January 28, 2022: Japanese engine maker IHI is partnering with Britain’s Rolls-Royce to develop a new engine for Japan’s FX stealth aircraft. Over half a billion dollars will be spent by the partnership to produce a demonstrator (working prototype) within a decade. Rolls Royce has been developing aircraft engines for over a century. Rolls was one of the first firms to develop a jet engine for fighters during World War II. Right after the war Rolls sold the Soviets 25 of its Nene jet engines with the condition that they would not be used for military aircraft. Technically the Russians complied, but when shot down MiG15s were examined the “Russian” jet engine was clearly a copy of the Nene.

While Rolls-Royce still develops some military engines, most of its business is as a primary or secondary supplier of engines for Boeing, Airbus and other commercial aircraft makers. While the American firm General Electric is the largest supplier of airliner engines, Rolls is firmly in second place.

Rolls has also partnered with Japanese engine manufacturer IHI, which also builds engines for large airliners. IHI also built the engines for Japanese F-15s and F-16s. Rolls has some operations in Japan and seemed a good fit to develop a more powerful engine for the Japanese stealth aircraft as well as a similar project Britain and other European firms are developing.

In 2016 Japan successfully flight tested its prototype X2 stealth aircraft, which was a demonstrator that Japan could develop and build a production model stealth fighter. The X2 project took over a decade but Japan held off on proceeding with the FX until it received its first American F-35 stealth fighters and was able to examine what made it successful. Even before Japan received its first of (0f 147) F-35s in 2018 it seemed likely that Japan could create its own. Japan’s first F-35 squadron was operational in early 2019 and that confirmed that what made the F-35 special was something the Japanese could produce.

Japan confirmed that it could match the stealth of the F-35 and create software similar to what the F-35 used. Japan has long been a prolific developer of complex software systems and produced the most reliable initial releases of such software. Unique software was a key element of the F-35’s popularity with American and export-nation pilots. By the end of 2020 Japan decided that it could build its own stealth fighter for itself and export customers. In 2014 Japan finally changed its constitution to all weapons exports. There were two restrictions, countries at war or under sanctions were not allowed.

The ability to export its new FX stealth fighter made the project affordable. The FX project will cost $12 billion and the Japanese parliament provided $703 million in the 2021 defense budget to start work. Japan has been actively developing technologies for a new fighter for over a decade and for that reason the first FX prototype is expected to make its first flight in 2028 and enter service in the mid-2030s once the new Japan-British engine is ready for regular use. The FX prototype will be used to test the working prototype of that engine, which both nations will share the rights to. Japan is also willing to help Britain with their new Tempest sixth generation aircraft that will incorporate stealth as well as even more advanced software.

Britain was encouraged by Japan’s progress with its FX and both Tempest and FX are to enter service in the mid-2030s. Tempest is being jointly developed by Britain based multi-national firm BAE and Rolls-Royce along with European firms Leonardo and MBDA. Tempest will replace Typhoon, which entered service in 2003 and was developed by Airbus, BAE and Leonardo. Typhoon was developed from a British Aerospace prototype that flew in 1986. British Aerospace later became part of BAE. With Tempest Britain intends to develop an aircraft that will not just be a demonstrator.

Britain also bought F-35s and realized that a European firm would produce a similar aircraft that could compete with the Americans, who had long taken the lead in developing the latest aircraft, which then grabbed most of the export market. Fewer than 600 Typhoons were built, while contemporary American aircraft, like the F-35, are being produced in the thousands, mainly for export customers. By partnering with Japan, Britain gained an edge the Eurofighter lacked. With no American tech in the FX or Tempest the builders can export to anyone without restrictions the Americans often imposed on those using some of their tech.