Yakovlev Yak - 18 The Yakovlev Yak - 18 ( , also transcribed as Jak - 18 , NATO reporting name " Max " ) was a Soviet tandem two - seat military primary trainer aircraft . Originally powered by one 119 kW ( 160 hp ) Shvetsov M - 11 FR - 1 radial piston engine , it entered service in 1946 . It is also produced in China as the Nanchang CJ - 5 . Design and development . A member of the second generation of Russian aircraft designers , and best known for fighter designs , Alexander Sergeyevich Yakovlev always retained a light aircraft design section . In May 1945 , Yakovlev initiated design of the Yak - 18 two - seat primary trainer . He designed it to replace the earlier Yakovlev UT - 2 and Yak - 5 in service with the Soviet Air Force s and DOSAAF ( Voluntary Society for Collaboration with the Army , Air Force and Navy , which sponsored aero clubs throughout the USSR ) . In 1944 , an advanced version of the UT - 2 had been built and featured an enclosed canopy and fixed landing gear which bears a striking resemblance to the new Yak - 18 . The new aircraft flew a year later , powered by a 119 kW ( 160 hp ) Shvetsov M - 11 five - cylinder radial engine and featuring pneumatically operated retractable main landing gear and a fixed tailwheel . It entered service as a trainer later that year and was built by Yakovlev up until 1956 . Examples were exported to China in kit form beginning in 1950 . The Chinese began producing license built copies in 1954 with the designation CJ - 5 . The Yak 18 ' s greatest claim to fame is its use as a night bomber by the North Korean Air Force during the Korean War . The aircraft were modified with bomb racks on the wing center section and flew over UN troop locations at night to drop bombs and harass UN forces . The single most successful attack of the North Korean aviation during the war was destroying of a fuel dump with nearly 5 . 5 million gallons of fuel in Inchon area in June 1953 by 4 or 5 Yak - 18s . The five - cylinder engine reminded many of the US troops of the sound made by early gasoline powered washing machines earning them the name : " Washing Machine Charlie " . The name " Bed Check Charlie " was also used for these night intruders . The Yak - 18 ' s along with Polikarpov Po - 2 ' s became quite a nuisance until US night fighters began shooting them down . Other claims to fame for the Yak - 18 are an international speed record for class in 1951 as well as being the aircraft used for initial flight training by Yuri Gagarin ( 1st human in space ) and Ken Rowe ( No Kum - Sok : defected with a Mig - 15 during the Korean War ) . Later , as the need for conventional landing gear trainers abated Yakovlev re - designed the Yak - 18 with retractable tricycle landng gear and an Ivchenko AI - 14RF radial , 224 kW ( 300 hp ) and was designated the Yak - 18A . The design proved exceptionally easy to build and maintain . There are an estimated 40 original Yak - 18 ' s in existence worldwide . Two are currently flyable in the USA ( 1 crashed 06 / 23 / 2013 ) and three are flyable in Europe . Approximately four other aircraft worldwide are currently being restored for flight . Many are found in major aviation museums worldwide including the National Air and Space Museum in the USA . The CJ - 6a , produced in China , is sometimes quoted as a variant but is a completely different aircraft designed in China by Bushi Cheng and built by Nanchang Aircraft Company . Operational history . The Yak - 18 became the standard trainer for Air Force flying schools and DOSAAF , is in wide use in China , and in many other countries . Similar model designation . The Yak - 18T was developed as an Aeroflot training aircraft and also as a light passenger transport aircraft , with a 4 - seat cabin for one pilot and three passengers . It is not a variant of the Yak - 18 as it has very little in common , and was designed from scratch 20 years later .