Hindustan Aeronautics Limited (HAL) has opted for a five-bladed articulated rotor system for its upcoming Indian Multi-Role Helicopter (IMRH), moving away from the hingeless design used in earlier platforms like Dhruv. This decision reflects the higher load and performance requirements of a 13-tonne class helicopter. Articulated rotors incorporate hinges that absorb stress, reducing structural strain on blades during heavy-lift operations and turbulent conditions. The addition of a fifth blade increases lift efficiency without significantly expanding rotor diameter, while also reducing vibration levels. This is particularly important for troop transport and VIP roles, where comfort and structural longevity are critical. The design aligns with global standards seen in helicopters like the Mi-17 and Sikorsky S-92. Furthermore, the articulated system supports naval adaptations such as blade folding mechanisms. Overall, HAL’s decision represents a strategic shift toward durability, efficiency, and mission adaptability in medium-lift helicopter design.
