The HK-1 (H-4) Spruce Goose or Hercules, manufactured by Hughes Aircrafts, is a cargo-type flying boat aircraft. It had its first and only flight for just over a mile, on November 2, 1947. This trial was simple vindication from the detractors of the program and it is now looked back upon as a great moment in flight history.
The Hercules is the largest flying boat ever built, and has the largest wingspan and height of any aircraft in history. The engineers of the said airplane incorporated eight of the most powerful engines ever, 3,000-horsepower Pratt and Whitney radial reciprocating engines with 17-foot diameter props. To feed the engines, they created a mammoth fuel storage and delivery system. The entire airframe and surface structures are composed of laminated wood (primarily birch, not spruce). Birch was chosen because testing proved it light, strong, and resistant to splitting, dry rot and deterioration. All primary control surfaces, except the flaps, are fabric covered. The aircrafts hull is divided into two areas: a flight deck for the operating crew and a large cargo hold.
The H-4 was put into storage and carefully preserved, until after Howard Robard Hughes death in April of 1976. On February 27, 1993 the Hughes Flying Boat, commonly known as the Spruce Goose, arrived in McMinnville marking the end of the 1,055 mile, 138 day odyssey from Long Beach. It survives, in good condition, and became an exciting tourist attraction, at the Evergreen Aviation Museum. The popular Spruce Goose is now appropriately regarded as a true American icon.