The SM.89 attack aircraft, based on the SM.84 three-engined torpedo bomber, was its twin-engined version with the most powerful armament ever seen on an RAF aircraft. The transition to a twin-engine design made it possible to completely redesign the nose of the fuselage, creating a cockpit with a significantly improved visibility compared to the SM.84. At the bottom of the new bow section was a battery of two 37 mm Breda cannons and three 12.7 mm Breda-SAFAT machine guns (two more were in the gunners' turrets). Easily removable panels were provided for servicing and reloading weapons. Also at the testing stage, a Breda-type turret was installed, which was laid down at the design stage.
The power plant from two engines allowed to get the same power as from three 1000-horsepower Piaggio P.XI RC40 engines, the new Piaggio P.XII RC.35 motors had a power of 1500 horsepower. each. To improve flight performance, it was planned to install a Piaggio P. XV with a capacity of 1,650 horsepower, but the production facilities of Piaggio could not cope with all orders and, as a result, they had to limit themselves to the existing power plant.
Structurally, the SM.89 attack aircraft was a two-engine four-seat low-wing aircraft of mixed design. The fuselage of rectangular cross-section is welded from steel pipes and up to the gunner's turret (nose) is covered with duralumin. The tail section of the fuselage is made of wood and covered with plywood and canvas. Three-spar wooden wing with plywood sheathing. Ailerons and flaps (Handley-Page type) with a metal frame and covered with canvas. The tail unit is double-keeled with a metal frame made of welded steel pipes and covered with linen plating.
The main landing gear is partially retractable by turning back from the nacelle (parts of the wheels remain unremoved). The tail wheel is swivel, non-retractable.
The pilot's cabin is armored, two-seater with the location of the pilots in tandem (the second pilot is also loading 37-mm cannons), two workplaces are installed in the fuselage: an arrow with a turret (immediately behind the cockpit) and a radio operator (middle of the fuselage).
|Wing span, m
|Wing area, m²
|2 × PE radial Piaggio P.XII RC.35, power, hp
||2 × 1500
|Weights and loads, kg:|
|Maximum speed, km/h
|Cruising speed, km/h
|Service range, km
|Service ceiling, m
|2 × 37 mm Breda cannon, 32 × 12.7 mm Breda-Safat machine gun, bombs, kg
In April 1943, the prototype SM.89 was transferred to the 173rd Squadron for military trials. On this, traces of the SM.89 are lost and, despite the desire of the General Staff to use the SM.89 to combat the Allied landings in Salerno, this aircraft never took part in hostilities. Officially, it was not accepted for service and, most likely, after the signing of the armistice, it was dismantled.
- Encyclopedia of Military Equipment / Aerospace Publising /
- "Savoia Marchetti 89" con motori PIAGGIO P.XII RC.35/Ministero dell' Aeronautica, Roma 1939/