The principal and most obvious goal was to replace India's ageing MiG-21 fighters, which had been the mainstay of the IAF since the 1970s.
The principal was to replace India's ageing MiG-21 fighters. Most obvious goal was to replace India's ageing MiG-21 fighters. India's ageing MiG-21 fighters had been the mainstay of the IAF since the 1970s.