The Clipper Flying Cloud, shown in the photograph above, was one of three delivered to Pan-Am in March 1940, and was used for commercial scheduled flights between Miami and Latin America. The Clipper Flying Cloud is now on display at the Smithsonian National Air and Space Museum’s Steven F. Udvar-Hazy Center, in Chantilly, Virginia - it's the only remaining Stratoliner in flying condition, of the original 10 ever built.
(for more photos of aircraft displayed a the Smithsonian National Air and Space Museum, click here.)