Safran and HAL have a 50-year-long relationship during which they have developed a variety of engines that have been powering our helicopter fleet. As such, the induction of Safran for producing the engines for IMRH has a fair chance of being a successful journey that should lead to the latest engine technology powering our future helicopter fleet.
Helicopters use horizontally spinning rotors to generate lift and thrust, allowing them to fly vertically and hover. The rotors require power to spin, which comes from the engine. While turboshaft engines are the most common type of engine used on helicopters today, a few light helicopters continue to use the piston engine due to benefits accruing mainly related to cheaper running costs.
The earliest helicopter designs were concepts that relied on rubber bands or spindles to generate power. The first breakthrough came with the introduction of the internal combustion engine, which provided enough power to lift helicopters into the air and hence, the first powered helicopters had custom-built or rotary engines – automobile engines were also used in some early helicopters. These designs did not succeed as the engines were not capable of proving sufficient power to generate enough lift for sustained flight. The creation of the VS-300 by Igor Sikorsky in 1939 used a single four-cylinder 75 hp piston engine to power both rotor systems. After that, four-cylinder piston engines became standard in helicopters until the advent of the turboshaft engine in the late 1950s. The turboshaft engines revolutionised the aviation industry as they were lighter, more reliable, and capable of providing sustainable high-power output.
In the following decades, helicopter engines were further refined and improved to provide better performance. Currently, most helicopters in the world, both military and civil, are powered by turboshaft engines, while, as brought out earlier, a few light helicopters continue to be powered by piston engines and are mostly used for the initial training of pilots.
The entire current helicopter fleet of the Indian military is also powered by turboshaft engines only, the Russian Mi-4 being the last piston-engine helicopter, which was phased out of service in the late 1970s. While heavy and medium-class helicopters may use two or three turboshaft engines, light helicopters typically use a single engine. However, there are exceptions to the same – the Russian Ka-226T helicopter, which was in the pipeline to replace our ageing Cheetah/Chetak fleet, is powered by two engines.
Helicopters Power Plants/Engines: Indian Context
Currently, the world’s leading countries for turbine engine manufacture are the US, UK, France and Russia. While the US is the leader with manufacturers like General Electric Pratt & Whitney, the UK boasts of Rolls-Royce, France has the Safran Helicopter Engines and Russia with Aviadvigatel and NPO Saturn – Safran is the largest manufacturer of helicopter engines worldwide. While China is also in the business of production of turbine engines, the technology is not as advanced and hence, they suffer from power issues. A clear example is the Chinese much touted Z-10 attack helicopter losing out to the Turkish ATAK-129 attack helicopter due to their performance in high altitude areas, wherein Pakistan was the acquiring country.
India, unfortunately, has been a laggard in the area of development of engine technology, especially for the military, despite its distinct achievement in the indigenous design, development and manufacture of combat aircraft like the Tejas and advanced state-of-the-art helicopters like the Dhruv, Light Combat Helicopter (LCH), the Light Utility Helicopter (LUH) which is in the pipeline and of course HAL’s future Indian Multi-Role Helicopter (IMRH) project.
However, India attempted to develop a jet engine GTX-35VS KAVERI, which was first tested in 1996. This engine was developed and manufactured by the Gas Turbine Research Establishment, along with Godrej & Boyce. While this engine has been tried out on the initial model of the Tejas combat aircraft, it has fallen woefully short of the performance requirements despite some claims being made to the contrary. In this context, HAL signed an agreement in June this year with General Electric of the US for joint production of its F414-GE-INS6 engines in India to power the Tejas fighter jets. The company is also expected to fulfil an order of 99 x F404 engines that will support India’s Light Combat Aircraft programme.
Safran Engines & Helicopters
The French ‘Safran Helicopter Engines’ is not only the world’s leading manufacturer of rotorcraft turbines but the only one dedicated to this market. Operating worldwide, it offers the widest range of helicopter engines from 500 to 3000 SHP. The company has a history of commitment to design and manufacturing excellence for more than 80 years and has 21000 engines in service presently – Safran is also looking at electric helicopters.
The French firm’s partnership with HAL began more than 50 years ago, starting with the manufacturing of Turbomeca Artouste IIIB turboshaft 550 SHP engines for the Cheetah & Chetak helicopters – both the helicopters and engines were produced under licence by HAL, and it continues to be so even today. Presently, the Indian military is one of the largest operators of Safran-designed helicopter engines, with a fleet of over 1500 engines. Safran and HAL have also co-developed the Shakti engine (the Ardiden1H1), incorporating innovative propulsion technology, which powers the Dhruv, the Armed Dhruv as well as the LCH. Each of these helicopters is powered by two engines, each producing a SHP 1400-2000 per engine – more than 500 Shakti engines have been produced at Bengaluru.
In addition, the Safran Helicopter Engines ‘Ardiden 1U’ variant also powers the new LUH, which is a single-engine helicopter. In a major development in July this year, HAL and Safran Helicopter Engines have signed a major agreement to build advanced helicopter engines in India. HAL’s tie-up with Safran will involve design, development, certification, production, sale and support of helicopter engines for the Indian military. The initial focus will be on the 13-16 Ton IMRH project conceived as a replacement for the Mi-17 fleet of helicopters. One of the important features of this agreement is that HAL will hold the type certificate for the engine on completion of the development project – this is indeed a path-breaking development and will go a long way in boosting HAL’s capabilities in this sector.
Let us also look at helicopters which have been inducted into the military ex-import, some in the last three to four years with the process still on, like the Apaches for the Army and the Sea Hawks for the Navy. These helicopters are the Russian Mi-17V5 and the American AH-64E Apache, Chinook CH-47F and the MH-60 Romeo Sea Hawk, which have been inducted with engines manufactured in their respective countries.
The Mi-17V5 is fitted with two Klimov TV3-117VM or VK 2500 turboshaft engines with Shaft Horse Power (SHP) of 2100 and 2700, respectively, enabling the helicopter to operate at high altitudes. The Apaches are fitted with two General Electric T700-GE-701D powerful turboshaft engines with a SHP of 2000 each, which enables it to carry a lethal package of armaments, making it the most dreaded attack helicopter in the world. The Chinook, the highly battle and combat-tested heavy lift helicopter in the world, is powered by two Honeywell T-55 engines, which gives it the capability to lift artillery guns and carry tanks in its body. Lastly, the Sea Hawk, a multi-mission helicopter capable of operating from ships and aircraft carriers, is powered by two General Electric T700-GE-401C.
The path to strategic autonomy is complex and expensive, but its potential benefits are inarguable. Surprisingly, a nation that can land a spacecraft on the moon and has developed a strong eco-system for designing and developing technologically advanced missile systems has been struggling to develop suitable engines for its military’s combat aircraft and helicopters. A nation’s power today is as much about It’s military and economic strength as it is about its technological capabilities. In this regard, the agreements signed by HAL with General Electric of the US for co-producing the F-414 engines for the Tejas fighter aircraft in India and with French Safran Helicopter Engines for the design and development of a suitable engine to power the future IMRH project are a great leap forward, as this will further boost India’s push for Atmanirbharta. However, a prominent caveat lies in the reluctance of these companies to fully share their technology, especially when it comes to transferring sensitive technology – despite the agreements on how this part will play out, only time will tell.
Lt Gen BS Pawar (Retd)