Wikipedia H-4 Hercules entry:
The Hughes H-4 Hercules is a one-off heavy transport aircraft designed and built by the Hughes Aircraft company, making its first and only flight in 1947. Built from wood due to wartime restrictions, it was nicknamed the "Spruce Goose" by its critics, who accused Howard Hughes of misusing government funding to build the aircraft. The Hercules is the largest flying boat ever built, and has the largest wingspan and height of any aircraft in history. It survives, in good condition, at the Evergreen Aviation Museum.