 In the 1940s, the museum had a large collection of propellers from the First World War era and engines from both World Wars.These are now all gone save for a single propeller attributed to a Hansa-Brandenburg C.I.A search of the National Air and Space Museum Collections Database reveals that four of the engines were given to the Smithsonian in 1972, followed by a World War I USMC balloon basket in 1974.