While working for the Moscow Air Force Engineering Academy, Aleksandr Sergeyevich Yakovlev designed his first aircraft in his spare time. Designated AIR-1, this was a compact biplane two-seat trainer powered by a 60 hp (45 kW) ADC Cirrus engine. An improved version, the AIR-2, introduced interchangeable floats, while the AIR-3 was a monoplane version with braced parasol wing. Further development with extra fuel tankage resulted in the AIR-4 and a military liaison variant was known as the AIR-8.

In 1931, Yakovlev designed the AIR-5 which was a braced high-wing cabin monoplane powered by Wright Whirlwind engine. When licence-production of this engine fell through, the aircraft was redesigned to accept the indigenously designed Shvetsov M-11 5-cylinder air-cooled radial engine and redesignated the AIR-6. Twenty such aircraft were built for civil transport and ambulance duties.

State Acceptance Trials took place in 1936 for the cantilever low-wing monoplane, the UT-1 with a 100 hp (74.6 kW) Shvetsov M-11 5-cylinder air-cooled radial engine. After minor modification and installation of a 115 hp (86 kW) M-11G 5-cylinder air-cooled radial engine the aircraft was presented again in 1937 and after successful trials production was ordered. Later aircraft were equipped with a 150 hp (112 kW) Shvetsov M-11E 5-cylinder air-cooled radial engine improving performance once again. In 1939 the engine cradle was extended forward, making handling easier. Some other modifications included a new fuel injection system, allowing inverted flight.

In 1937 the UT-1 had floats installed, and proceeded in setting two records in October of the same year. On 2 October, Yu.I.Piontkovsky set a speed record of 133.5 mph (218 km/h) and on 21 October D.N.Fedoseev flew a UT-1 floatplane from Moscow to Ufa covering 729 miles (1174 km) non-stop. The UT-1 would eventually establish eight international records for speed, ceiling and range.

Under the design bureau designation AIR-14, the UT-1 (Uchebno-Trenirovochnyi - Educational Trainer) was used as an aerobatic trainer by the Soviet air force (VVS). The aircraft was stressed to a load factor of 10 for unlimited aerobatics. A total of 1,241 were built and several were used in 1942 with machine-guns and rocket launchers, when attack aircraft were in short supply. The armed version was produced called the YAK-UT1 Moskit (Mosquito) with various armaments but usually consisting of two 7.62mm ShKAS machine guns mounted above the wings and four RS-82 rockets on four underwing pylons (two per wing).

Deriving from the AIR-10 cantilever low-wing monoplane, the Ya-20, initially powered by a 120 hp (90 hp) Renault engine, was intended as a military trainer. Under the VVS (Soviet Air Force) designation UT-2, the type was built in considerable numbers (7,243) and continued in service long after 1945. There was an attempt to arm this version as well, but newer aircraft such as the IL-2 Shturmovik were becoming available in large numbers, so there really was no need. Yakovlev's first twin-engined design was the AIR-17 (UT-3 in VVS service), a low-wing monoplane military crew trainer which featured a glazed nose for the bomb-aimer. Only 30 were built, powered by two 220 hp (164 kW) MV-6 engines and carrying two 7.62 mm (0.30 in) ShKAS machine-guns. A five passenger civil version, the Ya-19, was abandoned in 1938 because of the worsening international situation.

Post-war the aircraft proved very popular with civil owners flying until the 1950s as an aerobatic and sport aircraft.

Variants

Yakovlev (AIR-14) UT-1 - A single seat low-wing cantilever monoplane used as an aerobatic trainer by the Soviet air force (VVS) under the designation UT-1. Initially powered by a 100 hp (74.6 kW) Shvetsov M-11 5-cylinder air-cooled radial engine, but most production aircraft were equipped with a 150 hp (112 kW) Shvetsov M-11E 5-cylinder air-cooled radial engine. It was the first Soviet monoplane trainer to be used in great numbers (1,241 built).

Yakovlev Yak-UT1 - Early in the war, the Soviets desperately needed attack aircraft so the UT-1 was pressed into service. An armed version was produced called the YAK-UT1 Moskit (Mosquito) with various armaments but usually consisting of two 7.62mm ShKAS machine-guns mounted above the wings and four RS-82 rockets on four underwing pylons. The number equipped this way is unknown. 

Yakovlev (AIR-10/Ya-20) UT-2 - Basically the two-seat version of the UT-1. Initally powered by a 100 hp (74.6 kW) Shvetsov M-11 5-cylinder air-cooled radial engine driving a two-bladed fixed pitch wooden propeller, but later aircraft were equipped with the 150 hp (112 kW) Shvetsov M-11E engine. An attempt was made to arm this version as well as the Yak-UT2, but IL-2 Shturmovik production was well under way and sufficient numbers existed, so the Yak-UT2 was soon abandoned (7,243 built).

Yakovlev (AIR-17) UT-3 - Yakovlev's first attempt to develop a twin-engined crew trainer. Powered by two 220 hp (164 kW) MV-6 engines and equipped with two 7.62mm ShKAS machine guns (30 built).

Yakovlev Ya-19 - A proposed 5 passenger civil version of the (AIR-17) UT-3. Due to the worsening internation situation it was abandoned in 1938.  

Specifications (Yakovlev "Uchebno-Trenirovochnyi" AIR-10/Ya-20 UT-2)

Type: Two Seat Primary Trainer & Light Ground Attack

Accommodation/Crew: Pilot & Student sitting in tandem open cockpits with dual controls.

Design: Designer Aleksandr Sergeyevich Yakovlev

Manufacturer: Moscow Air Force Engineering Academy (Later he formed the Yakovlev Design Bureau)

Powerplant: One 100 hp (74.6 kW) Shvetsov M-11 5-cylinder air-cooled radial engine driving a two-bladed fixed pitch wooden propeller. Later aircraft were equipped with the 150 hp (112 kW) Shvetsov M-11E 5-cylinder air-cooled radial engine.

Performance: (Shvetsov M-11) Maximum speed 130 mph (210 km/h) at sea level; cruising speed 110 mph (177 km/h); service ceiling 11,485 ft (3500 m); landing speed 59 mph (95 km/h). (Shvetsov M-11E) Maximum speed 143 mph (230 km/h); cruising speed 127 mph (205 km/h).

Range: 311 miles (500 km) on internal fuel.

Weight: Empty equipped 1,358 lbs (616 kg) with a normal take-off weight of 1,887 lbs (856 kg) and a maximum take-off weight of 2,068 lbs (938 kg).

Dimensions: Span 33 ft 5 1/2 in (10.20 m); length 22 ft 11 1/2 in (7.00 m); height 8 ft 3/8 in (2.55 m); wing area 184.28 sq ft
(17.12 sq m).

Armament: (Yak-UT1) Two 7.62 mm (0.30 in) ShKAS machine-guns one mounted on top of each wing out side of the propeller arch, to compensate for this increase in weight the under carriage spats were removed plus four RS-82 rockets on underwing racks.

Variants: AIR-14 (UT-1), Yak-UT1 (attack), AIR-10/Ya-20 (UT-2), AIR-17 (UT-3).

Equipment/Avionics: None.

Wings/Fuselage/Tail Unit: - The wings are of the low-wing cantilever monoplane type with a taper on the leading and trailing edges. Flat centre-section. Dihedral on outer sections. Construction was of a wooden structure with a plywood or fabric covering. The fuselage was also of wooden structure with a plywood or fabric covering. The tail unit was a braced monoplane type with a single fin and a balanced rudder. Trim tab on rudder.

History: First flight (AIR-5) 1931; end production 1940.