Global Combat Air Programme


The Global Combat Air Programme is a multinational initiative led by the United Kingdom, Japan, and Italy to jointly develop a sixth-generation stealth fighter commonly, but not formally referred to as Tempest. The programme aims to replace the Eurofighter Typhoon in service with the Royal Air Force and Italian Air Force, and the Mitsubishi F-2 in service with the Japan Air Self-Defense Force.
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: the United Kingdom-led BAE Systems Tempest developed with Italy, and the Japanese Mitsubishi F-X. This was formalised with a treaty signed in December 2023 in Japan.
There are around 9,000 people working on the programme worldwide, with 1,000 and more suppliers from across the three partner nations. 600 such suppliers are based in the UK, and 400 are based in Italy and Japan.
Under the current timeline, formal development is expected to begin in 2025, with a demonstrator aircraft to fly in 2027, and production aircraft to begin entering service from 2035.

Background

Japan (F-X)

Japan, an island nation, has a disproportionately vast air defence identification zone given the size of its land territory, and it was expected that the country would have to protect it with a smaller fleet of fighters compared to those of its growing neighbours with much larger populations. To address this issue, the Ministry of Defence decided in 2010 that Japan's next-generation fighter had to be highly information-based, intelligent, and capable of instantaneous response. At the time, the fighter fleet of the Japan Air Self-Defence Force mainly consisted of the Mitsubishi F-15J and the Mitsubishi F-2. The former is a variant of the F-15, manufactured by Mitsubishi Heavy Industries under licence, while the latter was developed by Mitsubishi and Lockheed Martin based on the F-16 in the 1990s. While the F-15J was set to be replaced by the F-35, a replacement for the F-2 needed to be found before its planned retirement in the 2030s.
Following the USA's decision not to allow the export of the F-22 Raptor to any other country in 2007, Japan began looking for a domestic solution to field a new fighter aircraft to replace its Mitsubishi F-2 fleet. From the mid-2000s Japan began funding various research programmes involved in fighter design culminating in the Mitsubishi X-2 Shinshin experimental aircraft which took flight on 22 April 2016. This research and the data collected from the X-2 programme would feed the development of Japan's main fighter effort, the Mitsubishi F-X programme. The IHI Corporation completed a prototype for the XF9 engine in 2018. In 2018, after more than a decade since America's refusal to export the F-22, Lockheed Martin proposed a potential Japan-America collaboration project to develop the F-2 successor based on the F-22 and F-35, but this was rejected by Japan.

United Kingdom & Italy (Tempest)

The 2010 Strategic Defence and Security Review committed the United Kingdom to operating a Royal Air Force fast-jet fleet comprising Eurofighter Typhoons, F-35s, and uncrewed combat and reconnaissance aircraft by the 2020s. In preparation for the 2015 SDSR, the UK launched a two-year Future Combat Air System programme to assess options for the post-2030 fleet, including new Uncrewed Combat Air Vehicles, additional F-35 orders, life extension of Typhoon, or a new crewed fighter design.
Following the 2010 Lancaster House Treaties, the UK and France agreed to collaborate on future combat air technologies, including UCAVs intended to replace Typhoon and Rafale aircraft in the 2030s. In 2012, both governments and industry partners funded joint studies, leading to a £120 million FCAS Feasibility Phase contract in 2014. Drawing on the Dassault nEUROn and BAE Systems Taranis demonstrators, the study aimed to support a joint UCAV procurement in the 2030s and possible integration into future crewed platforms.
The 2015 SDSR introduced the Future Combat Air System Technology Initiative which had three core strands for the development of combat air technologies: international projects ; national projects; and an open mission system architecture project. In 2016, the feasibility study led to a £1.54 billion prototype UCAV project.
In 2017, France and Germany announced plans to develop a joint fighter to replace the Rafale and Typhoon, forming the European FCAS programme. This initially raised uncertainty over the UK–France UCAV effort, though in early 2018 both governments confirmed its continuation; France intended to pursue a crewed platform with Germany and an uncrewed demonstrator with the UK.
At the 2018 Farnborough Airshow, a mock-up of 'Tempest' was revealed, a BAE Systems led sixth-generation fighter programme that would be developed to replace the RAF's Typhoons in the mid-to-late 2030s. Developed by “Team Tempest”, the programme was accompanied by a new Combat Air Strategy highlighting technological competitiveness and industrial sovereignty. In 2016, the UK combat air sector generated £6.5 billion annually and supported 46,000 jobs.
In February 2019, the FCAS UCAV demonstration programme between the UK and France had seemingly been downgraded to a technology demonstration and study effort, as France deepened its collaboration with Germany.
On 19 July 2019, Sweden signed a Memorandum of understanding with the UK to work together to develop concepts and understanding for both nations' FCAS for the future of air combat platforms, and Italy joined the Tempest programme in September 2019. In 2020, Sweden and the UK expanded their partnership through SAAB's £50 million investment in a UK centre of excellence, though Sweden did not formally join the Tempest project. The UK, Italy, and Sweden signed a trilateral FCAS MoU in December 2021.
A number of new technologies were being explored for Tempest, including:
  • Directed-energy weapons
  • Augmented reality cockpit - control scheme featuring little-to-no physical controls, instead displaying features virtually on the heads up display via the pilot's helmet. This would reduce aircraft weight, improve upgradability through a software-based approach, and provide additional display space for information outside of the typical flat-screen arrangement. This also includes examinations into interactivity such as motion-control and eye-tracking.
  • Biometric and psycho-analytical monitoring - exploring pilot health monitoring during combat and training to identify issues such as stress, confusion, cognitive load, as well as hypoxia or G-LOC.
  • Manned-unmanned teaming - crewed aircraft like Tempest working cooperatively with uncrewed aerial vehicles known as 'Adjuncts'
  • Artificial intelligence - known as the Intelligent Virtual Assistant that could assist with aircraft operations or data processing in certain operations or situations.
Much of the technology envisioned for use on Tempest would initially be fielded on two distinct testbed platforms. The first is 'Excalibur', a Boeing 757-200 modified by British firm 2Excel in conjunction with Leonardo UK to serve as a flight test aircraft to de-risk and validate the technologies being examined for use on the fighter including the aerodynamics of the fighter's nose section and testing the aircraft's sensor suite. The second would be a crewed supersonic demonstrator aircraft announced in 2022 and expected to take flight around 2027, which would test, among other technologies, the integration of stealth compatible features.
It was envisaged that the programme would agree to funding and manufacturing arrangements by 2025 with an expected in-service date for the aircraft in 2035.

Development

Programme Initialisation

Discussions for both parties combining their respective fighter development efforts as a means of reducing their overall development costs began as early as 2017. In December 2021, the first results of this endeavour appeared when the UK and Japan announced they would jointly cooperate to produce a demonstrator for a new fighter engine as well as the signing of a memorandum of cooperation to explore future air combat technologies together. On 15 February 2022, a further agreement was reached between both nations to jointly develop sensor capabilities for their respective fighters known as the 'Japan and Great Britain Universal Advanced RF system' or 'JAGUAR'.
In July 2022, Reuters reported from anonymous sources within both programmes that both parties were close to a deal that would combine both Tempest and F-X into a single joint programme. On 9 December 2022, this was proven correct when it was officially announced by British Prime Minister Rishi Sunak that the Tempest and F-X programmes would merge into a single endeavour to procure a common multi-role fighter now called the "Global Combat Air Programme". The resulting aircraft would also be expected to be available for export to further reduce the per-unit costs.
The programme is envisaged as an equal partnership between the member nations. In the UK, BAE Systems will act as prime contractor and handle the airframe, Rolls-Royce the engines, Leonardo's UK division the electronics, and MBDA UK the weapons. In Japan, Mitsubishi Heavy Industries will act as prime contractor, with IHI Corporation handling the engines, and Mitsubishi Electric handling the electronics. In Italy, Leonardo S.p.A. will be prime contractor, with Avio Aero working on the engines, and MBDA Italy will also work on missile development. By around 2024, detailed development and cost sharing for each company would be clarified, production to begin around 2030, and the first aircraft to be deployed in 2035.

Joint Venture and Corporate Structure

GCAP international government organisation

In September 2023, the UK, Italy, and Japan signed a trilateral collaboration agreement to outline long-term working arrangements and capability requirements for GCAP. In December 2023, an international treaty was signed in Tokyo, formally launching the joint development of the future fighter aircraft. The treaty confirmed that both the programme's governmental headquarters and industrial hub would be based in the UK, with Japan providing the first CEO and Italy the first business leader. It also established the GCAP International Government Organisation, which would oversee the aircraft's development once ratified by each country's political bodies. The Japanese Ministry of Defence stated that technical officials would be dispatched to support GIGO, and that secure facilities and daily coordination between governments and industries would underpin the development process.
On 6 March 2024, Prime Minister Fumio Kishida announced that further defence export reforms were needed to reduce production costs, strengthen Japan's security posture, and enhance its reliability as an international defence partner. Later that month, the government approved revisions to its strict export rules, permitting the transfer of defence equipment, including the jointly developed fighter, to partner nations that have signed defence cooperation agreements and are not involved in active conflicts. Komeito, the junior coalition partner, expressed reservations in line with its pacifist principles. In June 2024, Japan's National Diet ratified the treaty, formally establishing GIGO.
Japan's 2024 Defence White Paper explained that these reforms were necessary to align with the UK and Italy, both of which viewed exports of the finished aircraft as essential for cost reduction and international influence. To support this, Japan revised its Three Principles on Transfer of Defence Equipment and Technology and their Implementation Guidelines, introducing three specific restrictions governing GCAP exports:
  1. At present, direct transfers of GCAP material from Japan are restricted to finished products only.
  2. Transfers are restricted to nations who have signed international agreements obligating the use of Japanese defence equipment transferred in a manner consistent with the purposes and principles of the Charter of the United Nations.
  3. Transfers can not be made to a country where combat is currently deemed to be taking place as part of an armed conflict.
The UK ratified the GCAP convention in October 2024, followed by Italy in November 2024. On 15 January 2025, the UK Ministry of Defence announced that the GIGO would be headquartered in Reading and led by its first Chief Executive, Oka Masami.