When I was watching G19Tony's video today of a U-2 landing on an aircraft carrier, I ran across this marvelous video of the XB-70 Valkyrie when it was still undergoing flight testing. Before I moved away from Ohio I only lived about an hour's drive from the Museum Of The USAF and I used to spend a lot of time there, so I have seen the only remaining copy of the XB-70 many times, and once while it was in the air. In spite of having studied it and read several books about it, I actually learned a few things about it that I didn't already know from watching this video. If you ever have a chance to visit Dayton, Ohio, I highly recommend visiting the Museum of The USAF and take a look at this unbelievable airplane. Vintage documentary about the XB-70 Valkyrie aircraft. The North American XB-70 Valkyrie was the prototype version of the B-70 supersonic bomber proposed for the Strategic Air Command of the United States Air Force . Designed in the late 1950s , the Valkyrie was a large aircraft propelled by six turbo-reactors and capable of flying at Mach 3+ speeds at an altitude of 21,000 meters, which would have allowed it to avoid interceptors , the only effective anti- at that time. The introduction of effective high-altitude surface-to-air missiles, high program development costs, and changes in the technological environment with the introduction of intercontinental ballistic missiles (ICBMs) led to the cancellation of the B-70 program in 1961 . Although the proposed fleet of B-70 bombers was canceled, two prototypes with the designation XB-70A were manufactured and used to conduct supersonic test flights from 1964 to 1969 . One prototype crashed after a mid-flight collision in 1966 ; The other is on display at the National Museum of the United States Air Force in Ohio .