The Chinese have learned a lesson: "Never build a jet engine without designing the airplane first.''
The Spey Jet engines that China has been building in Xian under license from Rolls-Royce have turned out to be expensive failures. The Chinese Air Force will not buy the engines, saying they are too small for bombers and too large for fighters. China apparently bought the engines before designing a plane in which they could be used.
What now? The Chinese Navy is being persuaded to adapt the engines for use in high-speed patrol boats.