North American Aviation X-15A-2 56-6671 and Boeing NB-52B Stratofortress 52-008 Published on October 2, 2013 in 3 October 1967Full resolution (1600 × 1251) ← Previous Next → North American Aviation X-15A-2 56-6671 is carried to launch altitude under the right wing of the Boeing NB-52B Stratofortress 52-008. (U.S. Air Force)