In 1975 the 1st Squadron (in Dobroslavtsi) transitioned to the outstanding for its time MiG-21MF fighter and declared operational readiness the following year. At the time these events occurred the squadron leader was Georgi Ivanov Kakalov, the country's first cosmonaut. The major re-armament program of the Bulgarian Air Force, started in the 1970s saw the squadron once again converting to a superb fighter type, when a group of pilots and ground engineers went to the Soviet Union (The Operational Conversion Center at Lugovoye, Kyrgyz SSR) for a conversion course to the MiG-23MF in 1978. On the 10 October the first of 12 MiG-23MFs and 3 MiG-23UMs arrived at Dobroslavtsi AB. The aircraft's ability to intercept enemy machines unspotted, using its IR sensors and the armament of R-23R/T BVR Air-to-Air missiles in addition to the new R-60 short-range Air-to-Air missiles made the BAF the best air arm in southeastern Europe. The live firings at the Astrakhan Range, USSR, made shortly after achieving operational readiness and being graded "excellent" have shown that the Bulgarian pilots have been trained to the fullest of the aircraft's capabilities. During the Warsaw Pact's major scale maneuvers in the 1980s the Bulgarian MiG-23s were even able to intercept Soviet MiG-25 recon planes, entering Bulgarian airspace from Romania and flying at speeds of Mach=2.5+ and altitudes of 20000+ meters.