Military & Aerospace

Future Military Helicopters — Design & Development
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Issue Vol. 33.3 Jul-Sep 2018 | Date : 11 Aug , 2019

Military Aviation today is looking at the next generation of military helicopters and the strategy to modernise vertical lift capability with improved avionics, electronics, range, speed, propulsion, survivability and high altitude performance. The philosophy is to improve upon the present limitations by examining emerging technologies within the realm of the possible, with speeds in excess of 170 knots, combat range of 800km, hover with full combat load under high/hot conditions and with a degree of autonomous flight capability. There is a need to harness technological innovation by looking beyond current technology and identifying possible next-generation solutions in areas such as propulsion, airframe materials, rotor systems, engine technology, survivability equipment, mission systems and next-generation maintenance techniques among others.

…the global helicopter industry is undergoing a significant transformation as are customer demands and the capabilities offered by cutting edge technologies.

Advances in design of military helicopters have not been as impressive as for fixed-wing platforms, especially fighter aircraft. While jet fighters are in their fifth-generation, helicopters are still strutting around with the same old designs and airframes, with mostly upgrades to its credit. There has been no new helicopter design since the induction in the 1980s of the Apache attack helicopter built by Boeing. The Apache AH-64E (Block-III), the latest version also called ‘The Guardian’, is a vivid example where even though 26 new technologies have been incorporated, relating mainly to more powerful engines, composite rotor blades, upgraded transmission system and capability to control UAVs, the main design and configuration remains the same.

However, the global helicopter industry is undergoing a significant transformation as are customer demands and the capabilities offered by cutting edge technologies. Significant advances in technology such as computation structural dynamics modelling, expanded use of additive manufacturing, fly-by-wire controls, advanced Condition-Based Maintenance (CBM), Health and Usage Monitoring Systems (HUMS) and advanced turbine engine programmes, promise a big leap in rotorcraft capabilities.

Military Aviation today is looking at the next generation of military helicopters and the strategy to modernise vertical lift capability with improved avionics, electronics, range, speed, propulsion, survivability and high altitude performance. The philosophy is to improve upon the present limitations by examining emerging technologies within the realm of the possible, with speeds in excess of 170 knots, combat range of 800km, hover with full combat load under high/hot conditions and with a degree of autonomous flight capability. There is a need to harness technological innovation by looking beyond current force technology and identifying possible next-generation solutions in areas such as propulsion, airframe materials, rotor systems, engine technology, survivability equipment, mission systems and next generation maintenance techniques among others.

World Rotorcraft Development – Leaders

Governments worldwide are initiating new defence procurements, while simultaneously developing and expanding indigenous production and development capabilities for both military and civil applications. The US remains the world’s largest purchaser and developer of military helicopters, with major aviation giants such as Sikorsky, Boeing and Bell taking the lead in the design, development and manufacture of state-of-the-art military and civil helicopters. The US military has embarked on the most transformative science and technology initiative in decades – the Joint Multi-Role (JMR) technology demonstration effort, where the industry plans to prove the revolutionary capabilities of high speed approaches for a family of future military products. In Russia, the Moscow-based ‘Russian Helicopters’ has been a lead player in the Global Helicopter Industry, with its major thrust being towards design and development of military helicopters.

Advances in stealth such as reduction in radar and acoustic signatures offer major advantages…

Europe has in the last two decades also emerged as a major contender in the helicopter market, both in the civil and military domain — Airbus Helicopters formerly ‘Eurocopter’ and Anglo-Italian AgustaWestland are the two major companies whose products have flooded the civil as well as military markets around the globe. India has also taken the lead in this area by its recent exposition of its ‘Make in India’ policy’ in the defence sector and has invited the private sector to be part of the growing defence aerospace industry. However, it is a pity that the typical Indian bureaucratic sloth and apathy is impeding the required progress and success of the ‘Make in India’ policy seriously impacting the helicopter industry.

Future Developments and Concepts

The new generation helicopter platforms are expected to feature the latest advances in aeronautics, giving military helicopters improved flight performance especially in relation to speed. This offers the new generation machines unprecedented capabilities such as increased autonomy, reduced acoustic signatures (enhanced stealth), more accurate navigation systems, enhanced data acquisition and protection systems, more effective weapons and munitions as also improved reliability and maintainability at lower operating costs. Helicopters will have to become truly modular, making it possible to change part of the system without affecting overall integrity. The concept of modularity is likely to increase, especially with the emergence of the concept of multirole machines.

World over today, the armed forces are seriously looking at the multi-role concept due to the changing nature of conflicts and financial constraints. This concept basically revolves around the use of utility helicopters both in the logistic support and armed role. The size of such helicopters would be between cargo and light observation platforms and their armament would generally be restricted to guns and rockets. Some of these may also have the capability to be fitted with air-to-air and air-to-ground missiles. The indigenously manufactured Advanced Light Helicopter (ALH) is a classic example of a multi-role helicopter with its utility and armed version (Rudra) available to the Indian Military. The US military is already moving in this direction and their JMR fleet vision envisages narrowing down the more than 20 helicopter types spread across the services to only three basic models, plus a new ‘ultra’ category extending vertical take-off and landing aircraft into the domain of medium-sized, fixed-wing transports. The vision lays down that no helicopter in all three basic categories i.e. light, medium and heavy, will be slower than today’s fastest conventional helicopter and should be powerful enough to carry their predecessors as external payload.

The X3 has two propellers on the side of the craft thereby removing the need for a tail rotor and is being projected by Airbus Helicopter for the military’s use in search and rescue, Special Forces operations and troop transport.

With regard to data acquisition, day/night observation and detection capabilities will increase and become more diversified specially in respect of information sharing and cooperation with other aircraft and UAVs. This aspect has already been incorporated in the Block III Apache model. Target engagement capabilities with regard to weapon range and precision is likely to remain the focus of future development. With sub-conventional operations gaining ascendency around the world, helicopter survivability will assume greater significance. Advances in stealth such as reduction in radar and acoustic signatures offer major advantages in this area, as does the development of early detection/jamming countermeasure capabilities.

Some of the above technologies are already being incorporated in the development of Airbus’s X2, X3 and X4 and Sikorsky’s X2 co-axial compound helicopter as technology demonstrators. The main emphasis is on speed, stealth, reliability and survivability. Many of these designs go well beyond the tried and tested rotor and propeller system that has defined generations of helicopter technology since their introduction into military use in the forties. The co-axial rotor design by cutting out the requirement of a tail rotor provides a whole heap of benefits to include more power (enhancing the payload capability), greater speeds, stability and noise reduction. In fact in its demonstrative flight, the Sikorsky’s X2 achieved a speed of 287mph, a major leap from the current standard helicopter speeds.

The X2 has a rear tail-fin rotor which provides speed boost rather than anti-torque thrust. Its military version, the Sikorsky ‘S-97 Raider’, is stated to be the future light tactical scout helicopter of the US Military. Airbus X3 technology demonstrator is another oddball chopper that cannot seem to figure out whether it wants to be a helicopter or a plane. But this aircraft is already turning heads by having achieved speeds that are fifty per cent higher than the conventional helicopters and lower vibration levels. The X3 has two propellers on the side of the craft thereby removing the need for a tail rotor and is being projected by Airbus Helicopter for the military’s use in search and rescue, Special Forces operations and troop transport. The X4 is expected to replace the Dauphin family in the four to six tonne class.

Finally, the development of innovative concepts along the lines of V-22 Osprey (tilt rotor technology), has generated fresh momentum in the utility/logistics domain. The V-22 has operated extensively in Afghanistan and was instrumental in the rescue of a downed US pilot in Libya in 2013. AgustaWestland has also come up  with a similar rotorcraft, the AW-609 — a significant player in the emerging tilt-rotor market. AgustaWestland sees the craft as a troop transporter similar to the Bell-Boeing V22 Osprey. Such an aircraft would be ideal for deployment in the North Eastern Region of India where infrastructure is woefully inadequate. The latest in the tilt-rotor field is ‘Bell’s V-280 Valor’ third-generation tilt-rotor demonstrator. Bell’s ‘Valor’ programme is a quantum jump in technology on its earlier V-22 Osprey aircraft and attacks affordability with technology. It had its first flight in December 2017.

The Indian Military is also seriously examining these unmanned options…

Future Military Helicopters — Design & Development

Another area of future development is helicopter UAVs. Two avenues are already being explored and implemented in different countries, the UAV-helicopter cooperation and development of rotary wing UAVs. Lockheed Martin’s K-MAX helicopter UAV was deployed in Afghanistan for logistic resupply and has proved to be quite a hit. It has been able to fly in adverse weather conditions when manned helicopters could not fly. Northrop Grumman’s ‘Fire Scout’, is another helicopter UAV which is already in service with the US Navy, capable of operating from the deck of a ship. The latest in the unmanned field is the unmanned version of Sikorsky’s UH-60A Black Hawk helicopter modified for both manned and unmanned flights. The Indian Military is also seriously examining these unmanned options – however, the HAL’s attempt to convert the Chetak helicopter into an unmanned version for the Navy did not meet with success and has finally been shelved.

The Scenario in India

The operational diversities of the Indian Armed Forces coupled with extremity and variety of terrain from sea level to high altitude, underline the need for state-of-the-art, modern technology helicopters capable of operating both by day and night in a complex battlefield environment of the future. The armed forces alone are looking to induct as many as 1000-plus helicopters in the coming decade ranging from attack and high altitude reconnaissance to medium and heavy-lift variants. Presently, the Indian military holds in its kitty approximately 600 helicopters of all types and class including specialised ones, but majority of these have far exceeded their life span and are either obsolete or nearing obsolescence.

Keeping in mind the emerging helicopter market in India, a number of Indian companies are in the process or have already formed Joint Ventures…

Recently, India signed a $3-billion deal for purchasing 22 upgraded version of the Apache Longbow Attack Helicopters and 15 Chinook Heavy Lift Helicopters. Both are leading helicopters in the world in their class and their induction is likely to commence this year. In a related development, the Government has cleared the acquisition of six Apaches for the Indian Army as a follow-on order for the earlier 22 Apaches. The process for their acquisition has also commenced. In another significant Government-to-Government deal under the ‘Make in India’ policy, India and Russia have jointly agreed to manufacture 200 Ka-226T Light Observation Helicopters in India. While 60 helicopters will be acquired in a fly-away condition, the balance 140 machines will be manufactured in India through collaboration between HAL and Russian Helicopters. As per reports, some private companies may also be involved in this project and the contract is likely to be signed soon.

The Indian Air Force has also acquired around 200 Mi-17 V5 helicopters from Russian Helicopters. These are the upgraded version of the existing Mi-17. The Mi-17 V5 is more powerful and has all modern and state-of-the-art capabilities in terms of engine, avionics, night operations and armament.

Keeping in mind the emerging helicopter market in India, a number of Indian companies are in the process or have already formed Joint Ventures (JVs) with foreign companies. Indian majors such as Tatas, Reliance, Mahindra and Dynamatic Technologies are already in the fray, looking at JVs with foreign majors such as Bell, Boeing & Sikorsky (now part of Lockheed Martin) from the US, Russian Kamov and European Airbus Helicopters. The requirements for 111 Naval Utility Helicopters (NUH) and 123 Naval Multi Role Helicopters (NMRH) for the Indian Navy have already been cleared by the Government. These projects will be undertaken under the ‘Make in India’ Strategic Partnership Model involving the private sector and a foreign OEM. It will be prudent to note that some of the above Indian companies are already manufacturing major components specially related to airframes for the Chinook, S-92, Apache and Bell 407 helicopters at their world-class facilities in India.

The involvement of the private industry in helicopter development needs to be encouraged by the Government in order to obviate the monopoly of HAL and ensure greater competition in the market.

Indigenous Development

Presently, the most significant development in the HAL helicopter development programme is the Light Combat Helicopter (LCH), stated to be a state-of-the-art attack helicopter with the capability to operate in the mountains. The LCH uses the technology of the existing ALH and its configurations, except that the fuselage is suitably modified and streamlined for tandem seating required for a modern day attack helicopter. An indigenous attack helicopter is a step in the right direction as it has been tailored to suit the terrain and climatic conditions of our area of operations. A number of development flights have taken place since its maiden flight on March 29, 2010 and it is currently undergoing trial evaluation phase. Both the IAF and the Indian Army are the potential customers for induction of the same.

Presently, the Government has already cleared ten and five LCHs for the IAF and the Indian Army respectively and the induction is likely to commence by end of this year. HAL is also developing a new-generation helicopter in the three-tonne class called the Light Utility Helicopter (LUH). This is to cater to the requirement of Light Observation and Reconnaissance class of helicopters for the military. While HAL claims to field it this year, the current progress on its development belies these claims. However, this is a very positive development in the indigenous capability domain. The HAL is also looking at the development of an Indian Multi Role Helicopter (IMRH) in the 12-tonne class for the Indian Military- a mock up of the same was on display during the Aero India Airshow in February last year. Currently, HAL is scouting for a suitable engine for this venture in to be manufactured in collaboration with a foreign OEM.

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The involvement of the private industry in helicopter development needs to be encouraged by the Government in order to obviate the monopoly of HAL and ensure greater competition in the market. The industry also needs to keep in mind the developing future helicopter technology and incorporate the same in its projects. There is an urgent need to develop a collaborative approach towards developing helicopter manufacturing base in the country for using the strengths of both the public and private sector towards fulfilling national aspirations.

Conclusion

The market for military helicopters is on the verge of a technological generational leap with next-generation compound helicopters and tilt-rotor crafts heralding the advent of a new era that is likely to witness a significant expansion of the operational spectrum, capabilities and performance threshold of these machines. This is likely to eventually redefine their role besides enhancing overall effectiveness in conducting a wide range of military missions and operations.

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The views expressed are of the author and do not necessarily represent the opinions or policies of the Indian Defence Review.

About the Author

Lt Gen BS Pawar

former Head of the Army Aviation Corps and Commandant School of Artillery.

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