X-Planes and Prototypes explores the boundaries of aviation research over the decades, with detailed features on than 150 of the world's strangest and most advanced aircraft designs. From America's Bell X-1 rocket research aircraft - the first manned aircraft to break the sound barrier - to the experimental Lockheed A-12 Mach 3 fighter, each prototype or experimental aircraft is covered in detail, with an annotated full-page photograph or artwork, in-depth text and full specifications.