The Yermolayev Yer-2 was a long-range Soviet medium bomber used during World War II. It was developed from the Bartini Stal-7 prototype airliner before the war. It was used to bomb Berlin from airbases in Estonia after Operation Barbarossa in 1941. Production was terminated in August 1941 to allow the factory to concentrate on building higher-priority Ilyushin Il-2 ground-attack aircraft, but was restarted at the end of 1943 with new, fuel-efficient, Charomskiy ACh-30B aircraft Diesel engines.
Although designed as a long-range medium bomber it was flown on tactical ground-attack missions during the Battle of Moscow with heavy losses. The survivors were flown, in ever dwindling numbers, until August 1943 when the last examples were transferred to schools. However, the resumption of production in 1943 allowed the aircraft to resume combat operations in April 1945. The Yer-2 remained in service with Long-Range Aviation until replaced by four-engined bombers at the end of the 1940s.