Historic Aircraft: Spruce Goose

One of the highlights of the Evergreen Aviation and Space Museum in McMinnville, Oregon, is the historic “Spruce Goose” – the one and only Hughes H-4 Hercules ever manufactured. With a wingspan of 320 feet and measuring 219 feet long, the H-4 is the largest flying boat ever to be constructed, and although it only ever made one flight on November 2, 1947, it proved that an airplane of that magnitude is able to fly. Due to restrictions on the use of aluminum and other metals during World War II, the H-4 was built almost entirely from birch wood and was designed to transport troops and goods across the Atlantic, but due to delays in its manufacture, the war was over before it could be put into service.

With Allied shipping across the Atlantic Ocean coming under attack by German U-boats, in 1942 the US War Department started investigating other methods of bulk transport between Britain and the United States. The concept of the flying boat was initially the idea of shipbuilder Henry J. Kaiser, who collaborated with aviator Howard Hughes to design what was then known as the HK-1 – an aircraft with the cargo capacity of 150,000 pounds. Critics and the media dubbed the proposed aircraft the “Spruce Goose” (a nickname Hughes reportedly detested) and the “Flying Lumberyard”, being a reference to the fact that it was primarily constructed from wood.

A contract for the development of the HK-1 was issued in 1942 with a deadline of under two years for the manufacture of three aircraft. The first (and only) aircraft was produced in 16 months, but Kaiser withdrew from the project and Hughes continued with the project, renaming the aircraft the H-4 Hercules and entering into a new contract with the government for a single prototype. Built at the Hughes Aircraft Company in Los Angeles, the H-4 was shipped in sections to Pier E in Long Beach, California, where it was assembled with a hangar being erected around it.

The “Spruce Goose” never did make it into military service as it was completed after WWII was over. Nonetheless, it remains as testimony to the innovative composite technology and other revolutionary inventions of the time, and is a fascinating centerpiece at the Evergreen Aviation and Space Museum.