Polikarpov I-15 (Chaika)

History

The Polikarpov I-15 was a biplane fighter designed and built by the Soviet Union during the interwar period. She gained extensive combat experience during the Spanish Civil War (1936-1939) and participated in the Second Sino-Japanese War (1937-1945) between China and Japan.

The I-15 was still in service with the Soviet Air Force in the early 1940s, and during the Russian-Finnish Winter War, the I-15 was used as a ground attack aircraft for some time in the offensive. During World War II, the I-15 officially won the battle against the world's modern monoplanes and is on its way out.

The I-15 series adopted the nickname "Chaika", which means "lapwing" or "gull", in reference to the upper wing assembly it was "equipped" with.

I-15 Origins

Nikolai N. Polikarpov designed and produced a single-seat biplane in 1927, codenamed "I-3". Such was the success of Polikarpov continuing his design efforts in aviation, culminating in the delivery of a similar but greatly improved two-seat "DI-2" fighter in 1929.

The DI-2 was armed with both offensive and defensive machine guns - one as a fixed forward firing position for the pilot and a pair mounted on flexible mounts for the rear gunner - very reminiscent of World War I reconnaissance aircraft the design of. world war.

Polikarpov was then assigned, along with other engineers, to the "I-6" fighter project, an ambitious program to deliver a modern - mostly wooden - combat platform by the mid-1930s. In true Soviet fashion, when the group failed to deliver due to about 450 engineers the target was arrested - including Polikarpov. Polikarpov was sentenced to death and spent time in a Soviet prison. Two months before his scheduled execution, he was transferred and his sentence was "commuted" to ten years of hard labor.

He was assigned to develop the I-5 fighter with "Design Bureau 39".

Next is the fusion of two design ideas. Polikarpov collaborated with Dmitri Grigorovitch and eventually developed the I-5 single-seat biplane. The new aircraft exhibited excellent handling and flight characteristics, which, of course, gave it excellent maneuverability. Four 7.7mm PV-1 series machine guns were installed in the design for maximum power (two on the upper side of the fuselage and two on the underside of the fuselage).

Prototypes were launched in April 1930, and about 800 prototypes were eventually produced. Such was the success of the I-5, that Polikarpov's sentence was further relaxed as conditional. In August 1932, he was subsequently fully pardoned and more or less a "free" man.

Soviet engineer Andrei Tupolev set out to develop a modern monoplane - the I-14 - entirely to meet the immediate needs of the Soviet Air Force. He demanded that his design be insured (fearing possible delays) and commissioned the development and construction of two biplanes -- the "I-14A" and "I-14B" -- as a security measure.

As fate would have it, Polikarpov himself was commissioned to work on the I-14A, relying primarily on his experience with the successful I-5 airframe as a guide.

The resulting I-14A design was an excellent fast fighter with excellent handling characteristics, just like the I-5 before it. The I-14A prototype (also known as the TsKB-3bis) made its maiden flight in October 1933 and soon became one of the better combat platforms around. Power is provided by a Wright R-1820 Cyclone radial engine imported from the United States.

Eventually, both the I-14 and I-14A were approved for quantitative production, and Polikarpov's future in Soviet aviation history was sealed.

Polikarpov's aircraft was designated "I-15" and mass production began in 1934. The engine of choice for the production model became the Shvetsov M-22, a licensed version of the Bristol Jupiter radial piston engine in the UK - an engine less powerful than the imported Wright radial engine, but still suitable for small fighter airframes.

However, production lasted only a short four years.

Polikarpov's company was eventually dissolved and closed in 1940, which is considered a product of Soviet politics. Polikarpov himself became a professor at the Moscow Aviation Institute in 1943, before dying of cancer on July 30, 1944.

He left the I-15 and I-16 fighter jet designs in his name - both of which played a key role in the survivability of several nations.

Polikarpov I-15 production and variants

The I-15 prototypes became TsKB-3bis and TsKB-3ter. The former uses imported Wright engines, while the latter uses the more powerful Shvetsov M-25V radial piston engine. The initial production example was identified by the base designation I-15.

The improved I-15bis was tested in 1934 after the base I-15. This model entered production in 1937 with a new, more powerful Shvetsov M-25V engine, which increased the top speed of the airframe. The I-15bis is known for its longer nose cowl and contoured gaiters on the main landing gear legs, as well as its straight upper wing layout (as opposed to the "gobbling" look of earlier production models).

The armament is centered on a 4 x 7.62mm PV-1 or ShKAS series machine gun that can be armed with up to 330 lbs of external underwing ammunition in a fighter-bomber role. A total of 2,408 such refining machines were produced.

The I-15 was somewhat modernized in the "I-152" proposed in 1938. However, this model was not selected for quantitative production and exists as a single prototype. The I-152GK is similar, but has an enclosed pressurized compartment for improved aerial work. Again only one example was made.

Another "unique" system became the I-152TK, with twin turbos to improve engine performance. The I-15ter (also known as the I-153) is a development model of the I-15 with retractable landing gear.

The UTI-1 was a limited operating two-seat trainer modification with 20 aircraft produced - each with redundant student/instructor controls in separate tandem cockpits. None of these were used by the Soviet Air Force.

Production of all I-15s ended in early 1939, with approximately 3,313 reported deliveries, most of which were from the mass-produced I-15bis variant.

Tour Polikarpov I-15

The appearance of the Polikarpov I-15 looks like a fighter jet sandwiched between two different aviation eras. She had a cylindrical barrel fuselage with large diameter radial engines mounted in the forward compartment.

The aircraft used biplane wing assemblies - a lower and upper assembly - with the upper assembly erecting a V-shape, or "throttled" upward sloping appearance (this was corrected in later production models, such as the I-15bis). Each wing retains separate compartments with large vertical brackets and sturdy wiring.

The pilot sits in the open-air cockpit behind the wings, with the head and neck protected from behind by the raised fuselage spine. Visibility is usually adequate, but is made worse by the rearward placement of the pilot, the forward placement of the engines, and the biplane's wings. The fin is short, with a round vertical fin and corresponding horizontal plane. The fixed-in-place landing gear consists of two single-wheel main landing gear struts (dotted with streamlined fairings on the I-15bis) and a small tail wheel located at the base of the tail. The main hull is made of steel and duralumin, while the rear hull is covered with fabric.

The wings are made of wood. The I-15 has a wingspan of 33.6 feet and a barrel length of 20.7 feet. Reported to be just over 7 feet tall.

Polikarpov I-15bis engine and power

The I-15 was powered by a 775 hp Shvetsov M-25V radial piston engine that turned a two-bladed propeller system. This arrangement offers a top speed of up to 230 mph, with service capped at 31,170 feet and a range of 329 miles. The climb rate is 2,500 feet per minute.

Polikarpov I-15 Weapon

Due to the previous I-5 biplane, the armament of the I-15bis was purely offensive in nature. It consisted of 4 fixed forward-firing 7.62mm machine guns with up to 330 lbs of external storage under the wings, making the I-15 an effective fighter-bomber while in the air.

In addition, the 6 x RS-82 unguided high-explosive rockets eventually played a role in the I-15's strike fighter role, resulting in a more valuable battlefield system.

History

The I-15 took part in the Spanish Civil War - soon involved in the Soviet Union - and adopted the nickname "Chato" ("The Snub Nose"). The I-15 was used by Republicans in the 1936-39 conflict, which also saw the use of several of Nazi Germany's key war machines, including the superb Messerschmitt Bf 109 fighter. The first I-15 deliveries began in October 1936, and Type quickly established himself as a strong, reliable and exhilarating performer.

The battle gave it a respectable reputation, and production facilities were established on Spanish soil to license the nimble Soviet fighter - which resulted in another 287 prototypes. Even after the Nationalist victory in March 1939, the I-15 continued to serve and was used primarily as a trainer.

The improved I-15bis ended up in Spanish stocks and was nicknamed "Super Chatos" by recipients.

During the Second Sino-Japanese War (1937-1945), China received a large supply of I-15s when it fought Imperial Japanese troops over Manchuria. The Soviet Union also reportedly delivered pilots to fly these I-15s.

Chinese nationalists were involved in bitter conflict with invading Imperial Japanese troops, and the I-15 was eventually replaced by more modern Japanese monoplanes.

The I-15bis model was also valued by the Soviets during the Russian-Finnish "Winter War" during the 1939-1940 invasion of Finland. The invasion ultimately proved costly for the Soviet Union, but still gained territory, but lost it again in the years that followed.

Other operators eventually included Mongolia, which began operating around 40 aircraft in 1939.

Other

By 1941, the Soviet Air Force still had more than 1,000 I-15s on its roster. However, these have passed their heyday as direct-attack front-line combat platforms, being relegated to a ground-attack role.

All of these were retained in secondary roles by mid-1942 and were replaced by more modern and better equipped combat platforms by the end of the year.

On December 31, 1933, just two months after the arrival of the I-15, Polikarpov demonstrated his I-16 cantilever low-wing monoplane during the first flight of the prototype. When introduced, the I-16 proved to be one of the best fighter jets in the world at the time until, like the I-15, it was replaced by a more advanced type.

But like the I-15, the I-16 continued to fight into World War II.

Specification

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