Forget F-47 or F-35: GCAP 6th Generation ‘NGAD’ Could Be a Showstopper

The acronym GCAP stands for an Anglo-Italian-Japanese fighter project that means “Global Combat Air Programme”.

The project’s goal is to develop a new tactical combat aircraft that will replace the Eurofighter with both the UK Royal Air Force and the Italian Aeronautica Militare, as well as replace the Mitsubishi F-2 that serves with the Japan Air Self-Defense Force (JASDF).

GCAP 6th Generation Fighter

The three nations formed the GCAP partnership at the end of 2022. The decision was to combine the existing BAE Systems Tempest fighter program with the Mitsubishi F-X project, which initially started in cooperation with the US. The partners intend to initiate the development of the aircraft in 2025, with a prototype to fly in 2027 and production aircraft to enter service in 2035.

Those looking at these three partner nations will notice a wide variance between the requirements of the two European partner nations and the Japanese air defense zone, which stretches over immense distances on the other.

Range and Performance of GCAP

Japan, with its much wider area and vast distances to cover, may have the greater challenge in creating a new aircraft that replaces the current types in its service. Up to the present, the JASDF has operated a specialized version of the McDonnell-Douglas F-15, designated the F-15J/DJ, and the Mitsubishi Heavy Industries (MHI) F-2.

The F-15 aircraft first flew in 1972 and was built under license by (MHI) and is the aircraft that is closer in size and range to what is proposed for the GCAP. In the 2000s, Japan began modernizing some of its F-15Js to enhance their survivability against Tokyo’s adversaries’ rapidly evolving technological capabilities.

These upgrades were focused specifically on regional threats to the island nation, most notably the rapidly expanding military potential of the People’s Republic of China (PRC) and the Democratic People’s Republic of Korea (DPRK). In response to these challenges, in 2019, the Japanese government launched a major effort to modernize the JASDF F-15s into “Japanese Super Interceptors.”

The upgrade brings the aircraft to near parity with the US Air Force’s F-15EX Strike Eagle II capabilities. The enabling improvements in this upgrade are the Raytheon AN/APG-82(V)1 Active Electronically Scanned Array (AESA) radar, a new advanced mission computer, and the BAE Systems AN/ALQ-250 Eagle Passive Warning Survivability System (EPAWSS).

U.S. Air Force Maj. Aaron Eshkenazi, F-15EX Test Director for the 84th Test and Evaluation Squadron, performs preflight procedures for the F-15EX with Lt. Gen. Michael Koscheski, deputy commander of Air Combat Command, at Eglin Air Force Base, Florida, January 29, 2025. During his visit, Koscheski gained valuable insights from the 84th TES and 85th TES to help inform future decisions regarding the platform. The future F-15 fleet will complement 5th generation aircraft, bringing substantial additional capacity for over-sized long-range fires, sensors, and electronic warfare capabilities to defend critical locations in highly contested areas. (U.S. Air Force photo by 1st Lt. Rebecca Abordo)

London and Rome have comparatively less challenging propositions for future air power requirements because they will face a far less capable Russian Aerospace Force (VKS). The most advanced Russian fighter, the Sukhoi Su-57, has been built in very small numbers thus far. Only 32 are in service (including 10 prototypes) for an aircraft that first flew 15 years ago.

In comparison, more than 300 of the PRC’s Chengdu J-20 have been built. This is for an aircraft that flew one year later than the Su-57—14 years ago. The Russian fighter poses a clearly greater threat to Japan than what it poses to the NATO-nation partners involved in the GCAP.

Replacing Generations

The UK and Italian air services have an easier path forward because they will be replacing their Eurofighters with whatever aircraft the GCAP program produces. Both nations will still be operating the F-35 they have in service today in conjunction with the new 6th-generation aircraft.

However, in Japan, some, but not all, of their F-15s, which are far older designs than the Eurofighter, will be replaced. The US defense industry representatives that 19FortyFive spoke to say that only some of the F-15s in JASDF inventory will be kept online to supplant the F-35. This is due to the smaller, single-engine aircraft not having the range of the F-15.

The aircraft that will be retired once the GCAP design comes online will be the F-2 fighter that Japan’s MHI designed in conjunction with the US. This “bigger, better F-16 derivative” was hoped to be the stepping stone to a next-generation F-3 fighter, but it has now been canceled in favour of the GCAP effort.

About the Author: 

Reuben F. Johnson is a survivor of the February 2022 Russian invasion of Ukraine and is an Expert on Foreign Military Affairs with the Fundacja im. Kazimierza Pułaskiego in Warsaw. He has been a consultant to the Pentagon, several NATO governments and the Australian government in the fields of defense technology and weapon systems design.  Over the past 30 years he has resided in and reported from Russia, Ukraine, Poland, Brazil, the People’s Republic of China and Australia.