E-16695 This side view shows the #1 XB-70A 62-0001 during take-off rotation. The high angle of attack is a result of the combined effects of aircraft weight along with the performance of the propulsion system. The XB-70A, capable of flying three times the speed of sound, was the world's largest experimental aircraft in the 1960s. Two XB-70A aircraft were built, serial numbers 62-0001 and 62-0207. Ship #1 was flown by NASA Flight Research Center now NASA Dryden, Edwards, Calif., in a high speed research program. 1967 NASA Photo