Boeing 307 Stratoliner NC19903, Pan American Clipper Flying Could, at NASM Published on January 4, 2013 in 31 December 1938Full resolution (2400 × 2400) ← Previous Next → The only existing Boeing Model 307 Stratoliner, NC19903, Clipper Flying Cloud, at the Smithsonian Institution National Air and Space Museum, Steven F. Udvar-Hazy Center. (Photo by Dane Penland, National Air and Space Museum, Smithsonian Institution)