The Czechoslovak Air Force operated the MiG-21 fr om two sources. The first was the licensed production of the MiG-21F-13, which was manufactured by Aero Vodochody between 1963 and 1973, with 194 units produced. Initially, these machines were referred to as S-106, but later changed to the original name MiG-21. The second source was supplies to the USSR. In 1964, the MiGy-21PF were delivered, and were phased out in 1990. In the years 1965 - 1966, the two-seater MiGy-21U were delivered, followed by the MiGy-21US in the years 1968 - 1970 and finally the MiGy-21UM between 1971 - 1978. From 1966 to 1969, deliveries of MiG-21PFMs took place, of which the last pieces were discarded in 1991. In 1969 and 1973, the Czechoslovak Republic delivered several MiG-21s to Syria and Egypt, wh ere they were to compensate for war losses. Between 1969 and 1972, the reconnaissance MiG-21R was delivered, which was in service until the division of the federation in 1993 and subsequently served in the Czech and Slovak air forces. In 1969, the first deliveries of the MiG-21M (MiG-21MA) were launched, which also served until the collapse of the Czechoslovak Socialist Republic and subsequently in the successor countries. Between 1971 and 1975, Czechoslovakia acquired the MiG-21MF, which then formed the backbone of the fighter units of our air force.