In 1947, Howard Hughes piloted his huge wooden airplane, known as the Spruce Goose on its only flight, which lasted about a minute over Long Beach Harbor in California. It was the first test of a U.S. plane with eight engines. Wing span was 319 feet, 11 inches. Originally conceived by Henry J. Kaiser, a steelmaker and builder of Liberty ships, the aircraft was designed and constructed by Hughes and his staff. The original proposal for the enormous, 400,000-pound wooden flying boat, with its spectacular 320-foot wingspan, came from the U.S. government in 1942. The entire airframe and surface structures are composed of laminated wood (primarily birch, not spruce).