The Heinkel HD 39 was a special-purpose cargo aircraft developed in Germany in the 1920s to distribute the Berlin newspaper B.Z.. It was a conventional single-bay biplane with staggered wings of equal span, and a fuselage that nearly filled the interplane gap. The pilot sat in an open cockpit, and the undercarriage was of fixed, tailskid type with divided main units. The sole example of the type was built after Ernst Heinkel found out, by chance, that B.Z. required such an aircraft and had ordered two machines from Albatros. Heinkel convinced publisher Ullstein-Verlag to purchase a third aircraft from his firm.