UTB-2 - first flight - 1946. By the Decree of the Council of People's Commissars of the USSR of February 26, 1946 and the order of the NKAP of April 27, 1946, an experimental aircraft construction plan was approved but in 1946, according to which the chief designer and director of plant No.34 P.O. Sukhoi was instructed to design and build a Training Bomber with ASh-21* engines based on the Tu-2 aircraft.

Work on the aircraft, which received the designation UTB, or UTB-2, among aviation wits - "neither Tu nor Su", began in February 1946.

In early June, the alteration of the aircraft was completed. On June 12, the test team of plant No.134 consisted of: test pilot N.D.Fixon, navigator V.I.Furdetsky, lead engineer F.M.Fisun, flight mechanic P.V. Zadneprovsky began testing the aircraft.

At the conclusion of the Act, based on the results of state tests, it was noted that:

"... 1. An experienced Training Bomber UTV... in terms of its flight tactical data and the amount of equipment meets the requirements and can be adopted by the Air Force for training cadets-pilots and navigators in flight and navigation Air Force schools, as well as for training the flight personnel of combat units of bomber aviation ... "

At the beginning of May 1947, factory No.381 completed the construction of the lead serial aircraft UTB No.3810001 with some changes in the design.

On May 7, 1947, the crew of N.K. Fedorov began flying under the factory test program, which ended on May 14. In the conclusions of the test report, it was noted that: "...Basic flight data ... meet the TTT of the Air Force of the Armed Forces ..."

In July-August 1947, UTB-2 aircraft of the head series (No. 3810004, 3810005) passed control tests at the State Research Institute of the Air Force. These aircraft did not have cockpit lighting equipment, they did not have RPKO-2B radio semi-compasses, RV-2 radio altimeters and AV-52 airborne sights. Based on the results of the control tests, an act was drawn up, in the conclusion of which it was noted: "1. Aircraft UTB 004 and 005 passed the control tests ..."

December 1947 arrived. Despite a lot of work on the reorganization of production, plant No.381 disrupted the plan for the supply of UTB-2 aircraft to the Air Force, instead of 120 copies, only 35 aircraft were handed over. However, the plant No.381 was not particularly guilty of this, because. Having transferred 31 Tu-2 aircraft for rework, Plant No.23 did not subsequently ensure the supply of units of unchangeable parts of the Tu-2. In addition, by the end of 1947, the Air Force handed over to the plant No.381 only 18 early series Tu-2 aircraft.

In February 1948, the UTB-2 No.3810510 aircraft, equipped with an experimental altimeter RV-2 and a modified scheme for switching on the RSI-6M radio receiver, successfully passed state tests at the State Research Institute of the Air Force. According to the results of the work of the plant No.381 for 1948, the percentage of the plan for the production of UTB-2 aircraft was 116%.

In 1949, plant No.381, in parallel with the production of UTB-2 aircraft, began the production of MiG-15 fighters. During 1949, 25 UTB-2s and 75 MiG-15s were produced. And in 1950, plant No.381 merged into plant No.30.

In connection with the cessation of production of UTB-2 aircraft, Tu-2 aircraft equipped with dual control began to be used in the combat units of the Air Force.

* - experimental 7-cylinder air-cooled engine ASh-21 (chief designer V.S. Nitchenko) manufactured by plant No.29, created on the basis of the 14-cylinder engine ASh-82FN.

Photo	Description
	Drawing UTB-2

Technical description. The design of the UTB-2, except for the skin of the rudders and ailerons, is all-metal. For the convenience of serial production and transportation, it was divided into a number of independent units.

The fuselage is semi-monocoque. Consists of three parts: bow, central and tail. In the bow there is a cockpit for two pilots and a navigator or a pilot and two navigators. The forward part of the fuselage has changed shape. The installation of two seats side by side, as in civil aviation, increased its width. The central part of the fuselage, after the elimination of the bomb bays, was greatly simplified and became lighter. A hole was made in it for communication between the pilots and the gunner, whose cockpit was located in the rear fuselage.

Wing of a caisson design, cantilever with a high location. It consists of three parts: a center section, integrally connected to the fuselage, and two detachable consoles. Along the edges of the center section are engine nacelles, the main landing gear is removed into their tail section. Sheathing - metal. The angle of the transverse "V" wing along the lower surface is 7°, the installation angle is 2°. The wing is powered by take-off and landing flaps (with two fixed deflection angles: 15° - on takeoff and 55° - during landing), mounted on the center section and consoles.

The tail of the aircraft is cantilever with two keels located at the ends of the stabilizer. The horizontal tail consists of a trapezoidal stabilizer (its left and right consoles are one piece) and an elevator, made up of two halves, synchronously controlled by one drive. Vertical plumage - two oval washers attached to the ends of the stabilizer consoles.

The ailerons, elevators and rudders are made of fabric-covered metal and fitted with electric remote-controlled trim tabs.

A significant reduction in the bomb load (only small-caliber bombs remained on the external sling) and the abandonment of cannon weapons made it possible to lighten the design of the retractable landing gear - two struts ending in symmetrical forks with two-brake wheels measuring 900 × 300 mm. Tail wheel 470×210 mm self-orienting. In flight, it is removed using a hydraulic lift.

Armament: the VUB-68 upper limited-mobility mount for a 12.7 mm UBT machine gun with 60 rounds of ammunition and four external bomb racks for hanging 50 and 100 kg bombs.

Bibliography

• History of aircraft designs in the USSR, 1938-1950. /V.B. Shavrov/
• Training Bomber UTB-2 /A&K. Vladimir Proklov/
• Training Bomber /Nikolay Yakubovich/
• UTB-2: lightness, efficiency /Nikolay Gordyukov/