Polikarpov I-16 Type 24 Tactical fighter
In a country once called the Soviet Union, the I-16 fighter was one of the most beloved and famous aircraft. The Polikarpov I-16 was a revolutionary design - the world's first low-wing cantilever monoplane fighter with retractable landing gear to attain operational status. When the Great Patriotic War came, I-16 stood up as a stout bulldog to protect his house. He died in that war. His silhouette was easily discernible on posters depicting the leaders of a mighty state. Flocks of these small airplanes filled children's books, in the movies of the pre-war era I-16 twisted unimaginable figures of aerobatics. In its appearance and flying qualities, the I-16 stood out sharply among Soviet and foreign fighters of the early 1930s. In fact, it was the first high-speed fighter - a monoplane of a new generation.
The Soviet government had made no effort to conceal the development of the I-16 and had, in fact, exhibited a pre-production example of the I-16 Type 5 at the International Aeronautical Salon at Milan, Italy, held between 12 and 28 October 1935. At the Milan Fair, the I-16 drew considerable attention due to its retractable landing gear and glazed canopy. The I-16 Type 5 was less suited to close in high G maneuvering combat than its biplane contemporaries, although it possessed the advantages of superior speed and climb. Its ailerons were feather-light and it had an exceptional rate of roll. It also had an outstanding zoom climb capability. The I-16 Type 5, however, was no aircraft for a novice. It was overly sensitive to control movements and longitudinal stability was marginal. The fighter also tended to stall out in a glide. Instability in a climb and in turns demanded the highest concentration on the part of the pilot and the rigidly-mounted engine produced an annoyingly high vibration level. Rear centering (more than 30%) made the aircraft unstable in flight, which was then considered quite normal and even desirable to increase maneuverability. Although the result achieved and subsequently brought a lot of trouble in the preparation of the pilots, he also played a positive role. The pilots who mastered the I-16 had, as a rule, sophisticated piloting technique and easily mastered other machines. The pilots called her ("Donkey" or "Burro" or "asshole"), loved him and scolded him.
An interesting situation developed in the Soviet aircraft industry in the period 1934-35. Finally, the focal points in the person of ministerial and army officials were from what to choose a fighter aircraft for the arming of the Air Force. As many as three fighter monoplanes - I-14 Sukhoi, I-16 Polikarpov, IP-1 Grigorovich with sufficient reason to claim the right to be selected. All three were similar - above all, the same type of air-cooled engine - all three, of course, were very different and, above all, constructively. All three cars tried their luck in mass production, but life and circumstances chose the most digestible for the domestic aircraft industry, namely the I-16. This circumstance could not but influence further the development of other designers.
Structurally, the aircraft was a classic example of a mixed design, based both on the capabilities and capabilities of the Soviet aircraft industry in the first half of the 1930s. While creating the I-16, Polikarpov remained true to his principle of building airplanes from domestic materials, namely wood, while at the same time he applied in reasonable quantities the duralumin and structural steel, so scarce in those years. It was the harmonious combination of wood, steel and duralumin that allowed such a plane to be considered cheaper than all-metal, and therefore more acceptable for the industry. At the same time, the technology of manufacturing I-16 did not have any unpleasant surprises for the production workers. Wooden monocoque fuselages were by that time a classic of constructive solutions, trusses made of steel pipes, universally applied were rather desirable, duralumin hoods and feathering are natural. The cloth covering of the wings, whatever it might seem archaic even then, worked at the time.
On December 30, 1933 test pilot Valery Chkalov first lifted TsKB-12 with an engine M-22. On September 7, 1934, the aircraft was sent to Shchelkovo, at the airfield of the Air Force Research Institute near Moscow for passing State tests, which lasted until October 12. Serial production of the aircraft, started in 1934, really turned around only the next year. Even those I-16s that were released and counted in the production plan of 1934, continued to be delivered in 1935. Then it became possible to install the M-25 engines on the aircraft, which are a Soviet copy of the American "Wright-Cyclone" F-3. The production of these engines was deployed at the newly constructed aircraft plant No. 19 in the city of Perm, in the Urals.
During the civil war in Spain in 1936-1939. I-16 was first used in combat conditions. The fighters were received by the Spanish Republic from the Soviet Union in late October, early November 1936. This was the first batch of delivered cars, consisting of the 31st I-16 type 5. Along with the airplanes, the first air brigade pilots from Bryansk arrived. A group of these pilots, consisting of 3 squadrons, was commanded by Captain Tarkhov. Already on November 9, 1936, the I-16 first appeared in the sky above Madrid. The appearance of I-16 radically changed the nature of air strikes. The new fighter was the first aircraft in the world capable of fighting in the vertical. The main opponents - the German fighter He-51 and the Italian CR32 were much inferior to it in their flight data - so much so that the pilots of these cars were strongly advised not to get involved in the fight, not having a numerical advantage. It was already superfluous. The horror of meeting with the suddenly appeared I-16, the nationalists initially was so great that they gave him the nickname "Rat" (rat). Republicans began to affectionately call their defender "Moska" (fly), and aviation publications around the world dubbed it "Boeing", while confirming that the aircraft is designed at this famous American firm. After the installation of high-altitude engines on the planes of the 4th Squadron, the pilots began flying with oxygen masks, for which they were nicknamed the squadron of "suckers". In total in the period 1936-1938 at least 455 I-16 and 20 UTI-4 were sent to Spain.
The results of aerial clashes in Spain and China led to the conclusion that I-16 needed a replacement. The plane, conceived in 1932, clearly began to give way to new enemy fighters. The need for such a step in 1938 becomes obvious. Type 24 was a further modification of the type 18, in accordance with the tests of 1937. The main changes:
- Established VISH AB-1 and the new cook-cowl.
- The motor is equipped with a regulator of constant revolutions "P-2", giving the pilot to keep the desired speed.
- Supplied strut dvuzvennikom chassis instead of the previously used splines. At the same time it increased the effectiveness of depreciation, increased stroke shock absorber up to 96 mm compared to 30-36 mm from the previous version.
- Crutch on type 24 found a small wheel and oil-pneumatic shock absorption.
- Introduced flaps with mechanical control. The handle is on the left of the pilot's seat.
- Established the second flap of the cockpit on the right side. Although the flap on the right side officially introduced on the type of 24, encountered similar improvements in other types.
- The aircraft is equipped with manual start of the starter handle, "RI". The handle in the stowed position, stored in the cockpit when starting inserted into the hole on the right side of the fuselage.
- On the right side of the fuselage between frames 7 and 8 cut through the hatch to the radio.
Polikarpov's attempts to create a replacement for the I-16, which primarily concerned promising developments to further improve the I-16 itself. Since the second half of 1936, the improvements of the aircraft were mainly carried out at Nizhny Novgorod aircraft plant No. 21.
One task concerned the I-16 fighters in a dive. This occurred in the case of installation of the stabilizer to the positive angles of attack. Several accidents forced undertaking a study of this phenomenon. It turned out that I-16 is extremely sensitive to changes in the angle of installation of the stabilizer. At the same time, the neutral and rear stabilizer centering pilots experienced very great pressure on the handle. The fact that the phenomenon before tightening into a dive was not noted, was linked to gradually shift the alignment of the airplane back from series to series, due to installation of battery, shields, bronespinki and radio.
Conducted in early 1939, tests showed that the total area of instability in the dive began between 32-33% at MAR landing gear. The danger was very great phenomenon, test pilot Captain Taborovsky engaged in these risky flight died. As a result, the value for the alignment of all the exploited machines was limited to 33%. The opinion was unanimously pilots - the aircraft has better performance characteristics from the front alignment. In the case of I-16 all the trouble rested in poor layout of the aircraft. For pilots, aiming fire from unstable machines was very difficult.
By 1939, few people doubted the end of the era of I-16. Even the installation of more powerful engines of the M-62 and M-63 had not allowed the fighter to exceed a speed of 500 km/hr. For a time it was believed that to achieve higher performance possible with the new engine M-64 possessed a takeoff power 1200-1300 hp Designers expected the appearance of the M-64 (there was also an M-65) until 1941, but this engine is the latest single-row nine-star and has not been adjusted.
Nikolai Polikarpov tried to improve the aerodynamics of the aircraft, replacing the fabric covering wings with plywood. In the summer of 1939, the aircraft was tested #1721103, in which the upper part of the wing was covered with plywood thickness of 2.5 mm, while in the same state tests in the Air Force Institute was presented to I-16 type 24, with plywood covering the wing. Last flying machine at a speed 489 km / h, which was slightly higher than in other machines. However, this result was attributed engine M-63. Although the wood paneling was recommended for production, production samples of its application were not found.
In 1939, studies were carried out with the I-16, proving that further improvement as a fighter was inappropriate.
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