Maximum take-off weight: 1648 kg
Dimensions: length x wing span: 6.7 x 10.2 m
Powerplant: how many. engine x power: 1 (M-25V) x 750 hp
Maximum flight speed at an altitude of 3500 m.: 379 km / h
Rate of climb (average): 12 m / s
Practical ceiling: 9800 m
Flight range: up to 770 km
Armament: 4 x 7.62 mm PV-1 machine gun (or 2 x 1 2.7 mm BS machine gun)
Maximum bomb load: up to 150 kg (6 x 25 kg)
The front of the fuselage was covered with easily removable duralumin panels, which provided convenient access to units and weapons;
Steel profiled brace bands provided each half-box of wings with the necessary rigidity and strength;
Cabin – open, with hinged doors. The armored chair of the chair covered from the fire from the rear hemisphere;
The tail of the fuselage was sheathed with canvas stretched over a light frame made of aluminum profiles;
The metal frame of the keel, stabilizer, and rudders was covered with a cloth;
The stabilizer was supported by V-shaped struts;
Like its predecessor, the I-15 fighter (TsKB-3), the I-15bis chassis was retractable, cantilever type, with oil-air cushioning. To reduce drag in the air, removable drop-shaped fairings were installed. In winter, the aircraft was equipped with special streamlined skis with rubber shock absorbers;
The aircraft used a fixed-pitch two-blade metal propeller;
Tunnel type hood with shutters;
After the First World War, fighters were created all over the world according to a biplane or one and a half wing plan. At the turn of the 30s, monoplane fighters began to appear. Specialists for a long time could not decide which of the two schemes to give preference.
In 1932, by the decision of the Central Committee of the All-Union Communist Party of Bolsheviks and the Soviet government, design bureaus began designing maneuverable and high-speed fighters of both designs.
In February 1933, the design team led by N.N. Polikarpova set about creating a single-seat maneuverable biplane fighter, designated TsKB-3.
Already in October, test pilot V.P. Chkalov performed the first flight on a prototype. It was from this time that the joint work of two prominent Soviet aviators – designer N.N. Polikarpov and test pilot V.P. Chkalova. Flight tests were carried out at the Central Aerodrome of Moscow and were successfully completed in late December. Over the next 1934, mass production of fighters, dubbed I-15, was mastered at Moscow aircraft plants No. 1 and No. 39.
For its time, the I-15 aircraft had good aerodynamics and rationally selected layout parameters. Good power supply, provided in a wide range of heights by a sufficiently powerful M-22 engine (power 480 hp) with a supercharger, excellent aerobatic qualities, the low weight of the structure and rather effective weapons provided high combat efficiency of the I-15.
Usually, the I-15 armament consisted of two 7.62-mm synchronous machine guns PV-1 with ammunition of 1,500 rounds. In reloading, it was possible to install either two more of the same machine guns, or four Der-32 holders for 10 kg bombs under the wing. In 1938, two 12.7-mm BS machine guns were installed on individual I-15 fighters.
For the characteristic shape of the upper wing, the I-15 fighter was often called the Seagull. The center wing of the upper wing adjacent to the fuselage created such a significant lateral surface that the aircraft could fly with a roll of up to 90 ° – almost on its side. In a bend in a bend (a turn time of 8 s!), It was possible to catch the tail of any of the fighters existing then. According to pilots, the aircraft was extremely easy to fly. In terms of flight speed, it exceeded the first model of the I-16 fighter-monoplane (TsKB-12) with the M-22 engine.
However, starting from the very first prototype, the attitude to the I-15 was ambiguous. The curved upper wing of the “seagull” type, used to reduce drag and improve visibility, was not unanimously approved by the military. It was believed that such a wing unacceptably worsened the forward-side view, especially when taking off. Experts claimed that if the wing was made ordinary, then the visibility and ground stability, which was assessed as insufficient, would improve — there was slight yaw, about 1-2 °, which prevented aiming and shooting.
Numerous attempts by Polikarpov to purge the aircraft in a wind tunnel, as well as through direct demonstrations in flight, to prove the groundlessness of such allegations has failed.
In 1935, it was decided to stop the serial production of the I-15 fighter. N.N. Polikarpov was proposed to radically improve the aircraft and introduce a new (“normal”) center wing into the machine’s layout.
I-15bis (I-152), prepared for serial production in the fall of 1937, was exactly the way the military wanted it to be. The design of the entire aircraft was strengthened. A more powerful 9-cylinder M-25V engine (750 hp) was installed with a single-speed supercharger.
The aircraft became 300 kg heavier, due to which its maneuverability and, despite the increase in power, the climb rate deteriorated. Compared with the “Seagull”, increased aerodynamic drag of the upper wing. Nevertheless, according to the characteristics of maneuverability and rate of climb, the I-15bis was one of the best machines of its time.
Despite the fact that the I-15bis fighter was clearly outdated by the beginning of its production, he nevertheless became a participant in several wars. The aircraft was used during the hostilities in Spain, China, and Khalkhin Gol, and was also actively used in the first months of World War II as an attack aircraft (until 1942).
In total, 2408 I-15bis vehicles were built. In 1939, the serial production of the aircraft was discontinued, and the plants switched to the production of the I-153 fighter.