THE LAST BIPLANE COUNTRY OF THE SOVIETS

THE LAST BIPLANE COUNTRY OF THE SOVIETSScout-bomber P-Z. Created in the late 20-ies of the last century, the Soviet biplane R-5 construction.N. Polikarpov for several years was a classic type of reconnaissance aircraft. In the international aviation contest in 1930 in Tehran, which was attended by the best companies of England, France and Holland, our air reconnaissance took first place.

 
However, at that time the development of aviation was such a rapid pace that within a few years after the adoption of R-5 adopted raised the question of its modernization. It was not about radical revision of the design. It was supposed only to replace the power plant and along the way make necessary corrections to increase the speed of low-speed biplane.
 
The project modernized reconnaissance aircraft was established on the initiative of the Director of aviation plant №1 (head enterprise for the production of P-5) A. M. Belenkovich, chief engineer E. P. Shikunova and designers D. S. Markov and A. A. Skarbowa. Initially the new machine was factory designation P-5Z (R-5 M34), and only during serial production it was given the name P-Z.
 
The experimental aircraft has set a new domestic engine M-34RN (geared supercharged), developed at the height of 3500 m power 750 HP, but on takeoff the forced mode 840 HP (engine M-17F serial P-5 develop, respectively, 500 and 715 HP). Instead of a wooden screw with a constant pitch set of metal, the sleeve is allowed to change its pitch on the ground. However, replacement of the power plant resulted in other improvements, which have affected almost the entire structure.
 
So that diminished chord (respectively at 200 and 300 mm) and thus the area of the upper and lower wings. In this narrower upper wing allowed to refuse to cut it above the cockpit. The junction of the lower wing and fuselage closed dural Salizada, which reduced the total drag. Was reduced fuselage length (800mm), while the lower part has given a rounded shape, building up the frames and installing the patch.
 
Radiator to reduce drag pushed back and closed fairing. Completely redesigned empennage, removing from the elevators and turn Horny aerodynamic compensation and replacing it with axis. In addition, the rudders mounted Flettner — rejected manually on the ground plates, removing excessive aerodynamic load on the pedals and control stick. On P-Z, in contrast to the P-5 have refused the opportunity of a rerun of the stabilizer in flight. On a new plane installation angle has varied only on earth.
 
Changes were made in the chassis design. Rubber plate dampers gave way to an oil-pneumatic, and wheels closed teardrop-shaped fairing. Replaced and the glass cockpit. We upgraded the scout cabin is fully closed lantern, the leaves of which leaned on the sides of the fuselage. The cabin Windows of the pilot-observer (arrow) incomplete — when boarding a plane it moved forward.
 
Finalized and weapons system — installed a new turret and beam holders. It was supposed to install retractable landing gear, but after preliminary analysis, this idea had to be abandoned.
 
Tests of a new aircraft in the summer of 1935 showed that in its flight characteristics P-Z is not much greater than serial R-5 and R-5ССС. While on the plane revealed many defects. So, the pilots spoke a bad word about the cockpit glazing, which is limited to a review on the take-off and landing (due to the low quality of domestic Plexiglas, which when exposed to sunlight quickly faded and lost the transparency). There have been cases of spontaneous extension, radiator on landing. Some of the flight modes were not provided the necessary cooling of the engine and it overheated. Especially clearly this deficiency was manifested in the steering.
 
All these flaws did problematic start of serial production of new machines. Savior it can be considered a test pilot NII VVS V. V. Shevchenko, which successfully demonstrated the aircraft in front of the government delegation. The decision to launch a series of aircraft followed immediately.
 
Until the end of 1935, the plant No. 1 produced the first 11 production cars and in 1936 launched a large-scale production of the new aircraft, which became the most massive in the country (production of R-Z in 1936 amounted to 885 copies).
 
Since the beginning of the 1936 new scouts began to arrive in the combat units of various districts, replacing there P-5. early series, and the formation of new units. Development of the aircraft was not smooth. The flow of complaints to the plant have increased proportionally with the production of machines. Pilots complained about poor visibility from the cockpit on takeoff and landing, a bad layout of the cockpit is the pilot-the observer (arrow), making it difficult for him to work with a camera and a radio, the poor ventilation of the cabin.
 
Difficult days came for the technical staff of the squadrons. Had the whole day to work on the airfield, eliminating factory and design defects. The aircraft had brakes of the wheels were broken skid, cracked the glasses shock-absorber struts, chassis, and panel hood engine ran constantly at the welds the wing fuel tanks. Launching the aircraft in the series, the factory did not care about picking their skis, and technical composition of the combat units had to be adapted to P-Z of romance from R-5 and R-5ССС. You need to recognize that the plant responded promptly to the comments and criticism, and by the end of 1936, most of the defects were eliminated. Subsequent events confirmed the timeliness of the carried out by plant.
 
Having made the decision to provide military assistance to the Spanish Republican government, the Soviet Union already in the autumn of 1936 began deliveries of military equipment to the Pyrenees. Scout-bomber R-Z was not included in the first batch of Soviet supplies of aviation equipment to the Republican government of Spain. But from 1937 to the end of the fighting, the aircraft was the main light bomber in the Republican air force, who worked by day in the ever-increasing anti-aircraft and air defense systems of the enemy.
 
The first batch of 31 vehicles arrived in the Spanish port of Cartagena in February, 1937, after which they moved to the airfield of La Rabas, where for several days the planes were assembled and test flown by Soviet pilots. These pilots were retrained Spanish crews who had to fight on R-Z. the Retraining took a lot of time, as new machines were selected by experienced pilots who flew before on the same type with R-Z French light bombers Bre 19. The rapid transition was facilitated by the presence on the plane paired control.
 
Organizationally, all R-Z brought in Grupo 20 dhaskalio composition, the command of which was assigned to the Spanish pilot Alberto Moreno the World. Squadrons are also commanded by Spaniards. This has become a distinctive feature of the unit. Formed in November 1936, Grupo 11, flying the f-5, originally fully staffed by Soviet crews, and in December became international.
 
In the course of relearning the Spaniards gave the aircraft P-Z the name “Natasha” that in the summer of 1937 was reflected in the designation of the aircraft — LN, which machine is carried through the entire war. It should be noted that during the first months, the aircraft had only the hull number, which was applied to the keel of white paint.
 
Since the summer of 1937, after the separation of aircraft in a separate branch in the Republican air force introduced the alphanumeric designator of the aircraft. The first letter indicates the class of the aircraft, the second its type and the number after the hyphen the number of aircraft in the total number. Letter that identifies the type of aircraft, was chosen for the name of the manufacturer or the informal name (which is what happened with R-Z.).
 
Scout-bomber P-Z
 
Scout-bomber P-Z
 
Scout-bomber P-Z
 
Scout-bomber P-Z
 
 
Scout-bomber P-Z:
 
1—metal two-blade propeller; 2 — engine M-34N; 3 — oil tank; 4 — filler neck oil tank; 5 — air tank; 6 — fill tube fuselage fuel tanks; 7 — course synchronous machine gun PV-1; 8 — filler cap wing fuel tanks; 9 — wing fuel tank; 10 — sight OP-1; 11 — control handle of the ailerons and Elevator; 12 — the steering wheel of the cleaning and release of water radiator; 13 — seat pilot; 14 — plate stations; 15 — oxygen tank: 16 — receivers and transmitter radios; 17 — turret ShKAS machine gun; 18 — frames; 19 — spars; 20 — power set keel; 21 — power set of the rudder; 22 — Flettner rudder; 23 — control cables, rudder; 24 — skid; 25 — control cables, Elevator; 26 — camera AFA-13; 27 — seat pilot observer (Navigator, radio operator-gunner); 28 — the steering wheel of the shutter of the camera; 29 — bombsight OPB-1 (in position); 30 — removeable control knob (in position); 31 — bellcrank steering system height, 32 — mine cleaning water cooler; 33 — retractable radiator; 34, the second fuselage fuel tank; 35 — absorber landing gear: 36 — first fuselage fuel tank; 37 is a motor frame; 38 — Kok hub screw; 39 — lateral operating panel of the engine hood; 40 — ANO; 41 — ailerons; a 42 — visor canopy pilot; 43 — hinged part of the canopy pilot (first series); 44 — the fixed part of the cockpit canopy; 45 — sliding part of the canopy radioman (extended); 46 — Kiel; 47 — rudder; 48 — foot pegs; 49 — the FAB-50 bombs; 50 — cone water cooler; 51 — wheel main landing gear; 52 — spinner wheels (first in series); 53 — operating courtesy; 54 — struts of the wing; the 55th wing brace; 56 lower removable panel of the engine hood; 57 — stringers keel; 58 — rib of the rudder; 59 — tubular spar; 60 — rib of the keel; 61 panel of the dashboard; 62 — the floor of the cockpit; 63 — the gas lines; 64 — bombs FAB-250; 65 — LDPE; 66 — hinged part of the canopy pilot (modified version); 67 end rib of the wing; 68 — front center section; 69 — unit mounting main landing gear; 70 — cable brace center section; 71 — back front center section; 72 — glass cockpit; 73 — fairing lower wing; 74 — installation of the twin ShKAS machine guns (attack version); 75 — main landing gear; 76 — struts stabilizer; 77 — turret ATUR-8; 78 — sliding part of the canopy radioman (in closed position); 79 — the canopy pilot in the open position; 80 — ratchet airfield to start the engine, 81 —strut main landing gear; 82 —Flettner rudder; 83 — the steering wheel height; 84 — stabilizer; 85 — the fabric covering of the wing; 86 — plywood leading edge of the wing; 87 — tie ribbon fastening wing fuel tank; 88 — the front spar of the upper wing; 89 — internal cable brace the upper wing; 90 — additional rib sock wing; 91 — rear spar of the upper wing; 92— the power range of the Aileron; 93 — rib of the upper wing; 94 — internal cable brace stabilizer; 95 — rib stabilizer; 96 — spars of the stabilizer; 97 — power set of the Elevator; 98 — clamp LDPE; 99 — place sentry gun; 100 — rear spar of the lower wing; 101 — reinforced rib (only when brake flaps); 102 — speed brake; 103 — removable panel of the engine hood; 104 maintenance hatches fuselage fuel tanks; 105 — additional rib sock of the lower wing; 106 — internal cable brace the lower wing; 107 — rib; 108 — the front spar of the lower wing; 109 — reinforced rib at fixing bomb racks; 110 — window sight; 111 —window camera; 112 — mooring point; 113 rocking Aileron; 114 — control rod Aileron; 115 — gun ShKAS

 
In late March 1937 the acquisition of the squadrons ended and they flew to their sectors of the front. The first squadron with great success beginning of their combat service in Andalusia, provoevav there until the fall of málaga in may 1937, and the 2nd squadron at that time operated in the sector of Madrid. She took an active part in the battle of Guadalajara. Almost a month of active fighting was not lost a single plane! This was mostly caused by bad weather, which allowed groups R-Z secretly get target area and suddenly attack the enemy.
 
The policy of using the R-Z was not new and have been used by units of the armed Bre 19 and R-5. The aircraft flew missions groups of 3 to 9 machines, approached the goal at a height of 50-100 meters, did the hill and dropped bombs from a height of 200-400 meters. If conditions allowed, the second time the target fired from course machine guns, and the flue from the turret. This tactic allowed them to minimize losses from the fighters, and for a short time over the target was given the opportunity to evade defenses of the enemy.
 
Stabilization of the Central front in the center of Madrid in April 1937 allowed the Republican command to attempt to transfer the 2nd squadron on an isolated Northern front in Santander. The aircraft took off on may 17 and headed North-West. However, the attempt failed. Already at the final part of the route, the aircraft got caught in a storm, a lost bomber is the leader of the security Council and, in the end, off course. The squadron commander decided to continue the flight to the North, and once out of fuel the aircraft landed on French territory. One machine crashed. The French returned the aircraft only a month after removing all armament and sighting equipment.
 
In June 1937, the Spaniards adopted a new party R-Z of 31 vehicles. This allowed the part of Grupo 20 to form a 3-squadron, which later became the 50th individual, and under the leadership of the Soviet pilot who fought under the pseudonym Miguel, to start the creation of the new Grupo 25.
 
During the summer and autumn of aircraft P-Z is actively used on all fronts. Especially a lot of to fly they Bronetsky during offensive operations and under Belchite. The crews solved a variety of tasks: performed reconnaissance flights, bombing bases and airfields of the enemy, stormed the advanced units and columns of enemy troops.
 
With the advent of the rebels of the German fighters Messerschmitt Bf-109 began to increase losses in the slow-moving squadrons of R-Z. Thus, on 12 June 1937 in the result of the meeting with the “Messer” was lost four R-Z. And June 20, after landing died of his wounds commander of Kurt Schmidt and 16-year-old shooter Juan Gonzalez. During a reconnaissance flight X. Gonzalez repulsed the attack of five Italian fighters Fiat CR.32, shooting down two of them, and K. Schmidt was able to bring a bullet-riddled truck to your airfield.
 
In September 1937 greatly depleted squadron, R-Z (there are only 46 cars) brought in Grupo 30 chetyrehjadernogo composition, headed by captain Luis Alonso. Since that time, the aircraft flew on a mission always accompanied by fighters, they not only defended R-Z in the air, but if necessary covered the crews of attack aircraft, made an emergency landing in enemy territory. Thus, during operation Trubeskoy fighters E. Stepanov and his slave Llorente and Monosomy cover the withdrawal of the crew of M. Gisbert downed stormtrooper, R-Z.
 
But at the final stage of fighting even fighter escort could not save excadrill R-Z from serious losses. Two dozen biplanes of the R-Z ground attack purposes in the reservoir area of Tremp 24 December 1938 was attacked by fighters CR.32 nationalists. Despite fighter escort group-16 losses could not be avoided. CR.32 knitted fight the escort fighters and managed to shoot down nine R-Z. On this background looks quite justified a reduction in the activity of the use of R-Z in the spring of 1938, although by the beginning of 1938 in the ranks there were still about 40, and the fall — about 30. The aircraft was used only on those parts of the front, where it is not expected serious resistance from the enemy. Gradually the functions of attack aircraft began to take on fighters I-15.
 
THE LAST BIPLANE COUNTRY OF THE SOVIETS
 
Various sources provide conflicting information about the number delivered in Spain of aircraft P-Z — from 62 to 88, and even up to 124 cars.
 
The report on the use of aircraft in combat was noted that although the R-Z and had the longest service in combat (575 days), it was not an indicator of its high flight performance, a consequence of their limited use in active sectors of the front. When circumstances forced you to use them in strong opposition fighters and antiaircraft means of the opponent, R-Z suffered heavy losses.
 
After the fall of the Spanish Republic at the hands of Franco fell 36 biplanes, P-Z in various States of health. Some of them under the designation 17W went to the staffing of air group 2-G-43, stationed in the territory of Spanish Morocco. The Spanish air force were used until 1946.
 
The results of the Spanish fighting showed that R-Z is obsolete and could not be used for its intended purpose. The result was a collapse in 1937, its serial production. Just released 1031 car. Since 1938, the aircraft began to withdraw from the combat units in the reserve and under the name P-Z pass in the CAF.
 
Despite its outdated design and mediocre for the late 30-ies of the flight characteristics, biplanes, P-2 in the Soviet air force and participated in all armed conflicts of the late 30-ies. They fought at lake Hassan on the Khalkhin Gol, was used in the “liberation” of Western Ukraine, the Baltic States and Bessarabia. And during the war with Finland, being a part of legkobombardirovochnogo regiments and separate reconnaissance squadrons and the correction.
 
After the loss of the first months of the war from the remaining R-Z formed five regiments, which fly mostly at night, but sometimes required to perform tasks during the day. The crews of the R-Z went on a reconnaissance, bombardment, and attack the advancing enemy units. As a night bomber R-Z were used until the beginning of 1943, and for operations in the rear — until the end of the war.
 
The plane R-Z was the last production scout-biplane in the USSR. In the future, the scouts and light bombers were built exclusively according to the monoplane scheme.
 
Design description
 
Scout-bomber R-Z was a single-engine single-column double polutoraplan mixed design. The purpose of the aircraft is the exploration and application of bombing and assault strikes on the forward positions and the middle rear of the enemy.
 
The fuselage had a wooden branded design. The cross section of the fuselage is rectangular with rounded corners. The power set consisted of four strength members made from Siberian spruce, and a set of frames collected from spruce and plywood. Sheathing — plywood with a thickness of 2 — 3 mm, in the rear part it increases pine stringers. All power nodes of the fuselage was made of sheet steel and had a curved, welded construction.
 
In the front part of the fuselage on the engine frame of steel pipes was installed engine. Motor mount was attached to increased the first frame at the junction of it with the spars. In the first frame are also mounted the oil tank and compressed air for engine starting on the ground. The entire engine was closed panels (hoods) sheet of aluminum. For easy operation of the power plant side panel opened up. Immediately after the first power frames were placed two fuselage fuel tank.
 
In the upper part of the fuselage in front of the dashboard mounted directional synchronous machine gun PV-1. Below and to the right of it — the battery feeding the radio and lighting equipment.
 
The cabin crew had a large area of glazing. On the machines of the first series, the cockpit was fully closed, but in the later series. was filmed, which improved the view on take-off and landing. Section of the pilot lamp can be tilted right and left. The shooter closed the lamp part. Section of the lantern in the arrow-radio operator could, if necessary, to move forward. The cockpit was equipped with a full complement of navigation equipment and devices control operation of the power plant.
 
In the cockpit of the arrow (pilot-observer) was established duplicate navigation instruments, instrument radio 13-IC-2, camera AFA-13 (for planned and future photography), removable backup control knob, removable bombsight OPB-1 and the turret gun. To use the scope and camera in the floor of the cabin, had glazed Windows. In the cabin arrow is a bag with side pike in the event of an emergency landing, and a signal flare. Seat the arrow on the first series aircraft was sliding (as in R-5), in the later — suspended canvas.
 
The upper and lower wings was performed dvuhlonzheronnoe scheme. The side walls are box-like structure. Their shelf — Siberian spruce walls from birch plywood. Rib wing had shelves made of spruce strips and plywood walls. The top wing was going from the center section and consoles. A center section mounted in the fuselage duralumin profiled on four pillars. It housed two fuel tanks, the fuel of which was received in the supply tank by gravity. To provide greater stiffness on the inside of the power set of the wing was assembled cable braces.
 
The ailerons were installed only on the upper wing. Control system the ailerons are cable driven control knobs. The lining of the wing plain, covered with two layers of dope. Toe wing to the first side rail trimmed with plywood. The junction of the lower wing with the fuselage closed zaletami. Fairings were closed and the connections of braces and struts to the wing and fuselage. Eight ribs of the lower wing, which was mounted bomb racks, were carried out reinforced. On some machines the last series on the lower wing installed brake pads. All the bent fins and rudders of the wings to extort from aluminum sheet. Between the upper and lower wings connected by N-shaped struts-a struts. On the right on the flight stand with clamps attached LDPE (Pitot tube). Additional rigidity of the wing box was provided by steel band-brace.
 
Tail dvuhlonzheronnoe scheme had a fully aluminum design. The covering of the stabilizer, fin, rudder, pitch and direction of the plain. Elevators and turn had axial compensation. The installation angle of the stabilizer could change on the ground. The Elevator control and directions of the flexible cable. To relieve the aerodynamic load from the pedals and control stick on tail surfaces were installed flattery. Control of the aircraft could be carried out from the front and from the rear of the cab.
 
Chassis tricycle fixed landing gear with tail crutch. Stand M-shaped type — tubular steel teardrop-shaped cross section, is pivotally connected between the two axles. Depreciation chassis oil-air. Wheels (900×200 mm) was supplied brakes with hydraulic drive. On the machines of the first series of wheels closed teardrop-shaped fairings (the type of aircraft P-5ССС). Skid — controlled, had retinovascular cushioning and are made of aluminum.
 
The power plant consisted of a 12-cylinder water-cooled engine M-34N or M-34RN takeoff power 840 HP and a rated capacity of 750 HP in the calculated altitude. Engine start on the ground — from compressed air or from autostarter. Propeller with a diameter of 3.1 m metal, variable on the ground step.
 
Fuel contained in two fuselage and two wing fuel tanks. If necessary, provided the opportunity to dump fuel in flight.
 
Flight performance of aircraft
 
Flight performance of aircraft
 
Retractable water radiator fairing was closed and was located between the fuselage fuel tanks and the cockpit. Release management and cleaning of radiator was carried out by the knob on the starboard side of the cockpit.
 
In front of the dashboard pilot with a small shift to the left was set the exchange rate synchronous machine gun PV-1 with 500 rounds of ammunition. Shooting with him was conducted by the pilot using the sight of OP-1 in front of the visor of the cockpit. In the cockpit at the radio operator-gunner on a mechanical turret TUR-32 (on the first 50 production machines) or electrified ATUR-8 mounted ShKAS machine gun with an ammunition supply of 1,000 rounds. Rotate ATUR-8 is a reversible motor supplied from a Dynamo DSF-500.
 
Bomber weapons were placed on eight beams D-2 with bomb racks Der-31 under the lower wing. Used bombs FAB-16 and FAB-250. Instead of bombs the plane could take four chemical spray device VAP-4 or two of the smoke generator of the WCT-100. Aiming — with the help of optical bomb sight OPB-1, which is for military use, was fastened to the floor of the cab radio operator-gunner, and in the stowed position with special clamps to the starboard side of the cabin. The bombs were dropped, the ASSOCIATED electrical-mechanical 1 or ASIO-2.
 
N. Food reserve was, A. CHECHIN, Kharkov

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