The Hughes H-4 Hercules goes by several designations. It was the fourth aircraft produced by the Hughes Corp. and therefore is designated H-4. Its co-designers were Howard Hughes and Henry Kaiser. Therefore it can also be designated as the HK-1. The most popular name for the aircraft, however, is the Spruce Goose, due to its all wood construction. The type of aircraft is called a flying boat, but sometimes a seaplane. Although the name seaplane is usually thought of as a smaller aircraft.

Development of the Spruce Goose, was in response to the sinking of large numbers of merchant ships by German submarines during WW II.

In July of 1942, transoceanic air transport was considered far safer than transport by ship. It was proposed that a fleet of large aircraft could carry cargo across the world oceans with fewer losses than ships were incurring.  This was the purpose of the Spruce Goose.

The U.S. government contracted with Hughes Corp. in the amount of US$18 million. Three Spruce Goose flying boat transports were to be built using non critical materials, primarily wood.

The Spruce Goose flying boat proposed by Hughes would be the largest winged aircraft ever to take to the sky, with wings longer than a football field.

Numerous delays followed. Building the Spruce Goose required vast amounts of research engineering. Especially challenging was the adaptation of wooden materials to the massive size of the flying boat.

The Spruce Goose giant aircraft finally flew, but after the war ended. On November 2, 1947, with Howard Hughes at the controls, the Spruce Goose flew for a distance of about a mile and attained a maximum altitude of 70 feet above the water.

On July 9, 1990 custody of the Spruce Goose went to the Evergreen Aviation Museum, located in McMinnville, Oregon where it is currently on display.

Specifications
Primary Function:     Crew:     Engine type:     Power:     Weight Empty:     Max. Weight:     Fuel Capacity:     Seating:     Length:     Wingspan:     Cruise Speed:     Max. Speed:     Range:     First Flight:	transport eighteen Pratt & Whitney 8 x 3,000 hp ea. 300,000 lbs. 400,000 lbs. 95,760 lbs. 750 troops 218' 6" 319' 11" 218 mph 370 mph 3,500 miles 11/21/47