Piaggio P.23

Built to fly the North Atlantic, with potential for development as a commercial transport, the Piaggio P.23 had inverted-gull shoulder-mounted wings and was powered by four 671kW Isotta Fraschini Asso XI R V-12 engines mounted in tandem pairs and driving two tractor and two pusher propellers. It had retractable main landing gear units and twin fins and rudders. A distinctive feature was the 'avion marin' boat-type hull underside to the fuselage, intended to assist in an emergency if the aircraft had to alight on the sea.

Maximum take-off weight was 18,400kg and maximum speed a claimed 400km/h; at a cruising speed of 300km/h its range was estimated to be 5100km. However, no transatlantic flight was made and the aircraft was dismantled soon after its appearance in 1935.