The Caproni Ca.91 was a proposed Italian flying boat designed by Caproni.
Design and development
Like the Caproni Ca.90, the Ca.91 had three tandem pairs of 1,000 hp (746 kW) Isotta Fraschini Asso 1000 W-18 inline piston engines, but all three pairs were mounted on the lower wing.[1]
^Gianni Caproni, Biplano Ca 90, in Gli Aeroplani Caproni - Projects Studies Realizations from 1908 to 1935, Milan, Edizioni d'arte Emilio Bestetti, 1937, pp. 229-45, ISBN not existing.
^AA.VV., Caproni Ca.90, in Grande Enciclopedia Aeronautica, Milan, Edizioni Aeronautica L. Mancini, 1936, p. 154, ISBN not existing.