Research and Development Institute) rolled out of the Mitsubishi Heavy Industries facilities on January 12, 1995. 63-0001 flew for the first time from Komaki air base near Nagoya on October 7, 1995 with Mitsubishi test pilot Yoshiyuki Watanabe at the controls. It stayed in the air for about 38 minutes. The second prototype single-seater (63-0002) flew for the first time on December 13, 1996.
In 1996, the designation F-2 was officially assigned to the FS-X project, with the single seater being designated F-2A and the two-seater being designated F-2B. The first prototype XF-2A (63-0001) was turned over to the JASDF Air Development and Test Wing at Gifu for flight testing on March 26, 1996, following official handover to the Japanese Defense Agency on March 22. The two twin-seat XF-2B prototypes (63-0003 and 63-0004) were delivered in August and September of 1997. Two static test articles were to undergo 6000 hours of fatigue and structural testing at the JDA/Technical Research and Development Institute's Tachikawa facility.
It had originally been planned that the flight test program would last until 1998, with first production deliveries beginning in 1999. However, in July of 1998 it was announced that some wing flutter and cracking problems had been encountered during flight tests, and the test program for the four XF-2 prototypes would extend to December 1999. It was also revealed that some problems had been encountered in roll characteristics and that some electrical problems needed to be corrected.
The JASDF originally planned to acquire up to 141 F-2A/B fighters if funding permitted. Service entry is currently set for 2001, with 74 examples to be distributed among three combat squadrons (the 2nd and 8th Hikotai at Misawa and the 6th Hikotai at Tsuike), replacing the Mitsubishi F1 ground attack aircraft. In addition, 21 examples will be operated by an operational conversion unit. Eight will go to the Tactical Fighter Training Group. It was originally planned that 11 aircraft would be provided to the Blue Impulse aerobatic team, but these aircraft were cancelled when the program was reviewed in 1997. The remaining F-2 aircraft will be held in reserve. Current plans call for a total of 130 F-2 aircraft to be acquired, including those for training units and reserves.
In 1999, the JASDF began withdrawing the Mitsubishi F-1 close-support fighter from service, in anticipation of the arrival of the first of the planned 130 F-2s. It is also possible that F-2s will begin replacing some of the JASDF's force of F-4EJ KAI Phamtoms, although this has not yet been officially announced and current plans include only the replacement of the F-1.
In December of 1997, the serial numbers of all four XF-2 prototupes were changed from the TRDI to the JASDF system. 63-0001 became 63-8501, 63-0003 became 63-8101, etc. Production examples of the F-2A will have JASDF serial numbers in the 8500 range, with the F-2Bs having serial numbers in the 8100 range.
63-8501/8502 Mitsubishi XF-2A Formerly serialed 63-0001/0002 63-8101/8102 Mitsubishi XF-2B Formerly serialed 63-0003/0004
Engine: One General Electric F110-GE-129 turbofan rated at 17,000 lb.st. dry and 29,500 lb.st. with afterburning. Performance: Mach 2.0 at high altitude and Mach 1.1 at low altitude. Combat radius in excess of 450 nautical miles. Weights: 21,000 pounds empty, 26,450 pounds gross, 48,720 pounds maximum takeoff. Dimensions: 35 feet 5.2 inches (without wingtip missiles),length 50 feet 11 inches, height 15 feet, wing area 114.3 square feet. Armament: One 20-mm JM61A1 cannon in the leading edge of the port wing/fuselage fairng plus up to 17,800 pounds of external stores.