I worked at Hughes Aircraft or most of the 80’s.
The hanger they built the plane in was the largest
wooden structure in the world. It was one of those
half-round designs. The whole inside from the floor
to the ceiling was varnished birch. Really beautiful.
The engineers perfected the wood laminating process
while building the hanger that was used to build
the Goose.
So, Goose was also made of birch. Hughes called it
the Birch B!tch. He hated being mocked in the press
who coined the name Spruce Goose.