The Hughes H-4
Hercules (registration NX37602) ("Spruce Goose") was a prototype heavy
transport aircraft designed and built by the Hughes Aircraft company.
The aircraft made its only flight on November 2, 1947. Built from wood
because of wartime raw material restrictions on the use of aluminum, it
was nicknamed the "Spruce Goose" by its critics. 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 in McMinnville, Oregon, USA.
Despite its
nickname, the H-4 was built almost entirely of birch, rather than
spruce. The plywood-and-resin "Duramold" process, a form of composite
technology, was used in the laminated wood construction, which was
considered a technological tour de force. The aircraft was not finished
in time for use in World War II and never advanced beyond the single
prototype produced .