spruce goose

The Hughes H-4 Hercules (registration NX37602) was a prototype heavy transport aircraft designed and built by the Hughes Aircraft company. The aircraft made its first and only flight on November 2, 1947. Built from wood due to 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.

Due to wartime restrictions on the availability of metals, the H-4 was built almost entirely of laminated birch, not spruce as its nickname suggests. The plywood and resin "Duramold" process,[1] a form of composite technology, was used in the laminated wood construction. The aircraft was considered a technological tour de force.[citation needed] It married flying boats to a massive wooden airframe that required some ingenious engineering innovations to function.

Ultimately, the plane was not finished in time for use in the war and never advanced beyond the single prototype produced. Contents [hide] 1 Design and development 2 Operational history 3 Display 4 Specifications (H-4) 5 Popular culture 6 See also 7 References 7.1 Notes 7.2 Bibliography 8 External links //

Design and development Rearward view of the H-4's fuselage

In 1942, the U.S. Department of War was faced with the need to transport war materiel and personnel to Britain. Allied shipping in the Atlantic Ocean was suffering heavy losses to German U-boats, so a requirement was issued for an aircraft that could cross the Atlantic with a large payload. For various reasons with regard to wartime priorities, the design was further constrained in that the aircraft could not be made of metal.

The aircraft was the brainchild of Henry J. Kaiser, who directed the Liberty ships program. He teamed with aircraft designer Howard Hughes to create what would become the largest aircraft built or even seriously contemplated at that time. When completed, it was capable of carrying 750 fully-equipped troops or one M4 Sherman tank.[2] The original designation "HK-1" reflected the Hughes and Kaiser collaboration.[3]

The HK-1 contract in 1942, issued as a development contract,[4] initially called for three aircraft to be constructed under a two-year deadline in order to be available for the war effort.[5] Seven different configurations were considered including twin-hulled and single-hulled designs with combinations of four, six, and eight wing-mounted engines.[6] The final design chosen was a behemoth, eclipsing any large transport yet built or even envisioned.[7][4] To conserve metal, it would be