The early MiG-21 fighter variants, MiG-21F and MiG-21F-13, were clear-weather daylight-only fighters. Although they were in use with the Soviet Air Force Frontal Aviation (VVS FA), due to their limitations, they were unsuited for the interception tasks of the Soviet Air Defence Forces (PVO).
The early MiG-21 fighter variants, MiG-21F and MiG-21F-13, were daylight-only fighters that operated in clear weather. Although they served with the Soviet Air Force Frontal Aviation (VVS FA), due to their limitations, they were not suitable for intercepting tasks of the Soviet Air Defence Forces (PVO).