The Beriev A-50 is a Soviet-origin airborne early warning and control aircraft that is based on the Ilyushin Il-76 transport plane. Developed to replace the Tupolev Tu-126 "Moss", the A-50 first flew in 1978. Its existence was revealed to the Western Bloc in 1978 by Adolf Tolkachev. It entered service in 1985, with about 40 produced by 1992.