Spruce Goose's model photo from wingtip to wingtip, in real life this length is about 320 feet. H-4 was powered by eight Pratt & Whitney R-4360 Wasp Major radial engines, each producing 3,000 horsepower, but critics state the seaplane was underpowered for its trans-Atlantic ferrying task (by 1950s with advent of the Jet age, Hughes may have elected to replace propeller radials with jet engines).

Anticipated loaded weight reached 400,000 pounds, cruise speed of 220 miles/hour, range of 3,000 miles, maximum flight ceiling circa 21,000 feet. Other operational seaplanes comparable to H-4 were Germany's Dornier Do X and Bohm & Voss BV 238, US JRM Mars and Boeing Pelican. List of seaplanes and flying boats - en.wikipedia.org/wiki/List_of_seaplanes_and_flying_boats

• JRM Mars - en.wikipedia.org/wiki/JRM_Mars

• Dornier Do X - en.wikipedia.org/wiki/Dornier_Do_X

• Blohm & Voss BV 238 - en.wikipedia.org/wiki/Blohm_%2B_Voss_BV_238

• Boeing Pelican - foxxaero.homestead.com/indrad_043.html

Inset 1 : Since 1947 maiden test flight, Hughes maintained H-4 for flying condition for over 30 years until his death in 1976. As Hughes estate began to liquidate various assets, the California Aero Club acquired the H-4 in 1980. A special dome was constructed at Long Beach-California to showcase the seaplane next to British ocean liner RMS Queen Mary.

Inset 1 Rollover : Photo of display dome after H-4 had been moved inside its mammoth interior. RMS Queen Mary - en.wikipedia.org/wiki/RMS_Queen_Mary

Rollover : H-4 model in final paint stage, silver top coat painted on, black paint wash applied to surface details. Paint Wash is paint heavily diluted with paint thinner, thereby making solution quite viscous. Although looking quite gouty, the wash flows into protrusions and crevices, once dried excess wash is gently removed by a thinner dosed cotton swab. UweM Paint Wash - UweMilitaria.org/Technique/wea2Wash.html

Inset 2 : In 1988, Walt Disney Corporation acquired H-4 exhibit but decided to sell seaplane due to lackluster revenue generation. Evergreen Aviation Museum acquired seaplane in 1993 and had it disassembled for barge transport to McMinnville, Oregon. Hercules now on display in large triangular hanger, along with other flight relics.

Inset 2 Rollover : Interior photo of Evergreen Aviation Museum of H-4, replica of Wright Brother's Kitty Hawk biplane, etc. The Evergreen Aviation Museum - www.shanaberger.com/mu_evergreen.htm

Inset 3 : Close-up of massive H-4 instrument panel at flight engineer station monitoring the eight radial engines. Radial Engine - en.wikipedia.org/wiki/Radial_engine