A necessary foreword. We are talking about the 30s of the last century, when two ideologies collided in design bureaus around the world: a high-speed and a maneuverable fighter. It just didn't work out right then, and it turned out that I had to work in two directions.
The maneuvering fighter was a biplane, the high-speed one was a monoplane.
Everything is fine here, physics, more precisely, aerodynamics. Ball of the rule is the specific load on the wing, that is, the ratio of the weight of the aircraft to the wing area. And at the indicated times, it was this parameter that largely determined the flight qualities of any aircraft.
Biplanes with a large wing area had a low take-off speed and a short take-off run, and were very maneuverable in the sky. But this had to be paid for by the low speed of horizontal flight.
Monoplanes, on the contrary, were faster in speed, but they needed longer runways and wing mechanization means: slats, flaps, flaps, aerodynamic brakes.
Something in between was clearly drawn, an airplane that could combine a short takeoff, good maneuverability, and high speed.
Such an attempt was made by the former Soviet inventor Ivan Ivanovich Makhonin.
Until 1921, he lived and worked in Russia, but then he was forced to leave for France, since at home they did not show interest in his projects, of which there were many.
In September 1929, Makhonin presented a project of a monoplane aircraft with a variable wingspan. Exactly so, the length of the wing varied from 13 to 21 m, and the area from 19 to 33 sq. m.
The outer parts of the consoles could telescopically retract into the root parts of the wing when there was no need for excess lift. Due to this, when flying at high speed, air resistance was significantly reduced. The first flight of the Mak.10 aircraft, equipped with a 480 hp Lorraine 12Eb engine, took place on August 11, 1931. After 4 years of testing, it was significantly upgraded and received the new Gnome K.14 engine (800 hp) and the designation Mak.101. The plane managed to reach a speed of 378 km / h.
It is the world's first aircraft with variable wing geometry.
The Germans became interested in the plane. As soon as the occupation of France began, representatives of the Luftwaffe came to Makhonin. Ivan Ivanovich flatly refused to cooperate, and the plane was confiscated. The car, together with the test pilot, was taken to Rekhlin for testing, where on the very first flight, the French pilot, who shared his "love" for the Germans with Makhonin, smashed the plane to smithereens.
This is where the history of the world's first aircraft with variable wing geometry ended, and we begin the history of the first successful aircraft of this family.
In general, the author of the aircraft project, Vladimir Vasilyevich Shevchenko, in the direct sense of the designer was not. Yes, he graduated from the Moscow Higher Technical School, and even in the same group with Sergei Korolev, but the craving for the sky won in every sense. After graduating from VVTU in 1929, Shevchenko ended up in Odessa, and then served in the Red Army Air Force, flew on the R-1 and I-4 fighters.
Shevchenko turned out to be a very good pilot, as evidenced by his participation in the air parades over Red Square as part of the Stepanchonka units on the I-5 and Kokkinaki on the I-16.
And since 1933, Shevchenko worked as a test pilot at the Research Institute of the Red Army Air Force, where he took part in the tests of many aircraft: I-16, I-153, R-5, Pe-8, Il-2, I-180, La-5, Me-108, Me-110. And in 1939 he visited Germany, where he flew the Ju-88 and FW-189.
Based on his very extensive experience, Shevchenko tried himself in the development of a new aircraft for those times, combining the properties of both a monoplane and a biplane.
Shevchenko's idea was to fold the lower wing of the biplane after takeoff, thereby turning it into a monoplane. At the same time, the wheels were retracted into the side niches of the fuselage, the root part of the wing was also removed here with a special lifting mechanism, and the end fit into the recess of the lower part of the upper plane.
And Shevchenko submitted sketch calculations and drawings for consideration to the scientific board of the Air Force. The project was found very interesting and original, confused only by the fact that this had not happened before in world practice. It had no analogues in the world, so to speak.
The project was launched. Major Shevchenko, who became a designer overnight, was allocated a room in the old building of the Moscow Aviation Institute, funding (very modest at that time) and a team for the construction of the model were organized.
Having learned about the recognition of Shevchenko's project, the colleague was supported by outstanding pilots - Heroes of the Soviet Union Grigory Kravchenko, Stepan Suprun and Anatoly Serov.
And in April 1938, a group of pilots and engineers from the Air Force Research Institute was presented with a working model of a new aircraft, which Shevchenko and the team working on the aircraft gave the name IS-1.
In the 60s, a version appeared that the IS-1 stands for "Folding Fighter". In fact, no, the confirmed testimonies of Shakhurin and Poskrebyshev (Stalin's secretary, if anyone does not know) have survived that in his report to Stalin Shevchenko himself told about the initiative of the working collective to name the plane that way.
Stalin, by the way, did not particularly mind, but hinted that with such a name the plane is simply obliged to fly and fly well.
But in 1938, the plane caused an overwhelming reaction from pilots who understood the essence of the design better than others.
There were also downsides. The highest precision in the manufacture of components and assemblies of the aircraft was required, especially the hydraulics that retracted the wings. After all, the smallest backlash in the system could lead to under-cleaning of the wing, and, consequently, to possible structural breakdowns due to the oncoming air flow.
In general, cleaning and releasing the lower wing was fraught with many surprises, often unpleasant. Folding on the hinges and pulling up to the upper wing, the lower one moves across the stream flowing around the plane for a full seven seconds of flight. A complex take-off and landing pattern was drawn in terms of speed.
The current model was examined by the People's Commissar of Defense Voroshilov, the chief of the Air Force Loktionov, the People's Commissar of the aviation industry Kaganovich. In principle, everyone was satisfied. But the decision remained with Stalin, who did not pass by then developments in the field of aviation.
And Shevchenko got to a personal conversation with the leader, which took place after an extended meeting of workers in the aviation industry, where he received Stalin's formal permission to name the aircraft.
The IS-1 was an experimental aircraft, built primarily to study and test the wing and landing gear retraction mechanism in flight. Although in the future, weapons were planned for him. In the center section of the upper wing, four ShKAS were quite normally located.
The lower wing consisted of a center section and folding consoles. The hydraulic mechanism in the fuselage rotated the center section on the hinges of the fuselage attachment and folded the lower wing. The lifting mechanism consisted of a hydraulic cylinder and two rocker struts. An operating pressure of 60 atmospheres was created by a pump mounted on the motor. The landing gear and tail crutch were removed simultaneously with the wing retraction. The crutch was removed with a cable mechanism.
Let me draw your attention, this is 1938. The landing gear is retracted on several models, and on fighters this is done by rotating the cable handle. Here, except for the crutch, everything was done by hydraulics.
The chassis and crutch were equipped with shock absorbers, the wheels had brakes.
A separate masterpiece was the three-panel dashboard. The central panel had rubber anti-vibration dampers and backlighting, all flight and navigation instruments were placed on it.
Oxygen equipment control and motor control were placed on the right panel. On the left are warning lights for the hydraulic system, brakes, pressure gauges and magneto switches.
The plane caused a stir among the test pilots. It is not every day that a car that has been created by a fellow pilot rises into the air. There was a queue of people wishing to fly by plane.
The first flight was made on May 29, 1940 by test pilot Vasily Kuleshov. Kuleshov made five flights, however, without removing the wings. They did not expect much from the car, since the M-25 engine with 635 hp. and could not give the car any outstanding performance characteristics. It was important to test the IS-1's ability to fly in general.
The wing was removed in flight on June 21, 1940 by test pilot Georgy Shiyanov. The plane behaved flawlessly, which simply amazed Shiyanov, who wrote the following in the final report:
“The equipment of the IS-1 cockpit is similar to the I-153 and I-16 aircraft. The devices are conveniently located. The controls for the engine, aircraft and weapons are located expediently. Landing in the cockpit is comfortable, but the field of view for taxiing is too narrow.
On takeoff, the plane easily breaks off and is not afraid of the side wind (crosswind. - Author's note). Takeoff with detonation is possible (at the maximum angle of attack. - Approx. Auth.). There is no tendency to stall at high angles of attack. The most advantageous climb speed is 200-210 km / h. At a climb speed of 240 km / h, there is a slight vibration of the buffet-type tail.
The aircraft is easy to fly and "sits tightly" in the air. Slight shaking of the tail appears at low speeds. Turns steadily, but insufficient engine power is felt. The forward view in the air is also insufficient. According to the device, he brought the speed to 300 km / h at an altitude of 2000 m. The IS-1 plans steadily, allows planning with abandoned rudders. Approach to the ground on landing at a speed of 190 km / h. But the view for landing is insufficient.
The run is very stable. He landed with a crosswind up to 45 m / s and a force of 10 m / s. The plane does not raise any doubts."
The famous pilot Stepan Suprun also took part in the flight of the IS-1. The IS-1 under control of Suprun demonstrated both speed and high maneuverability. The pilot removed the wing and landing gear immediately after takeoff. In his conclusion on testing the IS-1, Suprun wrote:
“Forward visibility is insufficient when taxiing. Takeoff is simple. The damping of the chassis is normal. When passing to the climb corner, the plane shakes slightly, which is not dangerous. The wing and landing gear retraction mechanism is very convenient and simple. The wing and landing gear are easily retracted, the aircraft's behavior at this moment is normal, there is no drawdown. The plane is obedient in piloting. The turn and combat turn performs very well. You can make a 70 degree roll at a speed of 300 km / h. Withdrawal from combat turn at a speed of 220 km / h. A balanced plane flies well with a thrown stick. The lateral and longitudinal stability of the aircraft is very good. When the wing and landing gear are deployed, the aircraft behaves normally. The landing is easy."
In January 1941, the second aircraft, named the IS-2, was ready. This machine was similar to the IS-1, but the engine was installed M-88 with a capacity of 950 hp.
The miracle did not happen, but it turned out to be just a wonderful car. Since the M-88 was head and shoulders above the M-25, the IS-2 didn't just fly. The horizontal speed reached 600 km / h, the smaller size of the motor made it possible to install two BSs instead of two ShKAS. That is, the armament has become very sane: two 12, 7-mm machine guns and two 7, 62-mm.
The mass of a second salvo is comparable to the Yak-1 or Me-109. The LaGG-3 and MiG-3 (in the five-point version) were cooler, but these were the planes for other tasks as well.
In addition to the more powerful engine, the IS-2 had a significantly reduced fuselage midsection, increased its lengthening and made a more streamlined engine hood. The area of the wings is somewhat reduced.
The IS-2 went through a cycle of test flights, and that was it. The war began.
Of course, with the beginning of the war, all work was stopped. The IS turned out to be an expensive and technologically complex fighter, which was not an advantage in wartime conditions.
In addition, it turned out that, unfortunately, it was impossible to use the advantages of a biplane in maneuverable combat, since the wing and landing gear were retracted synchronously. The advantages of a biplane were realized only during takeoff and landing.
Shevchenko did not give up and continued to fight for the idea of his plane. The project of the IS-4 fighter with the M-71F 2000 hp engine appeared.
Its design maximum speed at the ground was assumed to be 660 km / h, and at an altitude of 6000 m - 720 km / h. The maximum design ceiling is 13,300 m. The armament was supposed to consist of 4 ShVAK cannons, two at the root of the upper wing, two synchronous in the engine compartment.
The ships, according to experts who got acquainted with the project in 1944, and these were Joseph Lazarev and Nikolai Polikarpov, the plane could really show such parameters.
Compared to the first aircraft, the IS-4 had a more elaborate fuselage shape with a nose wheel instead of a tail crutch.
The niches in the sides of the fuselage for cleaning the wing and landing gear had to be closed with special automatically retractable walls, the landing gear was retracted into the center section regardless of the lower wing retraction. Pressurized cabin with drop-shaped lantern.
Alas, the Air Force was not interested in the IS-4 either. The war was drawing to a close, and the era of propeller-driven aircraft was actually leaving with it. All eyes were already directed towards jet aircraft. The last work of the designer Shevchenko was the IS-14 aircraft, already a jet, and also of a new concept. But that's a completely different story.
Our story ends there. Shevchenko was out of luck. In 1938, our industry was not very ready to produce such a technically complex machine. And even more so during the war. Those LTH, which showed the plane, assembled and licked in the OKB, are not like the machine that the hands of women and adolescents would make in cold workshops. And the results could only hurt the designer.
It cannot be said that Shevchenko worked in vain. This is generally a person who has lived life with great benefit. 6,000 flight hours by test pilot and fighter pilot. During the war, the designer Shevchenko again became a fighter, the commander of a separate special-purpose air squadron. 122 sorties.
Plus four samples of aircraft that flew, even if they did not go into series. The idea has not sunk into oblivion. The principle that Vladimir Shevchenko and his team of engineers worked on, consisting of Vasily Nikitin, Pyotr Nosikov, Vladimir Teplyakov, Nikolai Stolbovoy, Vsevolod Smirny, Anatoly Frolov, Viktor Abramov, Nikolai Tsigir, Evgeny Kolesnikov, Anatoly Andreev, Tamara Reinvald!
You can change the wing area in different ways. And today, looking at the photo of this funny aircraft named after Stalin, it is difficult to imagine the fact that the descendants of this aircraft are the MiG-23, MiG-31, Su-24, Tu-160.
And this is a fact.
LTH IS-2
Wingspan, m: 8, 60.
Length, m: 7, 36.
Height, m: 2, 68.
Wing area (full), sq. m: 20, 83.
Weight, kg:
- empty aircraft: 1 400;
- maximum takeoff: 2 180.
Engine: 1 х М-88 х 950 HP
Maximum speed, km / h: 588.
Cruising speed, km / h: 453.
Practical range, km: 600.
Practical ceiling, m: 10 800.
Crew, pers.: 1.
Armament:
- four 7, 62-mm machine guns ShKAS or
- two 12.7 mm BS machine guns and two 7.62 mm ShKAS machine guns.
