During World War II, the United States needed a way to move soldiers and supplies across the Atlantic Ocean. German submarines were sinking metal ships. So the government asked Howard Hughes to build a giant flying boat that used wood instead of metal. Metal was needed for weapons, and wood was available in large amounts. Hughes designed the H-4 Hercules, the largest airplane ever built. Its wingspan stretched 320 feet, wider than a football field. The plane was made mostly from birch wood, which is lightweight but strong. People doubted it would ever get off the ground. They gave it a nickname: the Spruce Goose. Hughes hated that name. The war ended before the plane was finished. People said it had been a waste of money. On November 2, 1947, Hughes decided to prove them wrong. He taxied the plane across the water in Long Beach, California. Then it lifted off! It flew one mile at an altitude of seventy feet. The flight lasted about one minute. Hughes showed that his wooden plane could fly. It never flew again after that day. Today the Spruce Goose is displayed at a museum in Oregon.