In the early 1970s, Shenyang began looking into the development of a new fighter to replace their J-6/MiG-19s. When, in 1974, the PLAAF proposed the development of a new lightweight fighter with a top speed of Mach 2, Shenyang began serious design work, testing several wing configurations. The design that emerged had side-mounted intakes and a double-delta wing. While as early as 1976 Shenyang had finalized the design and was looking into the avionics and materials to be used in the aircraft, it was still without an engine. Plans called for the Rolls-Royce Spey derived WS-9 engine to be used, but when the engine finally emerged in 1980, it proved unsuitable for a single-engined fighter. In the late 1970s, the Chinese had got their hands on an Egyptian MiG-23MS complete with its Tumansky R-29 turbojet, which was hastily copied. However, when the new engine proved to be underperforming, the project was once again delayed. Further issues came in 1981 when the success of the J-8 caused the funding for the J-13 to be cut. Throughout the 80’s the project soldiered on with low priority, with new requirements emerging that called for the design to be competitive with the newest fourth generation fighters. Finally, the project was abandoned in the early 1990s as Chengdu’s J-10 proved to be more promising.