Since the F-104Gs were nearly 25 years old at the time and Lockheed had stopped making parts for them, the only way we could get parts was to buy old planes from countries like Japan and Italy. The F-5Es were made jointly by the U.S. and the R.O.C.
在更新、整補方面，由於我國空軍的主力機種為近百架 F-104G 及二百五十架 F-5E，而前者機齡當時已達廿五年，原廠洛克希德公司又已停止零件生產，故只好向日、義等國購買舊機，以汰換零件（此即阿里山九、十號軍品採購計畫）。