Blériot-SPAD S.56

The Blériot-SPAD S.56 was a family of French airliners developed in the 1920s as various refinements of the S.33 design. All versions shared two new features: a newly designed all-metal wing, replacing the wooden wing of earlier related designs, and a redesigned passenger cabin with two rows of double seats in place of the S.33's four single seats in a row, with a second access door added. Variants ran from the S.56/1 with a Salmson CM.9 radial engine, later a Gnome and Rhône 9Aa, to the S.56/4 with the cockpit moved between engine and cabin and six passenger seats, the S.56/5 with a convertible freight compartment and the S.56/6 banner tower. Operators included Air Union and CIDNA, and one S.56/6 ended up as a transport in the Spanish Republican Air Force.