Tags: Aircraft.
The Heinkel HD 40 was a special-purpose cargo aircraft developed in Germany in the 1920s to distribute the Berlin newspaper B.Z.. The success of Heinkel’s previous design for the publisher the HD 39 led to the order of a similar aircraft with greater capacity and Heinkel responded with a machine of similar layout but considerably enlarged. Like the HD 39 it was a conventional single-bay biplane with staggered wings of unequal span and a fuselage that nearly filled the interplane gap.