IL-4 Bomber Aircraft,Technical Specifications (The USSR)

IL-4 bomber aircraft
  • Crew – 4 people
  • Engines – 2 x M88B
  • Power – 1100 hp
  • Wingspan-21.44 m
  • Wing area – 66.7 sq. m
  • Empty aircraft weight-6421 kg
  • Maximum take-off weight-12,120 kg
  • Full load weight-2500 kg
  • Maximum speed at altitude/near the ground – 453/340 km / h
  • Practical ceiling – 8700 m
  • Maximum range-3585 km
  • Armament – 2×7. 62 mm SHKAS machine guns and 1×12. 7 mm UBT machine gun
  • Maximum bomb load – 2700 kg.

IL-4 Bomber Aircraft Details

In the second half of 1934, the Design Bureau of S. V. Ilyushin, who was also the head of the 1st Main Directorate of the People’s Commissariat of Defense Industry of the USSR, under the leadership of A. A. Senkov, developed a project for a high-speed long-range bomber TSKB-26. Based on the analysis of various schemes of the future bomber, the scheme of a two-engine free-bearing low-wing aircraft with M-85 engines was chosen.

S. V. Ilyushin believed that a new aircraft needed a wing with moderate elongation to achieve a long flight range. Calculations have shown that it will not only have the necessary range, but also its speed will be significantly higher than that of other similar aircraft. The low wing lengthening allowed to increase the rigidity of its structure and, accordingly, anti-flutter properties. As a result, a wing with a heavy load and powerful mechanization (retractable flaps) was designed. The designers also managed to achieve a significant reduction in the mass of both the fuselage-due to the rational choice of the power scheme and configuration of the bomb bay, and the wing – due to the design of wing fuel tanks according to the scheme, later called “caisson tanks”. Among the new design solutions was the duplication of machine controls (handle and pedals) mounted in the navigator’s cabin. This design made it possible to increase the effectiveness of a bomb (torpedo) strike: the navigator was able to control the aircraft on a combat course. Duplication of control could save the crew and the plane if the pilot was hit. On August 29, 1934, the technical requirements for the new aircraft were approved, and four months later a mock-up of the aircraft was built, which received the designation “TSKB-26”. Its flight tests began in the summer of 1935, which was conducted by test pilot V. K. Kokkinaki. They confirmed the high flight data, for the first time on an aircraft of this class, a Nesterov dead loop was performed.

Based on the results of flight tests of its first model, during which it set five aviation world records for speed, range and payload, a team of specialists led by S. V. Ilyushin, began construction of the second model of the new bomber, designated TSKB-30 (DB-3). The aircraft was a free-bearing monoplane of all-metal construction. The crew consisted of 3 people: a pilot, navigator and gunner. This vehicle was armed with three 7.62 mm SHKAS machine guns: one for the navigator and two for the radio operator gunner. The main bomb armament consisted of ten 100-kg aerial bombs. However, the design of the bomb bay allowed the use of two 500 kg or one 1000 kg bombs (torpedoes). In the reloading version-with a small combat range – the aircraft allowed a bomb load of 2500 kg. The aircraft was equipped with two M-85 air-cooled engines. In the spring of 1936, tests of the TSKB-30 aircraft began, and in August of the same year it was adopted by the Red Army Air Force and launched into a series under the designation DB-3. Already in 1937, the first DB-3 aircraft mastered in mass production entered service with long-range bomber units.

On June 27-28, 1938, V. K. Kokkinaki and A. M. Bryandinsky made a long – distance non – stop flight from Moscow to the Far East with a length of 7580 km in 24 hours and 36 minutes with an average speed of 307 km/h, and on April 28-29, 1939, V. K. Kokkinaki and M. X. Gordienko made a non-stop flight from Moscow to the United States (Misco Island) in 22 hours and 56 minutes, 348 km/h.

Serial production of the DB-3 was carried out at three factories, and at the same time, improvements were made to its design, and first of all to the engines, which were successively replaced on the DB-3 from the M-85 to more advanced ones – the M-86, M-87 and M-87A. All this taken together, as well as the replacement of fixed pitch propellers (VFS) for M-87A engines, carried out in 1939, with VISH-3 variable pitch propellers, gave a speed increase of 33 km / h – at an altitude of 4000 m, and up to 50-52 km/h – at an altitude of 5000 m, and the flight ceiling of the aircraft increased by 1300 m.

A total of 1,528 DB-3 bombers were produced, which, along with the Red Army Air Force, were also widely used in the Navy as long-range sea scouts and torpedo bombers. So, already in 1938, a new version of the aircraft was developed for the Navy aviation under the designation ” DB-3T (torpedo bomber)”. DB-3T became the first mass-produced Soviet torpedo bomber. In this variant, the suspension and attachment system made it possible to use equally successfully both the low-altitude 455-mm torpedo 45-36-AN (dropped from a height of 30 meters at a speed of 320 km / h) and the high-altitude 455-mm torpedo 45-36 – AB (dropped from a height of at least 300 meters, with parachute descent, and after landing-with circulation in a closed circle along the target’s course).

The DB-3T torpedo-carrying aircraft, along with torpedoes, could also carry aerial bombs and sea mines, which made it possible to use it as a conventional bomber and mine director. In addition, this aircraft, if necessary, could also be used as a long-range maritime reconnaissance aircraft.

From DB-3T aircraft in the Air Force of the Navy in 1939-1940, aviation mine and torpedo regiments were formed, the main purpose of which was to destroy enemy ships, mine enemy fairways and exits from naval bases. To expand the combat capabilities of mine-torpedo aircraft of the Navy in 1938, another modification of the DB-3TP aircraft was created – a float version of the serial DB-3T. In the pre-war years, there was a constant modernization of the DB-3 aircraft in order to expand its combat properties (a variant of the long-range bomber escort aircraft; a variant of the aircraft for amphibious operations of paratroopers and military equipment; a variant of the flying laboratory). The DB-3 bomber first took part in combat operations against Japanese troops in China, where the Soviet Union delivered 24 vehicles in 1939. Then the DB-3 participated in the Soviet-Finnish war of 1939/1940, where its first modifications, without having powerful small arms, suffered heavy losses from Finnish fighter aircraft.

Since 1938, the Design Bureau of S. V. Ilyushin began work on its significant improvement. And already in May 1939, after the modernization associated with structural and technological changes, flight tests of the modernized aircraft began, which received the designation “DB-3F”. It looked different from its predecessor with improved aerodynamics, including smoother contours of the elongated nose of the fuselage, which received better glazing for the convenience of the navigator. The design of the airframe, radically changed in accordance with the use of new production technology, has become more technologically advanced in mass production and relatively simple. The new, more powerful high-altitude M-88B engines, equipped with TK-3 turbochargers, produced 1,100 hp at take – off and 1,000 hp at an altitude of 6,000 m. In the storage aircraft, soft fuselage protected fuel tanks with a neutral gas filling system were used for the main fuel supply, and a pneumatic landing gear cleaning system was introduced instead of an oil-pneumatic one. In addition, the wing tanks ceased to be tanks in the literal sense-fuel was poured directly into the sealed compartments of the planes. The upper rifle and lower hatch machine guns were replaced with more modern ones: a 12.7 mm Berezina UB machine gun was mounted in the upper hemisphere, and 7.62 mm SHKAS machine guns were mounted in the lower hemisphere. In August 1939, state tests of the DB-3F bomber aircraft began, according to the results of which it was adopted by the Air Force in the fall. Production of the DB-3F was completed in 1940.

By the beginning of the Great Patriotic War, the Soviet long-range bomber fleet consisted of 2,147 aircraft, including a significant part of the DB-3 and DB-3F twin-engine all-metal bombers (renamed IL-4 from March 1942). During the Great Patriotic War, the Il-4 aircraft, which became the main long-range bomber of the Soviet Air Force, was continuously improved. Already with the beginning of the war, the design team headed by S. V. Ilyushin undertook work to increase the production of DB-3F and simplify its production technology. Due to the acute shortage of duralumin from the autumn of 1941, wood and plywood were used instead of metal for the manufacture of the navigator’s cabin, the pilot’s cabin floor, the tail fairing, wing consoles and the nose of the fuselage, which led to a slight decrease in the maximum speed. Already the first battles revealed the need to introduce a second air gunner to service the lower hatch machine gun mount, and the ship’s crew grew to four people. The defensive armament was also reinforced, which initially consisted of three 7.62 mm SHKAS machine guns, but was soon replaced by two SHKAS machine guns and one 12.7 mm UBT machine gun (on the turret). On several series of aircraft, two 20-mm SHVAK air guns were mounted: one in the nose mount, the second on the turret. Bomb load normal (on internal suspension) for the IL-4, the maximum weight was 1000 kg, and the maximum weight was 2700 kg. In addition to the 9-mm armored back of the pilot’s seat, the shooters ‘ armor protection (6 – 9 mm armor plates) was also provided. To maintain the same flight range, the normal flight weight of the four-seat Il-4 was increased to 9420 kg. Fuel weight increased by 525 kg thanks to two suspended tanks. During the war, the maximum take-off weight of the IL-4 increased to 11,500 kg. With a cruising speed of 250 km / h, its flight range with a bomb load of 1000 kg on the internal suspension increased to 4265 km. Flights with bombs in overload became the rule, and the take-off weight in the overload version reached 12,120 kg with 2.5 tons of aerial bombs. Along with the main purpose, during the war the Il-4 bomber was also used as a towing vehicle for A-7 and G-11 gliders, and was also used to throw troops (up to 7 people) behind enemy lines. The IL-4 bomber, torpedo bomber (IL-4T) and scout variants were produced throughout the war.

Being the main strike force of the Soviet long-range aviation, this aircraft made a great contribution to the defeat of the enemy. From the very first days of the Great Patriotic War, units of long-range and naval aviation that were armed with DB-3 and DB-3F bombers took an active part in combat operations, starting to carry out bombing attacks on military-industrial facilities and airfields of the enemy. So, for example, already on June 25, 1941, as a result of an air raid by DB-3F bombers from the 207th long-range bomber Regiment on one of the airfields near Vilnius, German Messerschmitt Bf109 fighters from the second group of the 27th Fighter Squadron were almost completely destroyed, as a result of which, soon this squadron was withdrawn to Germany for re-equipment and additional personnel. On the same day, in the area of Molodechno, the commander of the 2nd squadron of the 207th long-range bomber aviation Regiment, Captain N. F. Gastello, performed a legendary feat, directing his burning DB-3F aircraft at a cluster of enemy military equipment.

In early August 1941, the Soviet High Command set the task of bombing Berlin, the capital of the Third Reich, from the Cahul airfield on the island of Saaremaa. Ezel) in the Baltic Sea. The Luftwaffe believed that Berlin’s powerful air defense, which included 736 anti-aircraft guns, hundreds of fighter jets, barrage balloons and 160 searchlights, reliably protected the German capital from air strikes. Therefore, the first bombing attack of Soviet aircraft on Berlin was of great political significance. On the night of 4 to 5 August, five DB-3F bombers performed a reconnaissance flight to Berlin. It was found that the anti-aircraft defense is located in a ring around the city within a radius of 100 km. On August 7, a group of 15 DB-3F bomber aircraft, under the command of the commander of the 1st mine and torpedo Regiment of the Red Banner Baltic Fleet Air Force, Colonel E. N. Preobrazhensky, took off. Around one o’clock in the morning on August 8, after dropping bombs on Berlin, the planes turned north to the sea. Only then did the Berlin air defense system catch on – searchlights turned on, anti-aircraft guns started working, German night fighters took to the air. However, all Soviet planes returned safely to the base. This raid was the first such operation of Soviet long-range aviation. Three days later, the capital of the Third Reich was hit again by a group of DB-3F Long-range aircraft of the Air Force under the command of Major V. I. Shchelkunov. Soviet raids on Berlin ended only on September 5, 1941. By this time, 10 raids (90 sorties) had been carried out, as a result of which 327 aerial bombs weighing 250 kg each were dropped and 32 fires were registered, while the losses of Soviet aviation amounted to only 4 bombers. In these raids, along with DB-3F aircraft, Pe-8 heavy bombers under the command of Hero of the Soviet Union M. V. Vodopyanov also took part. By decree of the Presidium of the Supreme Soviet of the USSR, ten pilots who participated in the raids on Berlin were awarded the title Hero of the Soviet Union, 13 pilots received the Order of Lenin and 55 were awarded the Orders of the Red Star and the Red Banner of Battle. Soon, due to the difficult situation that developed in the initial period of the Great Patriotic War, DB-3 and DB-3F aircraft were used mainly for performing tactical and operational tasks in interaction with front-line bombers. Moreover, due to the heavy losses incurred, they were used mainly at night from the autumn of 1941. Heroes of the Soviet Union V. S. Efremov, S. I. Kretov, A. I. Molodchiy, and V. I. Osipov successfully fought on the IL-4 twice. In August 1945, Il-4 aircraft bombed parts of the Kwantung Army, Japanese ships in ports and bases in North Korea.

In total, in 1940-1946, plants No. 18 (Voronezh); No. 23 (Moscow); No. 39 named after V. R. Menzhinsky (Moscow), whose production was evacuated to Irkutsk in 1941; No. 126 (Komsomolsk-on-Amur) built 6877 DB-3F (Il-4) aircraft in several modifications.

The Central Museum of the Great Patriotic War exhibits an IL-4 bomber (factory number 17404, manufactured at factory Number 126 in the first half of 1945) from the 10th bomber Aviation Regiment of the 9th Air Army of the Primorsky Group of Forces, which made an emergency landing during the Soviet-Japanese War of 1945 due to engine damage near the village of Muraveyka, Anuchinsky district, Primorsky Krai. Fragments of the plane were discovered by a group of the Poisk military sports club under the leadership of N. V. Akimchuk. After the restoration work carried out by Aviation Restoration Group LLC under the leadership of O. Y. Leiko, the Il-4 bomber was solemnly transferred to the museum on August 18, 2004.

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