HK-1 Spruce GooseHughes HK 1 H 4 Spruce Goose airplane model. The Spruce Goose was first conceived during World War II, when German submarines were sinking hundreds of Allied ships, and there was a growing need to move troops and materials across the Atlantic Ocean. Henry Kaiser conceived the idea of a massive flying transport and turned to Howard Hughes to design and build it. Hughes took on the task, made even more challenging by the governments restrictions on