Nanchang CJ-6 (CJ-5) Yak-18CJ 6 Nanchang 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