Yakovlev UT-2

The Yakovlev UT-2 (УТ-2, NATO reporting name "Mink") was a trainer aircraft used by the Soviet Air Force from 1937 until the 1950s. It was the standard Soviet trainer during World War II.

Development
The UT-2 was designed as a trainer, more suitable for training pilots of modern and fast aircraft than the older U-2 (Po-2) biplane. The new plane was designed by Yakovlev's team at OKB-115. The next design, AIR-10, was based upon the AIR-9, but it was simpler, with two separate open cockpits, and lacking slats and flaps. It was flown on 11 July 1935. The AIR-10 won the competition with other trainer designs in 1935 and, after changes, was accepted as the standard Soviet Air Force trainer. A temporary designation for this plane became Ya-20 (Я-20). This is just because of the original AIR was the abbreviated name of Alexey Ivanovich Rykov, a communist leader executed in 1938; Yakovlev changed names of his aircraft to the politically safe Ya. The mixed construction (wood and metal) of the AIR-10 was changed to wooden only, to simplify production. A prototype used the 112 kW (150 hp) Shvetsov M-11E radial, but production aircraft used 82 kW (110 hp) M-11Gs. Serial production started in September 1937. The plane was given the designation UT-2 (uchebno-trenirovochnyi {учебно-тренировочный}, primary/advanced trainer).

The UT-2 was used also by civilian aviation. However, it soon demonstrated it was not easy to fly, with a tendency to spin. After some changes to its construction, the plane became safer and was fitted with a 93 kW (125 hp) M-11D, as the UT-2 model 1940.

To improve handling and stability, a new UT-2M (modernized) variant was developed in 1941 and put into production. The shape of wings was totally new, with a swept leading edge instead of a straight one (the wing's trailing edge was now straight), and the tailfin was larger.

In total, 7,243 UT-2 and -2Ms were produced in five factories between 1937 and 1946. Despite all improvements, the handling and flight characteristics of the UT-2 were never excellent. In the 1950s they were replaced with the Yak-18 as a primary trainer and the Yak-11 as an advanced trainer. After the war, the UT-2 and -2M were also used by countries like Poland and Hungary.

Variants

 * AIR-10 UT-2 pre-cursor.
 * AIR-11 - Three-seat prototype.
 * Ya-20 UT-2 prototype.
 * UT-2 (initial production)- too prone to spin.
 * UT-2 (1940 standard) - modified to improve spin characteristics.
 * SEN (UT-2N) - Air cushion landing gear tests.
 * UT-2M - Production from 1941, re-designed wings.
 * UT-2MV - Light Bomber
 * UT-2V - Bombing Trainer
 * Yak-5 - Single-seat fighter trainer development of UT-2

Operators

 * Normandie-Niemen unit
 * Hungarian Air Force
 * Air Force of the Polish Army
 * Polish Navy
 * Mongolian People's Air Force
 * Romanian Air Force
 * Soviet Air Force
 * SFR Yugoslav Air Force
 * 1st Training Aviation Regiment (1945-1948)
 * 104th Training Aviation Regiment (1948-1956)
 * Liaison Squadron of 5th Military district (1952-1956)
 * Liaison Squadron of 3rd Aviation Corps (1950-1956)
 * Soviet Air Force
 * SFR Yugoslav Air Force
 * 1st Training Aviation Regiment (1945-1948)
 * 104th Training Aviation Regiment (1948-1956)
 * Liaison Squadron of 5th Military district (1952-1956)
 * Liaison Squadron of 3rd Aviation Corps (1950-1956)
 * Liaison Squadron of 3rd Aviation Corps (1950-1956)