CJ-6 airplane model. Built under license in China, the basic Yak-18 was known as the Nanchang CJ-5. Produced at the Nanchang Aircraft Factory from 1954 through 1958, the design showed deficiencies for jet pilot training that led the Chinese to independently revise the basic Yak-18 design to feature a retractable undercarriage, with the main gear folding inward toward the fuselage, and the nose wheel retracting backward into the fuselage. The wings were revised to have prominent dihedral, but, like the Soviet Yak-18A redesign, the CJ-6 retained the 145hp M-11ER radial engine with similarly disappointing results when it first flew in 1958. Revised power, in the form of an Ivchenko AI-14R engine, didn't solve the problem, which called for further redesign of the aircraft. Finally, in 1961, an improved CJ-6A gained approval and was produced from 1962 until 1965, using a 285hp Quzhou Huosai HS6A engine. More than 1,800 CJ-6As were produced, including those exported to nations such as Albania, Bangladesh, Cambodia, Tanzania and Zambia under the designation BT-6. An armed version, the CJ-6B, was produced between 1964 and 1966, possibly equipped with a 300-hp HS-6D engine, according to some sources.
More than 10,000 of all types are believed to have been produced. Both the Yak-18 and the Nanchang CJ-6 have become popular with pilots worldwide who appreciate the sturdy qualities, reliability and personality of these old warbirds.