Operational history and development of the Soviet Red Air Force's Ilyushin IL-4 medium bomber which also served as long-range reconnaissance aircraft, and torpedo attack aircraft. Includes the DB-3S, DB-3B, DB-3T, DB-3TP, DB-3T (Experimental), Capsule DB-3, TsKB-30, DB-3M, TsKB-30 N-1, DB-3F, DB-3F, IL-4, IL-4TK, and IL-6 variants. Book also covers the DB-3F in German service and IL-4s flown by the Finnish Air Force.