Training aircraft First flight: 1935 Polikarpov

UTI-2. In May 1935, a two-seater I-16 with an M-22 engine, designated UT-2 No.8211, was presented for testing. The airplane had a cockpit completely closed by a common canopy. Tests of UT-2 No.8211 were carried out in the period 1.07-16.08 1935. The flight weight was 1370.5 kg, empty weight 970.3 kg, flight balance 31.3% MAH, maximum ground speed 349 km/h, landing speed 127 km/h Pavlushev and Laryushkin flew, who noted the acceptable stability of the aircraft. The disadvantages included the desire to pitch up at speeds over 220 km / h and the ingress of exhaust gases into the cockpit. The aircraft was proposed to be improved and further used for retraining on the I-16.

Subsequently, two more such aircraft were built. It is known that one of them, UT-2 No.82120, released in December 1935, crashed on July 17, 1936. The pilot-deliverer of the plant F.F. Mech taught pilot D.M. Chebotenko to pilot this machine. While landing at low altitude, the plane went into a tailspin and killed both pilots in a short moment.

At the end of 1935, another two-seat version was tested - UTI-3 No.11211, equipped with the Soviet M-58 engine. During the tests, in which V.P. Chkalov took part, until the spring of 1936, the aircraft flew 33 hours. The experimental engine worked an additional 40 hours on the ground. Although the UTI-3 was rated higher than the UT-2 No.8211, due to the lack of the required number of M-58 engines, the aircraft remained in a single copy.

A variant, designated UTI-2 type 14, went into serial production, which did not have a common canopy, but only individual pilots' visors. The chassis did not retract at first. In 1935, 22 two-seat aircraft were built, including 3 UT-2 and 1 UTI-3. In 1936, 27 UTI-2s were produced, which makes it possible to determine the total number of training fighters with the M-22 at 45 copies. In the same year, a machine with the M-25 was launched into production, which received the name UTI-4. The first 8 copies were built before the end of 1936, but they were handed over as part of the general series already in 1937.

Subsequently, when the UTI-2 with a retractable landing gear was built (it was undergoing state tests in July 1937), it turned out that there were no more stocks of M-22 engines, and the production of the motor itself was discontinued. An attempt to get a cheaper training fighter did not take place (there were other options for savings - for example, installing the M-26 engine), so the aircraft with the M-25 engine - UTI-4 type 15 went into mass production.

Training aircraft First flight: 1936 Polikarpov

The UTI-4 training fighter is the most mass-produced version of the I-16. Over the years of serial construction, the factories built about 3,400 of these aircraft.

The UTI-4 was equipped with M-25A and M-25V engines, and in many respects it was structurally identical to the I-16 type 5 without armament. Due to the lack of machine guns, there are no hatches on the center section for their maintenance. Ailerons of increased span, the differential lowering mechanism was not used during landing, landing flaps were not mounted. Manual control of the aircraft and the engine is double. The landing gear lift and the mechanical landing gear indicator are equipped in the rear cockpit. The radio was not installed. For communication between the instructor and the student, a standard intercom was provided, representing a system of tubes with bells.

In the course of mass production, the UTI-4 underwent some changes. Cars with the M-25V had an oil cooler pipe on the frontal part of the hood, the chassis with a slotted strut was subsequently replaced with a chassis with a double link, a crutch with rubber cushioning was replaced with a crutch with oil-pneumatic cushioning.

Starting with UTI-4 No.1521109, small center-section gas tanks with a capacity of 39 liters each were installed. The total fuel supply in this case was 220 liters. In August 1939, pilot Frolov and observer Mikhailov conducted a range test for UTI-4 No. 15210Zh81. An aircraft with a takeoff weight of 1503 kg had 150 kg of fuel. In flight along the route, the range was 420 km, the flight time was 1 hour 18 minutes.

On January 1, 1939, the UTI-4 began to be produced with electrical equipment for night flights and fixed landing gear.

In the summer of 1940, the UTI-4 was tested with the AV-1 propeller, the blades of which were constantly set to a fixed position. For a propeller with a diameter of 2.8 m and a blade width of 220 mm, the most effective angle of rotation of the blades was experimentally determined - 32°. This position was optimal for training flights, circling flights and simple aerobatics.

UTI-4 was used to retrain pilots in Spain and China. In the autumn of 1940, 1047 UTI-4 M-25 and 22 UTI-2 M-22 were registered in the Air Force educational institutions, 129 UTI-4 M-25 and 3 UTI-2 M-22 in the aviation of the Navy. The use of UTI-4 in the training of Soviet pilots continued until 1946.

Bibliography

• History of aircraft designs in the USSR, 1938-1950. /V.B. Shavrov/
• Fighter I-16 - Rough "donkey" of Stalin's falcons / Eksmo. Mikhail Maslov./
• Fighter I-16 /Exprint. Mikhail Maslov./