Heinkel HD 35

The Heinkel HD 35 was a trainer developed in Germany in the 1920s, a conventional single-bay biplane with staggered wings of equal span. The design was based on the Heinkel HD 21 and, like it, had three open cockpits in tandem, the forward one usually faired over when not in use. The Swedish Air Force bought one to evaluate as a replacement for the First World War vintage Albatros B.II trainers it then used. Designated Sk 5, it was flight tested until March 1927 and then judged inadequate in performance. It was sold on to the civil market and eventually acquired by the Swedish Air Force Museum, where it is preserved. A 120 horsepower Mercedes D.II engine powered it to 138 kilometres per hour, and its general specification is comparable to the American Curtiss JN-4 Jenny.