Yakovlev UT-3

Yakovlev UT-3
Company type	Aircraft
Industry	Aerospace
Founded	1938
Founder	Alexander Sergeyevich Yakovlev
Headquarters	Soviet Union
Products	Military trainer aircraft

Template:Infobox aircraft

The Yakovlev UT-3, originally designated as the AIR-17 and later as the Ya-17, was a twin-engine, low-wing monoplane crafted by Alexander Sergeyevich Yakovlev to fulfill the training needs of the Soviet Air Force (VVS).

Design and development

Conceived to train pilots for multi-engine aircraft operations, as well as air gunners, bomb aimers, navigators, and radio operators, the UT-3 featured an airframe primarily built from wood with mild steel tubing covered by fabric. The prototype utilized French-imported Renault 6Q-01 engines delivering 220 horsepower (160 kW) from six cylinders arranged inline; however, production models likely employed the Soviet-produced Voronezh MV-6, a licensed version of the Bengali 6 engine.

Flight trials commenced in 1938, leading to official approval for manufacturing under the UT-3 designation. The initial prototype was equipped with two 7.62 millimetres (0.300 in) ShKAS machine guns and mounts for four FAB-50 bombs, but production variants were stripped of armaments and simplified in design. Manufacturing began in 1940 at two plants: Factory No. 135 in Leningrad and Factory No. 272 in Kazan. Approximately thirty units were completed before production halted after the VVS leadership opted to substitute dedicated trainers with dual-control versions of operational multi-engine combat aircraft.

Operational history

Although initially promising, the UT-3 saw limited production due to protracted development and the discontinuation of the MV-6 and Kossov MG-31F engine lines.

Variants

AIR-17: Also known as Samolyet No.17, S-17, Ya-17, UT-3, or M-17, this was a prototype bomber-trainer featuring three seats and powered by twin 220 hp (160 kW) Renault 6Q-01 engines, each driving a Ratier 1363 variable pitch propeller.

UT-3 2MV-6 (3-seat): The initial armed three-seat bomber trainer model, equipped with two Voronezh MV-6 engines coupled to AV-3 variable-pitch propellers. Of the ten ordered, only one was constructed due to inadequate performance and stability issues.

UT-3 2MV-6 (2-seat): In response to the unsatisfactory flight test outcomes of the three-seat variant, the design was modified into a two-seat pilot trainer. Nine units were produced and delivered to operational units for evaluation, but results remained poor owing to design flaws and substandard manufacturing. Production responsibilities were shifted to GAZ-47.

UT-3 2MV-6 (2-seat GAZ-47): At GAZ-47, modifications were implemented to correct deficiencies identified during service trials, achieving only partial success. This configuration saw a limited production run of eight aircraft.

UT-3 'standard setter for 1941': Referred to as S-17A, Ya-17, UT-3 2MV-6A, or UT-3M, this version was refined as a conversion trainer. The instructor occupied an offset starboard position behind the trainee seated offset to port, both under a shared canopy. The landing gear became fixed, powered by two 220 hp (160 kW) Voronezh MV-6A engines mounted on extended engine mounts to maintain the center of gravity within safe limits. Only one unit was manufactured.

UT-3 with MG-31F engines: A proposed model intended to use two 350 hp (260 kW) Kossov MG-31F 9-cylinder radial engines; however, it was never built.

UT-3 'standard setter no.2': An unbuilt variant based on standard setter no.1, featuring twin fins and rudders along with swept-back outer wing panels.

UTPB: Short for uchebno-trenirovochnyy pikeeruyushchiy bombardirovshchik (dive bomber trainer), this planned dive bomber trainer was designed to include dive brakes beneath the wings but was not constructed.

Ya-19: Also called S-19 or AIR-19, this civilian transport adaptation utilized the wings, tail, landing gear, and engines from the UT-3 combined with a new fuselage housing a two-person cockpit and a cabin configured for five passengers. Only one example was produced.