The Caproni Ca.73 was an Italian airliner produced during the 1920s which went on to serve as a light bomber in the newly independent Regia Aeronautica. Design and development The Ca.73 was an inverted sesquiplane with a biplane tail and two engines mounted in a push-pull configuration within a common nacelle mounted on struts in the interplane gap above the fuselage. The two pilots sat in an open cockpit, while ten passengers could be accommodated within the fuselage. The publication of General Giulio Douhet's seminal treatise on strategic bombing Il dominio dell'aria (The Command of the Air) in 1921 had left Italy's military planners acutely aware of a lack of this capability. Established as a separate service in 1923, the Regia Aeronautica relied upon World War I-vintage Caproni Ca.3 bombers, and a replacement was soon sought. The immediate solution was to repurpose the Ca.73 as a warplane by adding a gunner's position in the nose, dorsally, and ventrally amidships. Bombs were carried on external racks on the fuselage sides. Ca.73s remained in frontline service until 1934, and from 1926 onwards participated in Italy's military actions in North Africa. Variants Ca.73 – airliner powered by Isotta Fraschini Asso 500 engines Ca.73bis – airliner powered by Lorraine-Dietrich engines Ca.73ter (later redesignated Ca.82) – bomber version with gun positions and fuselage bomb racks Ca.73quarter (later redesignated Ca.88) – bomber with revised control systems and strengthened airframe Ca.73quarterG (later redesignated Ca.89) – bomber with glazed nose, underwing bomb racks, and retractable ventral gun turret Ca.74 (later redesignated Ca.80) – version powered by Bristol Jupiter engines Ca.80 – the Ca.74 redesignated Ca.80S – air-ambulance and paratroop transport version Ca.82 – redesignated Ca.73ter Ca.88 – redesignated Ca.73quarter Ca.89 – redesignated Ca.73quarterG Operators Military operators Regia Aeronautica Specifications (Ca.73) See also References Ca.073 1920s Italian airliners 1920s Italian bomber aircraft Biplanes with negative stagger Aircraft first flown in 1925 Twin-engined push-pull aircraft