Barling Bomber model

Officially the Wittemann-Lewis NBL-1, this early attempt at creating a strategic bomber was more commonly known as the Barling Bomber, although "Mitchell's Folly" was also a monicker for the giant aircraft. Already planning for a heavy bomber that could secure the Air Corp's future by sinking a battleship in a demonstration, Billy Mitchell contracted with Walter Barling to design such an aircraft.

Barling's  concept was  for a  semi-triplane (the  middle wing  was shorter, and without control surfaces) with a streamlined aluminum fuselage , six engines (four in push-pull arrangements, two in tractor configuration), ten-wheeled landing gear, and an internal bomb bay large enough to accommodate even the largest munitions then available.