Source: The Conversation – UK
The UK is building a next generation fighter jet in collaboration with Italy and Japan. The Global Combat Air Programme (GCAP) has taken on even greater significance since the collapse of a rival project called the Future Combat Air System (FCAS), a collaboration between France, Germany and Spain.
The GCAP aircraft, which will be known in Britain as Tempest, should enter service by 2035. For Britain and Italy, the project fulfils a need to replace their Eurofighter Typhoon fleets with a cutting edge combat jet capable of protecting national borders.
The plane could also participate in Nato-led missions, including protecting European skies against capable and determined adversaries. Japan too needs a fighter jet up to the task of protecting a large maritime region against incursions of its airspace.
So can these three partner nations succeed where FCAS failed and build a truly state-of-the-art combat aircraft?
The most advanced fighter jets in the world are known as “fifth generation”. Tempest is classed as a sixth generation fighter jet. China and Russia have fifth generation aircraft and are working on their own sixth generation combat jets.
Many European nations have been replacing their ageing fleets with America’s fifth generation F-35 aircraft. But the Trump administration’s wavering levels of support for Nato have made some governments rethink their reliance on American hardware.
This underlines the importance of sovereign capability for the nations behind GCAP, which was established in 2022. On July 3 2026, the UK, Italy and Japan signed a £4.6 billion deal to move the project into its next design phase.
The contract was awarded to Edgewing, a joint venture between three aerospace companies: the UK’s BAE Systems, Italy’s Leonardo and the Japan Aircraft Industrial Enhancement Company (which is jointly funded by Mitsubishi Heavy Industries and the Society of Japanese Aerospace Companies).
The award followed nine months of delay as the UK worked to finalise its defence spending plans.
What will distinguish sixth generation fighter jets from their predecessors is their ability to act as a “system of systems”. They will be packed with sensors to gather information about the battlespace. This will be combined in real time, along with data from satellites, naval assets and ground stations, to aid pilots in their missions.
Advanced jets like Tempest will be able to control drone aircraft, including a type called “loyal wingmen”. These drones assist missions by, for example, protecting the crewed fighter jet.
Meanwhile, stealth technology – which helps fighter jets reduce their chances of being detected by infrared and radar sensors – will be just as vital as it has been for fifth generation aircraft like the F-35.
So do GCAP partner nations have the technological capability to build such an aircraft? Yes, with a couple of caveats. In 2016, Japan became only the fourth country to test-fly a homegrown stealth demonstrator aircraft.
The Mitsubishi-built X-2 prototype demonstrated the success of Japan’s domestic stealth design and engineering techniques, its radar-absorbent materials and thrust vectoring (an aircraft’s ability to steer by changing the direction of its engine exhaust).
The UK flew its own stealth demonstrator, BAE Systems’ Taranis drone, in 2013. It showed the success of British-developed stealth technology and autonomous systems technology. Both stealth programmes have fed directly into GCAP; BAE Systems and Mitsubishi Heavy Industries are the same companies designing Tempest.
Italy and Japan also host F-35 final assembly lines, the only such facilities outside the US. This has created a workforce already experienced in the assembly of a fifth generation stealth jet, along with the production of full wings for the F-35. These skills transfer directly to building Tempest.
What remains unproven by the GCAP partners is the ability to integrate stealth, combined data from multiple aircraft sensors, and artificial intelligence into a single aircraft. Another uncertainty is the ability to sustain a production line of aircraft destined for national fleets. This is a harder engineering problem than it might seem and deserves closer scrutiny than it currently receives.
Equal terms
The FCAS project succumbed to disputes between the industrial partners, France’s Dassault and Airbus, representing Germany and Spain. Sticking points included which company led the design, the distribution of work and intellectual property issues.
Do the GCAP partners have the industrial and organisational discipline to avoid the same fate? GCAP’s Edgewing industrial venture reflects in its structure key principles that could prove vital for the project’s success.
The GCAP industrial partners each hold an equal 33.3% stake, with no single nation designated as lead. They have freedom to act on and modify the technology. This is a far cry from the F-35, where partner nations fly the aircraft with no control over changes to modernise the jet’s hardware or software, which is overseen by the US.
GCAP is not immune to future problems, but it settled its industrial leadership question before cutting metal, a distinction that may matter more than any single technological choice.
Inaccurate budgeting could yet prove a stumbling block for GCAP. Historically, multinational fighter jet programmes have underestimated the true costs.
Even after the Defence Investment Plan’s £8.6 billion commitment, the total cost of GCAP remains unquantified, since neither the unit price of each aircraft nor the size of the UK’s order has been fixed.
History tells us that pilot training is another thing combat air programmes get wrong. As a pilot myself, I know that moving experienced crews onto a new aircraft, even a mature one, takes months of study in ground school, extensive simulator time and supervised flying before it is trusted for operational use.
GCAP crews must be trained not just to fly the jet, but to direct other uncrewed aircraft such as loyal wingmen.
Nevertheless, the evidence suggests that Britain, Italy and Japan possess the technology to build a genuinely cutting-edge sixth generation fighter. Do they possess the industrial and organisational discipline to deliver it? Probably, but it remains conditional on funding and training keeping pace with ambition over the next nine years.
Marco Chan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.