Staff Writer (Updated: 5/1/2015):
The CANT Z.506 offered up a very unique design appearance making her one of the more recognizable aircraft of the period. This was primarily due to her tri-motor configuration in which engine nacelles were affixed to both wing leading edges as well as the fuselage nose. The fuselage was well-streamlined from nose to tail, the latter capped by a conventional single-rudder tail unit. The fuselage sat atop a network of reinforced struts which attached it to a pair of long-running floats allowing for sea-based landings and take offs. The design was clean and well thought out for the period, combining a wooden understructure with canvas-and-wood skinning techniques which made it strong, light and cost-effective - only the floatplanes were actually constructed of more expensive metal. First flight was recorded on August 19th, 1935 with the prototype (powered by 3 x Piaggio P.IX radial piston engines of 610 horsepower each) giving rise to the original commercial model designated as the "Z.506A". The aircraft was formally introduced in 1936.
After the prototype proved the design highly sound, the Z.506A was ordered into serial production which begat an initial batch of 38 airframes in 1936. The first operating line of the type became Ala Littoria. The Italian Navy had taken notice of the record-setting aircraft and moved to adopt the tri-motor design in its military guise as the "Z.506B". This version was more-or-less a copy of the civilian-minded A-models though slightly reworked with a deeper fuselage to incorporate an observer's station/bomb bay and raised cockpit for improved outward visibility. Also in this version, the Alfa Romeo 126 series RC.34 radial piston engine of 750 horsepower was adopted for all three powerplant installations (2,250 horsepower combined) giving the airframe considerably more output power than previously designed. Crew accommodations amounted to five personnel. Fixed offensive/defensive armament was a network of machine guns - 1 x 12.7mm Breda-SAFAT heavy machine gun and 3 x 7.7mm Breda-SAFAT medium machine guns at various spots about the fuselage including dorsal and beam positions. The aircraft was cleared to haul up to 2,650lbs of stores (including a single 1,800lb torpedo in lieu of conventional drop bombs).
Initial Italian Navy units to receive the aircraft type became the 31st and 35th Naval Bomber Groups. With its steady powerplants in place, the Z.506B military model went on to raise even more aviation distance and ceiling records for her class including a nonstop jaunt from Cadiz, Spain to Caravelas, Brazil covering 4,362 miles during October of 1937. As the Italian Navy found increased usefulness in the Z.506 design, production was equally increased and ultimately involved Piaggio factories. The Regia Aeronautica (Italian Air Force) also adopted the type.