ASME-Landmark:Howard Hughes Flying Boat, HK-1


Better known as the "Spruce Goose," the Howard Hughes Flying Boat was designed and built by Hughes Aircraft Co., to be the largest wood-constructed and the largest wingspan airplane ever built. As Hughes perfected his craft, he added significantly to what is known in areas of large-lift capability and power-boost systems.

The ship was conceived in the midst of World War II, when America had just lost 800,000 tons of supply ships to German U-boats. Henry Kaiser, industrialist and builder of "Liberty" ships, proposed a fleet of flying transports to meet troop and material transportation needs, flying just high enough to evade submarine attacks. Kaiser approached Howard Hughes with his idea, and together they formed the Hughes Kaiser Corporation and obtained an $18,000,000 government contract to construct three flying boats.

The mammoth aircraft was designated the HK-1 (Hughes Kaiser design number 1) in 1942. Laminated wood (mostly birch) forms the airframe and surface structures of the seaplane, minimizing the use of critical war materials like aluminum. It was powered by eight Pratt & Whitney 3,000 horsepower engines. After the war's end in 1945, Hughes invested his own money to keep the project going.

Howard Hughes piloted the flying boat on its only flight, Nov. 2, 1947, in Long Beach Harbor, Los Angeles, California. The flight covered approximately one mile and reached an altitude of approximately 70 feet above the water's surface. See ASME website for more information