02/28/2011. In 1914, the Abteilung Flugzeugbau (Aircraft Section) of the Gothaer Waggonfabrik (Gotha Railcar Factory) at Gotha, Germany, produced six examples of the WD 1. It was derived from the Avro Type H (also known as Avro Type 503) by Karl Rösner and the two-seat floatplane had wings of unequal span and was powered by an 100 hp Gnome rotary engine. Serialed 285 to 289, five were delivered to the Reichsmarine (German Navy).