The Sovereign Effects Partners (SEPs) – MBDA UK, MBDA Italia, Mitsubishi Electric and Mitsubishi Heavy Industries – have signed a new collaboration agreement aimed at supporting the Global Combat Air Programme (GCAP) and the development of its next-generation combat air capability.

The agreement was announced at Farnborough International Airshow 2026 and establishes a new international operating model through which the four companies will work collaboratively in support of Edgewing’s delivery of the core GCAP combat aircraft.

The Global Combat Air Programme (GCAP) is a trilateral programme involving the United Kingdom, Italy and Japan to develop a next-generation combat air system centred on a new advanced fighter aircraft intended to enter service around 2035.

GCAP was formally launched in December 2022 through the combination of the UK and Italy’s Future Combat Air System/Tempest activities with Japan’s F-X next-generation fighter programme.

The future aircraft is being designed to operate at the centre of a wider networked combat air environment, combining advanced sensors, communications, data processing and weapons with extensive digital connectivity. It is expected to operate alongside other crewed and uncrewed platforms and exchange information across multiple domains.

A major objective of GCAP is therefore not simply to produce a replacement fighter aircraft, but to create a highly connected combat air capability able to respond to evolving threats over several decades.

The programme is also intended to preserve and develop sovereign combat-air technologies and industrial capabilities within the three participating nations.

At the industrial level, Edgewing – the joint venture bringing together BAE Systems, Leonardo and Japan Aircraft Industrial Enhancement Co. (JAIEC) – is responsible for the design and development of the GCAP combat aircraft.

Under the new agreement, the Sovereign Effects Partners will undertake a broad range of joint activities, including providing specialist engineering services and expertise related to effects optimisation technologies and the digital integration of effector systems.

The objective is to ensure that advanced weapons and other effectors can be effectively integrated into the future GCAP platform while maintaining the sovereign capabilities of the United Kingdom, Italy and Japan.

Importantly, the agreement does not cover the joint development of new effectors. Instead, it is intended to align national and sovereign approaches to effectors while establishing the technological and digital framework necessary for their integration with GCAP.

The initiative represents another step toward transforming GCAP from separate national activities into an increasingly integrated multinational defence-industrial enterprise.

The Sovereign Effects Partners are transitioning from national contracting arrangements toward a sustained international structure and operating model designed to allow the companies to operate effectively as a single collaborative team during future phases of the programme.

MBDA contributes decades of experience in developing and integrating complex weapon systems for combat aircraft. The company has been involved in the UK’s Team Tempest initiative since 2018, with its participation expanding as Italy joined the programme in 2019.

Mitsubishi Electric brings significant expertise in defence electronics, including experience from Japan’s F-2 programme and the F-X next-generation fighter effort. The company is also working with Leonardo and ELT Group on GCAP’s integrated sensing and communications activities.

Mitsubishi Heavy Industries (MHI) brings extensive experience in fighter aircraft and guided weapons development. As Japan’s principal fighter aircraft manufacturer, MHI has served as prime contractor for the development and production of the F-2 fighter and has participated in F-15 production. It also develops guided weapons for Japan’s Ground, Maritime and Air Self-Defense Forces.

The collaboration agreement highlights the increasingly integrated industrial architecture being established around GCAP as the United Kingdom, Italy and Japan advance toward their common next-generation combat aircraft.

By coordinating expertise in weapons integration, digital technologies and effects optimisation, the Sovereign Effects Partners aim to ensure that GCAP can incorporate advanced sovereign effectors while retaining the flexibility required to integrate new weapons and capabilities throughout the platform’s operational life.