Hughes H-4 Hercules Flying Boat

The H-4 Hercules was a vast wooden flying-boat transport prototype created by Hughes and Kaiser during the Second World War to carry people and materiel without exposing ships to submarine attack. Built largely from laminated birch because strategic metal was restricted, it combined an unprecedented wingspan with eight piston engines. The sole aircraft became airborne once during 1947 taxi trials, proving that the completed machine could fly but arriving too late to enter its intended wartime role.