The Yer-2 (DB-240) was a Soviet piston-engine strategic bomber that served in the Soviet Long Range Aviation during World War II. Originally developed as a passenger aircraft, the Stal-7, by Robert Ludwigovich Bartini, the aircraft had a range of 5,000 km. However, after Bartini's arrest in 1938, his design bureau proposed converting the aircraft into a strategic bomber to the Soviet leadership. After receiving approval, the Stal-7 was redesigned under the direction of the new chief designer, Vladimir Grigoryevich Yermolaev, and entered operational service in May–June 1941 under the designation Yer-2. The bomber did not become widely used due to its poor flight characteristics, frequent accidents, and engine fires. From 1940 to 1945, a total of 462 Yer-2 bombers of various modifications were built.

Initially, early versions of the Yer-2 were fitted with M-105 engines. However, with the start of serial production, the aircraft were equipped with M-105R engines. These engines were specifically developed for bomber installation and featured a lower reduction gear ratio. Additionally, to improve protection against rear attacks by fighters, the "MV-2" ventral installation with a 7.62 mm ShKAS machine gun was replaced with the "LU-MV-2B" installation with a 12.7 mm Berezin machine gun during serial production.

The Yer-2 (M-105R) LU has been in the game since the start of the Open Beta Test prior to Update 1.27. The bomber is notable for its heavy bomb load, which allows it to easily destroy one or two bases. However, its extremely poor flight characteristics and weak defensive armament require it to avoid encounters with enemy aircraft. As in reality, the Yer-2 (M-105R) LU is distinguished from the Yer-2 (M-105) by the ventral mount heavy machine guns replacing the ShKAS guns, which slightly increase its chances of surviving encounters with enemy fighters.