In 1938 the RA issued a request for proposal for a BGR (Bombardiere a Grande Raggio, long-range bomber); proposals came from Caproni with their Ca.204 and Ca.211 projects, CRDA with Cant. Z.1014 (built only in mock-up form), Piaggio with the P.108B (a private venture project, offered as an additional entry) and the P.112. Also considered was the purchasing of a production license for the Boeing B-17C ‘Fortress’, but this idea was later discarded for reasons of autarchia (national self-sufficiency). The competition was won by the Cant. Z.1014, but since the development of the P.108B was already at an advanced stage, this aircraft was chosen to be produced in quantity. Designed by Casiraghi, who had worked in the USA and was familiar with B-17 technology, it was a sophisticated machine, although slower and heavier than the Fortress.

Piaggio P-108B
Engines: 4
Span 108 ft 3 in
Length: 81 ft 6 in
Max speed: 290 mph at 11,480 ft
Range: 2500 miles
Armament: 8 x 12.7 mm mg
Bombload: 7716 lb
Crew: 6-7

The Piaggio P.50 four-engine heavy bomber was the first aircraft to be designed for the company by Giovanni Casiraghi, following project outline by Giovanni Pegna. The P.50-1 (MM 369) prototype, test flown in 1937, was a shoulder-wing monoplane with a large single fin and rudder and four 544kW Isotta Fraschini XI RC V-12 engines wing-mounted in tandem pairs and driving two tractor and two pusher propellers. Three defensive gun positions included a nose turret, and offensive load was a maximum of 2500kg. A second prototype (MM 370) was damaged in a landing accident at Malpensa airfield in 1938. During that year the P.50-II (MM 371) appeared with a conventional four-engine layout, the 746kW Piaggio P.XI RC.40 radials driving four three-bladed tractor propellers. Defensive armament was increased to five 12.7mm machine-guns. Although no production ensued, the P.50 was the progenitor of the P.108 of World War II.

P.50-I
Engine: 4 x Isotta-Fraschini XI RC, 544kW
Wingspan: 25.76 m / 85 ft 6 in
Length: 19.8 m / 65 ft 12 in
Max. speed: 435 km/h / 270 mph

An entirely new design, bearing little resemblance to the original P.23, the Piaggio P.23R of 1936 had a pencil-shaped fuselage, a cantilever low-set wing with straight taper, and was powered by three 671kW Isotta Fraschini Asso XI R V-12 engines in sleek cowlings.

Intended purely as a record-breaker, the P.23R had a crew of two seated side-by-side in individual cockpits, each with its own windscreen and first flew in 1936.

Later modified by the installation of three 746kW Piaggio P.XI RC.40 radials, and with an enclosed canopy over each cockpit and revised main landing gear, the P.23R was used on 30 December 1938 to establish new world records, carrying a payload of 5000kg over distances of 1000km and 2000km at an average speed of 404km/h.

Although the P.23R appeared in Allied wartime recognition manuals as a potential bomber, development of the type had already been abandoned in 1939.

Engine: 3 x Isotta-Fraschini Asso XI R, 671kW

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.

Engine: 4 x Isotta-Fraschini Asso XI R, 671kW
Max take-off weight: 18400 kg / 40565 lb
Max. speed: 400 km/h / 249 mph
Range: 5100 km / 3169 miles