The Hughes H-4 Spruce Goose
The Hughes H-4, or Spruce Goose, was test flown by Howard Hughes only once on November 2, 1947. It was the largest seaplane ever built at that time. The H-4 used eight of the largest and most powerful radial seaplane engines in the world. It’s 320-foot wingspan tipped the scales at more than 300,000 lbs. Joseph Bok and his Aero Telemetry team were tasked with designing and building the world’s largest flyable Spruce Goose replica. Bok’s unmanned version would have to be both large and powerful enough to take-off from the water of Long Beach Harbor, Calif. and fly steady.
Aero Telemetry provided the latest technology for the electronics and telemetry (command and control) systems needed on both the seaplane and shipboard control station. For the composite sections of the seaplane, we used carbon fiber and Hex Cell with resin to build and strengthen both the fuselage and wing structure. Our Spruce Goose required 160 Nickel Metal Hydride batteries wired together in packs to power each of the eight electric motors. Once the engines were started and run up to full throttle, they could operate for about 15 minutes of total flight time before we had to land and re-charge them. Each time the H-4 landed in the harbor, a “recovery” barge pulled alongside to swap out the battery packs located in the forward compartment of the seaplane, in addition a bilge pump was utilized to pump out seawater which got into the fuselage during extended periods in the water between flights.
WINGSPAN: approximately 25 feet
LENGTH: approximately 25 feet
WEIGHT: 275 lbs
ENGINE: 8- electric motors with custom gear reduction propeller drive units.
The plane was flown several times at Long Beach Harbor, in Hughes’ original flight test area. The H-4 only flew for a little while back in 1947 but we flew our “unmanned” version (UH-4) for about an hour during all the flights. At times, we piloted the UH-4 from a converted Navy PT boat. The use of the radio controlled Spruce Goose provided The Aviator with exceptional flying sequences. The background at Long Beach Harbor provided a very realistic and historically accurate setting for the flights of the Aero Telemetry Spruce Goose, the world’s largest flyable replica of the Hughes H4 Hercules.