The production of the MiG-21s in India under license by Hindustan Aeronautics in Nasik started with the MiG-21FL in 1966 in four phases starting with the assembly of CKD kits, moving on to subassemblies, parts, and finally advancing to production from scratch. 205 MiG-21FLs, designated Type 77 and nicknamed Trishul ("Trident), were built in India between 1966 and 1972; the first one built entirely from Indian-made components was delivered to the IAF on 19 October 1970, with the first Indian-made R11F2S-300 powerplant leaving the assembly line on 2 January 1969. In 1971 HAL production was switched to an improved version of the MiG-21M (izdeliye 96), which was designated Type 88 by HAL; as this variant was produced exclusively in India, no izdeliye designation is applicable. The first Type 88 MiG-21M was delivered to the IAF on 14 February 1973 and the last on 12 November 1981, with a total of 158 built. The last variant to be produced by HAL was the MiG-21bis. 75 were built in 1977 from CKD kits, and a further 220 were built from scratch by 1984. Despite a series of crashes during the 1990s, the Indian Air Force has decided to upgrade about 125 of the MiG-21bis in its inventory to the MiG-21 "Bison" standard. These will serve the Indian Air Force until 2018.