The history of the Z.506 began when CANT ("Cantieri navali Trieste" - "Shipyards in Trieste"), the aviation department of CRdA (Cantieri Riuniti dell'Adriatico - "United Shipyards of the Adriatic") moved from building flying boats to float devices ... In 1935, the "postman" Z.505 appeared with three in-line engines "Isotta Fraschini" "Asso" XI RC.15. The letter Z in the designation of the aircraft indicates the authorship of Philippe Zappata, the chief engineer of CANT, who transferred from the French company Bleriot at the invitation of the fascist minister I. Bapbo.

"Five hundred and fifth" was overtaken in construction by the "twin brother", the prototype of the passenger CANT Z.506. At the "Shipyards in Trieste" several pre-production "five hundred and sixths" were laid down at once - an urgent order of the state airline "Ala Littoria" was fulfilled. A prototype with FIAT A.59RC air-cooled engines took to the skies in August 1935, piloted by the famous test pilot M. Stoppani.

Comparative tests of both prototypes with different types of power plants quickly showed that the "505th" develops 368 km / h at an altitude of 2900 m, against 356 km / h at an altitude of 3480 m, issued by the "506". Another advantage of the CANT Z.505A was its large payload, due, again, to a significant superiority in the power of its engines. Indeed, on tests, the "505" took off with a flight weight of up to 12.820 kg, while the "506" was able to lift off the water, having a mass of only 10.500 kg. But this was seen as a temporary advantage, since the power of its power plant exceeded that of a competitor by more than 25%. A much more significant role in choosing the type of power plant was played by "emergency" statistics. Six failures on serial liquid-cooled engines with one fire versus one emergency for air-cooled motors quickly persuaded the developers to install the latter on serial machines, showing that air-cooled "stars" are easier and cheaper to operate, and also noticeably lighter in weight. It should also be remembered that the aircraft was intended for operation over the sea, where the requirements for the reliability of the power plant were significantly higher, since even a successful forced landing did not guarantee a safe completion of the flight for passengers, crew and cargo. As a result, CANT Z.505A remained in the singular.

Although in Europe most of the multi-engine aircraft at this time were already built from duralumin, aircraft designers proposed to build the future aircraft from wood. There were two reasons: firstly, the Italian metallurgical industry could not provide aircraft factories with the required amount of duralumin rolled products, and secondly, the company's technologists had very extensive experience in developing protective compositions that significantly reduced the aggressive effect of salty sea water on wooden products. The company was also very successful in the production of special plywood, which was used for the manufacture of boats and small-tonnage vessels for the navy, and also enjoyed a steady demand in the foreign market.

Structurally, the machine was a two-float three-engine cantilever monoplane of an all-wood construction with a low wing. The exterior cladding, made of high quality tulip plywood, resulted in an excellent exterior finish.

The trapezoidal wing of a three-spar design with elliptical tips is also made entirely of wood with plywood sheathing, some of the ribs had solid walls and divided the wing into a number of watertight compartments. On the trailing edge of the wing there are controllable surfaces: two-section flaps and ailerons, also of an all-wood construction, covered with canvas. Inner flap sections are trimmed, statically and dynamically balanced. In the places where the wing is attached to the fuselage, there are fairly developed fairings.

The fuselage is an elliptical monocoque, it is based on one main spar, according to tradition (the aircraft was still built at the former shipyards) called the keel, and four auxiliary ones. The fuselage has three main bulkheads at the spar attachment points. In the front part of the fuselage, immediately behind the engine compartment, there is a pilot's cabin with dual control, behind it is the cabin of the radio operator and flight mechanic, then the cabin for passengers, premises for mail and luggage, and a toilet. The common floor of the cockpit and passengers is also traditionally called the deck. Under the floor of the cockpit there is mooring equipment, which includes a winch and an anchor. The crew and passengers board the aircraft through an oval door located on the left side behind the wing, from a float on a ladder. The sides of the fuselage have seven rectangular windows on each side.

The horizontal tail is attached to the keel and is equipped with struts and counter-braces and is similar in design to the wing. On the first prototype, the rudder had significant horn compensation, which was quickly abandoned after rebalancing. Vertical and horizontal rudders - wooden, covered with canvas and equipped with trimmers, statically and dynamically balanced.

All-metal single-ribbed floats are made of duralumin and are attached with N-shaped struts to the wing, and a pair of parallel struts with braces - from the inside to the fuselage. Each float is divided into two isolated compartments, the aircraft retains the possibility of a normal landing if one compartment is flooded in each float.

Eight duralumin tanks with a total capacity of 5200 liters are placed in the center section in pairs between the side members and are closed from above with reinforced duralumin panels, on which you can walk without fear of damaging the casing or breaking the tightness of the tank. In the leading edge - tanks for oil, their front surfaces served as radiators.

At the design stage, three nine-cylinder radial air-cooled Piaggio Stella XIRC engines with a rated power of 610 hp were considered as a power plant. and Alfa Romeo variable pitch propellers. However, it soon became clear that their capabilities for such a large car were clearly not enough, and for the first prototype they chose nine-cylinder radial engines "Fiat A59RC" with a capacity of 700 hp, which were licensed "Hornets" of the American company "Pratt & Whitney". which rotated three-blade variable pitch propellers "Hamilton-Standard". Later, the Z.506A was equipped with the 126-series Alfa-Romeo engines. The engines were attached to a steel tube-welded engine mount, which in turn was attached to a wooden wing or fuselage structure at four points.

Photo	Description
	Drawing CANT Z 506B
	CANT Z 506B

The tests were successfully completed in April 1936. On 7 July, the first prototype passenger Z.506, I CANT, set eight speed records for seaplanes at various distances. Then the "five hundred and sixth" was transferred to the 750-strong "Alfa-Romeo" 126 RC.34. On November 29 and December 1, CANT was able to improve its global reach by climbing to an altitude of 7800 m with a load of 2 tons and 6920 m with 5 tons on board.

The brilliant data of the Z.506A caught the attention of the Regia Aeronautica (Italian Air Force) command. The military saw the makings of a naval bomber and long-range reconnaissance. The Z.506B modification appeared, which differed from the civilian CANTa by the tandem arrangement of the pilots in a higher cockpit and a spacious compartment for bombs, 800-kg torpedoes or additional gas tanks.

The bomb load could consist of a land mine of 800 kg, in overload - from two ammunition of 500 kg and three of 50 kg. Instead of them, up to 16 small bombs of 1.5-2 kg could be suspended. In addition to the "hold", the elegant contours of the vehicle were spoiled by the upper turret of the "Breda" M1 type with a 12.7 mm machine gun, semi-recessed into the fuselage. In the lower aft "nest" was a SAFAT of 7.7 mm caliber.

Unexpectedly, the military version outperformed the civilian Z.506. Combat CANT was shown in Milan at the 2nd National Air Show in October 1937. In November, the prototype was followed by a series of 32 Z.506Bs. In October 39, a new order was received from the Italian Air Force for another 32 float bombers.

"Five hundred and sixths" were produced at the CANT facility in Monfalcone, introducing minor improvements to the Z.506B from series to series. The most advanced XII was distinguished by side mounts of 7.7-mm machine guns "Breda" -SAFAT, upper turret "Caproni-Lanchiani" "Delta" E with 12.7-mm "Scotti", bomb load of 1200 kg. The production of late series CANTs was loaded into an aircraft factory in Finale Ligure. A total of about 360 "five hundred sixths" were built, 38 of them were civilians. But these numbers are not indisputable.

A "polished" Z.506B with three 700-horsepower "Alphas" was intended for the assault on record "heights". With a load of a ton, he "climbed" 10 310 m. In November 37th this CANT exceeded the world record, having flown more than 7013 km from Cadiz to Caravellas in Brazil with an average speed of 265 km / h. The maximum speed is 390 km / h.

The return flight ended in disaster, with three crew members and a passenger killed in the waters of the Atlantic. Only the pilot Stoppani survived, he was picked up by the flying boat "Dornier" of the airline "Lufthansa".

In June 1938, Z.506B aircraft began arriving at the Italian naval bombers. The 35th regiment, based in Brindisi, was the first in "Regia Aeronautics" to re-equip with new CANTs, followed by the 31st in Elmas. Until June 1940, the "five hundred and sixth" were mastered in four of the 13 squadrons of the 85th reconnaissance group. Another 20 reconnaissance squadrons at numerous hydro bases scattered from Lero in the Aegean Sea to Menelao in Libya were preparing to replace flying boats CANT Z.501 with Z.506В.

Four Z.506Bs took part in the Spanish Civil War as part of the Italian Expeditionary Force and the Francoist Air Force. Ramon Franco, brother of the leader of the nationalists, fought in one of the CANTs. The pilot who conquered the Atlantic in 1926 on the Dornier Val under the name Plus Ultra did not return from a sortie.

Many countries are interested in the float CANT, but only Poland made a rather large order. The first and only Z.506B arrived in the Baltic on 28 August 1939. A few days later it was destroyed by German bombers. The Japanese firm "Aishi" bought a license for the float CANT, but it didn't go any further. "Five hundred and sixth" - scouts also acquired Romania. Together with Z.501 they operated in the Black Sea,

Italy, which entered the war, had 25 Stormos, in which by June 10, 1940 there were 664 bomb carriers, among them 48 CANT Z.506 seaplanes. Machines of this type, almost 40, consisted of naval reconnaissance squadrons and various support units.

In the Mediterranean, beginning on June 12, 1940, Italian float bombers launched several attacks on the French naval base in Bizerte. Z.506B went into battle, more often loaded with bombs than torpedoes. July 8-9 - massive raids on British ships off the coast of Malta and a large convoy heading from La Valletta to Alexandria. Eight CANT Z.506B were among the 125 Italian bomb carriers participating in the operation.

Already at the beginning of the war, it became clear that the former advanced in all respects, CANT was already outdated. The last time the "five hundred and sixth" was used in large numbers during the battles in Greece, during the occupation of the islands of Kefalonia and Zante in the spring of 1941. The Z.506B of the 35th regiment was also supported by the airborne assault that captured Corfu. During a short campaign against Yugoslavia, the CANTs bombed targets in Croatia several times.

Although the Z.506B literally lagged behind its modern bombers, it turned out to be slow-moving, its range and excellent seaworthiness were still in value. CANT, which received its own name "Airone" ("Heron"), became a good scout. The Z.506B aircraft almost completely replaced the CANT Z.501 flying boats in the naval auxiliary aviation, which were no longer in service.

In June 1940, reconnaissance squadrons acquired 21 ex-CANT bomber. Their number increased sharply after the disbandment of the 31st regiment and the transformation of the 35th into a land formation. In 41st, up to 60 Airones operated in the interests of the fleet, at the end of 42nd - 64 Z.506B and 43 CANTa of other modifications. Several Z.506Bs were heavily exploited at the Seaplane School at Paula Puntisella and at the Naval Intelligence School at Orbetello.

Even with the entry of Italy into the war, the mobilization of personnel and the fleet of commercial airlines began. Four Z.506As entered the NAL, a division of Ala Littoria, which was taken over by Air Force Command. In 1941, three more were "recruited", and 12 transport CANTs, ordered in January, were under construction. NAL crews cruised without interruption, primarily in the interests of field communications on the most important routes between the headquarters and headquarters: Rome - Benghazi through Syracuse and Tripoli and others. Eight five hundred sixths were shot down.

Of 11 CANTs, auxiliary units were formed on the basis of the 612th and 614th separate squadrons. They were replenished during 1941 with three new "boards". In 42, the "five hundred and sixth" arrived in the 613th squadron, which had previously flown on the S.66 Savoy. The main task of the aforementioned air units was the search and rescue of the crews of downed aircraft and sunken ships.

From June 41 to December 42, CANTs, based in Lido and Brindisi, flew 418 flights and picked up 231 people: 167 Italians, 16 Germans, 37 British and 11 French.

Western historians call the fighting in the Mediterranean a "war without hatred", allegedly here civilized opponents were "mutually polite", respected international norms and the "red cross". But in the Mediterranean, as in other theaters of the most brutal of wars, ambulance and rescue aircraft were destroyed.

In 1942, Z.506S from the Piaggio factory, unarmed, originally intended for search and rescue, were added to the CANTs (former civilians). Their service was reorganized in 1943. 11 squadrons, subordinate to the "Regia Marina" (Italian Navy), were given the link "five hundred and sixth".

Z-506 operated in all sectors of the Mediterranean. In addition to reconnaissance, search and rescue, they were involved in anti-submarine operations, patrolling the coast and escorting convoys. "Five hundred and sixth" suffered significant losses. On the Aegean Sea, the British managed to capture the CANT intact, returning from a mission. The aircraft was subsequently used in Malta.

On the eve of the surrender, the Italian Air Force numbered about 60 Z.506s. After the conclusion of an armistice between the Allies and the Italian command, 28 CANTs remained at the disposal of the government of Marshal Badoglio, 35 were captured by the Germans. In the "Luftwaffe" Z.506 solved secondary tasks. Several Airones were also in the Air Force of the Italian Socialist Republic, organized by Mussolini in the north of the country.

Thanks to the restoration at the SACA plant in Brindisi, the number of CANTs in the Italian forces on the side of the Allies increased to 36. By the end of World War II, about 30 "five hundred sixths" survived, 12 - in flight condition. 20 Z.506Bs, which were overhauled and converted into rescue ones by SIAI - "Marchetti", and five Z.506S served 15 more post-war years.

Bibliography

• "CANT Z-506 Airone" /Aerei Italiani - Scheda Tecnica./