The Ilyushin Il-4 (DB-3F) (russian: Ильюшин Ил-4 (ДБ-3Ф)) was a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

twin-engined

long-range bomber A strategic bomber is a medium- to long-range penetration bomber aircraft designed to drop large amounts of air-to-ground weaponry onto a distant target for the purposes of debilitating the enemy's capacity to wage war. Unlike tactical bombers, ...

and

torpedo bomber A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...

, widely used by the

Soviet Air Force The Soviet Air Forces ( rus, Военно-воздушные силы, r=Voyenno-vozdushnyye sily, VVS; literally "Military Air Forces") were one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces. The Air Forces ...

and

Soviet Naval Aviation Soviet Naval Aviation (AV-MF, for ''Авиация военно-морского флота'' in Russian, or ''Aviatsiya voyenno-morskogo flota'', literally "aviation of the military maritime fleet") was the naval aviation arm of the Soviet Nav ...

during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

Design and development

In 1938, the Ilyushin design bureau redesigned the

Ilyushin DB-3 The Ilyushin DB-3, where "DB" stands for ''Dalniy Bombardirovschik'' (Russian: Дальний бомбардировщик) meaning "long-range bomber", was a Soviet bomber aircraft of World War II. It was a twin-engined, low-wing monoplane that f ...

to ease production and improve its performance, the revised version receiving the designation DB-3F (''Forsirovanniye'' or "boosted"). The aircraft's internal structure, particularly the wings, was extensively changed, eliminating the need for hand finishing of the structure, and with

duralumin Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age-hardenable aluminium alloys. The term is a combination of '' Dürener'' and ''aluminium''. Its use as a tra ...

replacing the large scale use of steel in the earlier version.''Air International'' May 1986, p. 133.Gunston 1995, pp. 100–101. The aircraft's fuel system was redesigned, increasing its internal capacity while reducing the number of fuel tanks. The fuselage nose was lengthened to give more room for the navigator/bombardier while reducing drag. The prototype DB-3F, powered by the same

Tumansky M-87 The Tumansky M-87 was a Soviet air-cooled aircraft radial engine that was developed in the late 1930s. It was a development of their licensed Gnome-Rhone 14K engines that started with the M-85. Development In 1934, USSR licensed the French ...

B engines of the DB-3M, was piloted on its maiden flight by

Vladimir Kokkinaki Vladimir Konstantinovich Kokkinaki (russian: Владимир Константинович Коккинаки; – 6 January 1985) was a test pilot in the Soviet Union, notable for setting twenty-two world records and serving as president of the ...

on 21 May 1939.Gordon, Komissarov and Komissarov 2004, pp. 91–92. It successfully passed through state acceptance tests and entered production in January 1940, with the

Tumansky M-88 The Tumansky M-88 was an air-cooled radial engine for aircraft developed in the Soviet Union shortly before World War II. Design and development The M-88 was designed to address the shortcomings of the Tumansky M-87. The improvements incorporat ...

quickly replacing the M-87.Gordon, Komissarov and Komissarov 2004, p. 92.Gunston 1995, p. 102. The DB-3F was redesignated Il-4 in March 1942. Some series had wooden outer wings and front fuselages to conserve

metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

s, and throughout the production,

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gen ...

s 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 Turret may refer to: * Turret (architecture), a small tower that projects above the wall of a building * Gun turret, a mechanism of a projectile-firing weapon * Objective turret, an indexable holder of multiple lenses in an optical microscope * Mi ...

, 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 Armour (British English) or armor (American English; see spelling differences) is a covering used to protect an object, individual, or vehicle from physical injury or damage, especially direct contact weapons or projectiles during combat, or fr ...

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 engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

s 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.

Operational history

Soviet Union

Although the Il-4 was only a medium bomber, it had the range to be used on strategic missions. The use of the bombers in this role was not a priority for the VVS, but nevertheless the Il-4 was used on several long-range bombing raids against

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

in 1941. Most would be used on much shorter range missions, often adding another 1,000 kg (2,204 lb) of

bomb A bomb is an explosive weapon that uses the Exothermic process, exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-t ...

s under the wings, in addition to the internal 2,500 kg (5,512 lb).

Finland

Finland bought four captured DB-3Fs from German stocks. These were given the Finnish Air Force serials DF-22 to DF-25 and flown from

Bryansk Bryansk ( rus, Брянск, p=brʲansk) is a city and the administrative center of Bryansk Oblast, Russia, situated on the River Desna, southwest of Moscow. Population: Geography Urban layout The location of the settlement was originally ass ...

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

to Finland (one aircraft, DF-22, was destroyed en route and crashed near Syeschtschinskaya airfield). The aircraft were later flown by No. 48 Sqn during 1943 (DF-23, DF-24 and DF-25), No. 46 Sqn during 1944 (DF-23 and DF-24) and No. 45 Sqn for a short time in 1945 (DF-23), until the last remaining serviceable aircraft went into depot on February 23, 1945. After the war, DF-25 was lost in a snowstorm, landed on the ice and crashed into the woods in Öja near the city of

Kokkola Kokkola (; sv, Karleby, ) is a cities of Finland, town and municipalities of Finland, municipality of Finland. The town is located in the Central Ostrobothnia regions of Finland, region. The town has a population of () and covers an area of of ...

. Most parts of the plane were rescued and taken to a depot.

Operators

;: *

Chinese Nationalist Air Force Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

24 aircraft ; *

Finnish Air Force The Finnish Air Force (FAF or FiAF; fi, Ilmavoimat, , Air forces; sv, Flygvapnet, , Air weapon) is one of the branches of the Finnish Defence Forces. Its peacetime tasks are airspace surveillance, identification flights, and production of Finnis ...

11 aircraft of the type DB-3M and four aircraft of the type DB-3F (Il-4) ; * ''

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...

'' (tests only) ; *

:Regiments as at 1945-46: :10th Guards Bomber Aviation Regiment :290th Bomber Aviation Regiment :303rd Bomber Aviation Regiment (Zavitinsk, Amur Oblast) :442nd Bomber Aviation Regiment (Belogorsk, Amur Oblast) with Il-4 :other regiments *

Specifications (Il-4)

References

Notes

Bibliography

* "From DB-3 To Il-4...The Soviet Long-Range Bomber: Part Two". ''

Air International ''AIR International'' is a British aviation magazine covering current defence aerospace and civil aviation topics. It has been in publication since 1971 and is currently published by Key Publishing Ltd. History and profile The magazine was fir ...

'', Vol. 30, No. 3, March 1986. Bromley, UK: Fine Scroll. ISSN 0306-5634. pp. 133–138, 154–155. * Gordon, Yefim and Khazanov, Dmitri. ''Soviet Combat Aircraft of the Second World War, Volume 2: Twin-Engined Fighters, Attack Aircraft and Bombers''. Earl Shilton, UK: Midland Publishing Ltd., 2006. * Gordon, Yefim, Dmitriy Komissarov and Sergey Komissarov. ''OKB Ilyushin: A History of the Design Bureau and its Aircraft''. London: Ian Allan, 2004. . * Gunston, Bill. ''The Osprey Encyclopedia of Russian Aircraft 1875–1995''. London: Osprey, 1995. . * Keskinen, Kalevi; Stenman, Kari and Niska, Klaus. ''Suomen Ilmavoimien Historia 9, Venäläiset Pommittajat (Soviet Bombers)''. Espoo, Finland: Tietoteos, 1982. . * Nowarra, Heinz J. and Duval, G.R. ''Russian Civil and Military Aircraft, 1884-1969''. London: Fountain Press Ltd., 1971. . * Stapfer, Hans-Heiri. ''Ilyushin Il-4 in Action (aircraft number 192)''. Carrollton, Texas: Squadron/Signal Publications, Inc., 2004. . {{Authority control Il-004 1930s Soviet bomber aircraft World War II Soviet medium bombers Low-wing aircraft Aircraft first flown in 1936 Twin piston-engined tractor aircraft