There were 2 prototypes built of the XB-70 Valkyrie, Mach 3 bomber. It was realized that the shock cone which developed during supersonic flight could be utilized to create more lift and speed during flight. The unique shape of the Valkyrie and the cantable wing tips were designed to take advantage of this phenomenon. This is a depiction of the magnificent XB-70 Valkyrie flying over the desert during a test flight.