We went to the Evergreen Aviation & Space Museum in McMinnville, Oregon specifically to see the Spruce Goose, the boat/airplane Howard Hughes built out of wood as a troop transport. I was amazed..largest wingspan of any aircraft ever. This thing is huge.  If you ever get the chance to go, do it even if you have to drive a hundred miles out of the way like we did.    I paid the extra money to sit in the seat where Howard Hughes sat when he flew the mammoth sea plane, and have the picture to prove it.   OK, what is amazing about it?  The cross beams that support the wings are made out of spruce to allow for some flexing but after they reassembled the Spruce Goose in the building and remounted all 8 engines, the wings have not dropped AT ALL..amazing.  ALL skin and truss pieces are made out of wood.  I thought at least the fuselage trusses or wing frames would be aluminum...nope, birch.  Why?  WWII war efforts prevented him from using materials that could be used in the war effort.  He also was prevented from hiring talented workers away from the aircraft manufacturers so he hired his own and trained them in the art of making Hughes new plywood technique called "Duramold", which they said used very specialized epoxy glues to make a 1/4" strong yet flexible material.  Sound like Okume eh?  They nailed the 1/4" plywood strips to the wood frame members, glued them in then removed the 8 TONS of nails...sounds similar to stitch and glue eh?   The specialized wood veneer was made by teams of young women ironing the (unusually thin) strong birch wood veneer before shipping to California.  The similarities of his construction methods in the 1940's is now in the hands of average boat builders....70 years later...amazing.

More info:

https://en.wikipedia.org/wiki/Hughes_H-4_Hercules

Curt