Aviation of World War II

R-10 (KhAI-5) - a multipurpose reconnaissance aircraft, light bomber and attack aircraft, created at the Kharkov Aviation Institute under the leadership of I. G. Neman in 1936. Structurally, it was a single-engine all-wood cantilever low-wing aircraft, made according to the classical aerodynamic design. The aircraft crew consisted of two people: a pilot and a navigator.

The fuselage is a monocoque glued from five or more layers of veneer with a thickness of 0.5 mm. The wing center section is one piece with the fuselage. In the fuselage, behind the first frame, the pilot's cockpit was located, closed with a transparent canopy, consisting of a fixed visor and a cover sliding back. In the fuselage behind the cockpit, there were fuel tanks: the main and upper (in the gargrot), and behind them was the bomb load. The bombs are placed horizontally in two (left and right) bomb compartments, each of which was closed from below by a longitudinal flap. Next was the cockpit of the second crew member, the navigator, who also served as an observer, bombardier, radio operator and gunner. The cockpit was covered from above with a transparent dome of the MV-3 ​​machine-gun turret.

The wing is a two-spar structure, it consists of a rectangular center section and two detachable trapezoidal consoles in the plan. The front edge of the console is swept, the rear edge is straight. Wing sheathing - plywood with a thickness of 1.5-2 mm. Along the entire trailing edge of the wing, there are two-section Shrenk-type flaps and ailerons. Shields - duralumin, with a deflection angle of 45 °. Ailerons had a metal frame and linen sheathing.

The power plant is an air-cooled piston engine M-25V with a two-blade variable-pitch propeller VISH-6. The engine was a 9-cylinder single-row "star" with a takeoff power of 730 hp. (at 2200 rpm).

Tricycle landing gear with a tail wheel. The main supports in flight were retracted into the center section of the wing, turning to the axis of the aircraft. Each main support was a shock-mount with a strut, on which a brake wheel 800 × 200 mm was installed. The tail wheel is 300 × 125 mm in size, it was not retracted in flight.

Armament. Small arms consisted of three ShKAS machine guns of 7.62 mm caliber: two fixed ones installed in the wing consoles (ammunition - 450 rounds), and one on the defense turret MV-3 ​​(600 rounds). The pilot fired from the wing machine guns using the OP-1 optical sight.

Normal bomb load - 300 kg (6 FAB-50 bombs), in the reloading version - up to 400 kg. The bombs were mounted inside the fuselage on two cluster bomb racks. The discharge was carried out by means of an ESBR-3 electric bomb release device. For aimed bombing, an OPB-1 sight was installed in the navigator's cockpit.

R-10M-25V No. 2/14 showed the best flight performance of all the machines tested. Its speed at the ground reached 342 km / h, and at an altitude of 5000 m - 379 km / h. However, according to the test results, they made a disappointing conclusion: the characteristics of the aircraft with the M-25V engine do not meet the requirements of 1939, and in the future it can only be used for combat training. The R-10M-25V aircraft was built at plant No. 135 until the end of September 1939. In total, 230 cars were delivered that year. Of these, 205 aircraft were transferred to the Air Force and 21 to the Navy's aviation. At the end of April 1939, all design work on the R-10 was curtailed. Chief Designer of Plant No. 135 appointed P.O. Sukhoi.

P-10M-25V was also produced by Saratov aircraft plant No. 292. The launch of the machine was difficult, simultaneously with the formation of the entire aviation industry and the training of specialists for assembly and installation work. The first series of 10 aircraft, assembled from units sent from Kharkov, was built at the beginning of 1938. Before the termination of production of aircraft of this type in early 1940, the plant produced 135 serial aircraft. In total, the aircraft factories of Kharkov and Saratov built 493 serial P-10s with M-52A and M-25V engines. From 1936 to 1940, 493 vehicles were produced in a large series. Produced in Kharkov and Saratov (since 1937). He took part in all armed operations of the Red Army in the late 1930s and early 1940s, starting with Khalkhin Gol in the summer of 1939.

In 1940, it was replaced by the Su-2 in production. Up to 60 R-10 units were transferred to Aeroflot, where they were operated under the PS-5 brand. He took part in the Second World War until 1944, from the second half - mostly as an educational one.

Photo	Description
	Drawing R-10 (KhAI-5)

The idea to use the P-10 as an attack aircraft arose in the Commission of the Defense Committee of the Council of People's Commissars of the USSR, headed by K. E. Voroshilov, who was working on the implementation of a large-scale program of rearmament of the USSR Air Force. At the request of the military, in October 1936, OKO-135 was instructed to manufacture the third production aircraft R-10, as an attack aircraft with more powerful weapons and an M-62 engine by June 1, 1937. The difficulties of launching the P-10 into mass production did not allow Neman to develop a draft attack aircraft by the appointed time.

In March 1937, the first assembly line for the M-62 motors was launched at the Perm Engine Plant. Unlike the M-25V, the M-62 had a two-speed supercharger, which provided not only more power in takeoff mode, but also better altitude characteristics. In May 1939, the M-63 motor went into mass production. A new carburetor was introduced on it and the engine was once again boosted, now in terms of boost and revs. Both motors with two-speed PNTs had an altitude of 4200 and 4500 m, respectively.

Neman divided the process of creating an attack aircraft into two stages. Initially, a prototype aircraft under the designation KhAI-51 was designed and built, on which it was thought to work out new units and systems, as well as eliminate the shortcomings identified during flight tests. The second prototype of the KhAI-52, after modifications, was outlined as a standard for mass production, replacing the P-10 aircraft on the stocks of the plant.

In June 1938, the KhAI-51 was taken to the factory airfield, and after adjusting the still "raw" M-62 engine, test pilot B.N. Kudrin made 32 test flights on it in August-September. The impression of the new aircraft remained good, but it was not possible to fully reveal its flight characteristics due to constant engine failures.

In 1937, there were changes in the attitude towards I.G. Neman in the country's top leadership. This was due to the failures of Soviet aviation technology in Spain, in December 1938 he was arrested.

The new chief designer of OKO-135 A.A. Dubrovin continued work on the modernization of the R-10, focusing on the KhAI-52.

The KhAI-52 attack aircraft was designed for the M-63 engine with a capacity of 930 hp. with screw VISH-28. Retaining the design of the KhAI-51, a second control of the aircraft and more powerful weapons were installed on it in the navigator's cockpit. In addition to the four wing-mounted machine guns, two more synchronous ShKAS were mounted. The bomb load was increased by installing external bomb racks with Der-31 locks under the wing. In this form, the KhAI-52, not yet tested in the air, in January 1939, according to the NKAP plan, was launched into mass production at plant No. 135, instead of the outdated R-10.

On April 6, 1939, at 8.30 am, the pilot of the factory military mission, Colonel Darsky, lifted the KhAI-52 on its first flight. It lasted 30 minutes. The airplane's behavior in the air was quite satisfactory, which made it possible to successfully complete a longer flight in the afternoon.

However, at the end of April, completely unexpectedly for plant No. 135, an order came from the People's Commissariat to "remove the Neman wrecker aircraft" from production and start manufacturing the aircraft BB-1 designed by P.O. Sukhoi, which successfully completed state tests on April 6, 1939. The M-87A engine installed on the BB-1 did not disappoint the designers, and the aircraft showed better flight data than the KhAI-52: the maximum speed at the ground is 375 km/h and at altitude - 468 km/h.

Combat Use

• Neman R-10 (KhAI-5). Combat Use

• History of aircraft structures in the USSR, 1938-1950. / V.B. Shavrov /
• Wooden aviation of Professor Neman / KR 1996-11-12 Vyacheslav Savin /
• Scout R-10 / V.R. Kotelnikov/
• Phantom R-10 / Mikhael Maslov /