The Mitsubishi F-X (unofficially called F-3) was a sixth-generation stealth fighter that was in development for the Japan Air Self-Defense Force (JASDF). It was to be Japan's first domestically developed stealth fighter jet and to replace the Mitsubishi F-2 by the mid-2030s. Its development also aimed to bolster the nation's defense industry and potentially enter the international arms market amid Japan's changing defense posture. In October 2020, Mitsubishi Heavy Industries was selected as the lead developer.Japan picks Mitsubishi Heavy to lead development of new stealth jet fighter Nasdaq On 9 December 2022 the governments of Japan, the United Kingdom, and Italy jointly announced that they would develop and deploy a common fighter jet under a project called the Global Combat Air Programme (GCAP), merging development of the latter two nations' BAE Systems Tempest and the F-X.
Development
Origins
The F-X program began when the United States banned exports of the Lockheed Martin F-22 Raptor as part of the 1997 Obey amendment in order to safeguard its technology. With Japan no longer able to purchase the F-22, a domestically developed fighter was chosen instead to replace Japan's aging fleet of fighter jets. Between December 2009 and August 2010, the Ministry of Defense (MoD) conducted a study of developing a future fighter jet to replace the F-2. The research conducted called for a new fighter jet that would be a generation ahead of contemporary fifth-generation fighters. The concept fighter was named the i3 Fighter (Informed, Intelligent, Instantaneous). Some technology and capabilities the concept fighter was to possess include advanced radar systems to counter stealth technology of other fighters, receiving targeting information from other platforms (drones, fighters and/or airborne early warning and control aircraft), use of fly-by-optics (much like the Kawasaki P-1) to process information faster, stealth technology, gallium nitride semiconductors to improve radar performance, and a new, more powerful and compact engine.
Mitsubishi X-2 demonstrator
Much of the development of the F-X program correlated with the development of the Mitsubishi X-2 Shinshin. The development of the X-2 demonstrator allowed Japan to obtain new information and develop new technology related to their next generation fighter jet. The X-2 made its maiden flight on 22 April 2016. The X-2's testing concluded in March 2018.
Continued development and procurement strategy Aircraft components Concurrent to the X-2's development and testing, Japan conducted a similar program of research focused on the F-X fighter. This research and testing continued while Japan sought international collaborators to join the program.
+List of F-X related evaluationsEvaluation periodName of evaluationDevelopment time periodTotal costPurposeOctober 2009Study on advanced integrated sensor systemPrototype: 2010 - 2014Testing: 2014 - 2016¥500 millionDetect stealth aircraft using various sensors working in tandem with each otherResearch on aerodynamic technology for weapon internalizationPrototype: 2010 - 2013Testing: 2013 - 2014¥1.3 billionSimulate the separation of internal weapons from weapon bays to study aerodynamic phenomenon acting on the mounted object at transonic and supersonic speedResearch on main components of next-generation enginePrototype: 2010 - 2014Testing: 2014 - 2015¥100 millionAchieve high thrust-to-weight ratio for next-generation engine by developing high-temperature combustor, high-temperature/high-pressure turbine and light-weight compressorJuly 2011 - August 2011Research on integrated fire control technology for fightersPrototype: 2012 - 2016Testing: 2015 - 2017¥9.1 billionDevelop a Network centered battlespace to enable data sharing and cooperation between stealth aircraft, conventional platforms, and enabling assets like AWACsSJuly 2012 - September 2012Study on engine elements for fightersPrototype: 2013 - 2017Testing: 2015 - 2017¥172 billionDesign high power engine to be slim and possess high thrustResearch on weapon release/stealthPrototype: 2013 - 2017Testing: 2016 - 2017¥3.8 billionDevelop internal weapons bay to reduce RCS and dragResearch on advanced RF self-defense simulationPrototype: 2013 - 2016Testing: 2015 - 2018¥1.6 billionDevelop electronic warfare equipment to counter aircraft and missilesJuly 2013 - August 2013Study on high power microwave technologyPrototype: 2014 - 2017 Testing: 2016 - 2018¥1.8 billionDevelop high power microwave technology to neutralize incoming missileStudy on high resolution technology of infrared imagePrototype: 2014 - 2017Testing: 2016 - 2019¥3.8 billionEnhance resolution of infrared imaging technology for various platforms, i.e. fighter jetsResearch on airframe structure weight reduction technologyPrototype: 2014 - 2017Testing: 2017 - 2018¥5.7 billionUtilize high-precision stress analysis technology to reduce weight of future fighter air-frame and analyze strength risk associated with weight reductionJuly 2014 - August 2014Study on technical feasibility of future fightersPrototype: 2015 - 2017Testing: 2016 - 2017¥5.4 billionDevelop virtual vehicle design to determine on whether to develop an F-2 successorStudy on engine system for fighterPrototype: 2015 - 2018Testing: 2017 - 2019¥14.2 billionDevelop and trial the XF9 engineStudy on electric actuation technologyPrototype: 2015 - 2017Testing: 2018¥2.3 billionDevelop electric actuators to replace conventional hydraulic systemStudy on radome for stealth fighterPrototype: 2015 - 2019Testing: 2018 - 2020¥5.4 billionDesign a radome to protect radar and maximize aerodynamic, stealth and radar performanceStudy on future HMD systemPrototype: 2015 - 2018Testing: 2018 - 2019¥3.5 billionDevelop future HMD system with wide field of vision and binocular, multi-color displayJuly 2015 - August 2015Study on thrust deflection nozzlePrototype: 2016 - 2019Testing: 2017 - 2020¥2.3 billionDevelop thrust deflecting nozzle to achieve high maneuverability, reduce steering area and improve stealthStudy on small heat transfer system for future fightersPrototype: 2016 - 2019Testing: 2018 - 2020¥1.9 billionDevelop cooling system based on vapor cycle In mid-September 2019, flight tests were conducted on integrated sensors to be used for the F-X. The sensors were tested on board an F-2 fighter and the results were said to be good.
F-X program and international collaboration In March 2017, Japan and the U.K. signed an agreement to explore the possibility on co-developing a future fighter jet. By March 2018, a Japanese MoD representative had stated that the Japanese government was deciding whether to develop the F-X as a clean-sheet design, either domestically or through joint-development, or to develop an existing fighter design. That year, the Japanese government sent out proposals to the U.S. and U.K., seeking proposals for an upgrade of their existing designs. Boeing, Lockheed Martin, BAE Systems and Northrop Grumman all responded to the proposal. Boeing reportedly offered an upgraded fighter based on their F-15, while BAE systems offered a similar proposal based on the Eurofighter Typhoon. Lockheed Martin proposed a F-22/35 hybrid fighter while also offering Japan the majority of the work in developing and producing the aircraft. Northrop Grumman expressed interest in the project; with unconfirmed speculation that they might offer a modernised version of their YF-23. At the same time, Japan and U.K. also further explored the possibility on merging the F-X project with the Tempest project to some extent.
By October 2018, the MoD had begun to rule out the possibility of developing a fighter based on existing designs. Boeing's F-15 and BAE Systems' Eurofighter Typhoon reportedly failed to meet the ministry's requirements. Lockheed Martin's hybridised stealth fighter was also met with doubt due to its expensive price, as well as uncertainties that the U.S. would allow the sale given the export ban on the F-22. One report indicated that the hybrid fighter could cost as high as $177 million per aircraft.
In early February 2019, the MoD announced that a 'Japan-led' Future Fighter program would be initiated, with collaboration with foreign defense contractors still being an option. The announcement further enforced that plans to develop or locally produce an existing foreign design had been ruled out. The program would occur between 2019 and 2023, in line with the MoD's Mid-Term Defense Program and would take 15 years to complete; entering service around the time the F-2 would begin to retire. The MoD prioritised five key aspects for the program's development: Capability for future air superiority Potential to expand capability by incorporating next generation technologies Ability to modify and upgrade the new platform Participation of Japanese industry Affordable cost
On 21 August 2019, the MoD announced that development of the stealth fighter would commence between April and December 2020, in accordance to the FY 2020 defense budget. The funding that the MoD acquired would be used to initiate the fighter program. By December 2019, the MoD had secured ¥11.1 billion from the FY 2020 defense budget to launch the program. In total ¥28 billion was used to fund the F-X development for FY 2020. Of the total budget, ¥16.9 billion (60%) was to be used for research projects, while the remaining ¥11.1 billion (40%) was to launch the program and begin conceptional design. The FY 2020 defense budget also revealed the name of the program has been officially changed from "Future Fighter" to "F-X".
On 27 March 2020, Japan rejected further design proposed based on existing aircraft by Lockheed Martin, Boeing, and BAE Systems, based on a hybridised F-22/35, the F/A-18E/F Super Hornet, and Eurofighter Typhoon respectively. According to an official from the Acquisition, Technology & Logistics Agency (ATLA) the designs still did not meet Japanese requirements. However, the decision did not rule out the possibility of international collaboration; as Lockheed Martin, Boeing, Northrop Grumman and BAE Systems were still listed as potential partners. This was confirmed by an MoD spokesperson, who stated that Japan had developed enough technology to possibly develop the F-X domestically, but was still pursuing the option of international collaboration. On 1 April 2020, ATLA established a dedicated team to develop the F-X. The team was led by a major-general from the Japan Air Self-Defense Force (JASDF) and consisted of 30 JASDF officers, engineering officials and others. Subaru Corporation also announced that it would establish a Technology Development Center to support the F-X's development.
, the MoD expected production of the first fighter prototype to begin in 2024, with flight tests starting in 2028. Full-scale production was expected to commence by 2031.
In June 2021, Japan said that it was in discussions with British officials regarding cooperation with Rolls-Royce on engine development.
On 9 December 2022, the governments of Japan, the United Kingdom, and Italy jointly announced that they would develop and deploy a common fighter jet, merging their previously separate sixth-generation projects into the Global Combat Air Program. Japan's merger into this multinational effort effectively ended F-X as a separate fighter program.
Design
Overview The F-X was a twin engine stealth fighter focused on achieving air superiority. By the Japanese MoD's own terminology, the technology and capabilities the F-X possesses would classify it as a sixth generation fighter jet.