Built from wood (Duramold process) because of wartime restrictions on the use of aluminum and concerns about weight, the aircraft was nicknamed the Spruce Goose by critics, although it was made almost entirely of birch.

[1][2] The Birch Bitch was a more accurate but less socially acceptable moniker that was allegedly used by the mechanics who worked on the plane.

[11][14][N 1] It would be built mostly of wood to conserve metal (its elevators and rudder were fabric-covered),[15] and was nicknamed the Spruce Goose (a name Hughes disliked) or the Flying Lumberyard.

[16] While Kaiser had originated the "flying cargo ship" concept, he did not have an aeronautical background and deferred to Hughes and his designer, Glenn Odekirk.

[16][18] Hughes continued the program on his own under the designation H-4 Hercules,[N 2] signing a new government contract that now limited production to one example.

The plane was built by the Hughes Aircraft Company at Hughes Airport, location of present-day Playa Vista, Los Angeles, California, employing the plywood-and-resin "Duramold" process[15][N 3] – a form of composite technology – for the laminated wood construction, which was considered a technological tour de force.

Hamilton Roddis had teams of young women ironing the (unusually thin) strong birch wood veneer before shipping to California.

After Hughes Aircraft completed final assembly, they erected a hangar around the flying boat, with a ramp to launch the H-4 into the harbor.

[1] Howard Hughes was called to testify before the Senate War Investigating Committee in 1947 over the use of government funds for the aircraft.

Afterwards a full-time crew of 300 workers, all sworn to secrecy, maintained the aircraft in flying condition in a climate-controlled hangar.

In the mid-1970s, an agreement was reached whereby the Smithsonian Institution's National Air and Space Museum would receive the Hughes H-1 Racer and section of the H-4's wing, the Summa Corporation would pay $700,000 and receive ownership of the H-4, the U.S. government would cede any rights, and the aircraft would be protected "from commercial exploitation.

Many convention groups held large dinners, sales meetings, and even concerts under the wings of the aircraft at night when the Spruce Goose Dome was closed to tourists.

The Spruce Goose geodesic dome is now used by Carnival Cruise Lines as its Long Beach terminal.

Scenes from movies such as Titanic, What Women Want and End of Days have been filmed in the 315,000-square-foot (29,300 m2) aircraft hangar where Howard Hughes created the flying boat.

The hangar will be preserved as a structure eligible for listing in the National Register of Historic Places in what is today the large light industry and housing development in the Playa Vista neighborhood of Los Angeles.