The preceding U-2 (Po-2) biplane was no longer a suitable trainer for the faster modern aircraft entering service, and to fill the role, the UT-2 was designed as a trainer.

The new aircraft was designed by Alexander Sergeevich Yakovlev’s team at OKB-115. Originally designated AIR-10, it was based upon the AIR-9, but it was simpler, with tandem open cockpits, also omitting slats and flaps. It first flew on 11 July 1935. The AIR-10 won the competition in 1935 and, after minor changes, was accepted as the standard Soviet Air Force trainer. With the disgrace of Alexey Ivanovich Rykov under whom Yakolev had been working, the initials AIR were replaced with Ya making what would have been the AIR-20 the Ya-20 (Я-20).

The wood-and-metal mixed construction of the AIR-10 was simplified to use only wood to facilitate production, and the AIR-10s 120 hp Renault inline engine was replaced with the 112 kW (150 hp) Shvetsov M-11E radial on the prototype, and the 82 kW (110 hp) M-11Gs in early production aircraft. Serial production started in September 1937. The Soviet VVS (Air Force) assigned the aircraft the designation UT-2 (uchebno-trenirovochnyi {учебно-тренировочный}, trainer).

The UT-2 (Russian: Яковлев УТ-2; NATO reporting name “Mink”) was not easy to fly and easily entered into spins. The UT-2 model 1940 featured a lengthened forward fuselage, and a change to the 93 kW (125 hp) M-11D radial to attempt to rectify the problem. Despite improvements, the handling and flight characteristics remained challenging.

To further improve handling and stability, the new UT-2M (modernized) variant was developed in 1941 and it replaced the original UT-2 in production. The wing planform was redesigned, with a swept leading edge and a straight trailing edge, and the vertical stabilizer was enlarged.

7,243 UT-2 of all types were produced in five factories between 1937 and 1946. In the 1950s, the UT-2 was replaced by the Yak-18 primary trainer and the Yak-11 advanced trainer.

Before and after World War II the UT-2 was used by civilian organizations, and after the war, UT-2s were also operated by the Polish and Hungarian Air Forces.

Operators:

France 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)
Letalski center Maribor

The Central Air Force Museum at Monino has an example on display, as does the Technical Museum of Vadim Zadorogny near the Arkhangelskoye Palace, and the Nikola Tesla Technical Museum in Zagreb, Croatia.

Variants:

AIR-10
Precursor
Engine: 120hp Renault

Ya-20
Prototype

UT-2
initial production variant
Engine: 1 x M-11, 74kW
Max take-off weight: 856 kg / 1887 lb
Empty weight: 616 kg / 1358 lb
Wingspan: 10.2 m / 33 ft 6 in
Length: 7.0 m / 23 ft 12 in
Height: 3.0 m / 10 ft 10 in
Wing area: 17.1 sq.m / 184.06 sq ft
Max. speed: 200 km/h / 124 mph
Cruise speed: 160 km/h / 99 mph
Ceiling: 3200 m / 10500 ft
Range: 750 km / 466 miles
Crew: 1
Passengers: 1

UT-2 (1940 standard)
improved spin characteristics.
Engine: Shvetsov M-11D, 93.2 kW (125.0 hp)
Propeller: 2-bladed fixed-pitch
Wingspan: 10.2 m (33 ft 6 in)
Wing area: 17.12 m2 (184.3 sq ft)
Airfoil: Göttingen 387
Length: 7.15 m (23 ft 5 in)
Height: 2.99 m (9 ft 10 in)
Empty weight: 628 kg (1,385 lb)
Gross weight: 940 kg (2,072 lb)
Maximum speed: 210 km/h (130 mph, 110 kn)
Cruise speed: 99 km/h (62 mph, 53 kn)
Range: 1,130 km (700 mi, 610 nmi)
Service ceiling: 5,000 m (16,000 ft)
Rate of climb: 3.3 m/s (650 ft/min)
Crew: 2

UT-2MV
Armament: 8 x RS-82 rockets or 2-4 x 50 kg (110 lb) bombs

UT-2 (1944 standard)

UT-2L
UT-2 with MV-4
inline engine for tests.

UT-2L
improved 1940 standard with canopy and engine cowling, fuselage similar to early Yak-18 but had fixed undercarriage.

UT-2M
production from 1941, new wings and empennage

UT-2MV
interim light bomber

UT-2N (SEN)
air cushion landing gear testbed

UT-2V
bomber trainer

VT-2
floatplane variant of basic UT-2

Compact monoplane aerobatic trainer with open cockpit. When the I-16 fighter came to service, it became obvious than biplane trainers (like U-2) do not provide enough training ground to fly fast and ‘hot’ monoplane fighters. A.S.Yakolev was one of the first designers who started to build monoplane trainers to match I-16 performance.
The AIR-14 construction was similar to the AIR-10: wire-braced fuselage of wielded soft steel tubes, with light wooden structure supporting the skin. Wings were single-piece with two spars, converging toward the wingtip (later this construction was used in Yak-1). Tailplane, tailfin and ailerons had aluminium frame. All skinning – fabric. Landing gear – fixed with rubber shocks. To prove its reliability Yu.I.Piontkovsky performed 300 landings during single day, followed by 1000 more (in few days).
State Acceptance Trials took place in 1936 with 100hp M-11. After minor modification and installation of 115hp M-11G the aircraft was presented again in 1937 and after successful trials production was launched. Later with 150hp M-11E performance was improved again. In 1939 the engine mount was extended forward, making handling easier. Same modification included a new fuel system, allowing inverted flight. Small series were built with oleo-pneumatic shocks and single machine-gun.
In 1937 UT-1 was installed on floats, setting two records in October same year: October 2: Yu.I.Piontkovsky set speed record 218km/h at 100km; October 21: D.N.Fedoseev flew floatplane from Moscow to Ufa, covering 1174km non-stop;
Total number of variants was about 10, with different wing section, new propellers, floating ailerons etc. Not all of them were successful.
UT-1 was too demanding for primary trainer, and biplanes were still used on early training stages.
In 1941 some UT-1s were armed in frontline workshops. Typical armament included two ShKAS machine guns and few RS-82 rockets under the wings.
1241 built 1937-1940. UT-1 established eight international records of speed, ceiling and range. Light trainer remained unsurpassed as aerobatic/sport aircraft until 50’s.

Engine: 1 x M-11E, 118kW
Max take-off weight: 590 kg / 1301 lb
Empty weight: 430 kg / 948 lb
Wingspan: 7.3 m / 24 ft 11 in
Length: 5.8 m / 19 ft 0 in
Height: 2.0 m / 7 ft 7 in
Wing area: 8.3 sq.m / 89.34 sq ft
Max. speed: 255 km/h / 158 mph
Cruise speed: 190 km/h / 118 mph
Ceiling: 7120 m / 23350 ft
Range: 670 km / 416 miles
Crew: 1

From 1933 Yakovlev and his design team developed a 2-seat low-wing monoplane sport aircraft with open cockpits, wooden wings, welded steel tube fuselage, powered by a Shvetsov M-11 engine. Fitted with landing flaps and automatic leading-edge slats, the AIR-9 design was submitted to a safe aircraft design competition, but was not proceeded with.

The original AIR-9 design was re-worked in 1934 to include enclosed cockpits, but dispensing with the automatic slats. The tandem cockpits were fitted with sliding canopies; the forward canopy slid rearwards over the fixed centre canopy section and the rear canopy slid forwards under the centre-section.

The structure of the AIR-9 followed Yavovlev’s previous designs with wooden plywood and fabric covered wings, welded steel tube fabric-covered fuselage and Duralumin fabric covered tail surfaces. The fixed spatted main undercarriage was supported by struts, later fitted with trousers as well as spats, with a fixed tail-skid or tailwheel (as exhibited at the 1935 Milan airshow).

The AIR-9 was powered by a single 100 hp (75 kW) Shvetsov M-11 five-cylinder air-cooled radial driving a fixed pitch 2-bladed wooden propeller, variously fitted with individual exhaust stacks, collector ring and Townend ring cowling.

In 1935 the AIR-9 was modified, or a second aircraft built, with a forward sloping windshield and re-designated AIR-9bis. The large number of variations in configuration suggest that there were more than one aircraft, but this cannot be confirmed.

The AIR-9bis was displayed at the 1935 Paris and Milan airshows, and in 1937, was flown by I.N. Vishnevskaya and Ye.M. Mednikova to set a women’s altitude record in the FAI Class C category.

Variants:
AIR-9
The original open cockpit 2-seat low-wing monoplane sport aircraft design, with split flaps and automatic leading edge slats; not proceeded with.

AIR-9
The original design reworked with closed cockpits and other refinements but without automatic slats. At least one built, at some stage seen with racing number 31.

AIR-9bis
Further modifications prompted re-designation to AIR-9bis, introducing a forward sloping windshield and undercarriage trousers. One converted from the AIR-9 or possibly several new built aircraft, seen wearing racing number 32.

AIR-9bis
Engine: 1 × Shvetsov M-11, 75 kW (100 hp)
Propeller: 2-bladed wooden fixed pitch
Wingspan: 10.2 m (33 ft 6 in)
Wing area: 16.87 m2 (181.6 sq ft)
Length: 6.97 m (22 ft 10 in)
Empty weight: 495 kg (1,091 lb)
Max takeoff weight: 768 kg (1,693 lb)
Fuel capacity: 63.5 kg (140 lb) fuel; 17.5 kg (39 lb) oil
Maximum speed: 215 km/h (134 mph, 116 kn)
Landing speed: 65 km/h (40 mph; 35 kn)
Cruise speed: 195 km/h (121 mph, 105 kn)
Range: 695 km (432 mi, 375 nmi)
Service ceiling: 6,080 m (19,950 ft)
Time to 1,000 m / 3,300 ft): 4 minutes 48 seconds
Time to 3,000 m / 9,800 ft: 16 minutes 24 seconds
Take-off run: 80 m (260 ft)
Landing run: 90 m (300 ft)
Crew: 2

A two seat low-wing monoplane built for record speed. Both cockpits were covered by a long and low transparent canopy. Engine covered by Townsend ring. The aircraft had mixed construction: steel tubes and fabric for fuselage, mostly wood and fabric in thin (8%) wing, duralumin and fabric for ailerons and tail surfaces. Fixed landing gear was enclosed into ‘pants’ fairings. Construction started in April 1932.
The aircraft was ready at the end of Summer 1932 and on November 19 325km/h was demonstrated, and in Spring 1933 – 332km/h. Flights continued until 1934, when an aileron broke off in flight due to flutter (then almost unknown and not understood). Test-pilot Yu.I.Piontkovskij managed to land on unprepared terrain.
Since AIR-7 fulfilled its goal (to demonstrate high speed), it was not restored.

Engine: 1 x M-22, 355kW
Max take-off weight: 1400 kg / 3086 lb
Empty weight: 900 kg / 1984 lb
Wingspan: 11.0 m / 36 ft 1 in
Length: 7.8 m / 26 ft 7 in
Wing area: 19.4 sq.m / 208.82 sq ft
Max. speed: 325 km/h / 202 mph
Range: 1300 km / 808 miles
Crew: 2

An AIR-5 adaptation for the domestic M-11 engine, designated AIR-6, was ready in May 1932, flew on September 8 and passed all trials easily. Adopted as short range liaison aircraft.
In 1934 a group of AIR-6 performed flight Moscow-Irkutsk-Moscow (with refuel landings), covering more than 10,000km.
During 1934-36 a total of 486 AIR-6 were built. Twenty of them were modified as air ambulance with room for a stretcher and doctor.

Engine: 1 x M-11, 81kW
Max take-off weight: 993 kg / 2189 lb
Empty weight: 620 kg / 1367 lb
Wingspan: 12.1 m / 40 ft 8 in
Length: 8.0 m / 26 ft 3 in
Height: 2.3 m / 8 ft 7 in
Wing area: 19.8 sq.m / 213.13 sq ft
Max. speed: 166 km/h / 103 mph
Cruise speed: 140 km/h / 87 mph
Ceiling: 4500 m / 14750 ft
Range: 650 km / 404 miles
Crew: 1
Passengers: 2

With his next design, the “AIR-3” of 1929, Yakovlev chose to go to a monoplane configuration, resulting in a tidy parasol-winged aircraft powered by a five-cylinder radial Czech-made Walter NZ engine; the AIR-3 had additional fuel tanks for long-range operation. A handful of “AIR-4” machines was built, featuring various improvements such as doors to make it easier for the two crew to get in and out.

The AIR-4s were used for various tests and trials, including one in which the aircraft was given translucent skinning as something of a “visual stealth” measure as the Kozlov PS.

Yakovlev also designed a specialized trainer version of the AIR-4, the “AIR-8”, very similar to the AIR-4 but with various tweaks, particularly reinforcement of landing gear and the like to tolerate the blunders of trainee pilots. Only one was built, the VVS (Voyenno Vozdushniye Sily / Red Air Force) evaluating it, then forgetting about it.

Variation: Kozlov PS

AIR-4
Engine: Walter NZ
Wingspan: 11.1 m / 36 ft 5 in
Wing area: 36.5 m2 / 392.88 sq ft
Length: 6.94 m / 23 ft 9 in
Empty weight: 395 kg / 871 lb
Take-off weight: 630 kg / 1389 lb
Max. speed: 150 km/h / 93 mph
Ceiling: 4000 m / 13,100 ft
Range: 500 km / 311 miles

A development of the AIR-2 in parasol monoplane configuration, it used an identical fuselage, powerplant, landing gear and tail. Finance for construction was provided by Osoaviakhim.
The aircraft was ready in the Summer of 1929 and on September 6 pilots Filin and Kovalkov (at the time students of the VVA, as well as a designer), flew nonstop from Mineralnye Vody to Moscow covering 1835km with average speed 166.8km/h, setting another International Record for Yakolev’s aircraft.

Engine: 1 x Walter, 44kW
Max take-off weight: 762 kg / 1680 lb
Empty weight: 392 kg / 864 lb
Wingspan: 11.0 m / 36 ft 1 in
Length: 7.1 m / 23 ft 4 in
Height: 2.4 m / 8 ft 10 in
Wing area: 16.5 sq.m / 177.60 sq ft
Max. speed: 146 km/h / 91 mph
Cruise speed: 125 km/h / 78 mph
Ceiling: 4200 m / 13800 ft
Crew: 2

The Yackey Aircraft Co was involved in converting surplus Thomas-Morse TM-1s into 2-3p civil models in 1923 for $1,275-1,475, as well as surplus Renault-powered Breguets into transports for $4,750 and up. Designed by Art Chester, two were completed; C672 and C1296.

Engine: Wright J-5, 225hp
Wingspan: 41’2″
Length: 26’2″
Max speed: 140 mph
Cruise: 115 mph
Stall: 40 mph
Seats: 3