Howard Hughes flies the H-4 Hercules nicknamed the Spruce Goose. It was the largest, heaviest and most expensive plane ever built. Yet aside from a one-mile test flight at 70ft (20m), it never flew again.
The plane was designed under an Air Force contract to carry 750 troops or one Sherman tank up to 5,000 miles and at a cruising speed above 250 mph at up to 21,000ft (6,400m) across the Atlantic, thus avoiding Nazi U-boats.. Shortages of materials and in-fighting with business partner Henry Kaiser meant that the only prototype ever built was not completed until 1947, two years after the war ended. More