Aircraft engine is one of the most complex systems onboard. It has parts turning at very high rotations per minute (RPM); these have to withstand very high temperatures; operate very efficiently from sea level to near stratosphere; and from zero to high supersonic speeds.
There are very few major aero-engine manufacturers in the world. Even countries like China, which have invested huge sums in R&D, have been struggling to build both the military and civil aeroengines. India had a fairly well-established aircraft industry at the time of Independence in 1947. Gas Turbine Research Establishment (GTRE) was set up under Defence Research and Development Organisation (DRDO) in 1959 in Kanpur, and in 1961 moved to Bangalore. It had indigenously developed centrifugal type gas turbine engine of 1,000 kg thrust in 1961. Aero Engines Research and Design Centre (AER&DC) was established within Hindustan Aeronautics Ltd (HAL) in 1960 for design and development of gas-turbine engines. Yet, India failed to manufacture a fighter aircraft engine in the last several decades. India’s indigenous light combat aircraft (LCA) Tejas Mark 1 & 2 are powered by the General Electric (GE) engine variants.
Lack of Success by GTRE
GTRE was established to design and develop gas-turbine engines for military applications. It was also to develop computational, prototype manufacturing and test facilities for components and full-scale engine development. The establishment has nearly 850 personnel drawn from science and engineering fields. In the 1960s, they re-engineered the Russian RD-9F engine for possible use on the HF-24 aircraft. The project was not successful. In the 1970s, GTRE modified the Orpheus 703 Engine with reheat capability. In the 1980s, GTRE designed the GTX series of engines with a flat rating concept.
In 1989, initial sanction was given for the development of the GTX-35-VS “Kaveri” engine. While GTRE did develop nine prototype Kaveri engines, as well as four core engines that undertook 3,217 hours of engine testing, including in Russia, they failed to meet the required parameters to power a fighter. The general arrangement of the Kaveri is very similar to other contemporary combat engines, such as the Eurojet EJ200, General Electric F414 and Snecma M88. Instead of the desired ‘wet thrust’ of 81 kilo-newton (kN), the Kaveri generated only 70.4 kN.
“GTRE has been unable to deliver an engine that could power the LCA despite a cost overrun of 642 per cent and a delay of about 13 years,” the Comptroller and Auditor General (CAG) noted in a sharply worded report released in 2011. GTRE tried to defend delays and lack of success on non-availability of state-of-the-art wind tunnel in India, and US technology restrictions. The programme was abandoned in 2014. Meanwhile, a 52 kN dry variant of the Kaveri engine may be used for the indigenous “Ghatak’ UCAV (Unmanned Combat Aerial Vehicles). The Government of India has cleared the funding. GTRE is also developing a new 4.25 kN thrust turbofan engine to power Nirbhay Cruise missile and future UAVs.
Engine manufacturing ecosystem in India
HAL Engine Division was established at Bangalore during 1956 for production of Orpheus Turbo Jet Engines under licence agreement with Rolls Royce. They have collaborated with many other companies. Till date the division has manufactured more than 3,100 engines and repaired and overhauled more than 16,500 engines. They have also exported engine components to foreign engine manufacturers like Safran, Rolls Royce, and Honeywell.
HAL’s Engine Division at Koraput was established in 1964 to manufacture MiG-21 R11 engines under licence from the erstwhile USSR. Subsequently they manufactured the R25, R29 and RD33 engines under licence from Russia for MiG-21BIS, MiG-27 and MiG-29 respectively. Till date the division has manufactured more than 1,300 engines and overhauled more than 7,000 aeroengines. They also carry out repairs, refurbishment and overhauls.
DRDO’s Defence Metallurgical Research Laboratory (DMRL) has recently established the near isothermal forging technology to produce all the five stages of high-pressure compressors (HPC) discs out of difficult-to-deform titanium alloy using its unique 2000 MT isothermal forge press. It has been working jointly with Mishra Dhatu Nigam Limited (MIDHANI), a defence public sector undertaking and HAL. The HPC discs form a very important part of the jet engine, on which the compressor blades are mounted. The HPC Drum assembly needs frequent replacements.
The Kaveri project has helped India master some critical technologies and the ecosystem is partly in place for basic design, development, testing, assembly and manufacture. Of course, there are capability gaps. It is very important to have the core engine right. GTRE requires better qualified manpower and management.
This Indian DeepTech startup Paninian aerospace, has recently designed a state-of-the-art 4.5 kN turbojet-engine for cruise missiles and Large UAVs. They are working on more engines in the 3-12 kN thrust range. They are using AI and 3D printing technologies to produce the engines.
GE 404 Engine for LCA
India’s LCA was originally to be powered by the GTRE GTX-35VS Kaveri engine. However, because of lack of progress within its envisaged timelines it was officially delinked from the Tejas programme in September 2008. Meanwhile GE F404-GE-F2J3 engine had powered the LCA for its first flight in 2001. Later it was decided that LCA will power the first 40 Mk 1 aircraft with the GE engine. In August 2021 HAL placed orders for 99 more advanced F404-GE-IN20 engines and support services till 2029, valued at $716 million. These will power the LCA Mk1A. General Electric F-414 engines power the F-18 variants. The F414-GE-INS6 with a greater 110 kN thrust, has been selected for HAL Tejas Mark 2. As of now, the engine could also be expected to power the initial 5th generation Advanced Medium Combat Aircraft (AMCA) and the Twin Engine Deck-Based Fighter (TEDBF). The engine thrust would be upgraded to 120-kN by then.
Major global jet engine players
Aeroengine technologies are much more difficult to master than even space engines. The ability to manufacture combat jet-engines is the true test of a country’s military-industrial base. The US, UK, France and Russia are the main countries with aero-engine technologies. Others like Germany, Japan, and Canada have joint ventures. Among the top four aero-engine manufacturers of the world are, the CFM International, a joint venture between GE Aviation and Safran, who made the best-selling aircraft engine of all time, the CFM56, and now the high-bypass turbofan LEAP (Leading Edge Aviation Propulsion) engine. The CFM is now working on the new RISE (Revolutionary Innovation for Sustainable Engines) programme which will produce the next-generation CFM engine by the mid-2030s.
Pratt & Whitney has six variants in its GTF family of engines. They are already developing a hybrid-electric turboprop demonstrator. GE Aviation’s GE90 powers the Boeing 777 family. Their next, GEnx, was around 15 per cent more fuel-efficient and powered the Boeing 787 and 747-8. The GE9X is GE’s latest engine developed specifically for the Boeing 777X. The engine has the world record for the highest thrust, at 134,300 pounds. GE is also working on the MESTANG (More Electric Systems and Technologies for Aircraft in the Next Generation) technology. Rolls Royce has been famous for its high-bypass Trent turbofans. They have announced that they are working on building the world’s largest jet engine called the UltraFan demonstrator.
For long, China has been using Russian engines for all its fighter aircraft, and Western engines for their airliners. China’s fifth-generation J-20 fighter was initially equipped with the Russian AL31F engine, and later switched to Chinese WS-10 Taihang which is essentially derived from CFM-56II engines. They are now being replaced with the more powerful and modern WS-15, but still way behind the Western engines in maintainability, power and fuel consumption.
Defence Aeroengine Requirements
The Ministry of Defence (MoD) estimates that India’s military aeroengine market will amount to Rs 3,50,000 crore over the next two decades which means around Rs 17,500 crore per year. Currently this market is with original engine manufacturers (OEM). The repair and overhaul in most cases is with HAL. Engine maintenance constitutes 35 per cent of the overall cost of aircraft maintenance. More than two-thirds of engine maintenance costs are incurred on components, with labour accounting for another 22 percent. There is great scope for Maintenance, Repair and Overhaul (MRO) being set up by private players with Original Equipment Manufacturers (OEM). Lot of engine parts can be manufactured in India to give a boost to the overall ecosystem.
Civil Jet Engine Requirements
India is the world’s third-largest civil aviation market and among the fastest growing. Indian carriers flew 12 million passengers on domestic routes in May 2022. Indian airlines operate close to 700 aircraft currently. The Government of India’s UDAN-RCS scheme launched in 2016 has increased the number of operational airports and flying destinations considerably. The FDI limit for the sector has been raised to 100 per cent. As per the Ministry of Civil Aviation “Vision 2040” the air passenger traffic will increase six fold to 821 million domestic and 303 million international passengers and 17 million tons of air cargo. India will require 2,359 passenger aircraft. There is thus a great scope to set up aero-engine manufacture in India.
Predictions are that engines will also remain the fastest-growing sector of the commercial jet MRO business. The engine MRO market is also dominated by the major aero-engine manufacturers. Nearly 90 per cent of the Indian MRO work is outsourced to countries like Singapore, Dubai, UAE, Sri Lanka and others. Efforts now on to make India a MRO hub. There are currently eight major players in the MRO market in India, AIESL, Air Works, Indamer Private Limited, Deccan Charter, Taj Air, Bird ExecuJet, GMR Aero Technic Limited and Max MRO Private Limited. AIESL, a subsidiary of Air India, is the only player extending a full-fledged engine overhaul facility and Air Works has the second highest share in the market revenue.
Joint venture approach best for India
For long, analysts were suggesting a joint-venture route with a foreign partner for aero-engine development. Snecma, in a tie up with DRDO, had offered to revive and certify the Kaveri engine as part of the offsets deal for 36 Dassault Rafale jets purchased by India. Nothing came of it. By March 2020, over 30 years of Kaveri development, Rs 2,032 crore had been spent, said Minister of State for Defence Shripad Naik in a written reply in the Lok Sabha.
In July 2022, the Safran Group CEO Olivier Andries met Defence Minister Rajnath Singh. The meeting was to discuss transferring the technology for making engines for India’s indigenous AMCA that had been promised as part of Rafale offsets contracts. Safran has reportedly submitted a proposal to the MoD in July 2022 to co-develop with GTRE a 110 kN thrust engine for the AMCA. But it is believed that they are asking for a whopping €1 billion to transfer the technology. This is the price one pays for lack of own technology and capabilities. It is understood that the price negotiations may take longer. Meanwhile, the Cabinet Committee on Security (CCS) sanction for the design and prototype development of the AMCA has still to be accorded. HAL and Aeronautical Development Agency (ADA) are still working on the document. Albeit the design working is going in parallel. Of the €7.8 billion Rafale deal, France had committed to investing 50 per cent, or €3.9 billion, in India as offsets.
An earlier proposal for collaboration on jet engine technology under the India-US Defence Trade and Technology Initiative (DTTI) was suspended in October 2019 on account of American reluctance to share core or hot engine technology. A joint working group on jet engine technology under the DTTI framework was thereafter disbanded. Of late, the British Rolls-Royce, and the USA’s GE have also been making overtures to join India’s aero-engine program. The American turnaround is primarily to remain part of this important Indian programme. The revival of the GE bid to co-develop the AMCA engine coincides with the “Enhanced Performance Engine” (EPE) variant of the GE-F414 being developed for the US Navy. It will involve a new core. The thrust will increase nearly 20 per cent to 120 kN.
Aero-engine is now considered one of the key areas for India’s aspirations of achieving self-reliance in the defence sector. Indian private sector players are also likely to be part of the aeroengine programme. The French side also talked of plans to set up a MRO facility in India for overhauling LEAP-1A and LEAP-1B engines for Indian and foreign commercial airlines. Interestingly, the Safran group firm Turbomeca and HAL had earlier co-developed the Shakti engine, which powers India’s Dhruv Advanced Light Helicopter (ALH) and Light Combat Helicopters (LCH). 250 of these are already flying.
The future is in new propulsion technologies to burn less fuel, cut CO2 emissions and produce less noise. As they enhance engine efficiencies, they are simultaneously exploring electric and hybrid propulsion systems. Benefits of research and technology in propulsion will shorten engine development cycle, reduce engine weight, increase engine performance, reduce engine fuel consumption, enhance reliability, reduce emissions and noise, increase component life and reduce maintenance requirements. The engines being the most important, and most expensive, aircraft part, their development will shape the airline industry’s green transition. India must first get its core engine technologies right, but simultaneously look at next generation engine technologies. Joint Venture is the best way forward for India.
The writer is Director General, Centre for Air Power Studies. Views expressed are personal.
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