Yakovlev Yak - 12 The Yakovlev Yak - 12 ( , also transcribed as Jak - 12 , NATO reporting name : " Creek " ) is a light multirole STOL aircraft used by the Soviet Air Force , Soviet civilian aviation and other countries from 1947 onwards . Design and development . The Yak - 12 was designed by Yakovlev ' s team to meet a requirement of the Soviet Air Force of 1944 for a new liaison and utility plane , to replace the obsolete Po - 2 biplane . It was also meant to be used in civil aviation as a successor to Yakovlev ' s AIR - 6 of 1934 , built in a relatively small series . Yakovlev ' s first proposal was a four - place high - wing aircraft , the Yak - 10 ( first named Yak - 14 ) , built in January 1945 . It won the competition with a low - wing Yak - 13 , based on the same fuselage , and a series of 40 Yak - 10s were produced , powered with a 108 kW ( 145 hp ) Shvetsov M - 11 M radial . In 1947 , Yakovlev developed a new aircraft to replace the Yak - 10 . This was fitted with a more powerful 119 kW ( 160 hp ) M - 11FR , a new wing and undercarriage , and a fuselage with a revised shape ( lower tail ) . The new type was designated Yak - 12 , first flying in 1947 . 788 of the basic variant were produced , including military observation planes , some Yak - 12S air ambulance s , Yak - 12SKh agricultural aircraft and Yak - 12GR floatplane s . A distinguishing feature of the basic Yak - 12 , just like Yak - 10 , were engine cylinders with individual cowlings . It was a plane of a mixed construction and could take 1 or 2 passengers , apart from a pilot . The next generation Yak - 12 entered production in 1952 , starting with the Yak - 12R . It was fitted with a new 194 kW ( 260 hp ) Ivchenko AI - 14 R radial and all - metal construction . The wing area increased ( from 21 . 6 m² to 23 . 8 m² ) . This variant had the least wing loading of all Yak - 12s , and therefore best STOL performance ( take - off run 52 m / 171 ft , landing 81 m / 266 ft ) . After being lengthened to improve weight distribution , with further strengthening of the structure and other minor changes , from 1955 the Yak - 12M ( " modified " ) was produced . A visible difference was a lengthened , curved tailfin . This variant became more universal , offering a bigger payload . It took a pilot and 3 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 . It was an aerodynamically refined variant , with a slimmer fuselage and a new wing . The cowling was smaller diameter . The rectangular wings were fitted with trapezoidal ends and automatic slats , also single struts replaced twin struts . Navigation equipment and controls were improved , and performance also increased . In the USSR , 3 , 801 of Yak - 12s were built in all models ( 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 licence - built from 1956 in Poland as the WSK - 4 Okecie , or Jak - 12M ( Polish spelling of Russian name ) . From 1959 , the Yak - 12A was built in Poland ( 1 , 054 Jak - 12Ms , 137 Jak - 12As ) , most for export to the USSR . In 1958 , further development of the Yak - 12M was carried out in Poland , becoming the PZL - 101 Gawron . The Yak - 12 was also produced in China as Shenyang type 5 . Operational history . Yak - 12s first entered service in the Soviet Air Force as a liaison and artillery observation plane . Then , they were used also in the Soviet civilian aviation – mostly in the DOSAAF aero club for transport , pilot training , parachute training , and glider towing . They were also used as air ambulance s and agricultural aircraft . Apart from the USSR , Yak - 12s were used in Poland , Czechoslovakia , Yugoslavia ( civil and military ) , and Hungary ( civil ) . Licence - built Shenyangs were used in China and other countries . In some countries , including Poland , Hungary and Czechoslovakia , the Russian name was transcribed as Jak - 12 . In the Polish Air Force , about 90 Yak - 12s were used from 1951 , as liaison , patrol , and general utility planes . Most were withdrawn in the 1970s , the last in the 1980s . Most were next handed over to civil aviation . In Poland , the first civilian model was acquired in 1952 , and larger numbers were used from the 1960s ( at least 79 ) . They were used mostly in regional aeroclubs for pilot training , parachute training , transport , and glider towing . 21 were used as air ambulances . Some civil Yak - 12s ( mostly Yak - 12A ) remain in use in 2006 . On July 12 , 2012 , a Yak - 12 owned by Canada ' s Kinross Gold Corporation , crashed shortly after takeoff from an airport in Nouakchott , Mauritania . Description . Metal construction ( Yak - 12R , M , A ) or mixed construction ( Yak - 12 ) braced high - wing monoplane , conventional in layout , metal and canvas covered . Wings fitted with flaps and slats ( automatic slats in Yak - 12R , or fixed in other variants ) . Four - seat cabin ( in early variants of Yak - 12 – 2 or 3 seats ) . Conventional fixed landing gear with tail wheel . Single radial engine : 5 - cylinder M - 11FR ( nominal power 104 kW / 140 hp , take - off power 118 kW / 160 hp ) – Yak - 12 basic variant ; 9 - cylinder AI - 14R ( nominal power 161 kW / 220 hp , take - off power 191 kW / 260 hp ) – Yak - 12R , M and A . Two - blade propeller . Two fuel tanks in wings , 225 l ( 55 US gal ) each .