Analysis Too Long, Too Powerful: Why India Did Not Consider Japan's Advanced IHI XF9-1 Engine for AMCA Mk2 Fighter

Too Long, Too Powerful: Why India Did Not Consider Japan's Advanced IHI XF9-1 Engine for AMCA Mk2 Fighter


The development of a fifth-generation fighter jet is one of the most complex challenges in modern defence, and selecting the right engine is critical to success.

India's ambitious Advanced Medium Combat Aircraft (AMCA) program, which aims to deliver a domestically built stealth fighter to the Indian Air Force by the mid-2030s, recently concluded a high-stakes search for its advanced Mk2 variant engine.

Among the top contenders was a technologically advanced proposal from Japan. In mid-2025, Tokyo offered its cutting-edge IHI XF9-1 turbofan engine, not just for purchase, but for co-development and local production in India.

Despite the offer's alignment with India's 'Aatmanirbhar Bharat' goals, it was ultimately set aside. A deeper look reveals that the Japanese engine, while impressive, was a poor fit for the AMCA due to critical technical, dimensional, and strategic factors.

An Impressive but Ill-Fitting Offer​

The Japanese proposal was first formally discussed during a Defence Ministers’ meeting in Delhi in May 2025.

Japan's Acquisition, Technology & Logistics Agency (ATLA) and IHI Corporation presented the XF9-1 as the ideal solution for the AMCA Mk2, which requires a powerful engine in the 110-130 kilonewton (kN) class.

The offer was comprehensive, including full technology transfer (ToT), shared intellectual property rights (IPR), and an invitation for India's Gas Turbine Research Establishment (GTRE) to review the technology in Japan.

On paper, the XF9-1 engine's specifications are remarkable.

Designed as a "high-power slim engine," it delivers over 107 kN of dry thrust (without afterburner) and a massive 147 kN with its afterburner. This is significantly more powerful than the 98 kN thrust of the General Electric F414 engine that will power the initial AMCA Mk1.

Furthermore, the Japanese engine is packed with next-generation features. It uses advanced materials like ceramic matrix composites to withstand extremely high turbine temperatures around 1,800°C.

It also generates 180 kW of electrical power, a feature designed to support future systems like AI-driven avionics and laser weapons. Its three-dimensional thrust-vectoring nozzle also promised superior agility, putting its technology on par with engines used in top-tier fighters like the F-35.

The Deal-Breaker: A Problem of Size​

Despite these advantages, engineers at India's Aeronautical Development Agency (ADA) faced a fundamental integration problem.

The AMCA's airframe was designed around the compact dimensions of the GE F414 engine, which measures approximately 3.9 metres (154 inches) in length and 0.89 metres (35 inches) in diameter.

While the XF9-1's 1-metre diameter was considered manageable, its length proved to be the deal-breaker. At 4.8 metres long, the Japanese engine is nearly a full metre longer than the F414.

Fitting the XF9-1 would have required a complete and costly redesign of the AMCA's rear fuselage and engine bay.

This major structural change would have delayed the program by years, increased its overall cost, and likely compromised the aircraft's carefully designed stealth profile, weight distribution, and internal fuel capacity.

The AMCA has an aggressive timeline, with prototype flights planned for 2029 and induction by 2035. The XF9-1 was simply not a "drop-in" replacement.

A Case of "Overkill" and Strategic Risk​

Beyond the physical mismatch, the XF9-1 was also deemed too powerful for India's needs. Its 147 kN thrust far exceeded the AMCA Mk2's 120 kN requirement.

While this may seem like an advantage, such excessive power, or "overkill," can be inefficient for a medium-weight fighter, putting unnecessary strain on the airframe without providing a proportional benefit.

Broader strategic factors also played a role. Japan has since become a core partner in the Global Combat Air Programme (GCAP), a multinational project with the UK and Italy to build a sixth-generation fighter.

With Japan's resources and focus shifting to developing a new engine with partners like Rolls-Royce, Indian officials had valid concerns about Tokyo's long-term commitment to the separate XF9-1 project.

India could not risk a repeat of its own Kaveri engine program, which suffered from decades of delays.

The "Perfect Fit" Solution from France​

In July 2025, India announced it had selected France's Safran as its partner. The French proposal, valued at around $7 billion, involves co-developing a new 120 kN engine perfectly tailored to the AMCA's needs.

Crucially, the Safran engine is being designed to "seamlessly fit" within the existing F414-based engine bay, requiring only minor modifications. This decision saves invaluable time and resources for the ₹61,000 crore AMCA program.

The deal includes a 100% transfer of critical technologies, including the complex single-crystal turbine blades, and grants India full intellectual property rights.

The timeline aligns perfectly with India's goals, targeting the first engine test flight by 2028 and full-scale production by 2035.

This new engine is also expected to be scalable, allowing it to power the Indian Navy's future Twin-Engine Deck-Based Fighter (TEDBF), securing India's combat aviation future for decades to come.
 
This decision of not going with Japnese engin will cost huge for AMCA. Time and efforts in redesigning of aircraft will take less time when compair to negotiation time with unreliable Americans.
 
Is the AMCA made ?? No , is the engines tech non modify able?? Yes, see get the tech know how ,make it for yourself here , all things are slim and fat , from battery to laptops to mobile to pizza to dosa , with thin crust of course . Idea is to make here as per need, not buy as per need . USA and Russia have given a slip so go to Japan , tell them to start making a brand new , right size engine here with us and in 2 years , we will make it.I can't get the idea of making an jet around an engine or a missile ,these all are made as per need ,so Tejas is a totally failed plug and play matter now ,so save the AMCA.
 
Make 7 billion USD worth engines with France , make 7 billion worth engines with Japan , get the tech , make them 14 billion USD worth engines inhouse as per need ,so this matter stops, take 5 years from now, no problem,no body will attack us as we now got 4 dimensions to second strike nuclear capabilities from air,land , sea and now Railway based missile tech is added to land based deterrent force . Nothing to worry as Pakistani, Bangladeshi and Chinese forces are in rot due to internal politics and funding. We must keep steady on engine, get tech from France and Japan and junk USA, let it be ,losses happen .We are a 140 million people country , who damm can take us head on , the public is no push over so do what's needed and stop worrying about jets, get the engines, rest is ready
 
India Shall try Japanese engine for heavy fighter super sukhoi if suitable Also Safran 120kn engine Shall be used in both amca mk1 and amca mk2.ge414 Shall be restricted to Tejas mk2 only not amca and ge404 Shall also be replaced by kaveri 2 and 3 in the future
 

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