Soviet winged gyroplanes.

A-7-3A is the world's first armed autogyro, which took part in hostilities during the Second World War.
In fact, the development of an autogyro, which began in 1932 under the leadership of N.I. Kamov was carried out on an initiative basis. The Air Force was interested in such a machine and the People's Commissar of Aviation of that time, Yakov Alksnis, very willingly supported the idea of ​​​​building the first combat rotorcraft, but the TsAGI leadership was of a slightly different opinion. The fact is that the experience in building a gyroplane in the USSR was, frankly, not great, and Kamov could not promise a specific date for the completion of the construction of the machine, and even more so, the date for the start of its mass production. However, this problem was soon enough solved and they gave the go-ahead for the construction of the first prototype.

The autogyro was assigned the designation A-7 and in April 1934, the pilot S.A. Korzinshchikov made the first flight on it. During the next year, 1935, the military tested the A-7 for use as an artillery spotter and came to the conclusion that the gyroplane could well be brought to a combat-ready state in the very near future.

Nevertheless, the A-7 had a massive bouquet of flaws, mainly related to malfunctions in the propeller group. They tried to fix childhood diseases of the gyroplane on the second prototype - A-7bis. Outwardly, the machine practically did not differ from its predecessor, but due to various improvements, its take-off weight increased, which, although not much, still affected the flight characteristics. Tests of the A-7bis were carried out at a much higher rate - from May 1937 until the beginning of 1940, this gyroplane flew 80 hours. At the same time, the first A-7 from April 1934 to January 1940 managed to make sorties for only 90 hours.

The A-7 was a civilian autogyro. In 1938, having loaded it on board the Yermak icebreaker, they decided to use it in a rescue expedition heading to help the Chelyuskinites. Only now this car did not have a chance to make rescue sorties. But in the winter of 1939, the leadership of the Air Force decided to test the A-7bis in real combat conditions. Before being sent to the front, the engine was changed on the gyroplane, a new radio station RSR-3 was installed (instead of the outdated 13-SK) and a number of maintenance works were carried out - the gyroplane was to fly in the harsh winter conditions of the Finnish campaign of 1939-1940. A-7bis was sent to the 1st OKRA - a separate corrective and reconnaissance squadron, the basis of which was the multi-purpose R-5SSS (abbreviated as simply CSS). The detachment was stationed near Lake Kauk-Järve and before the end of hostilities, the autogyro made about a dozen sorties, flying a total of 11 hours and 14 minutes. The pilots who flew the A-7bis noted the excellent maneuverability of the car, high aerobatic properties, but at the same time, they complained about the insufficient speed of the device and the almost complete absence of armor for the cockpit and power plant. In general, it should be recognized that the front-line tests of the A-7bis were quite successful.

Meanwhile, it was decided to start serial construction of the A-7. The new version, which entered mass production, received the designation A-7-3A and was a development of the A-7bis. Plant No. 156 managed to produce the first five gyroplanes only by the beginning of 1941, and one of the serial machines was immediately sent to the Tien Shan to test the machine as an agricultural vehicle. On the A-7-3A, pesticide sprayers and tanks for them were installed on the sides of the fuselage and at the front pillar. In this capacity, the gyroplane made 49 flights, and along the way it turned out that gyroplanes are much more profitable to use in agriculture than the already well-proven U-2.

Before the start of the war with Germany, all five gyroplanes were brought to a combat-ready state, but the directive of the General Staff on the creation of a special gyroplane squadron was issued only on July 5th. All cars were brought into the 1st AKE (the first gyro-corrector squadron) under the command of Senior Lieutenant P. Trofimov, and M.L. was appointed the lead engineer. Mil is the future designer of the famous Mi helicopters. The flight crew fully mastered the new technology by August 1941, which allowed the command to immediately transfer part of the fresh forces to the Yelnya region, where a powerful counterattack was being prepared against the attacking German units. On August 29, all five gyroplanes took off in the direction of Gzhatsk, but two cars, due to technical problems, had to be sent back to the factory. The remaining three gyroplanes became part of the 163rd IAP under the command of Major V. Sukhoryabov, which consisted mainly of I-153 fighters.

On August 31, A-7-3A flew out on a combat mission for the first time, trying to correct artillery fire, but due to poor coordination between the squadron and the artillery regiment, the flight was essentially thwarted. Over the next week, the gyroplanes succeeded only in scattering leaflets over enemy positions, after which they were not used at all for some time, and only on September 23, the A-7-3A was successfully tested as a spotter for the first time. Accompanied by the I-153 flight, the autogyro quite successfully directed artillery fire at the German positions, and only the aimed fire of enemy anti-aircraft guns and the wounding of the letnab forced the autogyro to leave for its base.

In order to replenish the detachment, Kamov and a brigade of technicians arrived at the front on September 27-28, and on the 29th two repaired autogyros arrived. However, by this time the Germans had broken through the front again, and with the help of gyroplanes, our command tried to establish communication between the broken 24th and 43rd armies. The A-7-3A that took off, which was controlled by Major Trofimov himself, crashed during a night landing and was evacuated to the rear. A few days later, the rest of the cars followed him. After that, gyroplanes no longer took part in hostilities.

Of course, the combat use of the A-7-3A can hardly be called successful. However, during the entire period of operation, not a single gyroplane was completely destroyed and not a single pilot died. The general confusion, and in some places the complete chaos that reigned at that time in the control of combat units, and not only ground ones, also played a big role. So with more skillful management of available reserves, the experience of using gyroplanes could be much more successful.

Sources:
S. Kolov "The world's first combat autogyro"
V. Kotelnikov "Gyroplane over the Mannerheim Line" ("Wings of the Motherland")
G. Kuznetsov “Almost walking across the sky” (“Wings of the Motherland”)

Tactical and technical data of the gyroplane A-7 model 1936:

Rotor diameter - 15.18 m
Wing area - 14.7 sq.m.
Empty weight - 1300 kg
Take-off weight - kg
Maximum speed - 210 km / h
Range (flight duration) - 2 hours
Ceiling - 4800 meters
Engine - one M-22, air-cooled, 480 hp.
Armament - one 7.62 mm ShKAS turret machine gun

The autogyro "KASKR" was the first domestic rotorcraft to take to the air. It was the start of the Soviet autogyro industry, which became a technical school for the subsequent development of helicopters.
The next aircraft N.I. Kamov became a gyroplane, which received the code A-7. Its development was started in 1931 in the TsAGI Special Constructions Section. In this unique machine, both the ideas of using a gyroplane and new design solutions were embodied. The A-7 was developed primarily for military use, according to the terms of reference of the Red Army Air Force as an artillery fire spotter, a communications vehicle and a short-range reconnaissance aircraft. It was also envisaged to use it from the ships of the Navy.

First, let's understand what a gyroplane is. What an unusual word, right?

In fact, there is nothing strange in this word. It's just that it has a non-Russian origin and is formed from the Greek words αύτός - itself and γύρος - circle. The name gyroplane is more commonly used in Russia. In the west, the names gyroplane, gyrocopter irotaplan are more common.

But, in general, all these names are quite close and characterize the principle of flight, or, more precisely, the principle by which this interesting apparatus is successfully kept in the air. This is the principle of autorotation.

You probably know about it in relation to a helicopter. But for a helicopter, autorotation is an emergency mode. The helicopter can only descend in this mode in order to make as safe a landing as possible. And for a gyroplane, this is the main (and only possible) flight mode.

A self-flying autogyro, in addition to a free main rotor, has an engine with a pusher or puller propeller, which provides the vehicle with horizontal thrust. When moving forward, a counter air flow is created, flowing around the rotor in a certain way and forcing it to autorotate, that is, rotate, while creating lift. And that is why the gyroplane, alas, cannot hover in place (with the exception of special conditions of a large headwind) or rise strictly vertically like a helicopter.

It is thus believed that the gyroplane occupies an intermediate position between an airplane and a helicopter. In order to stay in the air, he needs to move forward, but the lifting force itself is created by a rotor, similar to a helicopter (only without an engine).

The pattern of flow around the main rotor for these devices is different. If the helicopter has an oncoming air flow from above, then for a gyroplane it comes from below. The plane of rotation of the propeller during horizontal flight is tilted backwards for a gyroplane (forward for a helicopter). The picture of the flow around the blades is as follows ....

As has been repeatedly (:-)) it has been said that when a blade (or, for simplicity, its single profile) flows around, an aerodynamic force is formed, which can be decomposed into a lifting force (we need it) and a drag force (which, of course, interferes). The angles of attack (blade settings) for the existence of a stable autorotation must be in the approximate range of 0° - 6° degrees.

In this range, the total aerodynamic force is slightly inclined to the plane of rotation of the blade, and its projection onto this plane just gives us the force F, which acts on the blade, causing it to move (rotate). That is, the screw maintains a steady rotation, while creating a lifting force that keeps the device in the air.

It can be seen from the figure that the lower the resistance X, the greater the force F that rotates the blade. That is, the surface of the blade for a good result must be sufficiently clean, or, in aerodynamic terms, laminar

A-7 - winged autogyro with a mechanical spin-up of the main rotor before takeoff. The fuselage was a truss structure and had two separate cockpits for the pilot and the observer. In order to improve visibility and firing angles of the rear lower hemisphere, the tail section of the fuselage was greatly narrowed, almost turned into a tail boom, typical of modern rotorcraft designs.

The low-lying wing folded up along the connector with the center section, which, in combination with the folding blades, created convenience for transportation and placement in hangars and on ships. To improve controllability at low flight speeds, slotted ailerons and a reverse slot on the horizontal tail were used. The tricycle chassis with a nose wheel and an additional tail support ensured the stability of the takeoff run and the horizontal position of the main rotor at the time of its spin-up and braking, which reduced the oscillations of the blades relative to the vertical hinges. The landing gear with a nose strut helped to reduce the takeoff run due to the lower resistance of the propeller. All supports had hydraulic suspension struts. It was planned to install the aircraft on skis. The three-bladed main rotor of the autogyro had a sleeve with horizontal and vertical hinges.

The successful layout of the gyroplane in terms of ensuring an acceptable frequency response and the installation of a chassis with a nose wheel made it possible to do without vertical hinge dampers in the design of the hub, using only a slight springing of the blades in the horizontal plane. In general, the sleeve was simple, and there were no comments on its operation in the test reports. The blades of the gyroplane were distinguished by the care taken in manufacturing and balancing. Mechanical spinning of the main rotor was carried out using a transmission consisting of two shafts - horizontal and inclined - and an intermediate gearbox.

When developing the autogyro, special attention was paid to the aerodynamic shape of the airframe. The use of fairings on the boar mounts and the boar itself, the engine hood, and landing gear fairings anticipated the achievement of perfect aerodynamic shapes on modern helicopters. All this contributed to a decrease in the total resistance of the gyroplane, which has a mass of 2230 kg, an air-cooled motor M-22 with a power of 480 hp was mounted on the A-7. with fixed pitch propeller.

The intended military gyrocopter had the necessary armament, which consisted of a PV-1 synchronous machine gun and a Degtyarev system machine gun with 12 magazines on the rear turret. It was also planned to install twin machine guns on this turret. The A-7's four bomb weapon hardpoints were equipped with mechanical and electrical drop systems. Subsequently, jet weapons were also used on the autogyro. A 13SK-3 receiving and transmitting station was installed on the A-7, later replaced by RSI-3. A POTTE 1B camera was mounted for aerial photography.

Three modifications of the gyroplane were built: A-7 - an experimental machine; A-7bis experimental car after modifications, differing from its predecessor in an enlarged boar, improved aerodynamics and modified plumage; A-7-3a is a serial machine, which differs from A-7bis in reduced weight. Its maximum speed was 219 km / h, and the length of the takeoff run was 28 m.

Flight tests of the A-7 rotorcraft began in the summer of 1934, and in the spring of 1937 they were continued on the A-7bis. The tests carried out and the subsequent fine-tuning of the gyroplane became the fundamental basis for the subsequent development of rotorcraft.

In the winter of 1939, the war with Finland began. Two gyroplanes A-7 and A-7bis were sent to the front to ensure the correction of Soviet artillery fire. These machines were piloted by test pilots A. Ivanovsky and D. Koshits.

During the preparation of the material part and during test flights on gyroplanes, there were problems. On one rotorcraft, during an emergency landing, the front ski was damaged, on the other, a capacitor was pierced in the onboard radio station. Engineer I. Karpun and mechanic A. Kagansky eliminated the malfunctions and prepared the vehicles for the combat mission. Before the end of the war, when they broke through the Mannerheim line and stormed Vyborg, the gyroplanes made several reconnaissance missions.

In early 1939, factory #156 laid down a series of five A-7bis. Four cars quickly flew around and presented to the customer. But due to the lack of a ground radio station, it was impossible to assess the quality of radio communications. Then the customer checked radio communications simultaneously on all gyroplanes, of which one flew over the airfield, the other went beyond it, and two stood on the ground. The communication between all the machines was excellent, and they passed the acceptance.

The fifth gyroplane was significantly delayed in completion, since several times when the engine was turned on, the main rotor spin-up mechanism failed. The cause was hard to find. It turned out to be a displacement of 0.2 mm of the guide rod of one of the 18 release springs. The autogyro took off and was accepted by the customer.

From the first day of the war, the plant urgently began to prepare a detachment of five A-7bis. Soon they got up from the Ukhtomsk airfield and flew to the front in formation. Then they were sent to the First Adjustment Squadron of the Air Force. These machines participated in the Great Patriotic War, performing assigned tasks on the Western Front near Smolensk.

In the first sortie at the front, the gyroplanes were not fired upon by the Germans, since they did not yet know what kind of car it was (a captured German told about this). The next time, one of the gyroplanes came under fire, but the enemy hit with great pre-emption, incorrectly estimating the speed, and when he corrected the fire, the gyroplane had already disappeared into the clouds.

In the night sorties, autogyros silently planned over the Nazi positions, scattering leaflets. The difficulty of using rotorcraft at the front was their camouflage. Masking the rotor was very problematic. The positive quality of the A-7bis was high survivability. One of the autogyros was hit by a heavy machine gun. The car was broken in many places. The fuselage, plumage, rotor blades were damaged. The observer was wounded in the legs, and the pilot was wounded in the arm, but the autogyro retained control and flew safely to the location of the unit.

During the war years, artillery fire was adjusted on A-7 gyroplanes, and a number of night flights over the front line to the locations of partisan detachments were carried out.

Having a temporary superiority in technology, the enemy moved inland. At one of the sites, our military units were surrounded - and the plan-order to leave the encirclement was delivered to them by autogyro. The management of the autogyro plant received an order to urgently evacuate from Ukhtomskaya near Moscow to the Urals, to the village of Bilimbay. There, an assembly shop and other workshops were located in the church building, and a machine shop was equipped in the church annex. They quickly began to repair the A-7bis, which returned after the battle near the city of Yelnya.

The machines were soon repaired, and military pilots began flight training, building a landing pad on the ice of the pond. But one morning, the pilots discovered that the surface of the site was completely covered with ice holes. It turned out that the employees of the Design Bureau V.F. Bolkhovitinov was fishing at night and spoiled the site.

The flights continued from the clearing, which was cleared on the hill. It is interesting that the factory pilot wanted to land on a new site on his Po-2, but, having studied it and the approaches to it, he changed his mind, since the site was too small even for such an aircraft. He was surprised that gyroplanes landed on her.

At the end of training flights, a detachment of three cars went to Moscow. The rotorcraft were loaded onto two platforms, and the crews were located in two warm cars. Over two weeks, the cars reached the destination station in the city of Lyubertsy. When the echelon arrived, the flight crew did not recognize their territory, it was so cluttered. Part of it was dug up for vegetable gardens, the other was occupied by car repair shops. However, training flights were continued.

Later, two gyroplanes were sent to Orenburg, to a school for training spotter pilots. However, it was not possible to establish the operation of gyroplanes at the school due to the lack of instructor pilots who had mastered these machines.

In the pre-war years, the issues of using gyroplanes in the national economy were also resolved. In the winter of 1938, the A-7 rotorcraft on the Yermak icebreaker took part in the rescue of the group of I.D. Papanin from a drifting Arctic ice floe. And in the spring of 1941, an expedition was sent to the foothills of the Tien Shan, where pilot-engineer V.A. Karpov on a gyroplane successfully pollinated arrays of fruit trees.

In the development of rotary-wing aircraft, the A-7 autogyros played an important role. In particular, for the first time, and it was in the Soviet Union, they proved the possibility and expediency of using autogyros for military purposes for reconnaissance, communications, artillery fire adjustment, etc. Also fully justified their use in agriculture. The accumulated experience of the practical operation of the A-7 included the training of flight personnel, maintenance, operation in a combat unit, and repair and restoration work.

The A-7 gyroplane remained the largest and fastest of all serial gyroplanes in the world. In 1940, the Kamovites began designing the AK autogyro. It was developed according to the tactical and technical requirements of the Red Army Air Force as a mobile artillery observation post for establishing the coordinates of the location of targets invisible from the ground and adjusting artillery fire by various methods. It was planned to transport the autogyro on a truck trailer following the combat columns. The transfer from the transport position to the combat position should not exceed 15 minutes.

The aircraft was developed in two versions: a helicopter gyrocopter and a jump takeoff gyroplane. The first option was a single-rotor helicopter with compensation of the reactive torque of the main rotor using control surfaces that use the energy of the air jet thrown off by the pusher propeller and partially by the main propeller. Structurally, this was supposed to be done in the form of a vertical tail, having three rudders with flaps and slats. To perform vertical take-off, hovering and acceleration, this device was supposed to be helicopter-like, and to switch in horizontal flight to autogyro mode - by reducing the overall pitch of the main rotor and disconnecting it from the motor drive.

TsAGI conducted research on various tail unit designs, including flaps and slats. In this case, the efficiency was evaluated at different slip angles and in the presence of a jet from the main rotor. At the end of the research, in June 1940, in the hover mode, a lateral force on the vertical tail was obtained, equal to 0.7 of the main rotor thrust value. Such a lateral force on the plumage made it possible to create a control moment relative to the center of gravity of the apparatus, 30% higher than the reactive torque of the main rotor. In the version of the autogyro-helicopter, the distribution of engine power between the main and pusher propellers provided a static ceiling of 2000 m.

However, the short deadlines for the government assignment and the lack of confidence that this 30% control moment margin would be sufficient for directional controllability forced us to abandon this very interesting version of the rotorcraft and choose a simpler second version of the gyroplane, taking off without a run. The jump takeoff of such an autogyro was carried out by using the kinetic energy of the main rotor by increasing the total pitch of the propeller, spun up to high speeds.

The AK apparatus was a wingless two-seat autogyro with an AB-6 engine with a takeoff power of 240 hp. The cockpit with the pilot's and observer's seats located side by side was located in the forward fuselage, and the engine with the pusher propeller was behind it. This layout provided a compact design, good visibility, crew comfort and better centering. Chassis - tricycle, with a nose wheel, which has proven itself well on A-7 gyroplanes. Shock-absorbing racks of supports and brakes - hydraulic. The developed tail unit was attached to light struts made of pipes to the landing gear and the boar.

The gyroplane was equipped with a three-bladed variable-pitch pusher propeller with metal blades. The presence of a speed controller made it possible to spin up the main rotor at high engine speeds and low propeller thrust. Low thrust made it possible to reliably hold the car on the brakes. The engine had forced cooling from the fan.

The main rotor mechanical spin-up system included a single-stage gearbox on a motor of two spur gears with an output flexible coupling, a short horizontal roller, a central gearbox with two bevel gears and a hydraulic friction clutch, a vertical roller with two Hooke's joints and an upper gearbox with two cylindrical gears. . The overall gear ratio was 6.33:1. The transmission torsional vibration damper was located in the large gear of the upper gearbox.

In the explanatory note to the preliminary design, the new gyroplane was compared with the most outstanding German two-seat short takeoff aircraft Fi-156 Storch at that time. This aircraft was used for similar purposes and, like the AK, had a 240 hp engine. The table shows some comparative data. As can be seen from these data, the AK autogyro was superior to the world's best aircraft, similar in purpose, crew size and takeoff weight. N.G. took part in the design of the AK autogyro. Rusanovich, M.L. Mil E.I. Oshibkin, A.M. Zeigman, A.V. Novikov and many others. Unfortunately, the construction of the gyroplane was not completed due to wartime difficulties.

It was with these unsightly and outwardly rude devices that our helicopter industry began. Obviously, without the A-7 flights, there would not have been such well-known combat vehicles as the Mi-24, Ka-28 and Ka-52.

Modern combat aviation cannot be imagined without rotorcraft. Helicopters have long earned a reputation as versatile aircraft capable of vertical takeoff and landing, and the list of their military professions is quite extensive. The use of helicopters (helicopters) in real battles began during the Second World War. Germans at the beginning. 1945 the only helicopter unit in the Luftwaffe, the 40th Transport Squadron, is formed in Bavaria. The squadron consisted of three Heinrich Focke Fa-223 transverse helicopters and five Anton Flettner FI-282 cross-rotor helicopters. Rotorcraft with a swastika on the fuselage participated in the Northern Alps in the adjustment of artillery fire, as well as in transport and communication operations. Overseas, Igor Sikorsky built his R-4 according to a single-rotor scheme. This small US Air Force helicopter was used in 1944 mainly to rescue the wounded from the jungle in Burma. But even before the adoption of the first helicopters, the military became interested in another rotorcraft, the gyroplane.
The very first C-20 autogyro was built in 1920 by the Spaniard Juan de la First. The designer set out to create a safe aircraft that, in the event of an engine failure, could parachute down using a rotor rotating from the oncoming flow. Following the C-20, first he produced a number of experimental gyroplanes, and in 1928 he made the first flight from Paris to London on the C-8. After a successful demonstration of his cars, the Spaniard moves to England, where he organizes a company for the serial production of gyroplanes. A number of foreign firms buy a license from the designer to build his unusual devices. Therefore, almost all pre-war gyroplanes in the world were a modification of the Sierva machines.
The military was going to use the new class of rotary-wing aircraft for a variety of purposes: reconnaissance, fire correction, communications and aerial photography. The sailors were interested in the capabilities of gyroplanes in the search for submarines, ship security, patrolling and rescue service. Although the speed of gyroplanes was less than that of airplanes, their main advantages were a short takeoff distance and a very short landing run. In addition, low speed when adjusting artillery fire and searching for submarines was even necessary.
The Americans were the first to test autogyros in military service. In September 1931, the Pitcairn RSA-2 autogyro (created with the direct participation of Sierva himself) for the first time demonstrated takeoff and landing from the deck of an aircraft carrier. But unusual vehicles did not enter service; the low speed and unreliability of the first vehicles continued to be insoluble problems.
The prospects for the use of autogyros in the army increased somewhat in 1933, when Juan Sierva introduced direct control of the rotor hub into the design. Until now, the gyroplane has been controlled in flight like an airplane: with the help of ailerons on the wing and tail. Now the propeller-driven vehicles became wingless, and the direction of the lifting force was changed by deflecting the rotor. This made it possible to improve the flight characteristics of autogyros and reduce weight, and the absence of a wing significantly increased the pilot's visibility.
The Royal Air Force of Great Britain allocated funds for the construction of five Sierva C-40 gyroplanes of the new generation with the so-called "jumping" start. On the S-40, the pilot, before taking off, spun the rotor from the engine, then increased the pitch of the blades and the autogyro “jumped” in place. At the top point of the "jump", the step was removed and, tilting the propeller forward, the gyroplane with a slight subsidence went into flight. Five C-40s successfully operated as communications vehicles with the British Expeditionary Force in France, but all of them were lost during the evacuation from Dunker in 1940. The remaining C-30s in England with direct control of the sleeve were mobilized to calibrate the locators. Formed for this purpose, a separate autogyro squadron of fifteen C-30s existed until the end of the war.
France also had a small fleet of military gyroplanes. By May 10, 1940, when the Wehrmacht units crossed the border of the first republic, the troops had 52 LeO C-30 gyroplanes (licensed version) and the fleet had eight more vehicles. French vehicles failed to play a significant role in the fighting, but several S-30s patrolled over the English Channel until the end of May 1940.
In the summer of 1941, the A-7-Za gyroplanes of the Red Army Air Force also managed to fight a little. But unlike the unarmed S-30 and S-40, it was a real combat aircraft, since it had a protective armament of three machine guns and could lift small bombs. For the first time in world aviation, weapons were installed on a rotorcraft, which can rightly be called the forerunner of modern combat helicopters.
The chief designer of the A-7 was N. I. Kamov, whose creative destiny from the very beginning was inextricably linked with the development of autogyro and helicopter construction in the USSR. Back in 1929, Kamov, together with N.K. Skrizhinsky, built the first autogyro KASKR (Kamov Skrizhinsky) in the Soviet Union, which received its own name "Red Engineer". According to its scheme, dimensions, parameters and design scheme, this machine completely repeated one of the gyroplanes First C-8. The first sortie, which took place on September 1 and lasted only 80 seconds, was attended by Kamov himself and the pilot Mikheev. Due to the insufficient stability of the KASKR during takeoff on October 12, an accident occurred and the gyroplane overturned. The pilots escaped with only bruises, and after repairs and improvements, the tests continued.
N. I. Kamov managed to obtain the consent of the leadership of the Air Force Research Institute to provide him with two test engineers, as well as secondment of test pilot D. A. Koshyts for flights. Once, on September 2, 1930, the head of the Red Army Air Force P.I. Baranov came to see the flight of the Red Engineer, and the car did not let him down. KASKR performed three flights lasting thirty seconds each at an altitude of 12-15m. The demonstration flight was not in vain. The commander of the Red Air Fleet helped to get a new Titan engine (235 hp) for the autogyro, since the power of the old Ron (120 hp) was clearly insufficient. With the new engine, the autogyro became known as KASKR-2 and first took to the air on January 11, 1931.
On May 21, 1931, at the Central Aerodrome in Tushino, the gyroplane of Kamov and Skrizhinsky participated in the demonstration of the latest aviation technology to the country's leadership. Stalin, Voroshilov and Molotov bypassed a long line of fighters and bombers, and an unusual rotorcraft closed the “parade”. Kamov himself reported to Stalin about the car, and "the best friend of Soviet aviators" became very interested in KASKR. Kosice also supported the designer with a spectacular flight. Having made three circles over the airfield, the pilot beautifully planned and landed KASKR-2 near the podium with members of the government, making a landing run of just a few meters. Baranov later said that the gyroplane really liked the high leadership and, first of all, Stalin.
The interest of the first people in the state in KASKR helped the development of the entire autogyro industry in the USSR. The creators of the "Red Engineer" are transferred to the Bureau of Special Designs at TsAGI (BOK TsAGI), where they begin to build new machines. N.K. Skrizhinsky participates in the creation of the A-4 gyroplane, and N.I. Kamov begins to lead the design of the A-7, which was developed on the instructions of the Air Force as a short-range reconnaissance and artillery spotter. Kamov was assisted by a very small design team: M. L. Mil, N. S. Terekhov, V. A. Solodovnikov, A. E. Lebedev, V. I. Barshev, V. S. Morozov and I. I. Andreeva.
The A-7 was a two-seat (pilot and observer) wing-type autogyro with a three-blade rotor and an M-22 air-cooled engine with an HP 480 power. The A-12 tractor propeller had two blades, the pitch of which could be changed on the ground. The fuselage of a truss structure made of steel pipes consisted of three compartments: an engine compartment with fuel tanks, a separate cabin for the pilot and observer, and a tail boom. The front part was covered with easily removable duralumin panels, and the tail boom had a fabric covering. The wooden wing with the MOS-27 profile consisted of a center section with V-shaped struts on top, closing on the fuselage, and consoles with ailerons. The ends of the planes at a slight angle were bent upwards. For ease of storage and transportation, the consoles were adapted for folding. The beam ended with a classic tail of a keel with a rudder and a stabilizer with an elevator. The plumage design was all-metal with fabric covering. A three-column "boar" of the rotor with additional steel tape braces in the transverse plane was attached to special nodes of the central part of the fuselage. In the upper part of the "boar" there was a sleeve, to which three blades were suspended on horizontal and vertical hinges. The blades had a spar of heat-treated and telescopically connected chromium-molybdenum tubes. Wooden ribs with the help of duralumin rosettes were mounted on the spar and the whole structure was sheathed with canvas, and the toe with plywood. The installation angle of the blade with the Göttingen-429 profile was 2°45". and a non-retractable crutch was placed behind, protecting the fuselage beam during takeoff and landing. The wheels were closed with fairings and were equipped with hydraulic brakes. To reduce the takeoff distance before takeoff, a system of mechanical spin-up of the rotor from the engine was provided. The gear ratio of the launch system was 5.78: 1, that is, with engine speed of 1130 rpm, the rotor sleeve did 195 rpm.The pilot launched the activation mechanism with a special handle in the cockpit, which was connected to the rotor brake.When the handle was rotated clockwise, the launch mechanism was turned on, and when rotated counterclockwise, the rotor brake was activated In this case, the hydraulic system acted on the wheel brakes simultaneously with the activation of the starting system. The equipment of the A-7 (electrical equipment, radio and photographic equipment) was similar to a conventional reconnaissance aircraft of the same purpose. As mentioned above, for the first time the autogyro received defensive armament from three 7.62 mm machine guns. The pilot was responsible for the front belt-fed PV-1, which fired through the propeller. And the observer led the defense of the rear hemisphere from two coaxial machine guns DA (Degtyarev-aviation) with disk magazines on the annular turret. In the future, nodes appeared at the bottom of the wing for suspension of four FAB-100 bombs and six RS-82 unguided rocket projectiles.
In April 1934, the construction of the first A-7 was completed at the experimental designs plant at TsAGI. In May, the rotorcraft was transported to the airfield, where they began ground engine races and short runs. And on September 20, 1934, a historic day came S. A. Korzinshchikov for the first time lifts an unusual car into the air. Tests of the A-7 continued until December 1935. Such a long period is associated with the fine-tuning of the new apparatus and with the identification and elimination of various abnormal phenomena. So, problems arose due to shaking of the rotor, vibrations of the tail unit, trembling of the pilot's handle and overheating of the engine.
Gradually, they got rid of the shortcomings, and the flight characteristics turned out to be quite high compared to the best domestic and foreign gyroplanes of that time. The maximum speed of the A-7 at 218 km / h was quite comparable to the speed of biplanes. The flight program turned out to be very intense. During the tests, balancing curves were taken, the behavior of the machine was checked in the full range of alignments, and stability was assessed in different modes. The takeoffs were carried out mainly on a wheeled chassis, but in winter they also tested a gyroplane on skis.
There were also incidents. Once during the flight, the engine control rod was disconnected. The autogyro began to autorotate, but unfortunately there was a wood below. As a result of a rough landing, the landing gear gave way and the wing-to-fuselage junction burst. But basically, the A-7 proved to be a reliable machine, and on August 18, 1935, pilot K.K. Popov demonstrated a rotary-winged reconnaissance aircraft at an aviation parade in honor of Aviation Day.
After the factory tests, the design of the gyroplane underwent thorough modifications, the main of which was the new design of the "boar", now made according to a two-legged scheme with a pair of side bracing tapes. This improved the visibility of the pilot and made it easier to leave the device if necessary. Two "washers" were installed under the stabilizer for better directional stability. In addition, the aerodynamic contours were ennobled in places of some nodes and joints.
From the middle of 1936 to May 1937, the backup A-7bis was built and received a ticket to the sky. At this time, the first A-7 passed and finished with a positive assessment of state tests. A-7bis completed the test program in July 1938. The results of its flights basically repeated the characteristics of the A-7.
In general, the gyroplane was a success, and the pilots treated the unusual rotorcraft with confidence. This is confirmed by the fact that at the beginning of 1938, among other rescuers, they decided to use the A-7 gyroplane to remove from the drifting ice floe off Greenland. The proposal was received by the government commission from the famous polar pilot Mauritius Slepnev. He telegraphed to Moscow: “I ask permission to fly to the place of the accident in a gyroplane or plane. I know the area well. Pilot of three polar expeditions, pilot Slepnev. The deadlines were tight, and in five days the A-7bis was urgently re-equipped so that two people could be transported in the rear cabin. The autogyro with spare parts was loaded onto a railway platform. From Moscow, he went to Oranienbaum, where he was loaded onto the icebreaker "Ermak". Together with the A-7bis, the pilot Korzinshchikov, the designer Kuznetsov and the mechanic Kogansky went on a long sea voyage. All of them were very worried about the safety of the experimental apparatus on the ship. However, the autogyro did not have a chance to fly in the Arctic. The hydrographic vessels "Taimyr" and "Murman", which left earlier, were ahead of the "Ermak" and removed the Papaninites from the ice floe.
A-7 did not have time to prove itself in the North, but after three years it did an excellent job in hot Central Asia. At the beginning of 1941, Narkomles and Aeroflot organized an expedition to the foothills of the Tien Shan to prove the possibility of using gyroplanes in forestry and agriculture. The slopes of the mountains were covered with thousands of hectares of orchards, which suffered from an insect pest, the apple moth. A-7bis came to the aid of diseased trees together with a team of specialists consisting of pilot V. Karpov, engineer G. Korotkikh and mechanics V. Ulyanov and G. Shamshev. First of all, we installed the necessary equipment for spraying pesticides. On top of the fuselage, in front of the front pillar of the "boar", an impeller was fixed, rotated by an oncoming air flow. From it stretched the transmission to the mechanism for spreading the powder pesticide from two bulk tanks on the sides of the fuselage. The A-7bis took off, the impeller began to rotate, and behind the autogyro a poisonous powder dispersed in a wide plume and settled on the trees. The autogyro coped with such tasks as well, if not better than the aircraft. Firstly, the rotorcraft did not need large areas for takeoff and landing; secondly, the air flow from the rotor directed the flow of pesticides straight down, and the efficiency of their application increased. The expedition spent a month in the foothills of the Tien Shan, and even the central press noted the results of its excellent work. The Pravda newspaper wrote about the experiment with a pollinating autogyro: “The other day, participants in an aviation chemical expedition of the timber industry trust of the USSR People's Commissariat of Forests returned to Moscow. The expedition conducted an experience of using a Soviet gyroplane designed by engineer Nikolai Kamov to control pests of fruit trees in South Kyrgyzstan. Piloted by pilot Vladimir Karpov, the A-7 went up steeply and, tacking along steep mountain slopes, quickly reached areas inaccessible to aircraft. The device easily maneuvered in narrow valleys, descended into bowl-shaped mountain tracts, turned around at the bottom and rose again. 32 flights were performed by an autogyro ... "
This article appeared on June 19, 1941, that is, just two days before the start of the war. Now N. I. Kamov's autogyro had to fight not with garden pests, but with the advancing hordes of the Nazis. As already mentioned, the A-7 was originally conceived as a full-fledged combat vehicle, and after successful tests, it was decided to build a small military series of rotary-winged reconnaissance and spotter.
Back in the spring of 1940, on the initiative of N. I. Kamov, the first plant of rotary-wing aircraft in the USSR was created at the Ukhtomskaya station. Subsequently, it was from this small enterprise that the Ukhtomsk Helicopter Plant grew, which today bears the name of its creator. Kamov was appointed director of the plant and chief designer, and M. L. Mil became his deputy. In the middle of 1940, the plant began building five A-7-Za military gyroplanes. Pilot Kositz began their tests. Trained to fly rotary-winged vehicles and military pilots. There was an accident on one of the flights. The pilot, when approaching the factory airfield, did not calculate the distance and landed on the roof of one of the buildings. Fortunately, the pilots survived, and the autogyro returned to flying after repairs.
With the beginning of the Great Patriotic War, five A-7-Za formed a separate gyroplane squadron, the first part of the rotorcraft in the Red Army Air Force. Kamov himself recalled the actions of his autogyros in battles against the Nazi invaders:
“A detachment of gyroplanes, organized by the Main Artillery Directorate, operated as part of the 24th Army in the area of ​​\u200b\u200bthe city of Yelnya and was based at one time at the airfield in the village of Podopkhay. The pilots of the detachment under the command of Senior Lieutenant Trofimov made a number of sorties to correct artillery fire and behind enemy lines to the partisans. The flights were carried out day and night.
It was especially difficult to carry out night flights. This was our first experience, and in war, as they say, one does not hesitate for a long time. As soon as the gyroplanes arrived at their location, the very next day, the command ordered to prepare for a combat mission at night. Flights were made in complete darkness. There was no talk of any lamps, at least "bats". The front-line airfield was only twenty kilometers from the front line. A few days before the arrival of the gyroplanes, the Germans spotted the airfield and nine "Messers" bombed it to smithereens. The commander of the fighter regiment, which was at this airfield, was constantly wary of another German raid. Therefore, as soon as the gyroplane taxied out of the shelter to unwind the propeller before takeoff, fuss began around the car and swearing was heard: “Take off soon !!! Don't freak out!" etc. At night, take-offs and landings were carried out in complete darkness - only by the sound of the engine it was possible to determine where the car was and what was wrong with it. If it buzzes, then it's intact ... "
Kamov knew all this not from the stories of pilots and technicians. He visited the front together with his deputy M. L. Mil. The main task of the designers at the forefront was the repair of gyroplanes shot down in battle.
In early October, the gyroplane squadron will relocate to the east. Two cars flew over to the 43rd Army. Two of those remaining in the A-7-Za unit were sent to Moscow for repairs, and on the third squadron commander Trofimov was instructed to urgently deliver a report to the headquarters of our troops in Gzhatsk. In a report signed by the leadership of the 24th Army, it was reported that the Germans had made a breakthrough in the area where the 24th and 43rd armies met. The flight was carried out in complete darkness, which protected the low-speed vehicle from the attacks of German fighters. But landing in such conditions was very difficult to perform. The pilot at dusk mistook the forest for the ground cover of the airfield and parachuted onto it from a height of 10 meters. The autogyro was seriously damaged, but Trofimov survived, and the package with the report was delivered on time. This episode was the last in the combat career of the rotary-winged reconnaissance and spotter A-7-Za designed by N. I. Kamov.
With the threat of the capture of Moscow, the plant was evacuated from Ukhtomskaya to the village of Bilimbay, Sverdlovsk Region. Here Kamov and his associates repaired the surviving A-7s. But the chief designer was already thinking about a new rotary-wing machine, the “jumping” autogyro AK (artillery spotter), the design of which began just before the war. This gyroplane with an MV-6 engine (225 hp) had main rotor control like on modern helicopters using a swashplate that changes the cyclic pitch of the blades. In difficult conditions of evacuation, the construction of the machine turned out to be impossible. The plant in Bilimbay was repurposed for the repair of automotive and aviation equipment, and N. I. Kamov was able to start design work only after the war. He did not return to autogyros, completely switching to the creation of helicopters.
In the story about this amazing machine, the word “first” is very often mentioned, although the A-7 remained the last flying gyroplane of the remarkable Soviet aircraft designer. It was the first combat gyroplane in the world and the first serial rotorcraft in the USSR, built at the first plant in our country for such equipment. It was with these unsightly-looking devices that the domestic helicopter industry began. Obviously, without the A-7 flights, there would not be such combat helicopters as the Mi-24, Mi-28 and Ka-50 today.

It all started with the fact that at the beginning of 1938, during the evacuation from a drifting ice floe off Greenland of the group of I. D. Papanin, the Ermak icebreaker was actively used first for search, then for evacuation of the A-7 autogyro.
The use of the gyroplane did not go unnoticed by the top leadership, although the military still strongly doubted the combat effectiveness of gyroplanes, the successful use of the Papaninets in the rescue and the incoming information about the active development of the C-30 Mk II gyroplanes abroad by the Sierva engineering firm, the Weir W-3 and the gyroplane Austrian designer R. Hafner, as well as the adoption of the French Air Force license mod. C-30 under the name LeO C-30.
A decision was made to produce a small series of A-7bis gyroplanes of 20 pieces by the fall of the 39th and conduct military tests.

The negative attitude of the Air Force leadership, which did not see the great advantages of the gyroplane over traditional aircraft, put an end to the further mass production of gyroplanes.
The outbreak of the conflict with Finland forced a different look at the capabilities of rotorcraft. Difficult weather conditions, low cloudiness, strong gusty winds, the absence of large landing sites, severely limited the use of traditional aviation.

High resistance to wind gusts, the ability to take off from a patch, as well as a high level of training of pilots who flew in low cloud conditions literally touching the tops of pine trees with their wheels, the A-7bis became a salvation for many of our wounded soldiers.
Autogyros were used as artillery spotters, short-range bombers taking the 4th hundred, attack aircraft firing machine guns and RS at ground targets, a liaison capable of landing vertically and if there was a good wind, then taking off, sanitary hanging two Grokhovsky sanitary containers under the wing.
An air battle with the Foker D-XXI fighter was recorded, in which the pilot V. M. Vorontsov (former fighter pilot), warned by the observer in time using the high horizontal maneuverability of the A-7 autogyro, met the enemy aircraft on a head-on course and damaged it from the PV-1 synchronous machine gun .

In the spring of 1940, the first plant in the USSR for rotary-wing aircraft was created at the Ukhtomskaya station. Kamov was appointed director of the plant and chief designer, and M. L. Mil became his deputy. In the middle of 1940, the plant began building five modernized A-7bis gyroplanes. Pilot Kositz began their tests.
In the middle of March of the 40th year, the A-7bis gyroplane was demonstrated to the country's leadership, headed by I.V. Stalin.
It turned out to be persuaded to a demonstration flight and landing on the territory of the Moscow Kremlin. Pilot Kosice at a minimum speed of 60 km.h. flew over the territory of the Kremlin effectively turned almost around the bell tower of Ivan the Great and made a parachute landing on Ivanovskaya Square opposite the military school. The All-Russian Central Executive Committee took off from it after a short run.
The demonstration flight made a good impression on Stalin.

The GKO made a decision before the commissioning of the Ukhtomsky plant to create a site for the production of autogyros at aircraft plant No. 1 (Moscow).
On which they began to produce the A-7bis gyroplane and the A-7UTI training gyroplane with dual control.

In the spring of 1940, Kamov began developing a modernized A-7 gyroplane. On which they installed the M-25B aircraft engine, swashplate, HB pitch control.
According to the experience of the Finnish, they strengthened weapons and protection; installed 2 synchronous ShKAS and one turret ShKAS, designed fuel tank, pilot armored back.
The high engine power made it possible to increase the speed to 250 km.h. (the aerodynamic resistance and strength of the HB blades no longer allowed), the carrying capacity and rate of climb increased,
Combat load - vertical (hopping) takeoff 600 kg: 4th FAB-100 2nd FAB-500, 8 RO-132 (or RO-82). 2nd suspension cassette G-61 (transport container) Grokhovsky in which up to 8 people could be transported, 4 in each.
Combat load (aircraft takeoff) - 1000 kg:
The catastrophe of the experimental A-7M showed that the swashplate was not finished and reliable, and they were forced to abandon it.
In November 1940, the A-7M went through a full cycle of tests and was put into service.
Newly formed fur. corps according to the staffing table provides for the presence of a separate squadron of gyroplanes.

TsAGI A-7 AUTOGYRO