The day of AI-powered UCAV is not far away. India has to right now sort out propulsion issues so that it can concentrate on the electronics and the software aspect of jet fighter/ UCAV designing

by Chiranjeevi Bhat

One of India’s enduring challenges in military and civil aviation has been the inability of Indian industry and research agencies to design and produce an indigenous jet engine. Indian civil aviation industry fully imports its aircraft, and the lack of an indigenous engine stymies any attempt by institutions like NAL and HAL from being able to bring out even a small jet-powered civilian plane. In military aviation, the same saga continues, with the much-hyped and then much-maligned indigenous Kaveri jet engine being separated from the TEJAS fighter jet program and then left to die a slow death. Our indigenous program to build fighter jets is having to make to do with foreign engines, which themselves are only doled out to us rather miserly by the US.

The fact remains that the GE-F404 Engine used by TEJAS is insufficient to power the aircraft, reducing its payload and range. Similarly, the GE-F414 engine planned for TEJAS MK-II is similarly underpowered to meet all the requirements of IAF in the medium-weight fighter class of 15–18-ton range to enable a 5-ton combat payload and a combat range of 600 km on internal fuel. Even the AMCA/TEDBF planned/fantasized about, are all slated to be powered by GE-F414, which would limit the size and payload as well as range of the fighter jets by design. So, why is India forced to compromise its expensive and extremely important fighter jet program with underpowered engines? Why cannot India successfully build its own engines?

The answer to the above question lies in the fact that jet engine technology has been more closely guarded by nations and their corporations than even nuclear reactor know-how. Jet engines are famously complex machinery, containing at least 30,000 moving and static parts, requiring high-end metallurgy research as well as a very high degree of precision and skill in forging, casting and machining. Once designed and put together, jet engines require extensive testing in wind tunnels and subsequently on flying testbeds, having to clock hundreds and thousands of hours to understand the fatigue characteristics as well as degradation of each individual part, among a hundred other studies. India lacks an ecosystem that is competent to design and build such systems as yet and therefore understandably is way behind other countries who have manufactured their jet engines.

India’s fighter jet building program hinges on the success of the TEJAS contract with HAL. The contracts for 40 MK-1 and 83 MK-1A jets are expected to deliver by 2027 a total of 123 Jets worth 6 fighter squadrons and 1 training squadron. These shall finally replace 6 of the 8 MiG-21 fighter squadrons, even if at least 3-4 years after the retirement of the last MiG-21 squadron. The MK-II TEJAS project is expected to use an F-414 IN engine from the GE stable and has already cleared the Comprehensive Design Review stage. Since no indigenous engine can be readied for powering the MK-II until 2035, the TEJAS MK-2 project shall proceed with the F 414 In engine of GE.

The TEJAS MK-II is supposed to replace the Mirage-2000 (3 squadrons), the MiG-29s (5- squadrons) and the Jaguar strike aircraft (6 squadrons) and the 2 remaining MiG-21 Bis squadrons. So, it is logical that out of the 16 squadrons retiring by no later than 2035, the Indian defence ministry will be able to find the need to order at least 8-10 of TEJAS MK-II are ordered (150-180 planes) and the rest is made up by the AMCA production line when it starts in 2030 (another 8 squadrons worth of planes is proposed presently).

This would bring the total strength of IAF to 39 fighter squadrons by the year 2040. The MK-II TEJAS is being planned for production by HAL from 2028 onwards and if they produce at least 1.5 squadrons worth of planes a year, it will take at least 2034 till the last TEJAS MK-II is produced. India is looking for a 110 KN class engine (dry thrust) for its AMCA Mark-II by 2035 which is the earliest it plans to get an indigenous engine into its planes. However, such a long timeline casts a doubt on the objective since 110 KN engines are already deemed as underpowered for 5th generation planes, which are powered by at least 130 -140 KN (dry thrust) rated engines (F-22, F-35 and Su-57).

Therefore, our dream project of a desi engine will only underpower our AMCA fighter, preventing it from meeting the fullest requirements of the IAF when it enters service. Such an under-designing of capability at even the design stage is baffling and smacks of a lack of enough thought or belief towards engine indigenization. India has to make at least a 130 KN (dry thrust) engine, either indigenously or as a licensed assembly and design the AMCA or any other plane it deems fit, with this engine in mind, considering the high-power requirement of 5th generation fighters.

110 KN or 130 KN, how are we going to make an indigenous engine when we don’t even make a single kind of jet engine in our country?

India has to innovate here. We have to entrust this project to private Indian and foreign companies with 100% FDI automatically allowed in the design and production of a jet engine. India should set aside at least $500 million for the 130 KN engine project. All jet engine manufacturers or consortia should be allowed to bid, with a detailed design and test program submitted to win a design contract. India should award at least 2 design contracts of equal amount to the top 2 entities and a time frame of 24 months should be given with amounts released in a staggered manner based on the progress of the design and testing contract.

At every stage of design review and testing, IAF and ADA/GTRE officials should inspect and recommend changes if any. At the end of the 24-month period, India should carry out a complete cost analysis of the two projects, to evaluate the lowest bidder who shall be given 60% of the contract to build engines while the other bidder should be given 40 % of the contract. Any export of the engines could be allowed with the permission of the government. The SQR for the engines should be limited to power ratings (dry and wet), specific fuel consumption, length and radius dimensions each stage, temperature/ compression ratio limitations and minimum power take-off from the alternator, minimum service life, maximum mean time between overhaul/ breakdown and integrated life cycle cost.

By assisting companies in designing an engine, India can also allow companies to innovate without risk, enabling smaller players a chance to shine. Moreover, new ventures with Indian private companies can also take off, with smaller foreign partners, apart from the big three of Rolls Royce, Pratt and Whitney and General Electric. It shall also allow joint ventures like Turbo Union, smaller European firms and Japanese IHI etc. to innovate in a mutually beneficial manner in conjunction with an Indian firm.

If design contracts are awarded by end of 2022, we can obtain a successful test of one or two proto-type engines by 2026 and by 2028, production can begin. The reason for such a short timeline is that no company can build a greenfield engine of this rating unless working over 10-15 years. Therefore, the proposed engine would be an up-gradation or an up-rating of an existing engine thereby requiring lesser time. This shall allow India to start the production of AMCA / TEDBF design with 130 KN engines right off the start.

Another modus is to get hold of an indigenous jet engine by entering into a joint venture with countries with similar programs. Japan is presently in the advanced stages of developing a compact Military Jet Engine that is already tested and is designed to output 180 KN in production variants. The IHI XF-9 design is very new and innovative and considering the good relations India enjoys with Japan, an offer to invest in research and production of components for the XF-9 can reduce costs for both and also help lay hands on an advanced engine pretty quickly for both countries.

India could in fact use this as a fall back for engine design just in case the indigenous jet engine proposal is delayed or fails. Either way, a new design that is tailormade for 6th generation war fighter requirements can help India quickly leapfrog the Chinese in Engine design. A jet engine of 180 KN (wet) at one of the highest fuel efficiencies currently available in jet engines can help evolve the AMCA into not just a nimble and expanded version of TEJAS but can allow for larger wings, longer fuselage, higher thrust to weight ratio and conversion into a Naval version with only a few modifications. India should therefore forget the attempts at trying to coax Rolls Royce and Safran into giving us underpowered engine models or footing the cost of their development and instead concentrate on the Japanese project, which is already in the prototype testing stage.

A third model is to again use diplomacy to gain access for India to use the GE F136 / XA100 models which are developed to the prototype stage. The F136 project was abandoned after Pentagon selected the F135 of Pratt and Whitney to be the sole propulsion for the F-35. Now with a new engine contract looming, GE has shifted onto a higher gear through its adaptive Engine technology which it has used to make the GE XA100 prototypes, which have recorded a maximum thrust of 200 KN already. Both the models can be pursued through diplomatic means and if controlled production is allowed in India by GE (who already partner India’s indigenous jet fighter program for propulsion) for either of the two engines, India can quickly beat the lead times and also offer GE crucial user operational data, which it can use for further research, either by itself or jointly with India.

While there shall be the need for development costs for either of the two models, India can share such costs with GE and jointly sell the engine in a new JV for the same on the lines of the ITU RB-199 Engine that powers the Tornado Jet. This is also a time-saving measure, wherein India can start production no later than 2026 for the selected jet engine. This method however requires a lot of diplomatic heavy lifting to convince the US into parting with a sensitive technology and India may have to accept curbs on sales / further development for now in order to gain access to either of the two Engines, which are sufficient to power our indigenous jet fighter development into the 2050s.

India has to make quick and judicious decisions regarding obtaining access to jet engine technology or at least the jet engine to safeguard its airpower indigenization plan. Lack of a jet engine can cause us to fail miserably and can ensure all plans of AMCA, TEDBF/ORCA etc remain on paper only. All the above three models have a cost and involve trade-offs. But all three models could ensure India has a workable military jet engine powerful enough and reliable enough to base our 5th and 6th generation fighter projects and also learn during the entire cycle of development. A spin-off of these projects could be the propulsion for our unmanned systems which all over the world are getting increasingly bigger and more complicated. The day of AI-powered UCAV is not far away. India has to right now sort out propulsion issues so that it can concentrate on the electronics and the software aspect of jet fighter/ UCAV designing.