Already in the year 1947 the US Navy required a new guidance system for the unguided 12.7 cm HVAR missile (High Velocity Aerial Rocket), to make a guided air-to-air missile of it. The former designation of this missile was KAS-1, later, in September 1947, it was renamed AAM-2 and finally, in 1948, it was renamed AAM-N-2. During development it was realized that the HVAR missile was simply too small, so that a 20.3 cm missile was developed. First unpowered flight tests took place in the year 1948 and first launches were made in 1952. Introduction began in the year 1956 and they were used by the F3H-2M Demon and F7U Cutlass fighter aircraft