21 Squadron, AF was formed on 16 October 1965 at 7 Wing, AF, to be equipped with Gnat Mk I aircraft. The Squadron initially flew aircraft borrowed from 2 Squadron, AF and 18 Squadron, AF, until on 14 May 66, when she got her first complement of ac. Thereafter the Squadron moved to 17 Wing, AF, Gorakhpur until the 1971 operations. The Squadron was visited by DASI in 72 and 75 and the Squadron moved to 7 C&MU at Bakshi Ka Talab and operated there til the time she was earmarked to be re-equipped with the Mig-21 BIS. On 1 December 1976, the Squadron moved out of C&MU to 2 Wing, AF Pune to be re-equipped with the MIG-21 BIS. The Squadron moved out from 33 Wing, AF where it had been located since 1 January 1987, to 12 Wing, AF. Sixteen fighter aircraft were ferried out on May 9-1, 1988.