The Yakovlev Yak-12 is a light multirole STOL aircraft that has been utilized by the Soviet Air Force and other countries since 1947.
The aircraft was designed by Yakovlev’s team to meet the Soviet Air Force’s requirement for a new liaison and utility plane in 1944, replacing the outdated Po-2 biplane.
Additionally, it was intended to succeed Yakovlev’s AIR-6 of 1934, which was produced in a relatively small series for civil aviation purposes.
Yakovlev’s initial proposal was a four-place high-wing aircraft, the Yak-10 (initially named Yak-14), which was constructed in January 1945.
It won the competition against a low-wing Yak-13, based on the same fuselage, and a series of 40 Yak-10s were produced, powered by a 108 kW (145 hp) Shvetsov M-11M radial engine.
In 1947, Yakovlev developed a new aircraft to replace the Yak-10, which was equipped with a more powerful 119 kW (160 hp) M-11FR engine, a new wing and undercarriage, and a fuselage with a revised shape (lower tail).
The new model was designated Yak-12 and made its first flight in 1947.
A total of 788 basic variants were produced, including military observation planes, Yak-12S air ambulances, Yak-12SKh agricultural aircraft, and Yak-12GR floatplanes.
The basic Yak-12, like the Yak-10, was characterized by engine cylinders with individual cowlings.
It was a plane of mixed construction and could accommodate one or two passengers, in addition to the pilot.
The next generation Yak-12 was introduced in 1952, starting with the Yak-12R, which was equipped with a new 194 kW (260 hp) Ivchenko AI-14R radial engine and all-metal construction.
The wing area was increased (from 21.6 m2 to 23.8 m2), and this variant had the least wing loading of all Yak-12s, resulting in the best STOL performance (take-off run 52 m/171 ft, landing 81 m/266 ft).
From 1955, the Yak-12M (“modernized”) was produced after being lengthened to improve weight distribution, with further strengthening of the structure and other minor changes.
A visible difference was a lengthened, curved tailfin.
This variant became more versatile, offering a larger payload.
It could accommodate a pilot and three passengers and could be fitted with dual controls for training, a stretcher for an ambulance role, or an agricultural spraying device.
It became the most numerous variant.
The last generation, produced from 1957, was the Yak-12A, which was an aerodynamically refined variant with a slimmer fuselage and a new wing.
The cowling was of a smaller diameter, and the rectangular wings were fitted with trapezoidal ends and automatic slats, with single struts replacing twin struts.
Navigation equipment and controls were improved, and performance was also enhanced.
In total, 3,801 Yak-12s were built in all models in the USSR, including 3,013 Yak-12R, M, and A.
An experimental Yak-12B biplane was also developed but did not enter production.
The Yak-12M was license-built from 1956 in Poland as the WSK-4 Okecie, or Jak-12M.
From 1959, the Yak-12A was produced in Poland (1,054 Jak-12Ms, 137 Jak-12As), mostly for export to the USSR.
In 1958, further development of the Yak-12M was carried out in Poland, resulting in the PZL-101 Gawron.
The Yak-12 was also manufactured in China as the Shenyang Type 5.
Variants
Yak-12
Basic variant built for military and civilian operators.
Yak-12GR
Floatplane version of the Yak-12.
Yak-12S
Air ambulance version of the Yak-12.
Yak-12SKh
Agricultural version of the Yak-12.
Yak-12R
Improved version of the Yak-12 powered by Ivchenko AI-14R engine and the plane construction became all-metal, built from 1952.
Yak-12M
Main production version with further construction strengthening, a lengthened tailfin and other minor changes, built from 1955.
Yak-12A
Aerodynamically refined version with a slimmer fuselage, engine cover with smaller diameter and some wing modifications, built from 1957.
Sources Yakovlev Aircraft Since 1924 – Bill Gunston & Yefim Gordon. OKB Yakovlev, A History Of The Design Bureau And Its Aircraft-Yefim Gordon, Dmitriy Komissarov & Sergey Komissarov. Soviet Aircrafts Illustrated-A.S.Yakovlev.
