Caproni Ca.90

The Italian grandissimo six-engine Ca.90 bomber, first flown in 1929, was almost certainly the largest biplane ever built. Designed to carry a 33.000lb bombload and armed with six machine-gun positions for
defence against attacking aircraft, the Ca.90 was the closet anyone came to producing the “aerial battleship” envisioned by the controversial Italian military aviation strategist Giulio Douhet. He had imagined bomber fleets attacking cities around the world, creating such terror that surrender would he be only option. There was no doubting the aircraft’s power, for on 22 February 1930 it claimed six world altitude and payload records, including a climb to 10,660ft with a 22,000lb load. The Ca.90 had an upper wing of much shorter span than the lower, a curious layout almost exclusively developed by the Caproni company. Its fabric-covered airframe was made of wood and natal. The six Isotta-Fraschini Asso engines were mounted as tandem pairs in three nacelles grouped in a triangle close to the fuselage; three of them drove massive two-bladed tractor propellers and the other three drove pushers. The bomber’s paired main wheels completely dwarfed anyone who stood alongside them.
The Italian air force, however, preferred smaller bombers and the Ca.90 never progressed beyond the prototype stage.