{| |} The Hansa-Brandenburg B.I was an unarmed military trainer and reconnaissance biplane of World War I flown by the Austro-Hungarian Air Service. Early models were known internally to the Hansa-Brandenburg firm as the type D, while later models with a more powerful engine were designated FD. This aircraft was one of the earliest designs of Ernst Heinkel, who was working for Hansa-Brandenburg at the time. It was an entirely conventional two-bay biplane with staggered wings of unequal span. The pilot and observer sat in tandem in a long open cockpit.