The proposed fleet of B-70 deep penetration nuclear bombers was cancelled in 1961 due to high costs and the introduction of ICBMs, but two prototypes of this awesome six-engined Mach 3 beauty were used in supersonic test flights from 1964 to 1969. One crashed following a midair collision with an F-104 while filming in 1966, the other became an outstanding exhibit at the USAFM, arriving on 4.2.69. One of the most memorable sights of my first visit to the USA