Twin-engine SIAI Savoia-Marchetti S.79B medium bomber.
During the pre-war period, SIAI actively tried to export the S.79. Alessandro Marchetti argued that twin-engine planes, not three-engine, would be best for export. So, in spite of the Royal Italian Air Force’s rejection of the S.79B bomber project, he continued work in this area, developing a prototype.
The S.79B had a completely redesigned nose section. A glazed cabin for the bombardier/navigator was placed where the centrally located engine used to be. The cockpit, to improve visibility, was moved forward and raised. The dorsal “hump” was moved farther back. Also, the area of the keel was increased slightly.
The plane was powered by two 14-cylinder star-shaped air-cooled Gnome-Rhone 14Kfs engines with 950 hp and a metal three-bladed variable-pitch SIAI propeller.
The engines were placed in elongated engine nacelles, and the aeroplane was given a more streamlined design, which fully compensated for the reduction in total thrust.
The aircraft’s defensive armament remained virtually unchanged: three heavy-calibre 12.7 mm Breda SAFAT machine guns, with 500 rounds per gun. One fixed machine gun was placed in the nose, and a second was located in the turret under the hump’s sliding panel. The ventral gondola was now used only for a third gun, defending the plane from attacks from the lower rear.
The twin-engine S.79B was offered to Belgium, Brazil, China, Czechoslovakia, Finland, Turkey, Yugoslavia, and the Soviet Union. However, no orders from any of these countries were ever received.
In the spring of 1937, Iraq ordered five S.79Bs. The aircraft for Iraq were equipped with Fiat A.80 RC.41 engined with a takeoff power of 1030 hp. The third, fourth, and fifth S.79Bs had larger cockpit windows. In early 1938, the Italian crews ferried the aircraft to the customer. All of these planes were eventually destroyed in 1941 during the rebellion in Iraq.
The largest order for the twin-engine S.79B was placed by the country of Romania. In autumn of 1937, the Romanians requested 24 of the aircraft equipped with IAR K14-II engines with a power of 900 hp. (A licensed version of the Gnome-Rhone engine, produced in Romania.)
When compared with the Iraqi planes, the Romanian version had several differences: the mobile 7.92mm Browning FN machine gun with rotary magazine and 350 rounds of ammunition (mounted in the nose) and various equipment modifications. In 1938, these aircraft entered service with two squadrons of the Forţele Aeriene Regale ale Romaniei (Royal Romanian Air Force).