Aviation of Word War II
R-5 is a two-seater one and a half-plane, a classic type of reconnaissance aircraft of 1928-1933. - belongs to the best examples of aircraft of this purpose. Its design, lines and aerodynamics had much in common with the U-2, P-2 and I-3 aircraft. The choice of the main dimensions and parameters of the R-5 was made especially carefully after numerous preliminary calculations and statistical studies. R-5 replaced P-1 and other scouts, showing undeniable advantages over them. The aircraft possessed more than sufficient general and local strength, was distinguished by thoughtfulness and quality of performance, without noticeable overweight and without a decrease in its flight qualities from this.
Its design turned out to be hardy, it was in operation for a long time. The P-5 was used by the Air Force in 1931-1937. as a scout, light bomber and attack aircraft. Used until 1944 in the Great Patriotic War. In addition, even before decommissioning and especially after removal, it was used in Aeroflot under the name P-5 as a transport, postal, and had many other purposes. The last P-5s were encountered even after the Great Patriotic War. The aircraft was produced in 1928, built in large series at Plant No. 1, mainly in the reconnaissance version.
More than a thousand copies were transferred to Aeroflot under the P-5 brand name.
The structure of the R-5 aircraft is made of pine and plywood, steel is soft in the knots, grade M (tensile strength 40-45 kgf/mm²) with a wide application of welding. The engine on the prototype was a BMW-VI of 500/680 hp, later - M-176 in 500/680 hp; and from 1934 - M-17f in 500/730 hp.
Thanks to well-established production, the mass of the serial structure of the R-5 aircraft was extremely stable and was equal to 1969 kg, the mass of an empty aircraft with non-removable equipment was 2169 kg, the flight weight as an army reconnaissance aircraft was 2955 kg, as a light bomber was 3247–3347 kg. maximum weight - 3800 kg.
The fuselage of the aircraft had a four-sided cross-section with a rounded top edge. The frame consisted of four spars, and 12 frame frames, upper stiffening frames, cab floors, stringers and individual braces. Sheathing - plywood from 3 to 2 mm. Assembly - on casein glue, iron galvanized screws and nails. The motor mount is a truss made of duralumin box beams, connected by an arcuate riveted frame, and of 12 steel and duralumin rods - pipes with tips, partly adjustable in length.
Wings - normal two-spar design. The spars are box-shaped 80 mm wide (in the front spar of the lower wing 55 mm) with the thickness of the shelves in the spans 30 mm, the walls are made of 5-mm plywood directed in layers at an angle of 45 ° Ribs are made of pine battens and plywood walls with oblong relief holes, through which the brace bands in the wings passed (single crosses). Racks of the wing box — drop-shaped duralumin tubes with adjustable forked tips. Braces - profiled belts with tips, bearing braces - paired No. 12 (initial diameter and thread 12 mm), reverse - single No. 11, under the center section — No. 10 and 7.
The tail unit is of the usual wooden structure, all the rims of the wings and rudders are duralumin. Control - cable, double - from the pilot and observer, control of the ailerons - differential, their deflection up - 32 °, down - 10 °3 '.
Chassis M-shaped scheme with rubber plate shock absorption. Wheels - originally spntsevye, since 1933 - disc brake with pneumatic dimensions 900×200 mm. The tanks are made of galvanized iron, the pipelines are copper, the radiator is a retractable honeycomb made of brass thin-walled tubes of shaped cross-section. Its control is from a wheel with a Gall chain.
Wing profiles - 10% thick, with a straight underside. The centering of the aircraft: empty - 24.5% of the MAR, in flight in the reconnaissance version - 33.7% of the MAR, of the bomber - 33.5- 35.8% of the MAR, with the burnout of gasoline it could reach 40% of the MAR.
Armament - one PV-1 machine gun synchronous and one (later twin) for the turrets, bombs on underwing holders 256 kg for a reconnaissance officer (normal load) and 300-400 kg for a bomber (overload).
Participation in the Second World War . During the Great Patriotic War, aircraft of the R-5 type did not participate in the combat composition of the Air Force, they were given a rear niche. They were used in flight schools, spare parts. But the Soviet aviation suffered heavy losses, and it was necessary to remember the honored veterans. In November 1941, it was decided to send 27 regiments to the front on R-5. The pilots had no time to prepare, and after several familiarization training flights, the R-5s were sent to the front.
The bulk of the R-5 aircraft were sent to the Western Front. R-5s bombed bridges and crossings across the Oka, Protva and Ugra rivers, delivered military strikes on roads, airports and concentrations of enemy troops. Already in December 1941, 45 R-5 units fought on the fronts, and every day, their number increased.
During the Lyuban operation, the purpose of which was to push back the enemy and lift the blockade of Leningrad, the Air Force arranged night sorties, bombed trains, adjusted artillery fire and helped the 2nd Shock Army in every possible way. But the number of aircraft was very small, and the number of sorties had to be increased.
In the 42nd year, the Air Force delivered 181 U-2, R-5 and P-Z aircraft to the breakthrough site, which took part in the Soviet offensive. The aircraft performed not only combat missions, but also missions to supply troops and evacuate the wounded. The Luban operation was not the most successful, but in spite of this, 27774 sorties were made, and a significant part of them were sorties on R-5 aircraft.
During this period, two R-5 aircraft were captured by the opponents, one of them was serviceable, and the opponents decided to overtake it to the aircraft factory, but the plane did not reach the cherished destination and crashed.
In 1945, only 38 R-5 aircraft remained at the front. By the time the Great Patriotic War ended, all aircraft were decommissioned, but, nevertheless, they were used in the Far East for border protection and were also operated in Mongolia.
Light transport aircraft
Conversion of the R-5 into a transport and passenger version of the Rafaelyants' designer. The project for the manufacture of a new fuselage for 4 passengers was proposed by Rafaelyants in the spring of 1934, under the impression of the "Chelyuskin" epic, hoping to operate such an aircraft, first of all, in Arctic conditions.
Pilot Piontkovsky took the prototype PR-5 into the air on November 18 and was very pleased with her behavior in the air. PR-5 developed a maximum speed of 245 km/h, which exceeded the speed of privates P-5.
The first serial PR-5 was tested by the pilot A.S. Shvedovsky in July 1936. Already after a short time, this machine was operated on the Ulan - Verkhneudinsk (now Ulan-Ude - Ulan Bator) line. A total of 200 passenger cars of the PR-5 type were built. A significant part of them were used in the southern regions of the Soviet Union and Central Asia. Some vehicles were improved during serial construction. The upper wing was moved forward 100 mm and a number of improvements were made. The aircraft received the designation PR-5bis.
A few years later, Rafaelyants replaced the biplane box with a cantilever, low wing with a canvas sheathing. The aircraft received the designation PR-12. After passing the tests, the PR-12 received the tail number USSR-L3600 and was transferred for operation to the Civil Air Fleet on the Moscow-Kharkov route. In 1940, the PR-12 flew 28,000 km, transported 9,532 kg of commercial cargo. Although the operation gave positive results, they did not build the aircraft in the series. PR-12 was the last modification of the R-5.