Originally Posted by S2K
So what does XB70 mean?
See the avatar? It was North American's Mach 3 bomber. Only 2 prototypes were built, one crashed and the other is in the Air Force museum. The Soviets thought it was going into production and designed and built the MiG 25 Foxbat, a Mach 3 interceptor that had to have its engines replaced after every Mach 3 flight.
The XB70 was so fast, North American had trouble keeping paint much less a wax/sealant on it.
You can still find bits of the plane at the crash site.