“SPANISH” BOMBER TUPOLEV

A new generation of bombers-the monoplanes, which differs from the preceding higher performance characteristics, appeared in many countries in the period between 1932 and 1935. As a rule, they all had all-metal construction, smooth lining, retractable landing gear and closed cockpit. The flight speed of some exceeded 350 km/h, which combined with strong defensive armament made them almost invulnerable in combat with fighters of that time.

 
In Germany, such machines include airplanes Do-17 (the maximum speed of 389 km/h) Non-70 (360 km/h), Ju-86 (325 km/h) and Not-111 (307 km/h). In Italy outstanding representatives of this class of machinery steel SM.81 (336 km/h) and SM.79 (354 km/h).
 
In the US, these bombers were created at the firm Martin (b-10, 343 km/h) and on the firm Boeing (b-9, 299 km/h). But the speed of 428 km/h, which reached established in the UK in 1935, the famous “Blenheim” Bristol company, has caused excitement in European aviation circles because it exceeded the speed of the best English fighter 48.6 km/h!
 
This enthusiasm can be explained only by lack of information about the appearance the year before the Soviet bomber SB-2, the maximum speed of 430 km/h And a sensation this bomber was in Spain, when in level flight, he easily walked away from enemy fighters, and very effectively attacked the compound of enemy bombers.
 
In the pursuit of speed
 
The design of the new high-speed bomber, which received the first designation ANT-40, began in late 1933 lead designer Arkhangelsky under the overall guidance of A. Tupolev. In the plane, radically different from corrugated topolewski bombers, everything was subordinated to the main goal the achievement of maximum flight speed.
 
Interestingly, the bomber was designed based on previously designed multi-seat fighter MI-3 (ANT-21). This, apparently, was the reason for the high aerodynamic performance of a high-speed bomber. Wing ANT-40 had a special lenticular profile — 16 percent of TSAGI-40, significantly reduces the drag of the aircraft. In addition, the stabilizer was removed from the swirling flow and is installed with a small excess relative to the wing, thus reducing the vibration of the horizontal tail.
 
In design was widely used in new materials that have increased strength and weight out of the airframe. In particular, the power components were made of hromansilevyh and chromium-Nickel steel, and cladding made from thin sheet aluminum.
 
In February 1934 the head of TSAGI N. Kharlamov was held a meeting at which Tupolev proposed to establish the plane instead of the American engine air-cooled Cyclone Wight with a capacity of 625 HP have not launched the serial production of the engines of liquid cooling M-100 with a capacity of 860 HP, designed by V. Klimov. To resolve this issue we decided to build two prototype aircraft with different power plants.
 
The first prototype took to the air April 25, 1934, the second — 30 Dec 1934. Its design took into account all comments identified during testing of the first aircraft and the takeoff weight has increased by 254 kg.
 
The machine is surely kept in the air, and factory test only lasted 20 days. The new bomber showed outstanding by the time the results: at a height of 4000 m it can fly at a speed of 430 km/h — faster than any existing in the world of the bomber, and the height of 5000 m were recruited for 9.4 min.
 
The flight of the second prototype almost ended in disaster due to flutter of the wing. This unpleasant phenomenon fixed, however the maximum speed of the bomber at an altitude of 5000 m fell to 404 km/h.
 
However, SB has launched, in parallel to eliminating the identified shortcomings. Stability enhancement achieved by the change in alignment, shifting the engines at 100 mm and increasing the forward sweep of the leading edges of the wing and its angle of transverse V. And for improved handling, expanded the area of the stabilizer and imposed axial aerodynamic and weight compensation of the Elevator.
 
In the autumn of 1935 started the second stage of state tests. In the report it was noted that the bomber is quite stable and easily managed, and rolling off at high speeds and overloading on the wheel are easily removed by the trimmer Aileron. Balanced trimming, the plane could fly even with abandoned control. The maximum speed at an altitude of 5300 m was able to raise up to 418 km/h (earth — 356 km/h).
 
In a series of SB went with increased to 56.7 m2 wing area and increased to 5628 kg takeoff weight. As a result, the airspeed fell to 393 km/h and a climb of 5000 m increased by 2.3 min, However, increased the flight range with load of 500 kg, it amounted to 2187 km away. the Classic three-bearing chassis with a tail wheel was provided by the use of SB unpaved airfields, and to take off required less than 300 m.
 
The deterioration of speed performance did not please the military and they hurried specialists Klimov design Bureau, which worked on M-100A — the new engine variant M-100. In December 1936, upgraded engines installed on serial SB, and it showed a speed of 423 km/h and an altitude of 5000 m were recruited in 8.6 min.
 
Serial production of the bomber, dubbed SB-2, was a very fast pace. In 1936 he built a 286 aircraft, and in 1937 the rate of production SB-2 were 12-13 cars per day. Production continued until 1941. Total built 6656 aircraft of various modifications.
 
The test of victory
 
Other early Soviet aircraft were purchased in 1936 by the government of the Spanish Republic, to combat the work was started exactly as SB-2. The first bombers (31 car) were brought to this country 13 Oct 1936 Maritime transports “Old Bolshevik”, “Zagros” and “KIM” and formed in three bomb squadron on 9— 10 aircraft each. The first commander was A. Zlatogorov, the second was commanded by V. Kholzunov and third — Century Ulanov.
 
All squadrons of SB-2 was merged in the bomber division Grupo 12, whose commander was appointed A. Zlatogorova (instead the first squadron was headed by E. Mines). Later the Grupo 12 was organized by a special unit of four SB-2 with the most trained crews for deep exploration of the territory occupied by Franco.
 
A flight of four SB-2 under the command of E. the mine in the first sortie 28 Oct 1936, bombed the airfield of Franco in Tablada, who brought terror to the rebels of serious destruction of the airfield buildings and heavy losses of aircraft on Parking. This operation, according to foreign aviation experts, was the first to demonstrate a new principle of air warfare in which the fighter bomber overcame resistance with defensive weapons, and due to the greater flight speed.
 
Group SB-2 made on 30 October and 1 November, once the raids on the military airport near Gamonal Alavesa, where the base of the Italian aviation (Aviation del Tercio). The last attack ended with the destruction of six fighters Fiat CR-32.
 
The first SB-2 the rebels managed to knock down only 3 Nov. Bomber from the second squadron was returning after exploration and before the front line suffered a surprise attack by two fighters Fiat CR-32. The crew commander P. Petrov, Navigator A. Vlasov, and gunner N. Zhigulev died.
 
Raids by the Republican SB-2 infuriated the rebels by the ease with which the aircraft reached almost anywhere in the country. Until the end of 1936 Grupo 12 lost six aircraft, and only two of them — as a result of interception.
 
Single SB-2, piloted by I. Sokolov, 18 November 1936, bombed at the hotel in Salamanca, where according to the intelligence data had to be Franco. With a height of 800 meters of the bombs landed right in the building, but the dictator left him for half an hour before the RAID.
 
In early January 1937, the bombers of Grupo 12 with mixed Soviet-Spanish crews returning from bombing the railway station in Cordoba, was shot down by a rebel fighter Fiat CR-32. However, in January 1937 SB did away with the raids on Cadiz, fee Balearic Islands, Arenilla and naval base of the insurgents in Ceuta (North African coast). At the same time a third squadron attacked the airfield of Getafe from its base, near Madrid.
 
In early 1937, the Republican command decided to pick three squadrons of Grupo 12 two due to the lack of revenue aircraft and spare parts from the Soviet Union.
 
In the same period, on the basis of the second squadron was formed a special squadron to communicate with the Navy. The debut of the newly created squadron was held January 20, 1937, when bombers struck the naval base of nationalists in Ceuta.
 
Sometimes SB-2 had to perform non-core functions. So, on January 21, 1937 six bombers under the command of N.Ostryakova attacked the troops of Franco in San Pedrosa de Alcanada and, despite the inability of aircraft to attack, they all returned to their base. Later SB-2 has successfully played the role of long range escort fighters, in two hours covering the Republican ship, EN route with military cargo from Odessa to Cartagena, reflecting the attack bombers Ju-52.
 
In may of 1937 the whole world has heard the message of the French news Agency “may 28, 1937 in the Mediterranean, off Malaga, the plane of the Spanish Republic was attacked by the German cruiser “Deutschland” and was struck by two bombs. From the ship’s crew of 31 people were killed and 83 wounded”.
 
He recalled how the Admiral of the Fleet of the Soviet Union N. Kuznetsov, former at the time of the naval attaché and chief naval adviser to Spain, the pilots took a German ship for the rebel cruiser “Canarias” or “Baleares”, which was one of the series with the cruiser “Deutschland”.
 
Great help Republican command had information obtained by the ad hoc group long-range reconnaissance. In it stood the crew of the City of Thora. On your bomber with the tail number “6” he has made more than 180 reconnaissance missions. At the battle account of crew: poteplenie the ship in the port of Cadiz, destroyed the artillery factory, 14 damaged trains, 200 vehicles destroyed and three tanks. The plane G. Thora eleven times subjected to attacks by enemy fighters and never was shot down.
 
Bombers SB-2 has been regularly used for attacks on enemy airfields. To catch his aircraft on the ground, a special team of two to four SB was involved in a protracted air battle as many enemy fighters. When the fighters of Franco, working out all the fuel, went to their base, and above it appeared the main impact group of Republicans and smashed everything that was on the ground.
 
 
Not less successfully acted pilots of the second squadron under the command of V. Khol’zunova on the personal account which had more than 100 sorties. V. Holzunova 27 July 1937 was awarded the title of Hero of the Soviet Union.
 
In the spring of 1937, the Republican air force played a decisive role in the defeat of the Italian expeditionary corps of General of Rooty coming to Madrid five columns from Guadalajara. More than 100 aircraft of various types, from SB-2 to I-16, waves hit the enemy. Republican aviation on March 21, 1937, he made 178 sorties, dropping on the heads of the enemy 500 bombs and expended 200 thousand rounds.
 
The first group of Soviet pilots stayed in Spain until mid-April 1937. Instead of departing home Zlatoslava A. Grupo 12 was headed by A. Senators.
 
Spanish cargo ship Aldeсоа delivered 24 Jun 1937 to the port of Cartagena 21 new bomber SB-2 with engines M-100A. Another 10 machines of this type, arrived on Board the ship Arteo Mendi July 1. Replenishment allowed to restore tragically a part of Grupo 12 and to start forming another group of bombers, headed by the Spaniard Mendiola.
 
The test of defeat
 
The group began combat operations on 3 July 1937 with the attacks at Talavera, Salamanca and Avila. Five days later the crews Grupo 24 first encountered Bf 109B German firm Messerschmitt of the Legion “Condor”. A fight ensued, during which were shot down two SB-2. Four days later, the crew of one of the bombers Grupo 24, in turn, knocked the Bf 109B, to avenge the deaths of their comrades. It is believed that this was the first Bf109В downed shooter SB-2.
 
The high performance characteristics of SB-2s allowed the crews to successfully use them as fighters in the struggle against slow-moving enemy bombers. So, in August 1937 the squadron A. Senatorov attacked a group of Italian SM-81 and, having brought down one plane and swept by machine-gun fire the enemy, thus foiled bomb attack on the positions of his troops.
 
The major battles of 1937 in Spain, which involved aviation, began an offensive at Brunete, Zaragoza offensive, and the fighting at Belchite. In the battle actively used by a small group of SB-2 (3-9 machines) attacking target columns. Massive raids were observed only twice: on 12 November, when 16 of these bombers struck at Pamplona, and on 18 November, when 36 planes bombed the city.
 
In the fourth quarter of 1937 in Spain was supplied five SB-2s, which only covered the loss of the aircraft incurred during the fighting.
 
In the midst of the fighting from the USSR to Spain arrived half a dozen crews for the next change of flight crews in the squadron Grupo 12. Command of the group from A. Senatorov took the captain I. Vizirov. The first squadron was headed by M. Lisov, the second — A. Stechishin.
 
The situation at the front made new crews to immediately engage in military work. In January 1938 and squadron of SB-2s attacked the most important objects of Franco in Salamanca (where was the headquarters of Franco), in Seville, in Valladolid, on the road to the South of Zaragoza. Bombed in Salamanca, one of the aircraft in error Navigator landed on Franco’s airfield Almarah. The crew of the bomber was captured, and in July 1938, the Republican government was able to exchange the captive pilots for the Germans and Italians.
 
The Republican cruiser “berthed” 6 March 1938 damaged the cruiser of the rebels”, Balearic”. For additional impact on the damaged cruiser caught the bombers SB-2s.
 
After a preliminary reconnaissance in the air lifted three of the nine bombers. The attack has been used 100-kg and 50-kg bombs. As a result of several direct hits, the cruiser was sunk. Of the 765 members of the crew survived only 400 people, which picked up two English vessel.
 
In the middle of the month Grupo 12 bombers struck a successful blow on the airfield and port Palmo fee Balearic Islands. All the planes without loss returned to their base. Caught off guard by the Italians and Franco did not have time to raise in the air fighters and even open anti-aircraft fire.
 
In the spring of 1938, the squadron often flew under SB Teruel without fighter cover. That such flights to avoid losses, the planes took off and approached the goal from the side of the rising sun. Using this technique, on may 20, the SB bombers without loss attacked the airfield of La Senia base of the Legion “Condor”, destroying airfield buildings and destroying several parked Bf109B.
 
At the beginning of may came a change for the flight crews. Squadron A. S. Stechishin took the red eyes and the squadron of M. Lisova, and D. Tsarkov.
 
First sortie newbies made to the bombing of Zaragoza the node that supplied the advancing enemy troops. The flight took place without losses, and in the future, the squadron C. Krasnoglazova were extremely successful. From may to September 1938, her loss amounted to only one aircraft, shot down by a fighter Bf109B.
 
In mid-June at an airfield near Albacete through the French-Spanish border came another group of Soviet pilots, navigators and gunners-radio operators. At the end of June 1938 in the same way managed to smuggle the last batch of bombers 24.
 
The last group of pilots, navigators and gunners-radio operators arrived from the Soviet Union on July 28. Arrived distributed to squadrons Grupo 12. And in early August they participated in the ongoing battles on the Ebro river.
 
Since the end of August 1938 the Republican losses in the bomber groups began to grow. The main reason is the growth ratio in the number of aircraft up to 5:1 or even 7:1 in favor of Franco. Often accompanied by Republican bombers flew only two or three fighters. Intensified and anti-aircraft cover objects of the rebels.
 
In mid-September went home airmen from squadrons D. Tsarkov and S. Krasnoglazova, and the remaining crews are United under the command of M. Karpenko. In the ranks were half of all aircraft of the 12th group.
 
Nevertheless, squadron of SB-2s continued to actively participate in the fighting. Grupo 24 made several daring attacks, one of which is 4 October 1938 proved to be successful: the strike was carried out at the air base-based Bf109B in La Zenia, destroying on the ground a few planes.
 
After the end of offensive operations on the Ebro Soviet pilots left Spain. After their departure in the air completely dominated by Franco’s aviation…
 
By the end of 1938 the Spanish squadrons remained three or four aircraft. At this time, the Soviet Union sent to Spain 50 bombers SB-2bis (SB-2 with engines M-103), but the French government strongly delayed the shipment of cargoes, and these new modified planes did not hit on Republican airfields. But, nevertheless, everything that could fly was up in the air. By December 23, when started the last attack of the rebels, in the ranks of the Republicans, there were only 18 serviceable bombers, which had covertly to transfer from one airport to the other to reduce losses on the ground.
 
The fighting ended on 31 March 1939. By this time, the 16 combat-ready SB-2s flew to the airfield Barajas, where he was captured by the nationalists. The crews of the three bombers managed to overtake their car in Algeria.
 
Only nationalists have at their disposal 19 units SB-2, which after a little repair under the name “Sophia” arrived at 13 Escuadra de Bombar-deo, based at two airfields in Los Lianos and Albacete. The last of the captured SB-2, flew in late 1948, after which he was sent to be scrapped.
 
Over the entire period of the war in Spain from the USSR was sent to 210 bombers, of which the Republicans were only 91 car. The Spaniards called this their favorite plane is a Russian female name Katiuska…
 
The use of bombers type SB in Spain can be divided into two periods: before and after the onset of the Franco German Bf109B fighters. In the first SB loss was minimal: using the advantage of speed, they flew over the whole Spanish territory without fighter cover, easily leaving the enemy aircraft. Time to re-attack the enemy did not.
 
With the advent of air battles in a growing number of new Bf109В, Bf109D and Bf109e began to emerge and the disadvantages of the bomber. The Soviet pilots returned from Spain, noted a lack of durability and reliability of the chassis — when a rough landing it sometimes bends sharply, and the airplane received substantial damage. But if the chassis were not issued and the pilot has landed “on the belly” the death of the Navigator was almost inevitable.
 
The handling characteristics were good, except for the large loads on the control stick and pedals. The most serious flaw of SB — tendency to the rocking and rotation on takeoff if too quickly raise the tail or sloppy work in the Gaza strip.
 
The aircraft was designed for action at altitudes up to 6000 meters, but the oxygen equipment, which was used by ekipaj, did not work. As the shortage of pilots noted the absence of aircraft effective communication device.
 
In the first phase defensive weapons SB was considered quite sufficient, but with the advent of the air fighters Bf109В it could not reliably protect the bomber. The pilots have offered to replace the 7.62 mm machine guns of 12.7 mm and to increase their sector of fire.
 
N. Food reserve was, A. CHECHIN, Kharkov
 
(To be continued)

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