History of Creation
Modern bomber at a high speed (at a rate commensurate fighters) and range, Russian designers have started to create for a long time before majestically Russian war. The first sign was SB — High bomber made Tupolev. The car was sent to the batch creation in 1934. It was an all-metal aircraft duralumin, equip with 2 engines of the M-100 has an output of 860 hp Unlike most previous generations of his bomber was not corrugated sheathing. This fact is significant way affected the properties of high-speed aircraft, SB could accelerate to 420 km / h The aircraft even overtook fighters, for example, the speed of coeval SB — I-15 was only 360 km / h A later fighter — I-16, filled the engine M-25, developed only slightly more — 454 km / h
Almost a year after the occurrence of SB own version of the distant high-speed bombers presented just made KB, driven by SV Ilyushin. It was at this time to test flights began CDB-26 — far bomber, filled with new air-cooled engines — M-85. CDB-26 presented himself as an all-metal aircraft with a fairly well streamlined fuselage, having a circular cross-section, smoothly passing in front of the hemisphere, and a rear fin. Cantilever wing bomber was smooth and had a duralumin casing, the sheer volume of the gas tanks were located in the interior of the wing. Estimated weight of fuel accounted for 27% of total flight mass bombers, which guaranteed him the highest range of over 3,000 km. The crew of the aircraft consisted of a 3-man defensive weaponry included a 3 machine guns.
Designing and building the CDB-26 was noticeable phenomenon for Russian aircraft and science. His appearance at the light became possible thanks to the dozens of basic works of Russian scientists who were able to develop a theory for calculation of spatial structures with smooth running trim. The new aircraft was variable pitch propellers, neotkaznoe retractable landing gear, closed turret machine gun, mechanized wing, which allows the aircraft with the highest specific load and landing rocket with a relatively low speed. All of these new items in the future become an indispensable feature of a huge number of aircraft.
By March 1936 the new aircraft entered the tests. First flight, who conducted the test pilot Vladimir K. Kokkinaki showed that the new bomber is quite simply off the ground, and has a good rate of climb and maneuverability. Check flights conducted to determine the maximum range shown that it even higher than estimated at over 4,000 km. With all of this car to reach speeds of 310 km / h For long it was plenty. It is in series production bomber DB-2 was equal to the maximum speed of 220 km / h With all of this available power and agility of the new twin-engine aircraft allowed him to make uncharacteristic for this class of aircraft aerobatic maneuvers, such as the well-known loop the loop.
Public display of new items was held in 1936 which has become customary in the air parade. In a longish series of aircraft provided by CDB-26 was the penultimate. Even after the passage of the airfield last car bomber suddenly all made a U-turn to re-pass over Tushino. One flew over the stands of spectators, plane rather abruptly took up, hovered for a moment in an inverted position, and here is easily slipped down in the sky outlining the luxury loop. This aerobatics plane showed a couple of times.
Immediately after the parade, Ilyushin and Kokkinaki invited to the Kremlin. At the meeting, which was attended by Stalin, Voroshilov and Ordzhonikidze, it was decided to launch a new bomber in the series. The new twin-engine bomber was a distant name — DB-3. It was the first plane Ilyushin and his young comparable size. Performance properties of the new bombers were so high that they have allowed quite rapidly establish a set of global records. For example, July 17, 1936 test pilot Kokkinaki made on this plane flying with a weight of 500 kg. to a height of 11,458 meters, or 1,174 feet higher than the previous record belonging to a Frenchman Sinerinu. In addition to high-altitude records at the DB-3, which received the title of "Moscow", VK Kokkinaki pilot and navigator AM Bryandinsky set a number of records at the range. One of the more prominent flights took place on the route Moscow — Khabarovsk, and the flight was made without the embodiment of crotch landings.
The appearance of IL-4
Meanwhile, work to improve the aircraft lasted. In 1938, the bomber was modernized. The new version has been called DB-3F (from March 1942, this is the car was designated IL-4). The new aircraft equipped with more powerful engines, to develop 1,100 hp, they allowed the aircraft to reach the speed of 445 km / h By plane decided to knit the problem of placing fuel. Now part of it was placed in a sealed cavity of the wings. With all this the main supplies of fuel were in the fuselage fuel tanks, which were retreading. Provided the designers and crew protection measures bombers from enemy fire — began to create the pilot's seat of a pretty thick armor plate.
IL-4 initially designed for speeds exceeding 400 km / h, significantly increased its real effectiveness in the rapidly changing combat criteria. Despite the fact that the plane had a number of common parts of the design with the previous version of DB-3, IL-4 had a number of significant differences. For example, the fuselage of the car was redesigned for the latest production technology, which was used for the Li-2 (manufactured under license from the South American DC-3). It has been improved aerodynamic properties, which together with the installation of new engines of growth to achieve the greatest possible speed flight. Despite the ability to overcome the 4,000 km., The plane is almost always used to have the smallest distances.
Bomb load of IL-4 was increased to 2,500 kg. To protect the aircraft from attack by fighters on it were installed 2nd motionless and one mobile infantry unit. The upper hemisphere of the bombers defended mnogokalibernym machine gun 12.7 mm Berezin design. Front and rear were installed 7.62-mm machine guns ShKAS design Shpitalniy. Of climb,
speed and range of IL-4 was on par with many aircraft of its own time.
Managed to achieve this through the use of the 10-s of innovations that have been proposed in KB Ilyushin. Among them may be noted the rejection of which have become classics of tubular spars and a transition to a more robust and light — from upressovannyh profiles. Placing the supplies of fuel specifically in the cavity of an airplane wing, also planted a constructive opportunity to continue the flight with the introduction of only the 1st motor. The correctness of the chosen concept initially states and the fact that the plane, which was created 5 years before the start of stateliness Russian war could quite successfully managed with the obligations imposed on it during the war. Specifically, IL-4 bomber, initiated raids on German towns: Berlin, Stettin, Frankfurt-am-Main, Dresden and Danzig. In the first few months of the war the Germans forced the Russian aviation bye with confidence that the territory of Germany will be inaccessible for the acts of Russian Air Force.
In addition to running distant raids behind enemy lines, the pilots on the IL-4 were nocturnal hunt for the German military echelons, destroying military equipment and the enemy soldier by creating a dot bomb attacks congestion at the railway communications of the enemy. Excellent and the aircraft was used for attacks on German airfields. Russian bomber crews tracked the German planes that vorachivalis with combat missions, and at the time of their landing, when pilots of the Luftwaffe at the time included kutsee landing lights were applied on parking planes bombed.
Go with a front-line bombers were working on creating and torpedo. This model was designated as IL-4T. Many torpedo installed finders RPK-2 with antennas mounted in the fairing before canopies canopy IL-4T. On ordinary aerial bombers RPK-2 was placed in the lower front part of the fuselage. Some machines instead of RPK-2 was equipped with RPK-10, without having the loop antenna radome. On the left side of the torpedo-established second venturi. Review for navigators IL-4T also been improved by the installation of additional windows enormous size on both sides of the cockpit. Each torpedo carrying a 45-cm torpedo 45-36-45 or AN-36-AB mass of 940 kg., Which was fastened under its fuselage pylon on the T-18. Instead of the torpedo plane could carry and sea mines. In this case it was used for the production of minefields from the air.
The performance properties of IL-4:
Dimensions: Wingspan — 21.44 m, length — 14,76 m, height — 4,10 m
Wing Area — 66.7 square meters. m
Aircraft weight, kg.
— Empty — 6421
— normal take-off — 10,055
— maximum take-off — 12,120
Motor Type — 2 PD M-88B, Power 1100 hp each
Most speed at the ground-332 km / h at an altitude — 398 km / h
Flight range — 4000 km.
Service ceiling — 8,300 m
Crew — 3-4.
Armament: 1×12, 7-mm machine gun BT 2h7.62 ShKAS-mm machine gun. Normal bomb load — 1000 kg, the limit — 2500 kg. In the version of torpedo — 1 torpedo weighing 940 kg.