HAL finalises 13t helicopter design to replace Mi-17s

The Indian Multi Role Helicopter (IMRH) is a project initiated by India's state-owned aerospace and defence company, Hindustan Aeronautics Limited (HAL). The IMRH is intended to be a versatile and adaptable helicopter designed to serve a variety of roles within the Indian armed forces. The development of the IMRH helicopter continues.

Discussions are also continuing with the Indian Armed Forces on the operational requirements for this new helicopter. Availability of an indigenous engine will enhance the self-reliance content on the platform and demonstrates the commitment of both Safran Helicopter Engines and HAL to the Indian Government’s vision of “Atmanirbhar Bharat”, or achieving self-reliance - particularly in defence technologies.

The Indian Multi Role Helicopter (IMRH) is envisaged to meet Qualitative Requirements of Indian Defence forces. IMRH will have significant improvements in performance over the existing contemporary Multi Role Medium lift helicopters with many features specially designed for Indian conditions. The IMRH airframe consists of three main sections:

1) Front-Fuselage
2) Centre-Fuselage
3) Tail Boom and empennage

The IMRH is expected to replace the current Mil Mi-17 and Mil Mi-8 helicopters across the Indian armed forces. It will be developed for both the Indian Army and Air Force. It will be capable of landing and take off from 5 km altitude.

Here are some key details about the Indian Multi-Role Helicopter (IMRH):

The Cockpit accommodates two or three crews with maximum crash protection and provides good all-round visibility. Normal emergency entry and exit is to be achieved by two hinged jettisonable doors one on each side. It should absorb loads imposed by the Nose landing gear. Flight controls, avionics etc. are also located in and around the cockpit region. The middle section of the fuselage i.e. Centre Fuselage contains the troop/passenger/cargo compartment and fuel. It should absorb loads imposed by the main rotor and Main landing gear.

The cabin dimension should in such that it allows up to 36 passengers in three rows and meets the specified mission requirements and should be able carry an internal cargo of 4000Kg. 

An external hook is to be provided to transport cargo up to 4,000 kg as an optional fit. 

The floors are to be made individually removable for accessibility. The cabin area to be provided with two sliding doors, one on each side, which are flush with outside surface. This gives a better aerodynamic surface, thus reducing drag. Minimum 4 windows to be provided on each side with jettisonable configuration for emergency exit.

Hard points are to be provided for jacking, towing, mooring, landing gear, armament boom, engine mounts, transmission deck and for other attachments. The rear side of fuselage contains a hydraulically operated Ramp, Tail Boom connection and Equipment bays on the inner sides of the fuselage. The Ramp and ramp door allows the loading of cargo.

The engine floor provides a three-point attachment for the engine. The hot section around the engine is to be constructed of Titanium alloy to meet the fire resistance requirements of DEFSTAN or FAR-29. 

The Tail boom supports the tail rotor, tail rotor gearbox, tail rotor drive shaft and the horizontal stabilizer with the vertical fin. Outside the tail boom the tail rotor drive system is to be housed. The Tail boom is to be mounted to Centre fuselage by bolted joint.

Engine Development

Safran Helicopter Engines and Hindustan Aeronautics Limited (HAL) signed a workshare agreement on February 15, 2023 at Bangalore for the joint development of the engine intended for the future 13-ton IMRH (Indian Multi-Role Helicopter) and its naval version DBMRH (Deck Based Multi-Role Helicopter). 

This agreement follows the MoU (Memorandum of Understanding) signed on 8th July 2022 and stipulates the sharing of activities within the joint venture where both parties have agreed on an equivalent repartition. In particular, HAL will take part in the design, development, and production of some of the core engine components, which is a breakthrough achievement in terms of expertise and know-how in the country.

IMRH Role

The IMRH is being developed to cater to both military and civilian applications. It is expected to offer capabilities such as troop transport, search and rescue, air-attack, anti-surface, anti-submarine warfare, electronic warfare, and more. With its multi-role capabilities, the IMRH aims to replace and augment various aging helicopter fleets currently in service.

This project reflects India's commitment to enhancing its indigenous aerospace and defence capabilities and reducing its dependence on foreign suppliers. As of my last knowledge update in September 2021, the development and production of the IMRH were ongoing, and specific technical details and operational status may have evolved since then.

The IMRH is expected to have significant improvements in performance over the existing contemporary Multi Role Medium lift helicopters. It will have many features specially designed for Indian conditions.