HAL Dhruv :
The HAL Dhruv (Sanskrit: ध्रुव-Dhruva,Hindi-Dhruv "Polaris") is a utility helicopter developed and manufactured by India's Hindustan Aeronautics Limited (HAL). The development of the Dhruv was first announced in November 1984, and it was subsequently designed with assistance from MBB in Germany. The helicopter first flew in 1992; however, its development was prolonged due to multiple factors including the Indian Army's requirement for design changes, budget restrictions, and sanctions placed on India following the 1998 Pokhran-II nuclear tests.
The Dhruv entered service in 2002. It is designed to meet the requirement of both military and civil operators, with military variants of the helicopter being developed for the Indian Armed Forces, while a variant for civilian/commercial use has also been developed. The helicopter was first exported to Nepal and Israel. It is also on order with several other countries for both military and commercial uses.
Military versions in production include transport, utility, reconnaissance and medical evacuation variants. Based on the Dhruv platform, the HAL Light Combat Helicopter (LCH) a dedicated attack helicopter and HAL Light Utility Helicopter (LUH), a utility and observation helicopter, are currently being developed. As of August 2013, more than 200 HAL Dhruv have been produced for different customers.
The Advanced Light Helicopter (ALH) program for an indigenous 5-ton multirole helicopter was initiated in May 1979 by the Indian Air Force and Indian Naval Air Arm. HAL were given a contract by the Indian government in 1984 to develop the helicopter; Germany's Messerschmitt-Bölkow-Blohm (MBB) were contracted in July 1984 as a design consultant and collaborative partner on the programme. Although originally scheduled to fly in 1989, the first prototype ALH (Z-3182) made its maiden flight on 20 August 1992 at Bangalore with the then-Indian Vice President K R Narayanan in attendance. This was followed by a second prototype (Z-3183) on 18 April 1993, an Army/Air Force version (Z-3268), and a navalised prototype (IN.901) with Allied Signal CTS800 engines and a retractable tricycle undercarriage. Development problems arose due to changing military demands and a funding shortfall in the wake of the 1991 Indian economic crisis.
Naval testing on board the INS Viraat and other ships started in March 1998, and around the same time a weight-reduction programme was initiated. However, further delays in development were caused when sanctions were implemented against India following a number of Pokhran-II nuclear tests in 1998 and India's continued refusal to sign the Comprehensive Nuclear-Test-Ban Treaty. As a result the intended engine for the helicopter, the LHTEC T800, was embargoed. The Turbomeca TM 333-2B2 turboshaft engine was selected as a replacement; in addition Turbomeca agreed to develop a more powerful engine with HAL, originally known as the Ardiden. Turbomeca also assisted in the development of the helicopter, stress analysis and studies of rotor dynamics were conducted in France. The first flight of a Dhruv with the new engine, renamed the Shakti, took place on 16 August 2007.