Despite the fact that in terms of its maneuverability and rate of climb, the I-15bis remained among the best aircraft of its time, its speed was no longer sufficient. The pilots who fought on the I-15bis found it difficult to fight faster fighters - monoplanes, such as the German Messerschmitt Bf-109 and the Japanese I-97. The Air Force needed a faster machine.

As if anticipating such a situation, back in 1937, Polikarpov developed a project for a new fighter - the I-153 biplane. It was a further development of the I-15bis, but had improved aerodynamics, a reinforced structure, and a retractable undercarriage. The upper wing again acquired the shape of a "gull", the same name was given to the fighter.

In 1938, the I-153 showed excellent flight qualities during tests (with the same engine, the speed increased by 41-45 km / h). Since 1939, mass production of the I-153 began. In the same year, the fighter began to be equipped with a more powerful and high-altitude M-62 engine and a variable pitch propeller, which improved the flight performance of this aircraft.

I-153 UD "Chaika" - "Seagull"

The I-153 showed itself well in air battles in Mongolia, where it had superiority over Japanese fighters. But still, the time of maneuverable biplanes has already passed. The scheme of a high-speed monoplane became dominant for serial fighters.

The Soviet aviation industry produced 3437 I-153 fighters (1939-1941).

Photo	Description
	Drawing I-153
	The second experimental I-153 with the production number 6005.
	The I-153 in standard silvery colouring. Shades metal and a fabric covering are well visible.

The first experiments with turbochargers were carried out on I-15bis fighters. On the side of the hood, on each side, one turbocharger of the TK-1 type designed by TsIAM was mounted. TK-1 was a centrifugal turbine, the spinning of which took place under the influence of engine exhaust gases. Each TC was fitted with an exhaust manifold from four cylinders. When the TC was turned on, the engine boost was increased, while the air supply to the carburetor increased.

When installing the TC, I was bribed by the possibility of finalizing aircraft in the field by the forces of aircraft mechanics of combat units.

After the first successful experiments with turbochargers, a military series of 10 fighters of the I-15bis TK type was built, which were tested in the winter of 1939-40. Work was further developed on the I-153. It turned out to be a little more difficult with him. First of all, it was necessary to redo the engine hood of the I-15bis type, and install heat-resistant fuselage sidewalls. The first built four aircraft of the military series, equipped with M-25V and M-62 engines, were tested from July 19 to August 29, 1939, which, although they were factory, were simultaneously counted as state ones. In some flights, the aircraft climbed to an altitude of 12,000 m.

I-153 TK with M-25V developed a maximum speed of 455 km / h at an altitude of 8750 meters, I-153 TK with M-62 reached 482 km / h at 10,300 meters. In 1940, 20 I-153 M-62 and one I-153 M-63 were additionally equipped with turbochargers. The total number of I-153 TK was 26 copies. The aircraft were supposed to be used in air defense units.

One of the directions of increasing the altitude of flights, along with improving other characteristics of aircraft, have become pressurized cabins. The first Soviet fighters equipped with pressurized cabins were I-15 and I-15bis. Nikolay Polikarpov was personally interested in this problem, so his team paid a lot of attention to high-altitude topics. Structurally, the pressurized cabins of the Polikarpov Design Bureau were soft shells made of rubberized fabric with reinforcements in the form of a metal frame. At the end of July 1939, by a government decree, Polikarpov's design bureau was given a task to equip one of the I-153 serial fighters with a pressurized cockpit with the simultaneous installation of turbocompressors (TC) on the aircraft to increase the flight altitude.

Alexander Shcherbakov received production facilities at the Moscow Region aircraft plant No.289, where by the middle of 1940 the main part of the work was completed (turbochargers were not installed at this stage). In July 1940, a converted "Seagull" (serial No. 6034) was presented for state tests. Almost without changing the design of the aircraft, a pressurized cabin was installed in it, which made it possible to fly at altitudes of more than 4 kilometers without oxygen equipment and special equipment for pilots - a thick warm overalls that impede movement.

Structurally, the cockpit was made in the form of a welded metal "cocoon" according to the shape and size of the seated pilot's figure. The upper flap was a hemisphere in the form of a steel frame with a duralumin shell and portholes cut through it. The necessary living conditions in the cockpit were maintained with the help of oxygen supplied from a 4-liter cylinder. Oxygen entered the cabin in an amount of 3-4 liters per minute and mixed with air, which, in turn, passed through special regenerating cartridges. The latter served as carbon dioxide absorbers. The air mixture purified in this way entered the front part of the cabin in the amount of 50-55 liters per minute. A constant overpressure of 0.2 atmospheres and a temperature of about 10 ° C were maintained inside.

Tests of the aircraft were carried out from 20 to 30 July 1940. Pilots, including Hero of the Soviet Union Stepan Suprun, noted that the flight qualities of the I-153 remained practically unchanged. The stability of the machine, despite the centering shift back by more than 2%, remained the same. The forward view due to the installation of the PAN-22 sight in a special casing has deteriorated, but backward it has become better, especially since it is incomparably easier to turn around in a light overalls than in thick winter uniforms.

A total of 11 flights were performed, 9 of them to the maximum altitude - more than 10 kilometers. The training battles conducted with the I-16 and standard I-153 were rather a tribute to the traditional types of tests, because it was almost impossible to reveal any features, except for the already mentioned slight deterioration of the view in such a short time. But all the pilots noted low noise in the cockpit and the absence of fatigue after flying in a rarefied atmosphere.

Although, according to the test results, it was recommended to release a small number of "Seagulls" with a pressurized cabin for the accumulation of operating experience, the series was not followed and, according to available data, I-153 No. 6034 remained in a single copy.

Fighter First flight: 1940 Polikarpov, Shcherbakov

The forced desire of the Soviet aircraft industry to save metal was the reason for the appearance of the "Seagull" with a wooden fuselage. In the aircraft, which received the designation I-153 UD, the tail section of the fuselage, starting from the 3rd frame, was made in the form of a wooden monocoque. The design was considered well mastered by the industry and was used in the I-16. The wooden fragment turned out to be 8.4 kg heavier than the metal one with linen sheathing, and in terms of contours they were absolutely identical.

Tests of the I-153 UD took place from September 30 to October 5, 1940, P.E. Loginov. In general, these tests were successful, but the I-153UD machine did not find implementation in the series due to the cessation of the construction of the base model.

Combat Use

• I-153 "Chaika" in the Great Patriotic War

Bibliography

• "History of aircraft in the USSR before 1938" /Shavrov V.B./
• "Planes of Stalin falcons" /Konstantin Kosminkov and Dmitriy Grinyuk/
• "Fighter I-153 «Chaika»." /Michael Maslov/
• "The Soviet planes" /Alexander Yakovlev/