Ilyushin Il-4 (DB-3F)

National origin:- Soviet Union

Role:- Long-range bomber

Manufacturer:- Ilyushin

Designer:-

First flight:- 31st March 1936

Produced:- 1936-1939 (DB-3), 1942-1945 (Il-4)

Number built:- 1,528 (DB-3), 5,256 (Il-4)

Primary users:- Soviet Air Force

Developed from:- Ilyushin DB-3

Developed into:- Ilyushin Il-6

The Ilyushin Il-4 (DB-3F) (Russian: Ильюшин Ил-4 (ДБ-3Ф)) was a Soviet twin-engined long-range bomber and torpedo bomber, widely used by the Soviet Air Force and the Soviet Naval Aviation during the World War II.

The DB-3F was redesignated Il-4 in March 1942. Some series had wooden outer wings and front fuselages to conserve metals, and throughout the production, engines and fuel tanks were upgraded for improved performance while retaining the same range. However the most notable change was the addition of larger defensive guns in the turret, using the 12.7 mm (0.5 in) UBT machine gun in place of the earlier 7.62 mm (0.3 in) weapons. In addition, it was found that the gunners were attacked first, so blocks of armor were placed around the gunner positions.

This extra weight was not offset by the newer engines however, and the Il-4 proved to be slower than the earlier versions at only 404 km/h (251 mph). An attempt to improve performance was made as the Il-6, adding large diesel engines and heavier armament. The engines proved unreliable and production was never started. The Il-4 remained in production until 1945, when just over 5,200 had been built.