Heavy bomber TB-5 (Central Design Bureau No. 8)
This sizeable aircraft appeared unexpectedly and not in the usual way, and besides, in times not very calm and prosperous. Therefore, until now in the history of TB-5, everything is not clear, and who knows what other documents or eyewitness testimonies can surprise.
As is well known, in the winter of 1929-1930, in the now "legendary" design bureau of TsKB-39, the VT-11 fighter was designed and built in the shortest possible time and became the prototype of the I-5. The leadership of the OGPU considered that successful experience should continue and in the spring of 1930 it decided again to create a bomber in the bowels of its system. According to the current version, the initiator of this project was the chief of TsKB-39 from the OGPU E.S. Paufler. Say, he caught the eye of the prospectus of the firm "Farman", in which one of the multi-engineered French high-rises with the engines under the wing was colorfully painted, so Paufler suggested that his prisoners create a similar one. All of the work was refused, and Dmitry Pavlovich Grigorovich agreed.
The story is quite plausible - during the period of economic and social experiments, and this could happen. The documents confirm that in the spring of 1930, practically without any traditional approvals and approvals, the Central Design Bureau-39 received the task of designing a heavy bomber that received the "brand" designation "Airplane No. 8" (TsKB No. 8), and in the Air Force - TB-5 . The task itself appeared for a number of reasons. At that time, the all-metal TB-3 was created in TsAGI, but its construction was delayed, besides, due to the shortage of aluminum alloys with mass production of the aircraft, problems could arise. Therefore, for safety, a similar machine was required, in the design of which more accessible materials would be used.
In the beginning of 1930 another "sharaga" appeared in the Soviet "correctional system" - a special technical bureau (OTB) of the OGPU for aircraft engines. There were well-known domestic motorists BS Stechkin, NR Brilling, AA Bessonov and others. They were instructed to design, test and launch a 24-cylinder FED engine (F.E. Dzerzhinsky), completed in accordance with X -shaped scheme, equipped with a drive of the central pressurization (CSP), it had to develop at an altitude of 3000 m very decent for those times, the power of 1100-1250 hp. FED was created for TB-5. The installation of engines on the plane was planned in two variants: in the leading edge of the wing or on the racks below it. However, by the time the FEDs were not ready, and the bomber decided to equip 4 Gnome-Rhone engines "Jupiter" VI, located tandem under each wing console.
To work on the TB-5, almost the entire staff of the Central Design Bureau was mobilized and most of the personnel of Plant No. 39 imeni V.R.Menzhinsky on Khodynka, where by that time the "sharaga" Paufler moved from Butyrskaya prison. "Airplane number 8" was created in a year, which, undoubtedly, was a record for such a large and time-consuming machine. It should not be forgotten that during the same period DP Grigorovich was engaged in the I-Z fighter, both of which were built almost simultaneously. Obviously, the actual readiness of both devices was determined in May 1931. It was then that designer Grigorovich was given a Soviet amnesty and then worked as a civilian.
According to the plan, TB-5 was a high-altitude planed with spaced vertical tail. The horizontal tail plane had an additional narrow rearrangeable plane, which was called stabilon. It was intended to reduce the forces on the steering wheel during planting and when the alignment was changed. The sufficiently bulky fuselage of the aircraft was a truss structure made of steel pipes, covered with a cloth. For transportation by rail, it was divided into three parts: the bow - to the rear edge of the wing, the intermediate - to the front edge of the stabilizer and the tail.
The entire bomb load (for an aircraft with FED engines - up to 2500 kg) was placed inside the fuselage along the sides on the beams of DER-18, and it was possible to move freely from the nose of the aircraft to the tail. The crew of TB-5 received unheard-of conveniences for those times - a toilet and four hammocks for rest. The wing of the TB-5 had three spars, with a frequent pitch of the ribs (therefore very laborious, especially in terms of fastening linen plating), had a slight bump to the fuselage. The additional role of the struts is to obtain a more rigid structure for securing the engines. On the plane, on each side of the fuselage under the wing, two Gnome-Rhone "Jupiter" VI engines with a power of 480 hp were installed in tandem. (subsequently licensed M-22 ), and the rear engine was equipped with a Townend ring to improve the cooling of the cylinder heads. Air screws are wooden, front - pulling, rear - pushing.
The defensive armament consisted of three aircraft turrets TOUR-5 with machine guns Spark YES: one was above the navigation booth, in front of the pilots' lanterns, another - just behind the wing and the third - in the tail part of the fuselage. In addition, in the nose of the machine was placed the front movable shooting tower, developed in the armament section under the direction of A.V. Nadashkevich. In fact, this was the first application in the country for a serious mechanized and electrified defensive installation.
G.Mozharovsky, then a young specialist who took part in that work, later recalled: "The tower was a cylindrical shaped glass, rotating around the vertical axis, had a narrow slit for the movement of two machine guns in the vertical plane. The movement of machine guns in the horizontal plane was carried out simultaneously with the rotation of the tower. The shooter was placed inside this glass and, if necessary, could be thrown through a large door, located behind him. This nasal tower was supposed to contain a number of novelties. It was for the first time to install two twin machine gunsPV-1 , made on the basis of infantry "maxims", which instead of water used air cooling. The tower, which was a mobile installation, was armed for the first time with machine guns with continuous tape feed (that is, it was not necessary to rearrange stores with cartridges, know yourself to shoot). The turn of the tower in the horizontal plane occurred from the electric drive, in the vertical plane it was produced by the shooter sitting on the seat and weighing the weight of the weapon with his weight. In order to navigate the weapon in a vertical plane, it was enough for the shooter to easily rest his feet on the floor."
In early summer of 1931, TB-5 was taken to the airfield. After checking and adjusting it was decided to release the aircraft into the air. On June 30 pilot BLBukhgolts made the first test flight in the Khodynsky airdrome zone. Before the flight, concerns were voiced about the handling of such a heavy machine, everyone was interested in particular, how the stabiliron behaves. Buchholz after the landing of fears dispelled, stating literally the following: "The stability in the air is good. The ease of controlling the aircraft is unprecedented. Very small loads on the handlebars."
By July 20 the plane made 4 successful flights. With a mass of 11,200 kg, a fuel reserve of 1,850 kg, the flight range was 1100 km, the duration was 6.7 hours at a cruising speed of 162 km / h at an altitude of 3000 m. The maximum range with a total fuel load of 2,410 kg was 2,100 km. The flight mass is 12060 kg, of which 500 kg are bombs. The maximum speed was 180 km / h near the ground, the practical ceiling is 3,500 m, the takeoff run was 400-420 m.
The flight characteristics of TB-5 obtained during the tests were assessed as low, especially in comparison with the TB-3 that had already flown in six months. The reason for this was not quite a successful motor installation. The engines were equipped with propellers, more suitable for fighters. In addition, the screws of the rear "Jupiter" had to be significantly reduced in diameter due to their placement under the wing. However, in comparison with TB-3, the bomber had advantages. TB-5 had a more perfect layout of defensive installations, an internal suspension of the entire assortment of bombs, had smaller geometric dimensions. Its main advantage was considered to be lower cost and less labor for production (identical to TB-1). Hopes to improve the aircraft's performance by installing FED engines remained. In the summer of 1931, at the engine plant No. 24, there were 12 FEDs in production, and another 10 workpieces.
In connection with these circumstances, on July 25, 1931, the Council of Labor and Defense (STO) ordered the All-Union Aviation Association (VAO) to build six TB-5 (one went as an experienced, the other - the military series). Moreover, all these machines were taken into account in the plans for the formation of new bomber squadrons for 1932. At the same time, the chief of the Air Force PI Baranovbelieved that, in anticipation of FED engines, the construction of TB-5 should be braked and postponed to 1932. With this proposal, he turned to the Supreme Economic Council of the USSR.
However, the Chairman of the Council of People's Commissars of the USSR, VM Molotov, was guided by some special considerations, and therefore rejected this idea and proposed to take all measures for the speedy construction of the TB-5 series. The reason was possibly that this bomber was created under the patronage of the OGPU. Moreover, the results achieved by the Chekists were visually demonstrated on July 6, 1931 to Stalin, who, in addition to TB-5, was shown modifications of I-5, P-5 , TSh-1 and cannon fighter I-Z.
In all, it turned out that the heads of the OGPU really managed to find the most productive form of the aviation industry. And after a short time, on August 27, 1931, TsKB and TsAGI united in a single organization - TsKB-TsAGI. S.Paufler was appointed as the senior.
In the meantime, the hastily trained TB-5 was subjected to continuous improvements and alterations. Beginning in June 1931, the fuselage was strengthened by the car (in the flight twisting of its tail part was noted) and fastening of the engines, the upper hatches in the cockpit of the pilots were cut, glazing was installed in the region of the trailing edge of the center wing, and the "townhouses" were removed from the rear engines. In the winter the plane was put on skis and carried out a number of flights on it. The design work on equipping TB-5 with FED engines continued. The aircraft variants with the installation of engines in the leading edge of the wing were tested in the TsAGI wind tunnel. The work was conducted under the guidance of S. A. Kocherigin. The plane also noted other, subsequently known designers, for example, B. I. Cheranovsky , V. Yatsenko and A.N. Rafaelyants.
As for the serial production of the bomber, this question was postponed indefinitely. The main obstacle was the insufficient capacity of the aircraft plant No. 39, engaged in the production and modification of experimental vehicles.
Flights on the experimental TB-5 continued and the famous test pilot M.Gromov took part in them. On his watch fell an emergency, which occurred in the air in one of the May days of 1932. When the plane was at an altitude of 800 m, suddenly a violent shaking began. It turned out that the left rear engine had broken off from the motorola and was hanging menacingly, clinging to the chassis. Mechanic Vasin saw that the propeller of this "Jupiter" struck the fuselage and rested against the mock-up of the bomb. At this time, petrol caught fire. Gromov immediately ordered the engines to be shut off and began planning with the left slip, trying to bring down the flames. In the end, it succeeded, after which he made a successful forced landing at the aerodrome of aircraft plant No. 22 in Fili. Already on earth it became clear that at the most dramatic moment, when the flame took on alarming dimensions, engineer A.Chesalov, who was in the compartment behind the wing, jumped out with a parachute and landed safely.
After this incident, the TB-5 remained in Fili until December. Repair it was not carried out. Grigorovich completely switched to fighter jets with dynamo-reactive guns, and it was believed that the plane should be further dealt with by the representatives of TsAGI. According to the accepted division, TsAGI now specialized in heavy bombers. The fact is that in 1931, almost simultaneously with the TB-5, the ANT-14 passenger aircraft began to fly. This five-engine giant was created by TsAGI in just one year, thanks to the use of the wing and other elements of TB-3, was designed for military purposes. Does the air force like a high-flying circuit with a capacious fuselage? Very much. The militarized version of ANT-14 was designated as TB-X, instead of a fuselage engine, a nasal turret with the "Oerlikon" gun was installed, and a special glazed cabin was equipped for the navigator's work. The aircraft in many ways suited the customers, but was even more labor-intensive in production than TB-3. Therefore, at the end of 1932, an attempt was made to return to TB-5 again.
To assess the possibility of repair of the bomber, a commission was set up, headed by a representative of TsAGI, VN Chernyshev, who met on December 1, 1932. Naturally, the plane was mercilessly criticized: the design was heavier, the layout of the engines was unsuccessful, vibration was observed in flight, and so on. In addition, the TB-5 dismantled motors, equipment, instruments, weapons, and to bring the car into a flight state required 75-100 thousand rubles. According to the commission, it was reasonable to remodel the aircraft by placing the engines in the wing (which were not called, but obviously the same "Jupiters"). The speed thus increased to 190-200 km / h, the ceiling to 4000 m, but increased to 200 thousand rubles. and cost of rework. And yet such a modernization option was adopted, and TB-5 itself was offered to return the manufacturers to plant No. 39.
However, later, in February 1933, the head of the GUAP Baranov ordered: "To disassemble the plane. Further work on this aircraft to cease. TsAGI to work out the issue of creating a heavy bomber from chrome-molybdenum pipes and linen plating as an understudy to TB-X or a class below. " This is all over. TB-5 was not re-made and was transferred to the Department of Strength of Aviation Constructions of TsAGI. TB-X was also not created, because at the end of 1933 the Air Force issued new demands for a bomber with much higher characteristics.
Concluding the story about TB-5, it is necessary to mention that in 1931, based on its design, a marine long-distance reconnaissance vehicle MDR-3 ("Airplane No. 11") was created, which had the same wing, tail and a number of power elements. Development, as well as TB-5, this seaplane did not receive.
And what about "Farmans"? It turns out that the scheme survived until the outbreak of the Second World War. Several aircraft, like TB-5, took part in hostilities. The most distinctive was specially constructed for long-distance passenger transportation NS-223-4, which had its own name "Jules Verne". Mobilized for military service, this ship in 1940 was the first among allied aircraft to air a night bombardment of Berlin.
|Wing span, m||31,00|
|Wing area, m2||150,00|
|Type of engine||4 x PD Gnome-Rhone Jupiter-VI|
|-power, hp||4 x 480|
|Maximum speed, km / h||200|
|Cruising speed, km / h||182|
|Practical range, km||2100|
|Practical ceiling, m||3500|
|Bomb load, kg||1000|
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